November, 1959 Vol

www.americanradiohistory.comAmericanRadioHistory.Com the big PLUS FOUR ,111.1111 in tubes for hi-fi!

"low noise and low hum" characterize the performance of this From pre -amplifier to power amplifier, mono high -mu twin RCA -7025... triode-ideal for your pre -amplifier designs. or stereo, you can design a comprehensive line of "versatility" high-fidelity products around these 4 RCA keynotes the applications for this tube-a sharp - tube types. And your designs with RCA cutoff pentode and a medium -mu triode in tubes one envelope-for add up to recognition RCA -7199... low-level stages. ... for quality, performance, prestige. Contact your RCA Field Repre- "compact, but powerful" can describe monophonic and stereo- sentative for details. For technical data, write phonic power amplifiers designed around this 9 -pin miniature RCA Commercial Engineering, Section RCA -6973... -a pair in Class AB1 can deliver up to 20 watts output. K -91 -DE, Harrison, N. J. "power deluxe"-up to 76 watts with only 2% distortion from a pair in Class AB1 audio service-new structure design pro- 744 Broad St.. Newark 2, New Jersey. HUmboldt 5-3900 RCA -7027-A vides exceptional electrical stability and reliability. MIDWEST. ANOTHER WAY RCA SERVES YOU THROUGH ELECTRONICS Suite1154, Merchandise Mart Plaza, Chicago 54, III., WHitehall 4-2900 RADIO CORPORATION OF AMERICA WEST: Tube 6355 East Washington Boulevard. Los Electron Division Harrison, N. J. Angeles 22, Calif.. RAymond 3-8361

www.americanradiohistory.comAmericanRadioHistory.Com NOVEMBER, 1959 VOL. 43, No. 11 Successor to RADIO, Est. 1917. Model S-5000, 20 -f -20W Stereo Dual Amplifier-f189.50

Model S-3000II, FM Tuner-$105.50

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AU Io Model S-4400, Stereo Preemp.+36W Amp.-$159.50 ENGINEERING MUSIC SOUND REPRODUCTION

C. G. McProud, Editor and Publisher Henry A. Schober, Business Manager 4550 Harrie K. Richardson, Associate Editor Linda Sueskind, Assistant Editor Janet M. Durgin, Production Manager Edgar E. Newman, Circulation Director Model 5-1000 II, 34W Monaural Amplifier -5109.50

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Sanford L. Cahn, Advertising Director The "complete matching home music center" MEMRER Midwest Representative- -monophonic or stereophonic. or ( MAHO W. A. Cook and Associates Again another year -recommended by one of >n 161 East Grand Ave., Chicago 11, 111. the most respected and authoritative Re- CW West Coast Representative- search Testing Organizations as embodying .pC more numerous, more advanced engineering James C. Galloway "firsts"-more inherent quality for trouble - . tNC e 0 5 6535 Wilshire Boulevard, Los Angeles 48, Calif. free operation-more real value for every dollar than many competitive products selling for more. PLUS: Features that in their CONTENTS unsurpassed engineering win the most discriminating audio -hobbyist; but also features I; if, reio-Ili 2 that in their simplicity and ease of opera- Letters 6 tion appeal to everyone-housewife, audio - A udioman of the AConti] 12 novice, or just plain music lover. Cabinetry of quiet that A udio ETC-Edward Tetuan Canby 14 elegance blends with any decor. Editor's Review And Sherwood, unmatched at any price, is 16 Fair Trade priced for your assurance that once Universal Stereo Control Center-Francis A. Gicca 19 you have bought Sherwood, you didn't in Calculation Chart for Vented Cabinets-Victor Brociner 22 a better "deal" someplace else. ' Puzzled About Amplifiers '1-Norman H. Orowhurst 24 is only for those who want the Defense and the Hi-Fi Bachelors-C. H. Malm.stedt-Part II 29 For further details write: Sher Tape Guide-Tape Recorder Accessories-Herourti, Burstein 32 tronic Laboratories, Inc., 4300 N A Figure of Merit for Output Tubes-Robert M.. Mitchell 40 Avenue, Chicago 18, Ill. Visual Stereo Monitoring-Burwell Graham and George L. Foster 45 Series -Tuned Push -Pull Oscillator-E. J. Cuddy 48 Transistorized Microphone Presinip-Horace E. West 50 most honored of them ail= Speaker System for Perfectionists-James A. Mitchell 52 Equipment Profile-H. H. Scott 299 and 222 stereo amplifiers-Koss Stereo- phone headset-Fisher X -101A stereo amplifier 59 Record Revue-Edward Tatnall Canby 66 SHE RVOOD Jazz and All That-Charles A. Robertson 70 New Products 82 New Literature 84 About Music-Harold Lawrence 86

Coming Hi-Fi Shows _ ...... _ ___ _ .____-_... 87 Advertising Index 108

COVER PHOTO-The Forecast Music Sphere, latest in Aluminum Company of America's continuing series of designs in aluminum for tomorrow. This unit, created by industrial designer Lester Beall, was on display at the recent New York High Fidelity Show. The components installed in the Sphere are : Pickering Gyropoise 800 Stereotable, 196 Unipoise arm, and 371 Stereo-Fluxvalve, Gronunes 209 preamp-control unit, Dynakit Stereo 70 amplifier, and Jensen Galaxy II speaker system. The dual -coil woofer is in the lower half of the hemisphere with the two satellite tweeters on the "outriggers."

AUDIO (title registered U. S. Pat. Olt.) Is published monthly by Radio Magazines, Inc., Henry A. Schober, President; C. O. McProud, Secretary. Executive and Editorial Offices. 204 Front St., Mineola. N. Y. Subscription rates--C. S. Poserions. Canada and Mexico. $4.00 for one year. $7.00 for two years. all other countries. $5.00 per year. Single copies 50g. Printed In C.S.A. at Lancaster. Pa. All rights reserved. Entire contents copyrighted 1959 by Radio Magazines. Inc. Entered as Second Class Matter February 9, 1950 at the Post Office. Lancaster. Pa. under the act of March 3, 1879. RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y.

Postmaster: Send Form 3579 to AUDIO, P. O. Box 629, Mineola, N. Y. FOR COMPLETE SPECIFICATIONS WRITE DEFT

AUDIO NOVEMBER, 1959 1

www.americanradiohistory.comAmericanRadioHistory.Com AUDI_clinic

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JOSEPH GIOVANELLI ,.. ,_ A I ,Sc ,,,k,..... Stereo Adaptor resi-l:uice compared to that of the attenuator, and place it in series with the ,..., My problem concerns mom , r.sion to Q. hot side of the stereo. I have the following midipnient: attenuator. The potentiom- a eter sections should Fisher 80-R AM -FM tuner, an Rico HFT90 be wired as rheostats. (The reason you Íl,0 FM tuner, a Fisher 80-C audio control, a cannot use a potentiometer to do the is 60 -watt McIntosh power amplifier, a Scott entire job that ganged potentiometers which track uniformly FOR EVERYONE 2100 preamplifier, a Ferrograph tape re- be- tween gangs are difficult obtain.) corder, and two speaker systems. I know to Of ...perhaps for you course, the that I could build a stereo adapter which attenuator sections will not track unless all resistors making up would suffice to mate my equipment if cer- the attenuator are 1 -per -cent units. The tain questions were answered. These are use of the questions: the series potentiometer may be justified in two ways: 1. How can I design a single volume (A) Although this potentiom- is placed in control for both channels after they have eter series with the load, thereby causing the load to see different been balanced using the controls on the impedances Scott 210C and the Fisher preamplifier? with different control settings, the effect will be negligible since the 2. Where do I tap off the signal total resistance from of the pot the Scott and the Fisher, and into what section is small compared to that kind and resistor, and of the total into which the load works. (B) There will be some so on do I lead it? error in tracking between the two sections of the 3. Next-how do I feed the signal back potentiometer because the total resistance of the to what place in the Scott and McIntosh? potentiometer is small compared to that of the at- 4. Monophonic playback I'm not worried tenuator. The amount of tracking error about since the McIntosh will do nicely cannot be severe enough to without help. However, nowhere have I cause sufficient unbalance between channels to be detected Tandlwry n how you can parallel two dissimilar aurally, and that is the only kind of -SPEED, 4 -TRACK amplifiers. John A. Timm, Boston, Mass. de- 3 tection which really matters. I RECORDER A. 1. The problem of adjusting the vol- STEREO It should have been stated ume of both channels with one potentio- that the total PLAYBACK resistance of the potentiometer should meter is a difficult matter. The best solu- be The Tandberg 5 is not everyman's figured in such a way tion is the use of a two -deck step switch that it can give a tape recorder. It is an instrument of 3 made up as an attenuator. The maximum total variation perhaps db when built to incredibly rigid standards of placed in series number of switch positions you can find with the attenuator. perfection, designed to provide the 2. There will probably be 24. This will mean that are two ways of tapping the discriminating listener with a life- signal: (A) The easiest is simply to feed you must design your attenuator in 3 or time of listening pleasure. To the the output of each preamplifier into the educated car, the difference be- 3.5 db steps. With such an arrangement there may be times where might desire series combination of attenuator and po- tween Tandberg reproduction and you tentiometer, having a volume control setting somewhere the output of each preampli- conventional recorder playback is fier going between these positions. This can be done to its respective gang. The arm immediately apparent. of the by using a potentiometer having a fairly attenuator would be connected to Yet, the difference is subtle. It is re- the input of its appropriate power ampli- flected in shadings and nuances that * 3420 Newkirk Ave., Brooklyn 3, N. Y. fier. In some instances, low capacitance most recorders ignore. If your car is finely attuned to musical perfection .. if you relish the certainty that o you own the finest ... then the O CHANNEL A Tandberg 5 will give you more SELECTOR O pleasure -per -dollar than any other SWITCH O tape recorder, anywhere.

See and hear the Tandberg 5 et your high fidelity dealer. The instrument illustrated here / VOLUME CONTROL is the Tandberg Model 5-2. Complete with two GANGED POTENTIOMETERS TM -2 microphones for home stereophonic re- POTENTIOMETER 24 -STEP GANGED PREAMP) cordings, input-output cords, reels and hand- ION some Transport luggage case, $513.95. Other ATTENUATOR Tandberg models from $249.50.

For full information, write Dept. A-11. O

O I CHANNEL B o of America, Inc. SELECTOR I/ Tandberg SWITCH O V 8 Third Avenue Pelham, New York *MAY HAVE TO BE REPLACED BY LARGER UNITS

2 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com "Use our new giewer3(WCZ cartridge and a GARRARD changer for top stereo quality," says

Vice -President, Sales, Electro-Voice Inc.

"Garrard changers performed magnificently during the months of testing and development of our new 31MD stereo cartridge. We knew that this was to be expected because, in fine component systems, more Electro-Voice stereo cartridges are used in Garrard changers Electro-Voice 31 -MD than in all other turntables and changers Stereo combined. Our new cartridge is designed for Cartridge in a the most critical stereo performance. The Garrard Shell Garrard changer insures this performance."

In thanking Mr. LeKashman and Mr. Wirth, we also wish to emphasize the reasons why Garrard changers are so popular for stereo with all outstanding manufacturers of stereo cartridges, including Shure, General Electric, Pickering, Fairchild, etc.

Vibration -free turntable. Vertical and lateral rumble completely inaudible. Wow and flutter far below exacting "broadcast tolerance" standards, Exclusive Aluminum tone arm precision -mounted at engineering works for optimum tracking angle, perfect sound reproduction. Unrestricted choice of stereo cartridges-any of them will track at the manufacturer's lightest specified weight. Record handling gentler than the surest human hand. The important convenience of manual play plus completely automatic operation without compromise in performance. These are the FACTS, no one can deny them with authority- and they are backed by the 36 years of experience that have created Garrard's unique reputation for unsurpassed quality.

"We receive compliments, not complaints, from Garrard/EV users," says JON WIRTH Chief Engineer, Cartridges E/ectro- Voice Inc. "We're the first to hear when For the best in Stereo... a cartridge and player combination doesn't give the Insist on a kind of stereo performance expected. But Garrard owners usually write to tell us hoe., excellent their stereo systems sound. There is no distortion or rumble. The Garrard CHANGER changer tone armor tracks perfectly THE WORLD'S FINEST! at the pressure we specify." Send for free Garrard Comparator Guide. Your Name_ Address City State GS -19 at address

ere's a Garrard for every high fidelity system... all engineered and wired for Stereo and Monaural records.

RCN r- RC 121/12 TPA/12 301 !HF sumo T/13 Deluxe J- Intermix fl Stereo Transcription Transcriptionr paned Chance, Tone Arm Turntable Changer ( ' .:f'Manual Mayor $59.50 0' $42.50 V $19.50 $89.00 `/' $59.50Piarer t.50 GARRARD SALES CORPORATION, Division of British Industries Corporation, PORT WASHINGTON, N. Y. Canadian inquiries to Chas. W. Pointen, Ltd., 66 Racine Road, Rexdale, Ont. Territories other than U.S.A. and Canada to Garrard Engineering & Mfg. Co., Ltd., Swindon, Wilts., England

www.americanradiohistory.comAmericanRadioHistory.Com shielded cable should be used. This is true when the attenuator load is 1 megohm or higher. (B) An alternative method would STEREO ON DISPLAY be to make wiring changes in the preamplifiers themselves. Tap the signal from the arms of the selector switches in the preamplifiers. Feed the signals to the proper gangs of the attenuator network, feed the arm of the attenuator back to the volume controls of the preamplifiers. This can be in your city... made clearer by schematic of Fig. 1. No values are given for the components since their values will be determined by the impedance of the output circuit and by the impedance of the circuit into which the attenuator feeds. 4. I do not believe it necessary to paral- 4nudce lel two dissimilar amplifiers. Merely ar- HIGH FIDELITY SHOWS range some switching on your proposed stereo adaptor in such a manner that it will feed the same signal simultaneously to the inputs of the two power amplifiers. The outputs of the amplifiers are connected to their respective speakers. As stated in your letter, the sound in each channel can be balanced by means of the separate volume controls of the pre- with the newest and latest in stereo high fidelity amplifiers. You can, however, include another refinement to your adaptor-namely, from leading high fidelity manufacturers a balance control. This consists merely of a ganged potentiometer, with each section wired backward to the other. This means that as the potentiometer rotates, the level of one channel will be raised while that of the other channel will be lowered. Tracking error of the pots is of no importance. Don't miss these public showings Amplifiers - Pre -Amplifiers - The idea of this type of balance control of hi-fi equipment ... from the FM -AM Tuners - Turntables circuit is an interesting and simple one. most economical units for the - Record Changers - Phono If this method is used, however, considerable gain will be lost. Therefore, if there - to spectacular Microphones budget minded Cartridges - - is insufficient reserve gain in your equip- home music theaters ... compare Music Control Centers - Speak- ment, adoption of this circuit is inad- and enjoy them all. ers Speaker Enclosures - visable. In this event, you may wish to - try the more elaborate stereo balance con- Equipment Cabinets - Finished trol circuit shown in AUDIOCLINIC for June, Complete Stereo and Mono- and Assembled or Do -It-Your- 1959, under the heading, "Stereo Balance phonic High Fidelity Systems self Kits Control."

Tonea:m Chatter Q. I have a Livingston Universal play- THREE FULL DAYS OF CONTINUOUS DEMONSTRATIONS ing arm and a GE magnetic pickup which I to play 78 -rpm records. When FRIDAY, SATURDAY, AND SUNDAY pia q i n p 12 -inch records, an excessive amount of chatter or vibration of the FROM 1 P.M. to 10 P.M. FOR EACH SHOW needle occurs which is very undesirable when playing the outer grooves. As the needle moves an inch or so toward the center of the record, the annoyance gradually diminishes and disappears. The needle RIGO HIGH FIDELITY MUSIC SHOWS, Fall 1959 force is as recommended by GE, and increasing the force does not eliminate the trouble. Eccentricity of the outer grooves seems to be one cause of the trouble since Buffalo, New York October 30-31-Nov. 1 Statler Hotel it does not occur on all records and seldom on 10 -inch discs. What is the cause Seattle November 6-7-8 New Washington Hotel of this condition? How can it be corrected? Howard J. Murray, Philadelphia, Pa. Portland November 13-14-15 New Heathman Hotel A. The chatter in your tonearm may be Philadelphia November 20-21-22 Benjamin Franklin Hotel caused by loose side screws. These can be Heide/led by first loosening the locknuts, tightening the screws slightly, and reset - tine the locknuts. ADMISSION 75¢ When following this procedure, be sure that the screws are not tightened too much. By so doing, the freedom of the arm to move vertically will be restricted. This vibration may also be caused by the car - RIGO ENTERPRISES, INC. 500 N. Dearborn, Chicago 10, III. (Continued on page 106)

4 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com ."ir4Cf _74 1QflLz

NEW! Lorenz S-388 Armored horn -type 21/2" tweeter with plastic cone for 120 -degree high frequency sound dispersion. New ferrite magnet hermetically DUAL CONES sealed. Frequency response: 2,000 to 18,000 cps. Impedance: 5.5 ohms. Power rating: 2 watts peak. The perfect mate for Lorenz 12"or 8" speakers. $8.50

NEW! LORENZ S-1288 HP -1 High Pass Crossover Crosses over at 2,000 cps at Value -packed basic 12" loudspeaker with dual cones - for stereo or bril- rate of 3 db per octave - liant monaural. Twin voice coils provide 4, 8 and 16 ohm impedances feeds highs to tweeters, on lows to woofer. Extends one speaker! Frequency response: 18 to 15,000 cps. Magnet assembly speaker system range to weight: 61.5 oz. Power rating: 30 watts peak. $44.50 limit of audibility. For use with 2 or 3 way systems. $4.95

NEW! KAL NEW! AUDETTE III AUDETTE Blg performance In small space! Use NEW! OMEGA I singly or pair for stereo. Completely finished on four sides for use hori- Completely finished on four sides for Comi act for bookshelf or table - or at- zontally or vertically. Features Lorenz use horizontally or vertically. Inside, a tach brass legs for consolette. Houses 8" woofer with matching tweeter and full spectrum Lorenz 12" speaker, two superb Lorenz 8" woofer, tweeter and crossover. 30.17,500 cps. 8 ohms tweeters and high pass crossover. crossover. 35-17,000 cps. 8 ohms. f8 watts peak. 11" x 233/4" x 10" NEW! AUDETTE SR. 18-18,000 cps. 16 ohms. 40 watts It watts peak. 11"x 233/4"x 10". 20 lbs. Infinite baffle construction for x x 46 lbs. peak. 27" 143/4" 111/2". 1( lbs. Unfinished Birch $57.50 "big system" performance. Corn - Unfinished Birch $109.50 Brown or Blond Leatherette $49.50 Assorted Finished Woods 64.50 plete with 4" legs. Houses fa - Assorted Finished Woods 119.50 Matching Brass Legs 5.95 Matching Brass Legs 5.95 mous Lorenz 8" woofer and tweeter with crossover. 30- 17,500 cps. 8 ohms. Dept. A 20 At High Fidelity Dealers Everywhere. FREE Catalog-Write watts peak. 221/4" x 221/4" x 101/2". 37 lbs. PRODUCTS, Ltd. 514 Broadway, New York 12, N. Y. WOrth 6-0800 Satin Mahogany $69.50 ..740772-. Blond or Walnut 74.50 Exclusive U. S. Distri)utors for Lorenz High Fidelity Loudspeakers

AUDIO NOVEMBER, 1959 5

www.americanradiohistory.comAmericanRadioHistory.Com one LETTERS word Validity of IM Measurements to be quite critical of the precise low frequency used. more SIR: The present trend in amplifier specifica- The October issue contained two rather tions is to give frequency response (not indefinite "knocks" at IM distortion meas- necessarily at maximum power), power, and about urement: (1), the IHFM standard on am- distortion figures. Even if the distortion plifiers omitted any reference to this form stated is IM, it indicates little about the the of measurement, without stating why; (2) low -frequency power capability of the am- Leon Kuby detailed methods for making plifier unless the measurement frequency is Amperex accurate measurements of this type, and also specified. Standardizing this frequency 6CA7/EL34 also showed that such measurements are would set an arbitrary industry standard often completely invalidated because an for low -frequency power requirement. in OUTPUT indication is obtained, but not identified PENTODE effect limiting the specification of fidelity. -by using a 'scope. Under the circumstances, I feel the new For a long while IM distortion figures term that the IHFM Amplifier Standards have enjoyed a superior social status over Committee introduced (Section 2.1.5) harmonic figures. It is true that the IM called POWER BANDWIDTH, as there defined, kinds of distortion are more representative is highly commendable. It gives a consistent of some forms that happen on musical pro- basis for measurement and comparison that grams than is harmonic measurement. At will tell more than a single IM test has the same time, the writer feels they have ever been able to. been given an exaggerated importance, due True harmonic measurement of a single to failure to correlate the different "vari- tone does not "catch" all forms of distor- ables" involved. tion. Nor does any known IM test. As we First there are at least three IM stand- do not yet have suitable test(s) to evaluate ards: the CCIF difference tone, the SMPTE some of these elusive but important forms 4:1 and a similar 1 :1. These represent two of distortion, I feel the IHFM standard is specific kinds of musical distortion. The a very definite step forward, as it provides COIF test is directly relatable to a trans- a simple means for giving consistent indica- fer characteristic that produces in -phase tion of the relative magnitude of "known" second harmonic. But this is the kind of forms of distortion. distortion produced by single -ended stages, NORMAN H. CROWHURsT, Consultant or push-pull ones working out of balance. 216-18 40th Avenue. As most people feel distortion measure- Bayside 61, N. Y. ments should indicate what is left when the amplifier operation is optimized to balance (NOTE: The Amplifier Standards Com- out this component, the SMPTE test is mittee had prepared a paragraph stating more popular in the U. S. This is the test the IHFM position on IM measurements to Mr. Kuby detailed. the effect that the standardization in this The SMPTE test has been shown to area was being studied and an addendum produce a rather unpredictable relationship would be presented as soon as possible. Un- to harmonic tests, for which reason it has fortunately, neither the official IHFM We are pleased to been felt that the SMPTE is probably the booklet nor our reprint of the Standards announce that as a result of the further better test. What seems to have been over- carried this paragraph. ED. exploration of the 6CA7's capabilities looked in this area is that harmonic tests ... its power output rating has been are usually taken at 1000 cps, while the Wrong Picture raised to 60 watts in a distributed load IM test is basically a measure of distortion SIR: circuit. This was achieved by increasing to the low -frequency characteristic. This is why the IM test can be very Inasmuch as the Leak preamplifier in the the screen grid voltage to 500V. The dependent on the low frequency chosen. As Equipment Profile in the September issue screen voltage rating now equals the Mr. Kuby points out, this may be anywhere was in actuality a Varislope III mono- plate voltage rating, thus greatly sim- between 30 and 100 cps. If harmonic meas- phonic preamplifier and not a Leak Stereo plifying the design of power supplies. urements are made at the same low fre- Point One preamplifier, as described, we quency, the results are much closer. The would greatly appreciate it if a picture IM test is then only slightly more sensitive of the re -styled Stereo Point One pre- Class AB, Audio Amplifier to the order of distortion than the harmonic amplifier could be shown in a forthcoming Distributed Load Connection method. But the result of either test is apt issue. Typical Operation (Fixed Bias-Two Tubes Push Pull) Plate Supply Voltage 500 V Grid No. 2 Supply Voltage (See Note) 500 V Grid No. 1 Bias (approx.) -44.5 V Plate to Plate Load Resistance....7000 S2 Plate and Grid No. 2 Current (Zero Signal) 2x57 mA Plate and Grid No. 2 Current (Max. Signal) 2x112 mA Input Signal Voltage (rms) 32 V Power Output 60 W Harmonic Distortion 2 5% NOTE: Screen voltage is obtained from taps located at 43% of the plate winding turns. An unbypassed resistor of 1KSt in series with each screen grid is necessary to prevent screen overload.

ask Ampere. about detailed data and applications engineering assistance on hi-fi tubes for hi -fl circuits. Leak Stereo Point One preamp. AMPEREX ELECTRONIC CORP. 230 Duffy Avenue, Hicksville, L. I., N. Y.

6 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com HEATHKIT

style performance quality STEREO EQUIPMENT CABINET KIT MODEL SE -1 (center unit) $14995 Shpg. Wt. 162 lbs. ge4tt MODEL SC -1 (speaker enclosure) $3995 each co* sow Shpg. Wt. 42 lbs. Superbly designed cabinetry to house your complete stereo system. Delivered with pre-cut panels to fit Heathkit AM -FM tuner (PT -I), stereo preamplifier (SP -1 & 2) and record changer (RP -3). Blank panels also supplied to cut out for any other equipment you may now own. Adequate space also provided for tape deck, speakers, record storage and amplifiers. Speaker wings will hold Heathkit SS -2 or other speaker units of similar size. Available in unfinished birch or mahogany plywood.

MONAURAL -STEREO PREAMPLIFIER World's of KIT ITv,o Channel Mixer) electronic instruments in kit form MODEL SP -2 (stereo) $56.95 Shpç. Wt. 15 lbs. MODEL; P-1 (monaural) $37.95 Shrg. Wt. 13lbs. HEATH COMPANY MODEL C -SP -1 (converts SP -1 to SP -2) $21.95 Benton Harbor, 25, Michigan Shpg. Wt 5 lbs. Special "building block" design allows you to purchase instrument in monaural version and add stereo or second channel later if desired. The SP -1 monau-al preamplifier features six separate inputs with 4 input level controls. A function selector switch on the SP -2 provides two channel mixing. A 20' remote balance control is provided.

HIGH FIDELITY RECORD CHANGER KIT MODEL RP -3 $6495 Turntable quality with fully automatic features! A unique "turntable pause" allows record to fall gently into place while turntable is stopped. The tone arm engages the motionless record, and a friction clutch assures smooth start. Automatic speed selector plays mixed 33!i and 45 RPM records regardless of sequence. Four speeds availab.e: 16, 33M, 45 and 78 RPM. Changer complete with GE -VR -11 cartridge with diamond LP and sapphire 78 stylus, changer base, stylus pressure PROFESSIONAL STEREO -MONAURAL gauge and 45 RPM spindle. Shpg. Wt. 19 lbs. AM-fM TUNER KIT MODEL PT -1 $8995 "EXTRA PERFORMANCE" 55 The 10 -tube FM circuit features AFC "automatic WATT HI-FI AMPLIFIER KIT frequency control) as well as AGC. An accurate A real work horse packed with top quality tuning meter operates on both AM and FM while features, this hi-fi amplifier represents a a 3 -position switch selects meter functions without remarkable value at less than a dollar per disturbing stereo or monaural listening. Individ- watt. Full audio output at maximum ual flywheel tuning on both AM and FM. FM damping is a true 55 watts from 20 CPS sensitivity is three microvolts for 30 db of quieting. to 20 kc with less than 2% total harmonic MODEL W7 -M $5495 The 3 -tube FM front end is prewired and pre - distortion throughout the entire range. aligned, and the entire AM circuit is on one printed Featuring famous "bas -bal" circuit, push- circuit board for ease of construction. Shpg. Wt. pull EL34 tubes and new modern styling. 20 lbs. Shpg. Wt. 28 lbs.

AUDIO NOVEMBER, 1959 7

www.americanradiohistory.comAmericanRadioHistory.Com HIGH FIDELITY AM TUNER KIT MODEL BC -1A $2695 Designed especially for High fidelity applications this AM tuner will give you reception close to FM. A special detector is incorporated and the IF circuits are "broadbanded" for low signal NOTE THESE OUTSTANDING SPECIFICATIONS: Power Output: distortion. Sensitivity and selectivity are 14 watts, Hi-Fi; 12 watts. Processional; 16 watts. Utility. Power Response: excellent ± 1 db from 20cps to20 kc at 14 watts output. Total Harmonic Distortion: and quiet performance is assured by a high less than 2%, 30 cps to 15 kc at 14 watts output. Intermodutation Disto,. tion: less than 1% at 16 watts output using 60 cps and 6 kc signal reined 4:1 signal-to-noise ratio. All tunable components Horn and Noise: mag. phono input, 47db below 14 watts; tuner and crystal are prealigned before shipment. Your "best buy" phono, 63 db below 14 watts, in an AM tuner. Shpg. Wt. 9 lbs.

14 -WATT HI-FI ECONOMY AMPLIFIER KIT MODEL EA -3 $2995 MODEL FM -4 From HEATHKIT audio labs comes an exciting new kit . Nev. $3495 Styling, New Features, Brilliant Performance! Designed to function as the "heart" of your hi-fi system, the EA -3 combines the preamplifier and amplifier into one compact package. Providing a full 14 watts of high fidelity power, more than adequate for operating the HIGH FIDELITY FM TUNER KIT (FM -4) average system, the EA -3 provides all the controls necessary for precise blending of musical reproduction to your individual taste. The all new model FM -4 incorporates the latest Clearly marked controls give you finger-tip command of bass and advancement in circuit design. Features include treble "boost" and "cut" action, switch selection of three separate better than 2.5 microvolt sensitivity for 20 db inputs, "on -off" and volume control. A hum balance control is also of quieting, automatic frequency control (afc) provided. The convenient neon pilot light on the front panel shows with defeat switch, flywheel tuning and prewired, when instrument is on. Styled to blend harmoniously into any room prealigned and pretested tuning unit. Prealigned surroundings, the handsome cover is of black vinyl coated steel with IF transformers and prewired tuning unit assure gold design and features the new "eyebrow" effect over the front panel easy. assembly with no further need of alignment to match the other new Heathkit hi-fi instruments. The panel is satin after unit is completed. The five tube circuit fea- black with brush -gold while trim strip, the control knobs are black tures a generous power supply utilizing a silicon with gold inserts. Shpg. 15 Wt. lbs. diode rectifier. Shpg. Wt. 8 lbs.

"MASTER CONTROL" PREAMPLIFIER KIT "UNIVERSAL" 12 WATT HIGH FIDELITY MODEL WA -P2 $1976 (Not Illustrated): AMPLIFIER KIT MODEL UA -1 $2195 All the controls you need to master a complete high fidelity system Ideal for stereo or monaural applications, this are incorporated in this versatile instrument. Features 5 switch - I2 -watt power package features less than 2% selected inputs each with level control. Provides tape recorder and total harmonic distortion throughout the entire cathode-follower outputs. Full frequency response is obtained within audio range (30 to 15.000 CPS) at 12 ± 11/2 db from 15 to 35,000 CPS and will do full justice to the finest full -watt output. Use with preamplifier models àvailable program sources. Equalization is provided for LP, RIAA, WA-P2 or SP -1 2. Taps for 4, 8 AES, and early 78 records. Shpg. Wt. 7 lbs. & and.16 ohm speakers. Shpg. Wt. 13 lbs. NEW! MODEL TR -IA: Monophonic hatf-track record/pla. back with fast forward and rewind functions. Shpg. Wt. 24 lbs. $9995

MODEL TR -IAH: Hali-tract monophonicand sterco record /Playback with fast forward and rewind functions. $14995 Shag. Wt. 35 lbs.

MODEL TR -1 AQ: Quart,-r-trach monophonic and r : rybac, fart forward and rewind

Shpg. Wt, 35 It $14995

NOW! TWO NEW STEREO -MONO TAPE YOU'RE NEVER OUT OF DATE RECORDERS IN THE TR -1A SERIES WITH HEATHKITS Offering complete versatility, the model TR -1 A series tape recorders Heathkit hi-fi systems are designed for maximum flexi- enable you to plan your hi-fi system to include the functions you want. bility. Simple conversion from basic to complex systems Buy the new half-track (TR -1 AH) or quarter -track (TR -1 AQ) versions or from monaural to stereo is easily accomplished by which record and playback stereo and monophonic programming, adding to already existing units. Heathkit engineering or the half-track monophonic record -playback version (TR -I A). skill is your guarantee against obsolescence. Expand your hi-fi as your budget permits ... and, if you like, Precision parts hold flutter and wow to less than 0.35c;; . Four -pole, fan cooled motor. One control lever selects all tape handling functions. spread the payments over easy monthly installments Each tape preamplifier features NARTB playback equalization, sepa- with the Heath Time Payment Plan. rate record and playback gain controls, cathode follower output, mike or line input, and two circuit boards for easy construction and high stability. Complete instructions guide assembly.

8 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com CONTEMPORARY Model CE -1B Birch CHAIRSIDE ENCLOSURE KIT Model CE -1M Mahogany MODEL CE -1 $4395 each Control your complete home hi-fi system right from your easy chair with this handsome chairside enclosure in either traditional or contemporary models. It is designed to house the Heathkit AM and FM tuners (BC -IA and FM -3A) and the WA -P2 preamplifier, along with the RP -3 or majority of record changers which will fit in the space provided. Well ventilated space is provided in the rear of the enclosure for any of the Heathkit amplifiers de- No Woodworking Experience signed to operate with the WA -P2. The tilt-out Required For Construction. shelf can be installed on either right or left side as desired during the construction, and the lift-top lid in front can also be reversed. All parts are pre- All Parts Precut & Predrilled cut and predrilled for easy assembly. The con- For Ease of Assembly. temporary cabinet is available in either mahogany TRADITIONAL or birch, and the traditional cabinet is available in Maximum Overall Dimensions: Model CE -1T Mahogany mahogany suitable for the finish of your choice. 18" W.x24'H.x35%"D. All hardware supplied. Shpg. Wt. 46 lbs.

"BASIC RANGE" HI-FI SPEAKER SYSTEM KIT IT'S EASY . . . IT'S FUN The modest cost of this basic speaker sys- AND YOU SAVE UP TO tem makes it a spectacular buy 'or any WITH DO-IT-YOURSELF HEATHKITS hi-fi enthusiast. Uses an 8° mid -range woofer and a compression -type tweeter to Putting together your own Heathkit can be one of the most cover the frequency range of 50 to 12,000 exciting hobbies you ever enjoyed. Simple step-by-step in- CPS. Crossover circuit is structions and arge pictorial diagrams show you where built in with balance control. Im- every part goes. You can't possibly go wrong. No prevhus pedance is 16 ohms. Power rat- electronic or kii building experience is required. Ycu'll ing 25 watts. Tweeter horn ro- learn a lot abou' your equipment as you build it, and, of tates so that the speaker may course, you wits experience the pride and satisfaction of be used in either an having done it yourself. upright or horizontal positon. Cabinet is made of veneer -surfaced furniture -grade plywood suitable for light or dark finish. Al wood parts are precut and predrilled MODEL $3995 for" easy assembly. Shpg. Wt. Legs: No. 91-26 Shpg. Wt. 3 lb. $4.95 26 1 bs.

DIAMOND STYLUS HI-FI PICKUP CARTRIDGE LEGATO HI-FI SPEAKER SYSTEM KIT MODEL MF -1 =ß2696 MODEL HH -1 $29995 Replace your present pickup with the MF -1 The startling realism of sound repro- and enjoy the fullest fidelity your library of duction by the Legato is achieved LP's has to offer. Designed to Heath specifica- through the use of two 15" Altec tions to offer you one of the finest cartridges Lansing low frequency drivers and a available today. Nominally flat response from specially designed exponential horn 20 to 20,000 CPS. Shpg. Wt. I lb. with high frequency driver. The special crossover network is built in. Covers "RANGE EXTENDING" HI-FI 25 to 20,000 CPS within ±5 db. Power SPEAKER SYSTEM KIT rating 50 watts. Cabinet is constructed of 3/4" veneer -surfaced plywood in The SS -1B employs a 15" woofer and super to extend overall response either African mahogany or white tweeter of basic birch suitable for the finish of your SS -2 speaker from 35 to 16,000 CPS ±5 db. choice. All parts are precut and pre - circuit is in. Impedance is 16 Crossover built drilled for easy assembly. Shpg. Wt. ohms, power rating 35 watts. Constructed of 195 lbs. 3/4" veneer -surfaced plywood suitable for light or dark finish. Shpg. Wt. 80 lbs. 9 HEATH COMPANY BENTON HARBOR 25, MICH. pioneer in (L- MODEL SS -1B I a subsidiary of Daystrom, Inc. "do-it-yourself" L Please send the Free Heathkit catalog. $9995 electronics

Enclosed find $ name Please enclose postage for parcel post-express orders are shipped delivery charges collect. All prices F.O.B. Benton address Harbor, Mich. A 20% de- posit is required on all ...... wsv C.O.D. orders. Prices subject to change with city & state out notice. SEND FOR FREE CATALOG QUANTITY ITEM MODEL NO. PRICE Describing over 100 easy -to -build kits in hi-fi, test. marine and ham radio fields. Also contains complete specifications 'and schematics.

AUDIO NOVEMBER, 1959 9

www.americanradiohistory.comAmericanRadioHistory.Com ROGER DANIEL., British Industries Corporation, 80 Shore Road, Port Washington, N. Y. You (The correct picture appears on page G, and thanks for correcting us. ED.) Say Open House SIR: Acoustic Research, Inc., (AR) will hold AUDIO its annual "open house" this year on Fri- day, November 27. Tours of inspection of the AR plant, which is located at 24 Thorn - Is dike St., Cambridge, Mass., will be conducted at 10:00 a.m. and 2:30 p.m. Visitors will have the opportunity to watch production and quality control test procedures, Publishing including speaker checks in AR's anechoic chambers. Coffee will be served, and all visitors A are welcome. ROY F. ALLISON, Assistant to the President, Cookbook? Acoustic Research. Inc., I'anshridge, Mass.

More on Doppler Effect Yes, AUDIO is publishing a cookbook- push himself away from the table before SIR: not that we intend to This is in reply to the letter by L. D. extend the subject upsetting the daily calorie count." Dalessandro and Larry S. of gastronomy to Rogers ÌI ques- include recipes in fu- Here is a tioning the audibility of Doppler distortion ture pages of AUDIO. cookbook that will enable you to recreate in your own homes superb in loudspeakers. (Published in the Septem- You may ask ...why? ber issue.) I assume they fed to a loud- dishes experienced only at the Mirror speaker a 40 -cps and a 10,000 -cps signal And we would answer-Simply because Lake Inn-dishes like Lake Trout Baked (and not a 10,000 -cps sine wave, the way we feel that people who read AUDIO, In Wine and Adirondack Apple Pie, rec- the letter read) and listened to the com- and enjoy the finest quality music repro- ipes for which are reproduced below- bined output, switching the low -frequency signal in and out. This test method is un- duction also enjoy really good food on LAKE their TROUT BAKED IN WHITE WINE tenable, because it compares unlike signals. tables. Remove heads and tails from a 2 -pound fish. Split open down The correct way of testing for Doppler Your back and rinse well. Remove backbone and rub inside with lemon, distortion is to place a microphone in front next question may be...Is it a dif- salt, pepper and thyme to taste. Knead I tablespoon of butter of the speaker, and then filter out the 40 -cps ferent kind of cookbook? and anchovy paste the size of a large pea: placing mixture inside fish. Place fish in a greased baking pan and cover with yes cup tone so that the reproduced signal of the Of course our reply would be-Yes! Oh, of white wine. Bake 25 to 30 minutes in moderate oven, 350 A -B test will always be 10,000 cps. This it doesn't have a revolutionary format degrees. Baste frequently. Garnish with parsley and lemon distortion becomes the more objectionable and it appears to look like any ordinary and serve with plain boiled potatoes. the more reflected sound is picked up by cookbook. the microphone, because the interference But, the secret of its goodness ADIRONDACK APPLE PIE pattern of the sound in the room is changed is the recipes that fill its 148 pages... I c. sugar 3 tbaps. white corn syrup by frequency modulation, due to phase recipes responsible for 2 shape. sifted flour 6 to 8 tart apples, thinly the heart warm- 1es tsp. grated nutmeg sliced shift, the frequency modulation distortion ing, flavorsome, homespun aromas expe- t/ c. orange juice pastry assuming the character of amplitude dis- rienced only in the kitchen of an Adiron- S/a c. melted butter tortion. dack country home. Mix together the sugar, flour, nutmeg, orange juice, corn The resulting sound is "rough," not syrup and melted butter. Add the sliced apples and mix thorough- "clean," "swimming." ly. Butter a pie pan The name of the book heavily before putting in your pastry. Fill the VIRGINIA RETTINOER. is PLACID pie shell with the apple mixture and make pastry strips for the 5007 Haskell Ave., EATING, and it is chock full of palate - top which should be dipped in melted butter before putting on tempting recipes compiled by Climena the pie. Bake in 400 degree oven for 15 minutes: reduce heat to Encino, California M. Wikoff, owner of the Mirror Lake Inn 250 degrees and hake 35 to 40 minutes longer. Errors Again ...at (you guessed it) Lake Placid, New This colorful book, York. plastic bound for easy SIR: handling, will contribute many wonder- Several errors Crept into the article "A Actually, the first edition (now out of ful adventures in food for everyone in ten -watt all -triode amplifier," by Robert print) was discovered by Mr. AUDIO the family. Order a copy today, the Lady- Ellis and the ivriter, in the September issue. (C. G. McProud) during his stay at Mrs. of -the -house will adore you for it. Inci- 1. The freque icy response curve shows Wikoff's Mirror Lake Inn, where, in Mr. dentally...it makes a wonderful gift for the amplifier cutting off at about 15 kc 50 McProud's own words-"... every meal is anyone. PLACID EATING, 152 instead of ke. (Mistake in drawing.) pages, 2. The power output curve extends down so tasty that eating becomes a real joy, Plastic Bound : $3.95. cps where to only 30 instead of 20. (Mistake in each night's dessert excels the one tt t'au i rag. ) from the night before, where one has to 3. In reference to Fig. 7 and the associated text, one other change is necessary for variable damping. The cathode resistor of the first, stage must now be connected to the "0" output terminal instead of ground ill order to complete the current feedback loop. This was an omission of the authors. 4. One other matter of interest is that ORDER TODAY... $3.95 after submission of the manuscript Mr. Ellis and 1 found that we could increase the low -frequency stability by using larger coupling capacitors to the output stage. We found 0.25 µf to be optimum. RADIO MAGAZINES, INC., Dept. L99 The authors would appreciate your call- ing these errors and additions to the at- P.O. Box 629. tention of your readers. Mineola, New York ROBERT M. Voss, 697 West End Avenue, New York 25, N. Y. 10AUDIO NOVEMBER, 1959 www.americanradiohistory.comAmericanRadioHistory.Com Collard stereo 410 record players with typical British precision steadfastly guard your records and stylus from wear and accidental damage

The Coronation Il, Model TSC-740-$42.50 The Constellation, Model TC -99-$59.50 The Continental Il, Model TSC-840-S49.50 `The Conquest Il, Model TSC-640-$38.50

ROCKBAR

TP -59-$29.95 Transcription Turntable, Model 4TR-200-$49.50 Manual Player, Model

engineered and rigidly tested to give truly Every Collaro stereo record player is built with typical British attention to every detail. They are precisior W Collaro the logical choice for stereo professional performance and the ultimate in operating convenience. Here are some of the important fea:ures that make actual performance test reports accom- or monophonic records. Performance specifications exceed NARTB standards for wow, flutter and rumble-with weight is carefully distributed for flywheel panying each model TC -99. Extra -heavy, die-cast, non-magnetic turntables (weighing up to 81/2 lbs.). Extra -heavy shields to provide extra 25 db reduction effect and smooth, constant rotation. Shielded four -pole motors are precision balanced, screened with triple interleaved TP two completely independent circuits, guaran- in magnetic hum pick-up. Detachable five -terminal plug-in head shells (on TC -99, TSC-840, TSC-740, -59) provide to permit the last record teeing ultimate in noise reduction circuitry. Transcription -type stereo tonearms are spring -damped and dynamically counterbalanced are handsomely styled, available with optional walnut, blond and on a stack to be played with virtually the same low stylus pressure as the first. All units need and budget! Prices slightly higher in the mahogany finished bases or unfinished utility base. There's a 4 -speed Collaro stereo record player for every in appearance to The Coronation.) E. West. For free catalog on the Collard line, write to: Rockbar Corporation, Dept. A-11, Mamaroneck, N. Y. (*Not shown. Similar

www.americanradiohistory.comAmericanRadioHistory.Com BEYOND COMPARE AUDIOMAN NO. 2 Ellett N. Shepherd, of Denver, Colorado, Deputy District At- torney, music lover, criminologist, and-by his own admission -"Audio Ham" becomes the second Audioman of the Month

I[EN A MAN DESIGNS :1 house to eon- t;Iin :I listening room and components wlll Ii reate reproduction as near as possible to perfection-or as far as the state of the art will permit-then lie well deserves to become an Audioman. His listening room is 16 by 28, with a 10 -foot ceiling, and one end has a corner right in its center, to aceommodate the folded horn mania -at ) 9. console built by Ben Drisko, erstwhile AUDIO con- tributor. The other end of the room con- Consumer Net $249 sists of windows that slant outward at the Cabinet 24 top at an angle of 22 deg. so :111v reflected Slightly higher in West sound is absorbed in an acoustical ceiling. The complement of speakers in the horn are an Altec 515 In pre -amplifiers and power ampli- for the low end and an Altec 802D with a Drisko horn fiers, Marantz has set today's highest sectoral for the highs, with an occasional switch to a standard of quality. pair of JBL D -175's in parallel. For stereo, the second channel is an AR -3. Consider the Marantz Stereo Console. For amplifiers, Mr. Shepherd uses Here is the essence of uncompli- a home -constructed Williamson for channel 1 cated, beautiful styling. So simple to and a 30 -watt McIntosh for channel 2. use, even the most non -technical For records, he uses a Garrard 301 turn- person can easily achieve matchless table with a 22 -in. home -constructed arum reproduction quality. Yet, this fine which has an agate pivot, with a Grado instrument offers an order of versa- Professional Stereo pickup for microgroove tility that pleases the most discrimi- and a Pickering for 78's. His tape machine nating professional users. Carefully is an Ampex 960, and he uses an Altee a package set for some $450, was dissatis- planned circuitry and M20 condenser microphone system for re- fied, and had someone else set up essentially wiring layout cording. result in unsurpassed freedom from the same system that had been recom- According to Leonard Rose, distortion, hum and noise. cellist (Co- mended. But now the acquaintance doesn't lumbia Records), Mr. Shepherd's sound is speak to hin1. Dedication to quality in every detail "better than any he has heard, Since the listening room is such a good cording studios." Since Mr. Shepherd is a studio, for is the reason why the Marantz 30 - particularly chamber music, Mr. devotee of chamber music, he attends all he Shepherd often records these watt power amplifier, too, is in a groups and can get to from Denver to the coast, per- he made the tape won 4 -year class by itself. The Marantz that 'cellist circuit haps ten a year, and he assisted in six scholarships at both Oberlin College and permits this superb amplifier to re- chamber music festivals in his home town, Curtis Institute this year. And with this cover instantaneously from sharp, as well as others in Colorado Springs, background, he offers a few suggestions to musical transients - to effortlessly Sewanee (Tennessee), and in Salt Lake manufacturers: drive loudspeakers of all types - to City. He seldom goes a month without 1. Make better power supplies. consistently outperform amplifiers of demonstrating his system, and some of the 2. Develop less -noisy input tubes. best systems considerably higher ratings. in Denver were planned by 3. Make functional parts, with easy -to - him. He gets calls almost weekly from read knobs like ham equipment rather than For both stereophonic and mono- strangers who want to know how to get fancy eye-catchers. phonic programs, Marantz is your the best results for themselves. 4. Realize that the real music lover and assurance Mr. Shepherd once laid out an installa- the Audio Ham buys most of the expensive of long, carefree operation tion for an acquaintance, and unprecedented performance. and the cost was parts. Madison Avenue doesn't sell the real determined in the vicinity of $1900. The Ilam. acquaintance balked to the point of buying 5. Promote tape of good music.

The attractive speaker system of the end of Mr. 30 -WATT AMPLIFIER Shepherd's specially built listening Net $147 Grill 7.50 room Slightly higher in West * Selected for demonstration at the AmericanmrffllnIm Natl. Exhibition in Moscow C O M P A N Y 25.14 BROADWAY, LONG ISLAND CITY 6, N. Y. y.

1? AUDIO NOVEMBER, 1959

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JBL RANGER-METREGON Stereo distributed smoothly over a wide area through radial refraction is available in a bass reflex acoustical enclosure of moderate dimensions -the JBL Metregon. Seven different speaker systems may be used with the Metregon.

JBL RANGER-MINIGON Newest stereo system by JBL 4111111111111111111111111111111111111111111 is the Minigon, an "infinite baffle" enclosure of minimal dimensions designed for the new JBL Linear - Efficiency Loudspeakers. Hangers for suspension on wall are built in. Small enough for placement on bench or in book cases. Halves may be separated. Choice of grilles.

JBL MADISON Owners of JBL single channel speaker systems Model C48 JBL DALE Model C49 may obtain for their second channel identical sys- measures just2334"x are matched for In is an elegant minimum tems that stereo. enclosures 131/4"x1134, yet re- volume enclosure for table such as the JBL C37. C40. C34, in which drivers are produces basstRnes or shelf. Dale and Madison asymmetrically mounted, a mirror -image arrangement .when a magnificently is are provided with brackets . for the second system advisable and available. for wall mounting. JBL Linear-Eff ciency Write for the name of the Authorized JBL Signature Loudspeaker is enclosed. Audio. Specialist in your community, free catalog, and new Finished five sides so it bulletins describing JBL Linear -Efficiency Loudspeakers. may be placed vertically or horizontally. JAMES B. LANSING SOUND, INC. 3249 Casitas Avenue Los Angeles 39. California

AUDIO NOVEMBER, 1959 13

www.americanradiohistory.comAmericanRadioHistory.Com You'll find the same thing reflected in the good looking instruction booklet, which is replete with three -color diagrams and art work. For each likely major function there's most of a page, telling you what cable to plug where, which buttons to push, always assuming you know nothing-but nothing. Reminds me, somehow, of those careful instructions that come with new cars-"to place the car in motion, depress the clutch pedal (A), move the gearshift lever (B) forward, and . . ." you know UDII what I mean. Depressingly elementary and therefore dismally complicated. When you award ratnall(anby start from the beginning, man, you start from the beginning. These instructions are well-nigh incomprehensible for the ordi- RCA'S CARTRIDGE sockets take the ceramic mikes; but if you nary hi-fi man, until the accessories and want to play tapes through your regular the switchings are translated into the TAPE RECORDER hi-fi use phono components you must the terms that we know so well. . . . And now we come to the much -her- inputs for outputs-a double -purpose circuitry I've never run into before. No fancy alded and long -postponed RCA Victor car- The Pushbutton Mind tridge stereo tape recorder, which has terms to confuse the button -pusher, no reached commercial form in an initial III LEVEL, LO LEVEL, PREAMP OUTPUT and Proceed no further. You can now quite model, SCP-2, that I've been trying out. so on-no "hi-fi stuff" at all. Only one vol- accurately infer the gist of RCA Victor's (Don't ask me about SCP-I, if there was ume control, ganged for both channels, for main attitude and intent with this tape such an animal.) It is a home -type re- both playback and recording; the nominal cartridge. It is meant for the pushbutton corder and player, complete with ceramic playback balance (to cope with speaker mind, for the person who doesn't want to mikes for making your own stereo and an vagaries) is actually just an extra volume know why or how-and there are millions extension second -channel speaker box. I've control on the second channel, over and of them. The cartridge will doubtless ap- had two of these machines on hand, which above the main control. The balance on re- peal to the soul who falls for electric tooth- has given me a chance to average out my cording is fixed-you aren't supposed to brushes and power can -openers, spray -can observations on this particular subspecies know anything about such things. There's enamel, and automatic car windows; it's of the genus cartridge. There'll be other a simple flashing -light record -level indi- ingenious. But more likely this new form examples later on, needless to say. cator, normal and overload, combining of tape is aimed, very simply, at the grand This SCP-2, let me note first, has done both channels (it flashes on playback too old-fashioned market we used to call "or- a great deal to clarify for me the inten- but you are told to ignore that) and you dinary" or "mass -production" home music tion of the tape cartridge (AUDIO prefers can't make a mechanical mistake with the equipment (now curiously labeled hi-fi, to to call it a magazine, but so long as "tape" pushbuttons because you must always push nobody's confusion). That is the market precedes "cartridge" we will probably have the STOP button between all other func- which has supported the bulk of the home . to go along. ED.) as RCA conceives it- tions-the buttons are interlocked. music entertainment business straight up for as you can imagine, the specific size, The whole thing is clearly designed to from the days of the morning glory horn shape, features and décor that a manufac- be worked by the man, woman, or child and the mantel radio and it still does, hi fi turer drapes around a basic device betrays who has never seen tape and probably or no, in this age of the transistor, the his thoughts and intentions better than any never wants to, who wouldn't know a hunk pop-up TV and the all -in -one stereo port- press release or advertisement. There's no of Sounderaft, Irish, Scotch, or Audiotape able. purely theoretical reason why the tape from a piece of sticky tape or ticker tape, (Pop-up TV? Haven't you seen the new cartridge should not be built into a super - or maybe elastic tape for underwear. folding TV sets? Convenient as a folding recorder with dual VU meters, multiple The machine comes complete and ready chair and much, less collapsible.) mike inputs, mixers, circuits for monitor- to play, that is, if you've bought the "ex- I beg you to note that, up to this very ing and so on. Needless to say, the SCP-2 tras" that complete it. You get built-in day, the tape recorder for all its terrific is not a recorder of this type, for the sim- speakers, a mike, all cords, controls and progress and expansion has not really in- ple reason that RCA's marketing intentions the rest, and just like Daddy's big new vaded the big mass market for home music are not in the direction of the professional car, the radio and heater are extra-i.e., in force. It has spread widely, it is spread- engineer. (For that trade, RCA might want your stereo isn't stereo until you buy an ing fast-but this can't hide the fact that to sell its fabulous cartridge tape dupli- "extra" mike and an "extra" speaker sys- millions of people have not even thought câtor with the air -jet pulleys, described in tem. This is perfectly normal standard of trying tape, have shied away from it, a recent technical journal.) practice in the package -goods industry refuse to touch it. There's the catch! Mil- these days, of course. Ah well, no use lions of them never will bring themselves grousing to touch it. Ready to Play about such ingrained American habit! But these people will buy the tape car- What you will find here, instead, is a For all the "extra" functions beyond the tridge. It fits their needs, their concept of large, somewhat gaudy semi -portable home basic one of .playing and recording car- a workable home machine, as no reeled instrument of the semi -suitcase type, tridge tapes, RCA lists more extra acces- tape will ever do. tweedy looking with fancy heavy gilt trim sories, cables to connect to particular RCA Ask any of your casual friends and inside (made of plastic) and a high -style phonographs for taping your disc records, don't just blame me for seeming to take set of modern clear -plastic saucer -shaped for example-one end plugs into the spe- sides. I'm on the other side. I use tape on controls to catch the eye as well as the cial jack on the phono's rear, and so on. reels and always will. I was shocked, the fingers. Everything is done by pushbutton These accessory cables are wired at both other day, when my own brother, who has and if you make a mistake the machine ends to match only specific RCA instru- played disc records these 25 years and has lets out a loud squawk (below) and stops ments. There's no mention of, say, a cable a species of hi-fi installation (with you before anything happens. There is that might connect a Columbia record changer), saw a roll of tape in my home nothing whatsoever of the technical in this player to the RCA tape recorder. (You for the first time in his life. So that's what "look," not even in usual hi-fi terms. The can do it, natch, but nobody is going to it looks like, he said. What's it made of? only cryptic indication at all was some- tell you so in so many words.) This, too, I was so surprised I said right back, why thing called STR. My musical mind read is merely standard practice in the industry tape, of course. I mean plastic-what did "strings" but, of course, it meant STEREO. and is surely not exclusive to RCA Victor you think? He didn't know. Hadn't even There aren't even the ordinary hi-fi in- -it's just an indication as to where this thought, had no reason to. puts and outputs on this machine. A pair cartridge tape machine finds its intended of phono inputs looks standard, and two place in the home scheme. (Continued on page 76)

14 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com Stereo Prearrplifie HF85

70W Stereo Power Amplifier HF87 28W Stereo Power Amplifier HF86

"The overall design of the HF -81 is conservative, honest and functional. It is a good value considered purely on its own merits, and a better one when its price is considered as well." FM Tuner I-FT90 - Hirsch -Houck Labs (HIGH FIDELITY Magazine) AM Tuner HFT99 Advanced engineering Finest qual ty -components "Beginner -Tested," easy step-by-step instructions LIFETIME service & calibration guarantee at nominal cost IN STOCK - compare, then take horre any EICO equipment - right "off the shelf"- from 1500 neighborhood EICO dealers. Stereo Integated Amplifier AF4

vcu. rll 12W Mono Integrated Fmpli=ier HFI2 Other Mono Integrates Amplifiers: 50, 30, & 20W (use 2 for stereo) iPEetE

Stereo Amplifier -Preamplifier HF81

HF81 Stereo Amplifier -Preamplifier selects, from 25 uv. IF bandwidth 260 kc at 6 db points. amplifies, controls any stereo source & feeds it Both cathode follower & FM -multiplex stereo thru self-contained dual 14W ampliifiers to a outputs, prevent obsolescence. Very low distor- pair of speakers. Provides 28W monophonically. tion. "One of the best buys in high fidelity kits." Ganged level controls, separate balance control, - AUDIOCRAFT. Kit $39.95*. Wired $65.95*. independent bass & treble controls for each Cover $3.95. *Less cover, F.E.T. Intl, channel. Identical Williamson -type, push-pull EL84 power amplifiers. "Excellent" - SATURDAY New AM Tuner HFT94. Matches HFT90. Selects wide (20c 9kc @ -3 db) or weak - REVIEW; HI-FI MUSIC AT HOME. "Outstanding "hi-fi" - 2 -Way Bookshelf (20c 5kc @ db) bandpass. quality ... extremely versatile."-ELECTRONICS station narrow - -3 Speaker System HFS1 WORLD LAB -TESTED. Kit $69.95. Wired $109.95. Tuned RF stage for high selectivity & sensitivity; Includes cover. precision eye-tronicie tuning. Built-in ferrite 3 -Way Speaker System HFS3 2 -Way Speaker System HFSS HF85 Stereo Preamplifier is a complete, master loop, prealigned; RF & IF coils. Sensitivity 3 uv stereo preamplifier -control unit, self -powered for @ 30% mod. for 1.0 V out, 20 db S/N. Very low Ir flexibility 8 to avoid power -supply problems. Dis- noise & distortion. High -Q 10 kc whistle filter. Kit $39.95. Wired $65.95. Incl. Cover & F.E.T. tortion borders on unmeasurable even at high sion, 8" woofer (45 cps res.), & 31/2" cone levels. Level, treble output bass, & controls inde- New AF -4 Stereo Amplifier provides clean 4W tweeter. 11/2 cu. ft. ducted -port enclosure. Sys- pendent for each channel ganged for or both 8W total Inputs for tem Q of 1/2 for smoothest frequency & best for per channel or output. channels. Irputs phono, tape head, mike, AM, ceramic/crystal stereo pick-ups, AM -FM stereo, transient response. 45-14,000 cps clean, useful FM, & FM -multiplex. One each auxiliary A & B FM -multi stereo. 6 -position stereo/mono selec- response. HWD: 24", 121/2", 101/2". Unfinished in each channel. Switched -in loudness com- input tor. Ciutch-concentric level & tone controls. Use birch $47.50. Walnut, mahogany or teak $59.50. pensator. "Extreme flexibility a bargain."- ... with a pair of HFS-5 Speaker Systems for good HFS1 Bookshelf Speaker System complete with HI-Fl REVIEW. Kit $39.95. Wired $64.95. Includes quality, low-cost stereo. Kit $38.95. Wired $64.95. factory -built cabinet. Jensen 8" woofer, match- cover. ing Jensen compression -driver exponential horn New HF87 70 -Watt Stereo Power Amplifier: Dual HF12 Mono Integrated Amplifier provides com- tweeter. Smooth clean bass; crisp extended 35W power amplifiers of the highest quality. plete "front-end" facilities and true high fidel- highs. 70-12,000 cps range. 8 ohms. HWD: 23" x Uses top-quality output transformers for undis- ity performance. Inputs for phono, tape head, TV, 11" x 9". Price $39.95. torted response across the entire audio range at tuner and crystal/ceramic cartridge. Preferred LGS-1 Brass Tip Matching 14" Legs - $3.95. full power to provide utmost clarity on full variabie crossover, feedback type tone control HFS2 Omni -Directional Speaker System (not illus.) orchestra & organ. IM distortion 1% at 70W, circuit. Highly stable Williamson -type power HWD: 36", 151/4", 111/2". "Eminently musical" harmonic distortion less than 1% from 20 to amplifier circuit. Power output: 12W continuous, - HIGH FIDELITY. 'Fine for stereo" - MODERN 20,000 cps within 1 db of 70W. Ultra -linear con- 25W peak. Kit $34.95. Wired $57.95. Includes HI -Fl. Completely factory- built. Mahogany or wal- nected EL34 output stages & surgistor-protected cover. nut $139.95. Blond $144.95. silicon diode rectifier power supply. Selector switch chooses mono or stereo service; 4, 8, New HFS3 3 -Way Speaker System Semi -Kit com- veneered EICO, 33-00 Northern Bled., L.I.C. I, N. Y. 16, and 32 ohm speaker taps, input level con- plete with factory -built 3/4" plywood (4 sides) cabinet. Bellows -suspension, full -inch ex- trols; basic sensitivity 0.38 volts. Without exag- SHOW ME HOW TO SAVE 50% on 65 geration, one of the very finest stereo amplifiers cursion 12" woofer (22 cps res.), 8" mid-range speaker with high internal damping cone for models of top quality: available regardless of price. Use with self - El Test Instruments smooth response, 31/2" cone tweeter. 21/4 cu. ft. D Hi-Fi powered stereo preamplifier -control unit (HF85 "Ham" Gear Free STEREO Hi-Fi Guide ducted -port enclosure. System Q of 1/2 for smooth- E recommended). Kit $74.95. Wired $114.95. Send FREE catalog 8 name of neigh- est frequency & best transient response. 32- HF86 28W Stereo Power Amplifier Kit $43.95. borhood EICO dealer. Wired $74.95. 14,000 cps clean, useful response. 16 ohms impedance. HWD: 261/2", 137/a",143/8". Unfinished NAME A-11 FM Tuner HFT90: Prewired, prealigned, tempera- birch $72.50. Walnut, mahogany or teak $87.50. ture -compensated "front end" is drift -free. Pre - ADDRESS wired exclusive precision eye-tronice traveling New HFS5 2 -Way Speaker System Semi -Kit com- CITY ZON tuning indicator. Sensitivity: 1.5 uv for 20 db plete with factory -built 3/4" veneered plywood (4 f quieting; 2.5 uv for 30 db quieting, full limiting sides) cabinet. Bellows-suspension, We" excur-

AUDIO NOVEMBER, 1959 15

www.americanradiohistory.comAmericanRadioHistory.Com EDITOR'S REVIEW

POWER RATINGS vs. DISTORTION since the power output figures have achieved an importance all out of proportion to their actual mean- FOOD FOR THOUGHT was contained in ing with respect to quality a recent announcement in of reproduction, we be- the columns of Home lieve that a brand new term should be employed CNSIDERABLEFurnishings Daily telling of the by intent of the all component high fidelity manufacturers to rate Electronic Industry Association to adopt a power their amplifiers, and this rating would be in- rating figure based on a distortion of either 5 per cent or 10 per cent. In this meaty announcement, it appears, the basic difference between real high fidelity, HI-FI WATTS as represented by the entire component industry, and "hi-fi" as presented in the daily newspaper advertise- which would, by definition, be the music power out- ments with various complete systems being offered put, in accordance with the IHFM Standard, at one anywhere from $49.95 up, is brought out. Since no per cent distortion. This would automatically differ- performance standards have been accepted by which entiate ordinary phono equipment from true high- the true quality of reproducing equipment can be fidelity equipment, and ratings given in Hi-Fi Watts assessed, who is to say that the stuff labeled "hi-fi" would almost invariably indicate the quality of equip- is not high fidelity ? Even in the area of real high ment that was being described in the ads. fidelity-components-neither the manufacturers in- Not everyone needs 50 -watt amplifiers, but even dividually nor the Institute of High Fidelity Manu- when listening at one -tenth or one -quarter watt levels, facturers have attempted to set performance stand- the critical listener still wants his distortion held ards; the amplifier and tuner standards that have down to less than one per cent. And that there is a already been adopted by the IIIFM refer only to the difference practically anyone who has listened to pro- methods of measurement and the ways in which the fessional -quality equipment will agree. results of the measurements may be set forth. Not once do the standards specify a minimum performance to entitle the product to be called "high fidelity." STEREO vs. HIGH FIDELITY In attempting to correlate the standards of the IHFM with the EIA-a practice that is common The faet that stereo has burst onto the advertising throughout all industry-it became apparent that the pages of the daily papers has made stereo the one idea of one per cent distortion was not at all accept- thing that attracts people, and we believe that the able to the EIA, whereas practically all high fidelity component industry has been a little lax in allowing components are rated at the one -per -cent point, some the importance of stereo to overshadow the real end even lower. For years, the tube handbooks have rated object of high quality sound reproduction-high fi- output tubes at 5 per cent, but with the better designs delity. Anything can be stereo, as we all know from of feedback amplifiers tubes are worked to about the the ads, but only high quality equipment will sound same outputs with distortions not exceeding one per good. It is as though the automobile industry decided cent. to push the station wagon as the greatest thing in the The horsepower race among automobile manufac- world. Anybody can make a station wagon, but only turers is quite closely paralleled by the radio, TV, Rolls Royce can build a Rolls Royce. and "hi-fi" manufacturers. Whereas many fine component amplifiers are rated at, for example, 30 or 40 or 50 watts, many of the other amplifier products on SPEAKING OF ROLLS ROYCE- the market employ much figures higher in rating their In case you equipment. No one didn't win the one Shure Brothers who has ever built an amplifier offered in their recent or who has ever made any measurements on one will contest, you may at least be interested in who did. Kenneth E. Shutts, of Chagrin believe it when he reads of a 40 -watt amplifier which Falls, 6V6's, Ohio, was the lucky man. But anyway, try employs a pair of but such statements appear again next time. in ads at times. Even the rating of "Music Power Output" which is specified as the "greatest single - frequency power that can be obtained without exceed- AES CITATION ing rated total harmonic distortion" becomes a large figure with good equipment, and if everyone used While we realize that it is not considered in the best the same method of measurement the performance of of taste to blow one's own horn, we also realize that different amplifiers could be compared fairly. The AUDIO readers are not likely to see any mention of it term "Peak Power Output" gave a higher numerical elsewhere. On the occasion of its Eleventh Annual figure to use in advertisements, since it is by definition Banquet, October 8, the Audio Engineering Society exactly two times the normal power output. However, honored us with a Citation this rating is not included in the new standard. If "in recognition of the contributions of some manufacturer should decide to use "Peak Music Aunt() magazine to the education of the Power Output," he would have some astronomical audio fraternity under our editorship." figures to advertise, particularly if his rated distor- We are indeed pleased, and we trust we may continue tion were to be 10 per cent. to enjoy the esteem of the Society.

16 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com an extra measure of quality 111Tw INCHES 1 4 5 6

10 12 14 16 18 20 22 24 26 32 34 36 38 40

1 2 3 4.__.5 15 I 17 19 21 2'? 1?S 2 M ; 31 33 35 3 7 39 II I I I 1111; I 11 1! ,: rf-s' Ers

The extra measure of quality in every PICKERING product adds extra value... extra convenience...to any high fidelity system! The beautifully simple sculptured lines...the low, sleek profile...the new look in quality stereophonic pickups-this is the shape of good things to come-this is the PICKERING Collectors' Series. Without question, the 380 is the finest- with more features and more flexibility than any other stereo pickup in the world. For example- the 380 is fully encapsulated in precious mu -metal for absolutely hum -free performance.

Visit your dealer for a demonstration today, you will love the live, eager response to every nuance in the record groove...you will find yourself listening to a bright, delightful quality...second only to the original live performance. The only true way to judge a high fidelity component is it with measure Only the Stanton Stereo FLUXVALVE features the safe, to compare another... comfortable, easily replaceable stylus assembly. its performance with the most vital instrument of all...the ear. Those who can hear the difference... choose PICKERING'".

COLLECTORS' SERIES Totally new and unique to high fidelity is the "Collectors' Ensemble" ...a complete quality "pickup -package" for reproduction of all records-stereo -microgroove -78's. Model 380E-Collectors' Ensemble, includes the Stanton Stereo FLUXVALVE with 3 "V -GUARD" styli for stereo, microgroove and 78 rpm records $60.00 Model 380A-Includes Stanton Stereo FLUXVALVE with D3807A "V -GUARD" stylus for transcription arms $34.50 Model 380C-Includes Stanton Stereo FLUXVALVE with D3807C "V -GUARD" stylus for auto -changer arms $29.85 *PICKERING - for more than a decade - most experienced manufacturer the world's PRO-STANDARD SERIES of high fidelity pickups ... supplier to the recording industry. It may interest you to know that in one short year, PICKERING'S Pro- Standard Series has become an industry standard...the universal choice of professionals. Now, the new and revolutionary PAC technique developed by PICKERING has effected economies in manufacture which permit a reduction in the price of the Pro -Standard Series. FOR THOSE WHO CAN HEAR THE DIFFERENCE Model 371A Mk II Stanton Stereo FLUXVALVE Pickup now $26.40 Model 371C Mk II Stanton Stereo FLUXVALVE Pickup now $24.00

Model 196 Mk II UNIPOISE Arm with integrated Stanton Stereo FLUXVALVE ickerino Pickup now $49.50 PICKERING AUTOMATED CRAFTSMANSHIP PICKERING & CO., INC., PLAINVIEW, NEW YORK FLVXVALVE. "V -GUARD:' "T -GUARD:' UNIPOISE,PAC

AUDIO NOVEMBER, 1959 17

www.americanradiohistory.comAmericanRadioHistory.Com At Bell Laboratories, Holmdel, N. 1, a horn reflector antenna is beamed skyward by scientists Edward Ohm, David Hogg and Robert DeGrasse. The maser amplifier, which employs a ruby cooled in liquid helium, is inside building at right. Over-all "noise" temperature of antenna, amplifier and sky is only 18°K at 5600 megacycles.

ANOTHER STEP TOWARD SPACE COMMUNICATIONS

The above antenna is part of a new ultra -sensitive radio The device uniquely combines the characteristics needed for receiving system under development at Bell Telephone Lab- practical space communication: extremely low inherent noise oratories. It has extraordinary directivity. Beamed skyward, and the ability to amplify a broad frequency band. it ignores radio "noise" from the earth, yet picks up ex- At present the receiving system is being used to pick up tremely weak signals from outer space. and measure minute radio noise generated by the atmos- The signals are amplified by the latest Bell Laboratories phere. It also foreshadows important advances in long "maser" amplifier. The maser principle was first demon- distance communications. For example, it could extend the strated, using gas, by Prof. C. H. Townes and his collabo- range of space -probe telemetering systems, could help make rators at Columbia University. Bell Laboratories scientists possible the transatlantic transmission of telephone and TV applied it to the solid state guided by a theoretical proposal signals by bouncing them off balloon satellites-and has nu- of Prof. N. Bloembergen of Harvard University. Their latest merous applications in radio astronomy and radar. traveling wave maser amplifier employs a ruby mounted in This pioneer development in radio reception is one more a waveguide. ruby The is excited to store energy. As signals example of the role Bell Laboratories plays in the pursuit pass through, they absorb this energy and are thus amplified. of better communications technology.

BELL TELEPHONE LABORATORIES WORLD CENTER OF COMMUNICATIONS RESEARCH AND DEVELOPMENT

www.americanradiohistory.comAmericanRadioHistory.Com Universal Stereo Control Center FRANCIS A. CICCA

Not for the absolute novice, but the more experienced constructor will find this preamplifier -control unit gives practically everything necessary in the way of flexibility to the modern stereo system.

THERE WAS A TIME when the audiofan FUNCTIONISELECTOR TYPE LEFT RIGHT TONE CONTR'' TONE CONTROLS SWITCH SWITCH SWITCH could feel fairly secure that his audio TREBLE BASS TREBL Sy system would not become obsolete. S3 ,. Si The last two years have created quite a bit of doubt. Disc stereo has so revolu- tionized high-fidelity and there can be BALANCE the R35 no doubt that stereo will dominate R75 industry from now on. Everyone wants to participate in this revolution and so many have quickly added another 5 HOC K speaker and power amplifier to allow MOJNTS them to play stereo discs. Frankly, the sudden rapid growth of inexpensive vI has caught nearly everyone un- CASCODE stereo PHONO awares and so the early problems of PREAMP high-fidelity are re-occuring. To the dis- may of long-suffering wives, once cabi- netted audio systems are now over -running the living room with additional amplifiers, loudspeakers, and "temporary" cabling. Perhaps the most urgent need is for a stereo control center from which all stereo and monophonic sources can be controlled conveniently. This would allow all temporary wiring and switching to be removed and amplifiers to be hidden. Over a year ago the author Inside view of the preamplifier. The two halves of the circuit are essentially identical tubes downward. realized the need for such a control cen- - one is mounted with the tubes upward, the other with the ter and began its design, testing and age amplification without any attempt for the eascode stage, and making cer- construction. The resulting control cen- at playback equalization. Similar retain that the d.c. supply is adequately ter meets all the original design objec- quirements obtain for the tape -head bypassed to ground. tives and provides performance which preamplifier. The final eascode preamplifier has a exceeds many monophonic control cen- Because of its extremely low noise signal-to-noise ratio of over 80 db and ters. capabilities, the "cascode" circuit so a signal -to -hum ratio of about 65 db. often used in TV tuners was chosen for Table I lists a figure of 63 db, which Design Consideration the first stage (V, and V5 in Fig. 1) . is predominantly hum. Actually, this When design was first started it was The eascode circuit uses two triodes represents the worst condition measured be no decided that there should skimp- connected grounded -cathode, grounded - and an actual figure of over 70 db can ing in this control center. No short-cuts grid which gives the high gain of a be obtained by careful lead dressing. In would be taken to either simplify the pentode with the low noise of a triode. any event, this spurious noise level can- circuit or reduce its cost at the sacrifice This high gain is very useful since it not be heard with even the lowest level of quality. It was also decided that the supplies the capability to handle all inputs. unit should be as flexible as possible in magnetic cartridges and allows the use Following the cascode input stage is order to prevent obsolescence. of feedback to reduce distortion. In a conventional triode voltage amplifier The most critical and important sec- order to further enhance the low -noise with feedback equalization. Unlike many tion of any control center is the pre- capabilities of the cascode circuit, the equalization circuits, however, at least amplifier, particularly since records and 12AY7 double -triode was chosen for this 10 db of negative feedback is main- tape predominate as stereo sources. An stage. tained throughout the frequency range ideal phono preamplifier must provide : Unfortunately, the eascode amplifier (feedback resistors R12 and R52 in Fig. (1), extremely accurate playback equal- has one main disadvantage. Since the 1) . This is extremely desirable in order ization throughout the audio spectrum; cathode of the grounded-grid stage is to lower distortion at very low fre- (2), high signal-to-noise ratio; (3), low "floating" above ground .(pin 3 of V, quencies where there is no equalization hum level; (4), low harmonic and inter - and V5), any stray voltage induced on feedback to help. Feedback equaliza- modulation distortion; and (5), high this cathode will appear at the output. tion requires reserve gain in the pre- gain. In order to preserve low distor- Therefore, the heater supply can easily amplifier since feedback will remove at tion, it is important that the first stage produce hum due to heater-cathode leak- least 50 db of gain if equalization is to be devoted to wide -band, low -noise voltage. This disadvantage can be overcome he maintained over the total audio band. is in the cas - * 46 Notre Dame Rd., Bedford, Mass. by using a d.c. heater supply, at least Since there gain to spare

AUDIO NOVEMBER, 1959 19

www.americanradiohistory.comAmericanRadioHistory.Com O V2A ee x 8+ 3 B+3 Iï Z INPUTS B+ 2 V3B I2AX7 e` -LEFT I 1/2 â B B+I HI LEVEL 2 12AX7 J2 J3 J4 TAPE OUT LEFT C3 V2B o .022 aaa ri o C21 A A 1/2 12AX7 V4 VI 131 R36 500 K C4 0A I 2AY7 SEE X S IA SEE C18 CW NOTE 1 .1 300V . 4.7yyF_ C12 NOTE 2 O 220 C5 X CIO SIC x C22 r--: N .068 C9 CW OUTPUT L 068 C23 0.1 3.5__O O 0.22 J6 40 C 2 i13 -0,c,0. 0.22 R31 100 K PHONO L ^ C6 Cl 0.1 C7 0.1 R23 A JI S3A OO coi , K 240 360 8 CB HIE m 0 S2A !D ff-----. Y .1 I= 510K Y ß12p. CI 9 z I 10 Meg. 31 u 13 GND BUS LI 2200 yyf GROUND ONLY AT INPUT

GND BUS R}- - - www.americanradiohistory.com C24e a 852 10 Meg. C43 40 Y Iz + 2200 Pe r yyf AmericanRadioHistory.Com 4,-Ì1l Iz MMA Y 1 560 510 K O Nyf ú z h 1528 12

C34 360 K B or« S3B 0.1 C44os I r --y R71 + -.wog O C37 100 K o II O 0.22 -"`I R°0001 0 C33 SID C47 .-O i I xrr".1°W 0.22 _-_ OUTPUT R 1 -T-0 .068 CW} X 2200 yyf SEE _ J C42 NOTE i \ 0.1«,n12`.3L WA IX SIOB VB VS 1/2 12AX7 220 yyf 0 NOTE 2 I2AY7 C35,11-.-..SEE 6C4 u O ,c 0.1 u C39 0.1 R76 500 K 0.1 \/ rI a J1 I J8 J9 JIO 8+3 TAPE OUT RIGHT D B I z B 2 B. 2 V7B V6A INPUTS -RIGHT V68 1/2 12AX7 HI 1/2 12AX7 LEVEL SWITCH POSITIONS P1 1/2 12AX7 AMPHENOL S I -SELECTOR 14 PIN MALE s D.C. FILS 1 -AUX 2 -TUNER (165-31) 3 -TAPE 4 -PHONO NOTES

52 -TYPE 1 -TO INCLUDE TAPE HEAD PREAMP, BREAK AT X's AND INSERT A-45/45 PREAMP - SHOWN IN FIG. 3. (SEE TEXT) MIN B VERT ICAL/LATERAL TO 2- IF AUX 606 53 -FUNCTION INPUT IS TO BE USED FOR POWER 1 -OFF 2- L -R CERAMIC STEREO : FILS CARTRIDGE, BREAK SUPPLY AllinallA.C. 3- R -L (FORWARD) AT X's, ADD DOTTED CONNECTION. (REVERSE) 4 -MONO (SEE TEXT) .MATCHED TO 1% O *LOW-NOISE DEPOSITED CARBON RESISTORS these signals and produce L + R and TABLE I L - R, or lateral and vertical outputs PERFORMANCE CHARACTERISTICS accordingly. The lateral component is

INPUT SIGNALS FOR 1 -VOLT OUTPUT- then fed to the left channel and the High-level channels 20 my vertical component is fed to the right Phono channel 0.66 my channel. For monophonic disc playback, FREQUENCY RESPONSE (tone controls set for flat response)- both speakers are connected to the left High-level input: 10-20,000 cps ± 0.5 db channel thereby playing only the lateral Phono input: ± RIAA 0.5 db from 10-20,000 cps component of monophonic LP's. TONE CONTROLS- The selector switch, is arranged so Bass, at S 50 cps 12 db boost, 16 db cut the can Treble, at 15,000 cps 13 db boost, 26 db cut that vertical or lateral outputs be HUM AND NOISE- only selected in the "Phono" position thereby avoiding inadvertent combina- High level inputs: 70 db below 1 .0 volts output with gain control set for 100-mv input tion of left -right signals from other Phono input: 63 db below 1.0 volts output with gain control set for 5-mv input stereo sources, such as tape or tuner. HARMONIC DISTORTION- Measured at 2.5 volts rms output, and corrected for source distortion Tone Controls 20 1000 15,000 cps Following the vertical -lateral mixing High-level inputs: 0.32 0.17 0.23 per cent circuit is a fairly conventional tone -con- Phono input: 0.83 0.24 0.44 per cent trol is important each INTERMODULATION DISTORTION- circuit. It that Measured with 60 and 7000 cps, 4:1 ratio. Tone controls flat, gain control maximum, output channel have individual bass and treble level control adjusted for required output. Phono input corrected for RIAA characteristic controls so that tone corrections may be Output level: 0.5 1.0 1.5 2.0 2.5 volts rms made separately in each channel since High-level inputs: 0.18 0.28 0.35 0.58 0.67 per cent there is no guarantee that both channels Phono input: 0.48 0.50 0.52 0.55 0.62 per cent CHANNEL SEPARATION- will require equal adjustment. However, tone control must be used with reserva- High-level inputs: 60 db Phono inputs: 50 db tion so as not to destroy the delicate BALANCE CONTROL RANCE- stereophonic phase relationships. With + 10 db on each channel; ± 20 db total most tone -control circuits, the flat response region is difficult to locate and code phono preamplifier, it is possible jectionable. Tests were made with mono- small control rotations produce large for equalization to follow the RIAA phonic frequency-test records in order tonal variations. The tone -control cir- playback curve within +1/2 db over the to determine how much distortion was cuit decided upon uses a shunted linear entire range of 10 to 20,000 cps. Be- present as vertical modulation. Distor- control which produces a broad middle cause of the universal acceptance of the tion as high as 60 per cent was meas- control region where control rotation RIAA characteristic, it is felt unneces- ured. Obviously, it is important to re- only slightly affects frequency response. sary to incorporate equalization other move this distortion component if we This allows the flat response region to than RIAA, particularly since older expect older recordings to sound as well be readily located. monophonic curves can be approxi- as they once did. A ganged volume control and separate mated with tone controls. The design Luckily, the conversion of 45/45 out- balance control for both channels is es- objectives for the preamplifier section put into vertical -lateral coordinates is sential. Nothing is more annoying than a of - have been met. Equalization is accurate relatively simple. If the 45/45 left - constant juggling separate channel to within ± 1/2 db, hum and noise are right modulations are in -phase, that is; gain controls to adjust volume and exceptionally low, and distortion is less one groove wall moves inward while the stereo balance. than 1 per cent (refer to Table I). other moves outward, and vice versa,1 Two cathode-followers fonts the out- Ceramic and crystal stereo cartridges the stylus will only (move laterally. put stages of the control center. The out- need no preamplification or equaliza- Therefore, if the 45/45 left -right output impedance of these cathode -follow- tion since their output is relatively high puts are added, the result is the lateral ers is about 500 ohms, so as much as a and the cut of the piezoelectric element component of the 45/45 groove modula- 100 ft of shielded cable may be used causes its response to approximate the tion. Conversely, if the 45/45 left -right between the control center and stereo RIAA characteristic when loaded as modulations are out -of -phase, that is, power amplifier without loss of high - recommended by the manufacturer. the groove walls move inwards and out- frequency response. In these days of universal 45/45 stereo wards together, the stylus will move Evaluation Tests releases, it is important that any con- only up-and-down, or vertically. There- trol center have the capability of play- fore, if the right 45/45 output is sub- Several stereophonic control centers ing conventional monophonic recordings tracted from the left output, the result have been built by audiofans at the without any loss in quality. This re- is the vertical component of the 45/45 Raytheon Manufacturing Company dur- quires that the vertical component of groove modulation. These relations can ing the past few months allowing exten- conventional lateral monophonic LP's be be readily checked by drawing a sketch sive evaluation tests on several models. removed from the output of the con- of groove wall motions. Table I gives the performance figures trol unit. Recent monophonic recordings A phase -inverter in the right channel, of the control center as verified on sev- have carefully controlled vertical out- V,B, produces two outputs, + R and - R. eral units. puts which are low in distortion. How- + R on the cathode of the phase -inverter It might pay to compare these speci- ever, in older monophonic LP's, vertical and -R on the plate. Correspondingly, fications with the specifications of com- modulations consist primarily of highly + L output is present on the cathode of mercially available stereophonic control distorted signals and groove noise. Un- an identical phase -inverter, V2$, in the centers. Certainly, few commercial units less the output of the stereo cartridge is left channel. Resistive mixers combine will produce one volt rms output with converted to vertical -lateral coordinates only 0.66 millivolts phonograph input and the vertical component removed while maintaining a signal-to-noise ratio I in -phase By industry agreement, signals of 63 db. This specification alone char - when monophonic LP's are played, the in the two channels result in purely lateral distortion apparent on older LP's is ob- movement of the stylus. (Continued on page 89)

AUDIO NOVEMBER, 1959 21

www.americanradiohistory.comAmericanRadioHistory.Com Calculation Chart for Vented Cabinets

VICTOR BROCINER

Calculations for port area or duct length are not difficult, but to fit a specific case it is much easier to refer to a chart so as to accommodate a number of variables with one solution.

WITH THE I S i'HEASING POPULARITY V range of designs. It involves no approxi- Compliance C= (1) of high -mass, high -compliance Pct mations2 and includes data for the speakers, and their use in small design of ducts as well as ports. enclosures, the vented cabinet'. has been where P= density of air, grams per The use of the chart comprises the cubic enjoying a new wave of popularity. The centimeter steps outlined below. e = velocity sound, vented cabinet is a Helmholtz resonator. of centime- If small vent openings are indicated ters per second Conventionally, its resonance is made by the chart, the use of a duct should be equal to the free -air resonance of the considered. Small orifices involve some Inertance M = P (2) speaker being used. With high -compli- S undesirable effects. The high air veloc- ance speakers having free -air resonances ity produced by them results in audible where P.= as low as 15-20 cps, it is considered de- effective length of the air "rushing" noise; non -linearity can also mass in the in sirable by some designers to tune the port, centimeters occur, causing distortion. If the use of a S = of port, in cabinet to about 30 cps, there being area the square simple port requires an area around 5 centimeters virtually no program material below this sq. in. or less, a duct can be used to At resonance: frequency. provide a greater area. Examination of 1 For resonance, the reactance of the woM (3) the chart will indicate that tuning a inertance of the air in the vent must coOC small enclosure (less than 3 cu. ft.) to equal the reactance of the compliance of Therefore 45 cps or less, requires the use of a duct. the box. S It might be well to add a word of MC1 C l'V (4) caution. The chart tells how to tune a * Staff Consultant, University Loudspeak- vented cabinet to a selected frequency ers, Inc., 80 So. %ensico Ave., White Plains, or of resonance. It does not provide com- N. Y. C S plete design data design of a system (5) for 'U. S. Patent No. 1,869,178, A. L. f0 2r l'V comprising speaker and cabinet. Selec- Thuyas. tion of optimum size a given The effective length of the port cabinet for speaker, correct damping, shape of cabi- l'=l+Al (6) net, its material and construction, shape where l= the physical length of the and location of the port or duct, are port matters that require careful considera- Al = the end correction. tion for good performance. Example: A University C12HC high - The end correction is somewhat approxi- compliance woofer, Fig. 1, is to be mate. A good intermediate value is given mounted in a 1.8 cu. ft. cabinet made in convenient form by of 3/4" thick wood. Resonance is to be at A/ =0.\/S (7) 30 cps. Find the port size. Inserting this into (5) we have Starting at 1.8 cu. ft. on the top, center, CU. FT. scale, move to the right C S to intersect the inclined line at B, then fo (8) 2n V (l+0.8\:5 down to the inclined line marked 30 cps RES. FREQ., at C. Then project hori- Transforming this formula to permit zontally to the left until you reach the dimensions to be expressed in inches: inclined DUCT LENGTH line marked 3/4". The intersection is slightly off the fo=2145- I chart, at D, indicating a port area less V (1+0.8VS than 1 sq. in. This is below the desirable Usually, we know V, and assign a value to f0. We then want to know S. 2 In some charts previously published, a simplifying assumption is made l For a simple port, l is the thickness of that the cabinet wall. Since S occurs twice in is negligible compared to 0.85. Then the expression for f0, the expression is C v/S fo = Tar. For wood thicknesses of 1/2 Fig. 1. University C-12HC woofer, typical difficult to solve. A graphical solution $n of the high -compliance speakers com- would facilitate design. to 3. in., the error introduced is not monly used in small enclosures. The accompanying chart covers a wide negligible.

22 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com 10". The correct length of 3" diameter USING VENTED CABINET CHART duct is 91/2"-

For a given volume3 of cabinet (in cubic inches) 3 Strictly speaking, the cabinet volume should have deducted from it the volume (1) Find with inclined line (lower right) for desired resonant intersection occupied by the speaker itself. The table frequency. (2) Carry point of intersection to the left to meet the inclined line for the below gives approximate figures for speak- duct length selected,4 in inches. ers of various nominal diameters. (3) From this point, move Diameter, in. Volume, cu. in. (a) down to find area, in square inches 6 13 or (b) up and to left for diameter of circular aperture or duct, in inches. 8 41 If the cabinet volume is given in cubic feet, start with this figure on the appropriate 10 100 vertical scale at the top of the chart; move to the right to intersect the inclined 12 227 line and so obtain the equivalent number of cubic inches. Now move downward 15 507 and proceed as in (1) above. 18 1050 4 This duct length includes the thickness of the cabinet wall. If a port is used instead of a duct, it is the thickness of the scale. E, move to the right ower limit given in the text, so the use DIAMETER wall. It may be more convenient to select of a duct is indicated. A 3" mailing tube to intersect the inclined line at F, then the duct area first, instead of the length. is easily obtainable and convenient to downward to cross the previous hori- In this case, the length will be given by use. zontal line from C, at G. This is near on intersection of the vertical "area" line with

At the upper left, find 3" on the the inclined DUCT LENGTH line for the horizontal line of step (2) above. .

VOLUME-CUBIC INCHES 4 6 8 1000 2 3 4 5 6 8 10,000 2 3 5 10

5 A 4 40

3 V 30 7 100 90 2 20 ____ B 80

10 10 60 8

6 50

4 40

3 35 F E ---t---- r 2

.25

.50 V .75 Z 1

VENTED CABINET DESIGN

I0 20

8 30 I

2 3 4 5 6 8 10 2 3 4 5 6 8 100

VENTED CABINET CHART

AUDIO NOVEMBER, 1959 23

www.americanradiohistory.comAmericanRadioHistory.Com Puzzled About Amplifiers?

NORMAN H. CROWHURST

Is a triode amplifier better than a pentode amplifier, or vice versa? The author shows you that either type of tube can be incorporated into an excellent amplifier if the design is correct-and then he tells you about some of the design problems.

IF YOU FOLLOW the reports of certain beyond just the simple specifications Let's take an example. A 25 -watt am- consumer testing organizations, you usually quoted, turns up a number of plifier is capable of handling a peak may be puzzled why it is a certain reasons for this difference. power of 50 watts. The average power manufacturer's product can be rated as In the first place, the transfer charac- in a program signal may not be more "best buy" one year, while the following teristic of pentodes contains much than 2 to 5 watts. But such average year the same product is rejected as "un- higher order harmonics than the triode program material may well include a acceptable, not worthy of further test." type characteristic which, single -ended, peak here or there that runs up to what The answer to that question does not ap- produces predominantly second har- should be 60 watts, 10 watts beyond the pear to be a technical one so we won't monic and, in push-pull, produces a rela- maximum handling capacity of the am- attempt it here. However, there are dif- tively small amount of third and not plifier. This is what causes the trouble. ferences in amplifier performance which much above this. A pentode -type output, Each such peak momentarily overloads make a very similar question-that is in contrast, produces third and fifth har- and blocks the amplifier so that, for a technical-quite pertinent. What really monics and sometimes even seventh in fraction of a second thereafter, it will is the best type of amplifier circuit? quite sizable proportion. True the feed- not even handle one watt and then it This question repeatedly occurs in back reduces these dramatically, but the comes back into action distorting the 2 - various guises, so it is not untimely to amount of feedback necessary to do a to 5 -watt level that follows the momen- review it. One still hears from people refit cleaning up job on the harmonic tary peak. who have triode amplifiers and who tell and intermodulation distortion can also Obviously such an amplifier will not us that their neighbors and friends produce other troubles. These occur appear to give as much good, clean out- testify the "good old amplifier" still under a variety of circumstances. put as one that handles say 15 watts and gives performance comparable with the then clips for a moment. Even though best modern one. Blocking the corresponding peak may still run up Others who hear reports like this want One of them is what happens at over- to 'what would be 60 watts, this just gets to know just what the score is. If the load. Measurements merely tell how pure lost and the following 2- to 5 -watt level "good old triode" was the best kind of an amplifier is up to a certain point. is amplified without further distortion. output stage for an amplifier, why is it They do not say what happens when a Using the latter amplifier, the level that manufacturers universally adopted sharp peak momentarily drives the am- could probably be turned up so it runs pentodes or tetrodes in various types of plifier beyond this point, as can often at from 6 to 15 watts instead of 2 to 5 output circuits? happen with program material. The watts, an increase in level of about 5 When we examine the difference be- average "good old triode" amplifier db, which is quite noticeably louder, tween the two types of tube we find that merely lopped off the high peak and and yet will still sound clean as com- the pentode is more efficient and conse- carried on working. More recent work pared with the 25 -watt amplifier work- quently, for a specific amount of dissi- with transistor circuits, which achieve ing at an average output of 2 to 5 pation, or dollars' worth of tubes, it is the same results by somewhat different watts. This comparison is illustrated at possible to deliver a larger output methods, has shown that such peak clip- Fig. 1. power. Also, having a higher gain than ping can become quite drastic before it Are we to conclude then that, in spite the older triode tubes, it is easier to ap- is appreciably audible. of the better figures a pentode will give, ply a greater amount of feedback and But many amplifiers employing a it does not really produce better results thereby reduce distortion to a lower large amount of feedback, particularly than the triode'? Not at all. A pentode figure. Consequently a modern amplifier, those using pentode output tubes, do properly used can produce quite good using the same dollars' worth of com- more than clip off the peak. When such results and still retain the advantages, ponents, can quote a higher power out- a high peak comes through, it throws apparent in the figures, of better effi- put with lower distortion than the "good the amplifier out of balance in such a ciency and improved gain which also old triode" amplifier. way as to block the signal that immedi- enable the distortion to be satisfactory One would imagine that such statistics, ately follows it. This produces a notice- reduced. which are measurable objectively, should able interruption or breaking up in the The twin -coupled amplifiers described be more reliable than the opinion of a program. As the amplifier comes back in these pages in November, 1957, is an number of people who listen to modern into action, after the blocking, it dis- example of this. A great many readers amplifiers against the older triode torts because the tube that was blocked have written in saying that they have counterpart and who still aver that the does not suddenly come back to its cor- compared this amplifier with others, triode sounds as though it does a better rect operating condition. Thus the effect using much larger nominal outputs, and job. However, a serious investigation of of the sudden peak is to block the ampli- the technical performance of amplifiers, fier and allow it to come back with a s Louis Bourget, "Stereo -monaural com- sort of strangled effect. This is generally psuiion amplifier for the Preamp with Pres- * ?l6-18 40th Ave., Bayside 61, N. Y. given the name "break up." CH ' ," Ammo, Nov., 1957.

24 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com that the twin -coupled gives superior school of thought recommends that the appearance of signals having excessive performance, both as to apparent undis- earliest stages have quite a nice margin amplitude. torted output and general cleanness. (which is easier to do), while the drive For example, suppose, at maximum And yet the twin -coupled circuit uses and output stages should run into over- output, the input is really 1 volt but is the output tubes strictly as pentodes load pretty well at the same point. Often held down at the grid of the first stage with a variety of unity coupling. This it has been recommended that the out- to an effective 0.1 volt because there is well illustrates that pentodes can be op- put stage should overload before all 0.9 volts of feedback. Then the onset of erated in such a way as to achieve the earlier stages, because this means that clipping results in a signal that suddenly benefits of their improved efficiency and only one stage is responsible for pro- looks like the 1 volt it really is because give performance that is quite accept- ducing distortion instead of many stages the 0.9 volts signal gets chopped off able to critical listeners. running into distortion conditions at the short. This results in a high peak being same time. amplified by the early stages of the am- The Best Circuit Each of these recommendations may plifier until some stage fails to handle What then is the best of the modern have its point, considering the amplifier it. An increase of actual input from 1 output circuits? This is a question quite without feedback. But when feedback is volt to 1.1 volts in a waveform at the often asked and one to which there is no applied, as it is on all modern amplifiers, first grid that suddenly shoots up from direct reply. It depends on how well the situation is considerably altered. 0.1 volt to 0.2 volts, and proportionately each type of output circuit is designed Feedback theory is usually confined through successive stages. (Fig. 2) or used. to the condition where the amplifier is What happens due to this sudden peak For quite a while, there seemed to be assumed to have all its gain. Unfortu- then depends on further details in the a belief among amplifier designers that nately, as soon as clipping occurs the amplifier design. If this sudden peak optimum performance is achieved if all amplifier does not have all its gain. This produces overload at a point where there the stages reach overload point at about does not necessarily introduce any in- is direct coupling, say between an ampli- the same level of amplification. Another stability, but it can result in the sudden fier and phase-splitter stage, the ampli -

180 A 180

150 ' 1 150 I I 120 I I 120 100 1 i 100 I 80 f y 80 I 60 50 WATT 50 _ _ _ _ 50 NOMINAL PEAK T+ 1 40 30 WATT 40 25 WATT (NOMINAL PEAK) 30 ji (RATED AVERAGE) 15 WATT a 70I_ 20 I_ (RATED III AVERAGE) I 0 10 - - - - 5 WATT -,mit 4 Y1- AVERAGE 2 ,

1 3 3 / 1 I I / 1 0 O 1 1 1 0 o I 2: ! a 2 I I R 1 1 1 Z 4 4 a 1 f/ /s I 2 5 --WATT , 2 10 - AVERAGE 10 I 15 WATT (RATED AVERAGE) 20 20 vl 25 WATT

(RATED AVERAGE) 3) WATT _ 30 30 (NOMINAL PEAK) 40

50 50 60 I 60

60 40'80 80

100 100

120 120 25 WATT AMPLIFIER 15 WITH WITH WATT AMPLIFIER iv. - BAD OVERLOAD PROPERTIES GOOD OVERLOAD PROPERTIES 150 150

180 180

Fig. 1. Comparison of the same transient waveform amplified by (left) a 25 -watt amplifier with bad overload characteristic, and (right) a 15 -watt amplifier with good overload characteristic. In each case, the solid line represents the actual waveform, while the dashed line shows the correct waveform where the amplifier departs from it. The 15 -watt amplifier is handling the same waveform at three times the power level.

AUDIO NOVEMBER, 1959 25

www.americanradiohistory.comAmericanRadioHistory.Com first is pentode, the second is triode. Connecting them to a tapping results in Ultra -Linear. This achieves practically the efficiency of a pentode while maintaining the linearity or low -order distortion of a triode. This would seem to be ideal. The diffi- culty is that, to work perfectly, the transformer must maintain the correct tapping, both in voltage and phase, at all audio frequencies. This is not too difficult for the low -frequency end but, at the high -frequency end, stray leakage inductances between different parts of the winding, along with winding intercapacitances, can really play havoc with an Ultra -Linear circuit resulting in some quite weird waveforms at some specific frequencies. The solution to this is to have a correctly designed Ultra -Linear transformer Fig. 2. What happens in any feedback amplifier when clipping occurs. This shows that avoids any spurious devia- the waveforms associated with the input stage. Dashed line is the waveform at tion from correct tapping up to a maximum undistorted signal level. Solid line at a level 10 per cent above this. frequency beyond the audio range and also beyond the cutoff of the transformer fier will not be disturbed by it. As soon output stage. These are almost invari- as a primary -to -secondary transformer. as the peak disappears the amplifier re- ably resistance/capacitance coupled and This is not impossible, but only rela- verts to its normal operating condition consequently, immediately following the tively few transformers manufactured and carries on amplifying normally. excessive peak, the output stage is mo- under the name of Ultra -Linear achieve But if this peak reaches its limit of mentarily over -biased so as to produce this objective. amplification at a stage that is resist- crossover distortion if not complete The McIntosh version of the unity - ance/capacitance coupled, a grid may blocking for the montent. coupled circuit relies on the famous be driven a long way positive, causing bifilar-wound output transformer.2 The a negative charge to appear on the grid The Cures fact that the high -voltage and ground - side of the coupling capacitor after the There are two ways of obviating this. voltage primaries are wound with the peak disappears. This biases that stage One is to use a cathode follower, direct wire actually side -by -side achieves a very momentarily back beyond cutoff and coupled to the output stage with ap- intimate coupling between the winding causes blocking. As the stage drifts back propriate negative supply to enable the connected to cathode and that connected into its normal operating condition some cathode follower to have an even more to screen of the same tubes. To try and distortion is evident before the amplifier negative return than the necessary achieve this version of the unity -coupled resumes proper operation. bias voltage for the output stage (Fig. 3). circuit without a bifilar-wound trans- Another place where the trouble can The other is much simpler and almost former would be asking for trouble. occur, if the amplifier is "held up" right as effective. It consists of interposing Of course, it is also necessary to use through to the grids of the output stage, what at one time would have been called the various refinements developed with is that the sudden removel of amplifica- a grid -stopper resistor between each that circuit for avoiding the other kind tion due to clipping results in an ex- coupling capacitor and the output tube of blocking we discussed earlier. In the cessive postive drive at the grids of the grids. It does not serve the one-time case of the McIntosh circuit the output function of stopping parasitic oscilla- tubes are driven by cathode -follower tion in the grid circuit, but does prevent direct -coupled stages. the large grid -current flow that momen- 2 Norman H. Crowhurst, "Realistic engineering philosophy," 1959. tarily occurs during the high peak condi- Ammo, Oct., (Continued on page 88) tion and thus avoids the radical over - bias condition after the peak (Fig. 4). These are some general measures to obviate the sudden overload troubles that beset high -feedback pentode -type amplifiers. But what about some of the other types of circuits, Ultra -Linear, unity -coupled, Circlotron, single -ended push-pull, and so on? "Which of these would you recommend as best?" is a not uncommon question. Here again it is not so much a question of choosing the best circuit as seeing that the one you do choose is correctly used. In the case of Ultra -Linear the choice of the tube operation is virtually one be- Fig. 4. A simpler method of at least re- tween The Fig. 3. One way to obviate output -stage pentode and triode. tappings ducing the effect is the use of grid -cur- blocking is to use direct -coupled cathode on the transformer primary "split the rent -limiter resistors, shown here in the followers between drive and output, as difference" between connecting the output -stage grids. They can also be used shown here. screen to B + or directly to plates. The at any stage that causes blocking.

26 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com "The new Citation Kits represent for me the successful culmination of years of research and experimen- tation to achieve the ultimate in high fidelity design."

Stewart Hegeman, Director of Engineering, Kit Line: the gram material for each amplifier is labora- Citation Kit Division, Harman-Kardon, Inc. sparked the new Citation incomparable Citation I, Stereophonic tory controlled. Preamplifier Control Center. Because of this vital consideration the The Citation I consists essentially of a Citation II is engineered to produce fre- group of circuit blocks termed active and quencies as low as 5 cycles virtually with- passive networks. Active networks incor- out phase shift. At the high end-the am- porate the vacuum tubes and furnish amplifier has a frequency response beyond plification; passive networks consist of 100,000 cycles without any evidence of resistors and condensers and provide pre- ringing or instability. cise equalization. The active networks are treated as one- or two -stage amplification Aunlo ENGINEERS have also found that units, flat over an extremely wide fre- the higher the degree of feedback-and quency range, and each one of these net- the consequent lower distortion-the more works is surrounded by a feedback loop. apparent the improvement in sound qual- This results in levels of distortion so low as ity and the greater the reduction in listener to prove unmeasurable. The passive net- fatigue. In order to increase the degree of works are constructed of precision com- feedback in the Citation II, a "multiple THESE ARE STRONG WORDS from ponents and are designed for minimum loop" technique is used in contrast to con- a conservative audio engineer. But phase shift. ventional "single loop" techniques. This the proof is overwhelming. All that's results in a 20/1 to 30/1 reduction in dis- necessary is a look at the technical speci- PROFESSIONAL STEP -TYPE tone tortion compared with the 10/1 to 20/1 fications of the new Citation I Stereo- controls are used on the new Citation reduction in conventional amplifiers. phonic Preamplifier Control Center and I. They overcome the limitations of Other important Citation II features in- Citation II 120 Watt Stereophonic Power continuously variable potentiometers; clude: video output pentodes in all low Amplifier.( We'll gladly send them to you.) each position on a step control can be level stages for exceptional wide frequency Hegeman is recognized as one of the engineered to perform a specific function response and low distortion; power supply world's great audio engineers. His original which is absolutely repeatable when nec- consisting of four silicon diode rectifiers, designs for the famous Brociner amplifier essary. The flat position of the controls choke and heavy duty electrolytics with and preamplifier, and the Hegeman-Low- by-passes all tone control circuitry, there- potted power transformer for superb regu- ther speakers, are still regarded as classics by eliminating transient distortion and lation and long life; bias meter to adjust by audio engineers and audiophiles. In phase shift. individually the plate current of each his capacity as head of the kit engineer- Other features include: The new Cita- KT88 for balance and lowest distortion. ing group at Harman-Kardon, he has again tion Blend Control which introduces a The Citation II is a handsomely styled created new classics. continuously variable amount of cross - brown and gold instrument with an op- feed between the two channels to elimi- tional Charcoal Brown protective cover. Easily Assembled- nate the "hole -in -the -middle" effect of The Citation 11...$159.95; Factory Wired stereo records; DC heated preampli- ... $219.95; Charcoal Brown Enclosure, Professional Performance many fier filaments; six silicon diode rectifiers to AC -2 ... $7.95. THERE ARE MANY exciting new concepts provide unexcelled B+ and filament regu- All prices slightly higher in the West. built into the Citation Kits. The engineer- lation; separate turnover and rolloff con- new kits write to is the in- trols to provide precise equalization. For a complete report on the ing so wonderfully precise that Harman-Kardon, Inc., Citation Kit Division, I is available with an op- strument constructed by the kit builder The Citation Dept A-11, Westbury, N. Y. will duplicate the precision of the finest tional walnut hardwood enclosure which factory -assembled products. Here are sets off its magnificent sculptured satin - some of the remarkable new assembly gold escutcheon. The Citation I. features that distinguish the Citation Kits: $139.95; Factory Wired... $239.95; Wal- Military Type Construction: For ease of nut Enclosure, WW -1... $29.95. assembly and durability, rigid phenolic boards are used. Special Cable Harness: The Citation II Unique harness template enables builder 120 Watt Stereophonic to make a professional cable harness to Power Amplifier facilitate wiring and insure accuracy. Spe- cial Aids: Resistors and condensers are HERE IS ALL the power required filed individually on special component from a stereophonic amplifier. Two cards so that they can be quickly identi- 60 Watt Channels-with a combined fied. Wire strippers are supplied free with peak power output of 260 Watts! each kit to produce clean wire junctions. The Citation II reflects a dramatic new approach to amplifier design. Audio en- The Citation I gineers have discovered that the charac- Stereophonic Preamplifier teristics of an amplifier in the non-audible Control Center range strongly influence sound quality in HERE IS THE FIRST brilliant expression of the audible range. This can be determined the advanced design concepts which in critical listening tests where the pro - Citation II

Build the Very Best CITATION KITS harman kardon by

AUDIO NOVEMBER, 1959 27

www.americanradiohistory.comAmericanRadioHistory.Com on the

The American RECORD GUIDE (Larry Zide)

"Given a good stereo source, a pair of AR -3's comes as close to musical realism in the home, I believe, as the present state of the art permits ... In sum, until someone comes out with something better that doesn't take up the entire house, the AR -3 is for me the reference standard."

f 1 (TITH report)

"A major problem of tweeter design has been the beaming effect of very high

frequencies ... The "fried egg" [nickname for the AR -3 tweeters] appears to be a major step forward in the smooth dispersion of sound at extreme high frequencies."

HI-FI SYSTEMS

"In terms of bass response, these two speakers 'the acoustic suspension AR -1 and AR -2] represent a phenomenal improvement in the state of the art.

"The complete AR -3 speaker system, in addition to containing a superb acoustic suspension woofer, which has enjoyed wide acceptance by professionals as well as audiophiles, constitutes, in our opinion, a mid and high frequency system which is in every way complementary to the bass quality. The new AR -3 rivals in overall quality the very best woofers and combinations."

The AR -3 is priced from $203 to $231, depending on cabinet finish ($216 in mahogany or birch). Literature is available for the asking.

ACOUSTIC RESEARCH, INC. 24 Thorndike St., Cambridge 41, Mass.

28 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com Defense and the Hi-Fi Bachelors

C. H. MALPriSTEDr

Continuing the description of how the BOQ at the U. S. Navy Postgraduate School on the Monterey Peninsula was the scene of a unique growth of an outstanding hi-fi system.

In Two Parts-Part Two

UP To THIS POINT, the system result- that the advantages more than outweigh recorders could be fed from the pream- ing from a joint interest in music this seeming disadvantage. For one plifiers with the use of only one set of among the young bachelors at the thing, the arrangement permits the plugs. Most conveniently of all, one ma- Navy's Postgraduate School had just marking of two tape copies at parties chine could rewind while the other con- arrived at a point where a third Ampex -and by now this hi-fi room was a fa- tinued the playback program after the had been added to the installation-the vorite meeting place for all and sundry, mere flipping of a couple of switches. latest addition being a second 601-2. By men and women, military and civilian- this time, the system consisted of fifteen without the use of extraneous mixing or Expansion major units, connected as shown in the switching facilities. For another, record- With the system now in full swing block diagram. ing from a multiple-mike setup was con- stereophonically, it was not long before With the two tape recorders connected siderably simplified: with the output of it ranged out beyond the confines of the in "series" it may seem a disadvantage recorder #1 fed into the Line input of BOQ. Although in some respects physi- in that #2 must also be turned on when recorder #2, a four -mike setup could be cally cumbersome, the system was still only #1 is being used, but it was deemed handled without external mixers. An- largely portable and experimental. So other advantage, especially in an out- were the hi-fi ideas of its owners. Why Carmel Valley, California. side portable installation, was that both confine their tape repertoire to AM -FM

King Hall, interior. Its acoustic treatment mainly of slatted varnished wood, modern sound reproduction capability is combined with the rustic motif so popular today. (Official photograph, U. S. Navy)

AUDIO NOVEMBER, 1959 29

www.americanradiohistory.comAmericanRadioHistory.Com Results were even better than had been expected. With excellent acoustics pre- vailing, a close -on -mike pick-up of the choral groups gave the tapes not only definition but as well a rich and mellow perspective-beauty that has since then often filled the BOQ room and its en- virons, successfully competing with the finest conuuercial recordings available. But a real test of this superb hi-fi installation was still to come, in both recording and playback. Meanwhile, it had already inspired into being sonic 14 or 16 other hi-fi installations, disc and tape, within the naval facility and outside it, among both men and women. Foreign students returning to their homelands carried with them not only the results of their official academic and practical training but as well a rich memory-accumulation of the world's finest music, perhaps all the more precious because of the friendly extracurricular manner in which it had been acquired. Many carried, in addition, hi-fi equipment carefully selected after consultation with Lt. St. Ville and such colleagues King Mall on the grounds of the U. S. Navy Postgraduate School. Low as a ranch house and hi-fi participants as lieutenants outside, the auditorium interior is as spacious as the amphitheaters of old-with John Coiner and Richard Avrit, each of acoustic design as modern as stereo. (Official photograph, U. S. Navy) whom had contributed much in time and equipment to the large installation radio reception and to recordings taped in came three Altec M-20 systems uti- even while having smaller ones in their own from available discs? Weren't there lizing Altec 21-D condenser mikes. They rooms; and two of whom had local musical goings-on that could, with- didn't have to wait long for an assign- been prime movers on the Sound out complications, be taped for noncom- ment. In Carmel, the St. Paul's Epis- Committee of the highly successful Monterey mercial home use There were, any copal Church was presenting a Jazz Christ- Festival of 1958. number of them. But that meant one mas program sponsored by the Monte- additional and expensive item in tripli- rey County Symphony Association. The cate-microphones; and the present in- performers were the Fort Ord Soldiers The Proving Ground stallation, with its almost 400 discs and Chorus, the Carmel Womens Choir, a The ultimate test of the big installa- 125 reels of recorded tape, was already harpist, and the church organ. What tion came at King Hall, where, upon the worth in the neighborhood of $6000! could sound better in stereo! invitation of Rear Admiral E. E. Yeo- But again the community spirit on Using one Ampex 601-2 and two of mans, superintendent of the Postgradu- behalf of more au.' Netter music now, the M-20 mike systems, the entire pro- ate School, an all -Brahms concert was and later at sea, paid off. On a loan, g:.am was taped in two -channel stereo. given by the Monterey County Sym- phony Orchestra, Gregory Millar conductor. Featuring such Brahms numbers as The Song of Destiny for Chorus and Orchestra, opus 54; Double Concerto for Violin, Cello, and Orchestra, opus 102; Rhapsody for Contralto, Male Chorus, and Orchestra, opus 53; and the Academic Festival Overture, opus 80, the challenge to hi-fi reproduction was a great one. There was also another challenge: King Hall, built in 1955 on the grounds of the naval facility, em- bodied in combination the best of the old and the new. Sloping deep into the ground toward the stage in the manner of the amphitheaters of old Greece, the auditorium design and construction also incorporated the very latest achieve- ments in the science of acoustics. The added challenge, then, was this: since the concert was not only to be recorded in its entirety but would as well be played back as a stereo demonstration to the audience after the concert-would even this fine hi-fi installation produce Setting it "just so" on the left-channel preamplifier. (Official photograph, U. S. Navy) (Continued on page 103)

30 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 31

www.americanradiohistory.comAmericanRadioHistory.Com Tape Recorder Accessories

HERMAN BURSTEIN

While you can dig a post hole with a tablespoon, you can do it much easier with the proper tool; similarly, these accessories become the desirable "tools" to the recordist, making his work much easier.

T1PE RECORDER ACCESSORIES are con- taken into consideration is the fact that -,iderable in number. As to their use- some splicers are sufficiently compact so fulness, an anology with automobile that with the aid of an adhesive they accessories may be in order. Some are can be mounted directly on the tape a virtual necessity (like a heater if you machine, where they are always conven- live in the northern part of the coun- iently at hand. try). Some are highly desirable (like a It is vital that one use a splicing tape radio or power steering). And some are specifically made for this purpose rather a matter of convenience (like the gadget than conventional cellophane tape. If that squirts water on your windshield) ; the latter is used, the adhesive is apt to nice to have but not indispensable. ooze out under the pressure exerted by is It impractical to attempt to sort Fig. 2. Robins Industries Corp's. medium- the capstan and pressure roller, and will the various accessories into these three priced splicer-Model TS4A-STD. be deposited upon these and other parts, categories of usefulness. What is merely causing wow and flutter and otherwise a convenience to one tape recordist may cision of undesired portions and the impairing operation of the machine. be a necessity to another because of the joining of desired portions, you will still As a further precaution against foul- manner or extent of use of his tape re- find a tape splicer handy for the acci- ing of the mechanism by the splicing corder. Therefore it should be clearly dental break that will inevitably occur. material, it is desirable to cut the tape understood that the order in which ac- True, you can use a scissors for the job, so that it narrows slightly in the area cessories are discussed below constitutes but it is rather difficult to do a precise, where the splice occurs. A number of only an extremely loose approximation neat job, which means bringing the two splicers make such a cut, as do those in to their relative importance. And this sections of tape together in exact align- Figs. 2 and 3, which produce what their order of importance is purely the sub- ment so as to avoid a thump when the manufacturer calls a "Gibson Girl" cut. jective view of one person-the writer. spliced portion passes the playback In the event you rely upon a scissors head. rather than a tape splicer, be sure to Tape Splicer Tape splicers come in a great variety make the cut at an angle of about 30 to One of the accessories most likely to of types and prices, ranging from as 45 deg. rather than 90 deg. A cut of fall into the category of necessities is little as approximately $1.50 to as high right angles to the length of the tape the tape splicer. Whether or not you as $50 or more. Figures 1, 2, and 3 show will result in a thump as the tape passes plan to go in for an appreciable amount three models, which are respectively the playback head. of tape editing, which involves the ex- low-, medium-, and high-priced units. The expensive ones are more rugged, * 280 Vein Lane E., TPantagh, N.Y. have a greater degree of automaticity, and operate more quickly. Yet one can do a perfectly adequate job of tape splicing with the least expensive units. If your only need for a tape splicer arises from an occasional accidental break, then a low-priced unit may be your best purchase. But if you plan to do a fair or substantial amount of editing, it is wise to investigate the more Fig. 1. A low-priced tape splicer-"Jiffy- sophisticated models as most suited to Fig. 3. A high-priced splicer,-Robins' Splice," by Rason Mfg. Co. your needs. One of the factors to be Model TS -250-1000.

32 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com AMPEX 960 STEREOPHONIC RECORDER/ REPRODUCER

ABOVE --960 PORTABLE STEREO RECORDER/REPRODUCER BELOW --MODEL 2560 PCRTABLE Stereo STEREO SYSTEM CONSISTING OF 960 AND PAIR OF 2010 Portable AMPLIFIER -SPEAKERS PLUS! Guiding the Ampex engineers who created the 960 was a dual objective- that of building a machine which was not only a superb example of engineering skill, but one which would also offer its user a range of capabilities far exceeding that of any other recorder made today. The result was not merely an improved stereo recorder, but an entirely new concept in home entertainment. The STEREO 960 fits into family life in literally dozens of ways, contributing many tangible benefits in musical, educational and recreational fun. You'll use it to keep up the family correspondence by sending "letters in sound", to tape stereo programs off the air, to preserve your best monaural and stereo discs on tape, and to acquire new musical and language skills. You'll have endless fun exploring the 960's many fascinating recording capabilities, including sound -on -sound, echo chamber effects, and other advanced techniques.

AMPH',X STH:RI r;O SIGNATURE OF PERFECTION IN SOUND

www.americanradiohistory.comAmericanRadioHistory.Com Relax and .joy the show- 'et your ArFex do the na'rctior! Nirh the RECORDER/ REPRODUCER comment ors an tape your color slick :lows ore more SPECIFICATIONS profession:l more complete, and more kas!

The true values of a recorder are best assessed through careful evaluation of its performance specifi- VOL,. f-3 .P's and Step cations and operating features. It is worthwhile noting here that these specifications are based not on Di:a Ire it the r exciti.c theoretical design parameters but on actual performance tests. They are specifications which the -vHle they're new recorder not only meets or exceeds today, but which years from now will still hold true. tat a.d u i c'aldl ed That r when to The Ampex Model 960 Stereophonic Recorder, Reproducer is capable of essentially distortionless !cpa then 3n you- Amp( a, frequency response from 30 to 20,000 cycles per second at the operating speed of 71/2 inches per crd pro -sane the r origir second, and from 30 to 15,000 cycles per second at 33/4 inches per second. Its precision -engineered l qt aliry f ar keel st timing accuracy is such that it offers perfection of pitch held to tolerances of less than one-third of a half -tone. Playing times, using standard (.002"), long play (.0015"), and extra -long play (.001") tapes are as follows: Wien you cpe it "off the (a) 4 -Track (b) 2 -Track (c) Monaural Tapes, a r" yor only cost is for Stereo Tapes Stereo Tapes half-track blanc taF e fet you musica' - 1200 foot reel 33/4 ips 2 hrs. 8 min. 33/4 ips - 1 hr. 4 min. 33/4 ips - 2 hrs. 8 min. reperto re r c n soon equal 71/2 ips - 1 hr 4 min. 71/2 - ips 32 minutes 71/2 ips - 1 hr 4 min. that of ail Fe stctiens 1800 reel 33/4 ips - 3 - 1 foot hrs. 12 min. 33/4 ips hr. 36 min. 33/4 ips - 3 hrs. 12 min y3u nec 71/2 - 1 ips hr 36 min. 71/3 ips - 48 minutes 71/2 ips - 1 hr 36 min.

2400 foot reel 33/4 ips - 4 hrs. 16 min. 33/4 ips - 2 hrs. 8 min. 33/4 ips - 4 hrs. 16 mir

71/2 ips - 2 hrs. 8 min. 71/2 ips - 1 hr. 4 min. 71/2 ips - 2 hrs. 8 min. There's a rea future in 'aniy RECORD INPUTS: High impedance line inputs (rad o/TV/phono auxiliary) 0.3V rms for program level; :u 1 like 'this-with your high impedance microphone inputs Ampex eou col live su:h Fcppy moment: over sec PLAYBACK OUTPUTS: Approximately 0.5V rms from cathode follower when playing program level tapes oeer ag sin, with c quollt- so PLAYBACK FREQUENCY RESPONSE: 30-20,000 cps at 71/2 ips; 30-15,000 cps at 33/4 ips lifelike you're almost liier ly Within ±2 db 50-15,000 cps at 71/2 ips, 55 db dynamic range carried bock. Within ±2 db 50-10,000 cps at 33/4 ips, 50 db dynamic range

FLUTTER AND WOW: Under 0.2% rms at 71/2 ips; under 0.25% rms at 33/4 ips In the Amex "Speech Testis HEADS: Manufactured to the same standards of precision that exist in Ampex broadcast and recording Game'; :.0 pit your wits studio equipment. Surfaces are lapped to an optical flatness so precise that they reflect specified agains- the trigger-quick . wavelengths of light, resulting in uniform performance characteristics and greatly minimizing the rnetneemi -he Anuex effects of head wear. Azimuth alignment of stereo head gaps in the same stack is held within 20 reaorder,.eproduaer. You seconds of arc, equivalent to less than 10 millionths of an inch - a degree of precision achieved can't wink but it's fun trying. through use of a unique process involving micro -accurate optical measurements within a controlled environment. Head gap width is 90 millionths of an inch ±5 millionths of an inch.

_otter -writing is -vo longe. a proolere, with an Ampex i, the house ... now it': a family oro;ect And can KEY TO THE EXCITING FUN FEATURES OF THE 960 -- more :ue then sending lelters THE AMPEX STEREO -GRAPH in sound is reco ving than! 1

Here's the simplest, quickest answer For "Iecherz in sound", the to almost every question about how to 3' tape re -el hold: as much perform the operations illustrated at as a 1 -3cee letter, mails right and numerous other recording first cas enywhe-e in the functions. The Ampex Stereo -Graph United :tales for 8c. shows you, quickly and clearly, the proper dial settings to make for more than a dozen of the most popular uses and other special effects. A convenient for the 960... including sound -on - tape footage/playing time indicator is sound, language and music instruction, included on the reverse side.

MODEL 2010 The Anoec, in private MATCHING AMPLIFIER -SPEAKER rehearse ,can be a wonderf confideece-builder for peop e ..Fo normally devel The Ampex Model 2010's ten -watt (20 watts peak) ampli- rubber knees when faced fier section provides operating characteristics (unequalized) with fr prospect of flat within =0.1 db, with total harmonic distortion less speatiç oefore a group. than 0.5 of 1%, throughout the maximum range of human hearing ability, at rated output. Noise and hum are 80 db .eernieg to 0eak a sew below rated is output, and input sensitivity 0.18V to language s n Ide develop rated power. nnea:ureabiy easier on The specially designed 8" speaker provides smooth, peak - the r.np ex; yo. can re ©-d free response throughout a remarkably wide audio range. you' cwr phrases side -by- ide Such superior design features as its massive die-cast frame sail- those of t,e instrcdor, t and edgewise -wound ribbon coil contribute effectively to and play them bade for higher levels of performance than ever before achieved cenp frison at any t me. with a speaker this size.

Whet y7J strike up the bah( in stereo., you don't need MODEL 960 DIMENSIONS: Portable cases 9" x 15" x 171/2". Unmounted recorder profeeisial musicians to 13" x 15" x'61fs" depth below top plate, 1%" above. Recorder weight 36 lbs., make professional speaker amplifier 31 lbs. reco -c rc. Advanced tech 1iiues are amazingly AMPEX AUDIO, INC. SUNNYVALE. CALIFORNIA 9004 cosy on the Ampex.

www.americanradiohistory.comAmericanRadioHistory.Com Cleaner for the Heads and Other Parts As important as the demagnetizer is head cleaner, frequently suitable for cleaning other parts as well. Due to friction, a layer of tape oxide builds up on the heads, capstan, pressure roller, and guides. These and other components may also become contaminated with oil. As a general rule, a cotton swab dipped in alcohol will serve effectively as a head cleaner. Whether it serves effectively for other parts depends upon the nature of the contamination. One can purchase fluids specifically from Fig. 4. Recording head demagnetizer- intended for removal of tape oxide Audio Devices, Inc., Type 400. heads and other parts, such as HC -2, Head Demagnetizer The record and playback heads tend to become magnetized gradually as the result of the asymmetrical wave -forms contained in speech and music; this Fig. 7. Walsco "Kleen-Tape/' designed asymmetry is in effect a d.c. component for cleaning heads. producing magnetization. The heads may also become magnetized due to heads prevents intimate contact between surges of current as the machine is them and the tape, resulting in high -fre- turned on or off. A magnetized head is quency losses. Extremely minute accu- mulations can produce significant losses. a source of noise; magnetized record __--,- and playback heads inscribe noise on Accumulation of oil and other materials the tape, while a magnetized playback on the guides, capstan, pressure roller, head also noise More- and soon tends to produce speed irregu- produces directly. __ over, such heads may erase the higher larities, manifest as wow and flutter. __19-011111.01110111111.111-1- frequencies. Also, they can cause deviation from correct speed. Therefore the individual wishing to Fig. 5. Head demagnetizer with inter- preserve his valued tapes in the best Another form of head cleaner is that changeable pole pieces-Lafayette Ra- shown in Fig. 7, namely a tape which possible condition should demagnetize dio's Model PK-238. the heads on his machine at frequent, bears not the usual magnetic coating, but instead a special material that cleans regular intervals. About every 8 to 10 made by Robins Industries. Or one can hours of use is a suitable period. and polishes the tape. This comes in a obtain an all-purpose cleaner, such as 100 -foot length on a conventional reel Figures 4 and 5 show several makes Long Life, made by Electrical Chem- of head demagnetizers. They operate and is operated past the heads in the ical Specialty Company. The latter con- same manner as a regular tape. from house current and apply an alter- sists of four different kinds of solvents, nating magnetic field of decreasing in- one for oxide, the second for grease, the Tape Conditioner tensity to the head, accomplished by third a general cleaner, and the fourth Some tapes, particularly after long bringing the pole pieces of the demag- a diluting agency to limit the potency use, develop increasing friction as they netizer in contact with the head and then of the active solvents. pass the heads, resulting in audible slowly removing them. The unit in Fig. The accumulation of tape oxide on the squeal and distortion. Several compa- 5 comes with three sets of removable pole pieces, each shaped differently to permit access to heads in various types of housing. WINDING If you are slightly handy and happen to have an old, inexpensive, two -pole motor, such as is commonly found in a cheap phonograph of the $20 variety, you can construct your own head demagnetizer, as shown in Fig. 6. First, remove the armature, so that only the field of the motor is left. Next, remove portions A and B, which are respectively a metal bar serving as a magnetic link for the motor and a heavy copper wire used as a short-circuiting ring.

Attach a strip of iron-a silicon steel (B) strip from the core of a junked trans- (A) former is fine-as shown, and you will SMALL MOTOR WITH SECTIONS A AND B REMOVED find there is sufficient magnetic field at ARMATURE REMOVED AND A STRIP OF IRON* ATTACHED the end of this bar to demagnetize the heads. The bar is attached by one of the 'SUCH AS AN I -PLATE FROM screws holding the field laminations to- A POWER TRANSFORMER gether. Fig. 6. Construction details for a head demagnetizer.

AUDIO NOVEMBER, 1959 35

www.americanradiohistory.comAmericanRadioHistory.Com handle, so that it rather than the reel of tape may be moved. The hulk eraser is useful when deal- ing with a tape that has been heavily over -recorded, because it is then difficult or impossible for the erase head to completely remove the signal, at least on the first pass. The noise level on the tape may be brought to a minimum by subjecting the tape to a bulk eraser prior to recording. The hulk eraser can prove a necessity rather than a mere Fig. 8. Applicator used to apply Long convenience in the event the tape re- Life Conditioner to the tape. corder contains no erase head, which Fig. 10. The Tape Strobe, a product of occurs in some instances where the erase Scott Instrument Labs. head has been removed to make room nies have therefore brought out prod- and screws that hold the casing and for another head, such as a separate ucts to lubricate and clean the tape. laminations together. Remove the E - record head, a four -track stereo head, One is the Long Life Tape Conditioner, shaped and I -shaped plates from etc. the made by the same company that manu- transformer core. Reinsert the E -plates A major disadvantage of the bulk factures the Long Life Cleaner previ- so they all face in the saine direction; eraser is that it erases the entire tape, ously described. A special applicator, as put the I -plates aside (you can use one not just the one or two tracks that one shown in Fig. 8, is used to make con- of these as the metal strip for a head wishes to eliminate. Another disadvan- tact with the tape as it is run from reel demagnetizer, as previously described). tage is that one cannot confine erasure to reel. Robins Industries produces what Bolt the E -plates together, using the to a given length of the tape with the is calls a Jockey Cloth, which is held in screws and nuts previously removed ; do saine precision as when using an contact with the moving tape and serves erase not replace the casing. head. Attach lamp to clean as well as lubricate the tape. cord and a plug that mates with the (As an incidental note, a bulk eraser house socket to the leads of the primary can be useful in other ways than in Head and Guide Lubricator con- winding. Be sure that you know nection with tape recording. which Thus it can are the leads of the For minimum wow and flutter, mini- be employed to magnetize or demagne- primary winding before you start on this job. Snip all mum distortion due to erratic tape tize tools, to demagnetize tubes, to de- other windings and tape them so they movement, and elimination of tape magnetize tube shields, and so on.) squeal, it is desirable to lubricate the will not make contact with each other. One should not attempt to bulk erase heads and guides. One of the products Wind the bulk eraser with rubber tape a reel of tape as it lies on the tape ma- designed for this purpose is Long Life to protect the core and windings. Insert chine, particularly if the machine em- Lubricant (the third of a trio of com- the plug into the house socket, and you ploys a meter as a record level indi- panion products), which contains sili- have a powerful electromagnet that can cator. Bringing the bulk eraser into the cone. An important caution is in order erase a tape in seconds. vicinity of the meter is apt to upset its here. Be sure that the lubricant does not Do not leave this bulk eraser con- get calibration or perform even greater in- nected to the house line for more than on the capstan or pressure roller, jury. as this will cause tape slippage. about one minute at a time, because it Bulk erasers, several of which are heats up fairly quickly. However, in one shown in Fig. 9, a Bulk Eraser are relatively expen- minute you can erase several reels of sive accessory, generally costing between tape. If your needs call for the bulk A bulk eraser is a powerful electro- $20 and $40. However, it is not difficult eraser to be operated an appreciable magnet that can completely erase a reel for the recordist to make his own at a length of time, you should consider the of tape in a matter of seconds and a very little cost. This assumes he can purchase of a commercial unit. good deal more effectively than the erase obtain an old power transformer, such head does. The entire reel of tape is as is found in a power amplifier, TV Test Tapes brought into contact with the bulk eraser set, or transformer -operated radio; these Test tapes will be discussed in detail and then slowly removed, meanwhile are often to he had in a surplus radio in a later article concerned with the test- describing a circular motion so that the parts store for a few dollars. The pro- ing, alignment, and adjustment of tape magnetic field cuts all parts of the tape. cedure then is as follows. Disassemble machines. It may be briefly stated here In some cases, the bulk eraser has a the transformer by removing the nuts that it is desirable to have one or more

Fig. 9. Various types of bulk erasers-left to right, Lafayette Radio ML -120, Rason Mfg. Co. "Jiffy -Rase," and Robins Industries' Model ME -99.

36 AUDIO NOVEMBER, 1959

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HI FI MUSIC DICTATION TRANSCRIPTION TAPE RECORDER

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AUDVO NOVEMBER, 1959 37

www.americanradiohistory.comAmericanRadioHistory.Com Fig. 13. Typical leader tape, Minnesota Mining and Manufacturing Co. majority of instances. On the other print -through from a tape without sub- hand, professional practice calls for stantially affecting the original audio speed error to be kept within limits of signal. As shown in Fig. 12, it is de- 0.3 per cent. Thus the deviation in a signed to be slipped onto pins that are half-hour program would be no more permanently attached to the tape deck. than 3.6 seconds. The tape contacts the Echoraser, and as At least two stroboscopic devices are the tape passes through the magnetic now on the market. One is the Tape - field of this device the print -through is Strobe made by Scott Instrument Labs, reduced by various amounts, depending shown in Fig. 10. The device is placed upon the age of the recording, the mag- on a Fig. 11. Orr Industries' Stroboscopic Tape convenient part of the tape deck netic properties of the tape, conditions Disc. and pressed slightly against the moving under which the tape has been stored, tape, causing the strobe to turn. The and the signal frequencies. test tapes that provide test tones to TapeStrobe has sufficient weight so that Echorasers are supplied in two check the following : it will remain in the position where it is strengths. One strength, according to 1. Azimuth (a tone of about 10,000 placed. The strobe markings are viewed the manufacturer, achieves up to 9 db cps is desirable). under the light of a bulb operating on removal of print -through without sig- 2. Frequency response (tones cover- 60 -cycle current. This may be an ordi- nificantly affecting high frequency re- ing the range of 50 to 15,000 cps). nary light bulb; to obtain a sharply de- sponse. The other strength, intended fo`r 3. Wow and flutter (a tone of about fined strobe image, however, a neon or the most serious cases of print -through, 3000 cps, at which frequency wow fluorescent lamp is preferable. If the achieves up to 18 db removal and in- and flutter tend to be most notice- pattern appears stationary, speed is cor- volves losses of about 2 to 3 db at high able) . rect. If it appears to be moving for- frequencies. 4. Correspondence of the record level ward, that is, in the same direction as Other Accessories indicator with the maximum per- the tape, speed is fast. If the pattern missible recording level. (The test appears to be moving backward, the There are a number of other tape re- tape should have a test tone at a speed is slow. To judge the degree of corder accessories which require a mini- frequency between 250 and 500 speed inaccuracy, count the number of mum of comment. These include the fol- cps, recorded at a level resulting bars that appear to be passing a fixed lowing. in 1, 2, or 3 per cent harmonic point during one minute (hold a pencil 1. Write -on labels for identifying the distortion.) point over a fixed spot on the strobe). contents of a recorded reel of tape. If the number of bars is 72, speed error These come on a dispenser in the same Tape Stroboscope is 1 per cent. A greater or smaller num- fashion as cellophane tape. It is desirable to have a means of ber of bars denotes a proportional error. 2. Leader tape (Fig. 13), which may checking whether the tape is running at To illustrate, 36 bars would signify a be attached to the beginning, end, or reasonably accurate speed. Of course, speed error of 0.5 per cent; 144 bars intermediate portions of the reel of what is "reasonably accurate" depends would signify an error of 2 per cent, tape. This can serve at least three im- upon one's acuity in detecting depar- and so on. This holds true for all speeds. portant purposes: (1) it can protect tures from true pitch. In the case of Another stroboscopic device is the the ends of the tape from wear and tear. semi-professional and professional users, Stroboscopic Tape Disc made by Orra- (2) It permits one to write in the con- accuracy in timing programs also be- dio Industries, Inc., shown in Fig. 11. tents of a reel of tape. Although the comes important. To most human ears, This operates in exactly the same fash- reel may bear a label, it is quite possible a speed error not greater than 1 per cent ion, except that it is held by hand that one may neglect to rewind the tape will be unnoticeable; in fact, many per- against the moving tape instead of be- hack onto this reel after it has been sons can tolerate errors as great as 5 ing positioned on the tape deck. played, particularly in the case of a one- and even 10 per cent. Thus the 1 -per way stereo tape. Such neglect may lead cent criterion will be acceptable in the Print -Through Remover to accidental erasure of a valued tape, unless one takes the precaution identi- When a tape has been heavily re- fying the contents on a strip of leader corded and/or stored for a considerable tape. (3) The leader can be used to length of time, the phenomenon known separate various portions of a as print -through tape, tends to occur, namely permitting quick and accurate the transfer of location the signal on one layer of desired sections. of tape to the adjacent layers. Hence 3. Tape clips (Fig. 14), which pre- one may hear what is known - as "pre vent the end of the tape from unravel- echo" and -echo." "post This effect is ing off the reel. more severe for the long-playing and (Continued on page 107) extra -long-playing tapes than for the standard tape, because the former are thinner and therefore present less of a barrier to signal transfer. Of quite recent vintage is a device known as the Echoraser, developed by O Fig. 12. Audio Devices' "Echoraser." Audio Devices, Inc., that can remove Fig. 14. Robins Industries' Tape Clip.

38 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 39

www.americanradiohistory.comAmericanRadioHistory.Com A Figure of Merit for Output Tubes

ROBERT M. MITCHELL

The right approach in making any selection of anything is to have all the information about it. Then, if you weight the information correctly, you will come out with the correct decision. The author tells you how to go about the weighing.

EVERY AUDIO DESIGNER has been faced TABLE II at one time or another with the problem of choosing tube types for a de- BASIC FIGURE OF MERIT sign. Since the design of an audio amplifier normally commences with the All tubes in Class AB, with 400 volts or less on plates power stage, the audio tubes output TYPE * BIAS Eb P E9g (rms) P/Egg D H F are usually the first to be investi- gated. If the designer had available 6V6 B FIXED 285 14 25.9 0.54 0.072 3.5 11.1 a method which helped him to select invariably the best tubes, it would reward EL84 P FIXED 300 17 20 0.85 0.11 4 23.4 him in both performance and pride, not 6L6 B SELF 360 24.5 28.7 0.85 0.19 4 40.4 to mention time and effort. How such selection may be readily done is described 616 B FIXED 360 26.5 31.9 0.83 0.14 2 58.0 below. 5881 B FIXED 360 26.5 31.8 0.83 0.14 2 The usual procedure of choosing a tube 58.0 is to consult the manuals, and compare KT66 B SELF 390 30 49.5 0.605 0.175 6 17.7 data by glancing hack and forth among the specification sheets, perhaps making EL37 P SELF 325 35 43 0.815 0.14 4.4 26.0 an occasional note. The information EL37 P FIXED 400 69 49 1.41 0.14 2.5 56.5 thus gleaned is combined with the designer's personal knowledge of how some EL34 P SELF 325 35 42 0.83 0.095 5 15.7 of these tubes have behaved in certain equipment. On the basis of this infor- EL34 P FIXED 400 55 54 1.02 0.095 5 19.3 mation a choice is made. In many cases 6550 B SELF 400 41 37.5 1.09 0.07 4 19.0 the choice thus made is a good one. In other instances, however, events prove 6550 B FIXED 400 55 32.5 1.69 0.09 3 50.7 that the second-best tube has been chosen. In such cases the wrong tube was chosen, 2A3 T SELF 300 10 110.0 0.09 3.1 5 56.5 not because the data sheet of a better one 2A3 T FIXED 300 15 88 0.17 1.87 2.5 127.0 was unavailable, but because the data on the available tubes was not properly 6CZ5 B FIXED 350 21.5 33 0.65 0.1 1 65.0 evaluated. * B = BEAM POWER P = PENTODE T = TRIODE It is therefore of considerable interest to the designer to have available a method gives a result which can be compared Specifically, a Figure of of systematically evaluating the charac- Merit for audio numerically with that of any other tube. output tubes should be so teristics of various tubes, so arranged that that an in- Such an expression is called a Figure of it indicates relative telligent choice can be made. worth not only when Merit, since it indicates the relative value tubes operate "tube The method discussed here consists of under manual" con- of the tube for a given application. The ditions, but grouping the various tube characteristics also under other practical phrase italicized is an important quali- and likely conditions. so that substitution of proper values For example, if we fication. A tube which may have a fine put tubes in parallel, or apply feedback * 13085 S.W. 124th Ave., Tigard, Ore. Figure of Merit for audio output service, around the tubes, our Figure of Merit may have a very poor one for class C formula should still be valid. We may TABLE I oscillator service, for example. then determine the relative value of dif- INVENTORY OF A Figure of Merit must adequately ferent tubes in parallel, TUBE CHARACTERISTICS or the relative reflect the variations of its make-up fac- value of different tubes with the same tors so that significant differences can he DESIRABLE UNDESIRABLE amount of feedback around each. We seen. In order to achieve this, it may may also, of course. compare two tubes sometimes be Damping focror Distortion QUALITY necessary to "weight" sonic of type A without feedback with two of the factors -that is, to assign them tubes of type B with feedback, and so Power output Driving voltage arbitrarily a multiplying factor which in- forth. Efficiency Heater power QUANTITY creases their relative value. This point In deriving any Figure of Moo. grid resistonce Cost Merit it will be discussed later in greater detail. must be understood that the cost of the

40 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com tube is a parameter of primary interest, even to the quality -minded purist. This is so because almost any Figure of Merit will include the power sensitivity (watts out per volt in) as one term, and it is obvious that the power sensitivity can be increased ad infinitum merely by putting more tubes in parallel with the initial set. However, since this cost factor can be evaluated only by the user we will not explicitly consider it. We will find, though, that it tends to enter indirectly in some of the other terms of the expression.

Important Factors To formulate our Figure of Merit we PACO is the kit division of PRECISION Apparatus Co., of the various factors Inc., world famous manufacturers of laboratory electronic first take inventory instruments for over a quarter century. The new Model which we wish to consider. Among these SA -40 is the first of a series of component high fidelity kits may be power output, driving voltage, A new from PACO...engineered for utmost performance and last- distortion at rated output, damping fac- 40 -watt ing value-designed for maximum eye -appeal. tor (ratio of load impedance to source stereo Whether you're an experienced audiophile or a newcomer impedance), efficiency, maximum grid to the thrill of high fidelity, the factors you must consider in choosing the amplifier you need are: circuit resistance, cost, size, and so on. preamp-amplifier POWER, DISTORTION, FLEXIBILITY and VALUE. These may then be sorted quite arbitrar- in kit form The PACO SA -40 offers you greater reserve power capacity ily into two groups : desirable and unde- than any other preamp-amplifier in its category. Its excep- sirable. The figure will be designed for only tional circuit design assures highly stable performance with low instructions so that a large desirable term makes extremely distortion. Step-by-step assembly $79.95 and giant -size wiring diagrams are so clearly detailed and a large undesirable a better figure and by simple that the technical difference between expert and one makes the figure poorer. This will novice disappears. And...the SA -40 provides maximum mean our figure is a fraction with the flexibility in any stereophonic high fidelity system...present desirable factors in the numerator and or contemplated. interested of the the undesirable ones in the denominator. also For those in engineering details, some more important technical specifications are listed below: See Table I. available In looking over this inventory of fac- factory wired for $129.95 POWER OUTPUT: tors we may find ternis which actually af- Steady State Power Output: 20 watts per channel, fect the merit -figure of the driver tube 40 watts total. more than the output tube. Driving volt- Music Waveform Power Output: 25 watts per channel, 50 watts total. age and maximum grid circuit resistance Peak Power Output: 40 watts per channel, are two such terms. Low driving voltage Ask your own 80 watts total. RESPONSE: 30 cps to 90 Kc, ± 1.0 db. is desirable because it means lower dis- Audio -Radio-TV Serviceman about DISTORTION: tortion in the driver stage, or possibly Harmonic: Less than .2% at 20 watts per channel output. lower voltage for a given distortion. A PACO and PRECISION Less than .1% at 10 watts per channel output. products. He'll tell you that Intermodulation: Less than 1% at full rated output. high permissible grid circuit resistance is 14 they always live up to their FRONT PANEL CONTROLS AND SWITCHES: controls desirable because it means that awkward including separate bass and treble controls for complete specs. That's why we can flexibility with any monophonic or stereo program source. coupling methods, such as transformers, say that the PACO SA -40 INPUTS: 14 total; 3 dual high-level and 4 dual low-level. are not necessary, or that the loading is the last preatnp-amplifier OUTPUTS: Dual tape outputs, separate preamp output as be made less, to well as standard dual speaker outputs. on the preceding tube can you'll ever have buy HUM AND NOISE LEVEL: or that the size of a coupling capacitor Available at leading electronic High Level Input: 80 db below rated output. can be made smaller for the same low - parts distributors and Low Level Input: 70 db below rated output. Tape Input: 65 db below rated output. wherever is sold. frequency time constant. good sound SPEAKER CONNECTIONS: 4, 8, 16, 32 ohms. The terms of the figure might be For complete information SENSITIVITY FOR RATED OUTPUT: Aux Input: .75 V Phono 1: (Magnetic) 5 Mv. grouped, if we desire, in terms of quality write to: Tuner: .75 V Phono 2: (Magnetic) 5 Mv. or Ceramic.3V and terms of quantity. The distinction INVERSE FEEDBACK: 25 db however, is not clear-cut and there is DAMPING FACTOR: 22 BEIM BASS TONE CONTROL RANGE: ± 15 db at 50 cps. overlapping of the groups. It is this Electronics Co., Inc. TREBLE TONE CONTROL RANGE: 2:15 db at 10 Kc. overlapping that the element of cost in- 70-31 84th Street RUMBLE FILTER: 6 db per octave below 50 cps. Glendale 27, L. I., N. Y. EQUALIZATION: Phono: "RIAA"; "EUR"; variably creeps into, whether we want it Tape: 33/4 and 71/2 ips, NARTB or not. If this cost element is neglected A Division of TAPE OUTPUT LEVEL: 2 volts per channel. minimum to the greatest possible extent we can PRECISION POWER SUPPLY: Silicon diode, low impedance for Apparatus Company, Inc. distortion on extended high level passages. make up a simple figure which is pre- EXTERNAL DESIGN: Gold and satin black hooded case, with dominantly a quality figure and therefore Export: panel illumination and satin gold panel. Morhan Exporting Corp. DIMENSIONS: 153" wide x 113/4" deep x 55/e" high very suitable for home constructors or 458 Broadway Model SA -40: Complete with case and step-by-step experimenters. N. Y. 13, N. Y, U.S.A. assembly -operating manual Kit Net Price $ 79.95 Model SA -40W: Factory Wired Net Price $129.95 A basic Figure of Merit is the follow- Canada: Atlas Radio Corp., Ltd. ing : 50 Wingold Ave. COMING SOON - MODEL ST -45 PD Toronto 19, Ontario ANI'/FM STEREO TUNER KIT Figure of Merit = F = matching companion EH for the SA -40 where P = power output-a "quantity" factor

AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com D = Damping factor (load Z/ by a factor of two, our quantity term in pends on how important the designer Source Z),a "quality" fac- the expression is reduced by two, making feels the individual factors are. The 2A3 tor the figure only one-half as good as be- has the highest Figure of Merit accord- E = Input voltage required to pro- fore. Our quality term has been increased ing to Table II. There are many design- duce P -a "quantity" factor by more than two, however. The dis- ers who would not agree at all with this H = Harmonic distortion at power tortion has been cut rating. They would point out that the P in half (for the -a "quality" factor same power output, of course), and this 2A3 achieved top rating almost solely on alone has brought the total figure back the basis of its damping factor, and that Damping factor is a quality factor for to its original value. The change in the conversely the 2A3 is by far the hardest three reasons. Not only does indicate a it damping factor, however, is considerably tube of the group to drive. measure of the transient response of the more than two to one, typical values for A glance at the columns for Power loudspeaker system, it also but indicates a triode being about two, and for a beam Sensitivity P/E and Damping Factor frequency response, since a low source power tube about 10. This is because the will show that, in these two respects, impedance relative to the reflected load plate resistance variation due to voltage they are right. It takes 88 volts rms or means a wider response from a given feedback is dependent on the amplifica- 125 volts peak to drive a pair of 2A3's in output transformer or (to let the factor tion factor, it, of the tube and not just fixed bias. This is quite a large voltage to of cost creep in) a cheaper output trans- on the stage gain. Whether we agree that achieve without distortion. It is therefore former for the same response. frequency the merit of our system has gone up by quite possible that the distortion in the Low source impedance also means less a factor of two (or ten) is a question of driver stage will exceed the distortion in distortion due to the transformer itself. how much weight we give the damping the output stage. There is no disputing The other terms are relatively self- factor term. The problem of what the fact that the 2A3 has a high damping evident. Power is wanted, but we want weights should be assigned to any of the factor. Is the damping factor, however to get it no at expense to the preceding terms is one which the designer must as important as we have made it appear? stage, that is, with as little driving volt- decide on in advance. Let us compare the 6V6 tabulation age as possible. Our quantity terms are With this basic Figure of Merit at for a moment. The 6V6 gives about the therefore : hand, let us see how some of the well- same power output as the 2A3 at almost the d.c. power out known power tubes fare. same supply voltage. It is there- = power sensitivity fore a tube that may be fairly compared driving voltage Determining the F with the 2A3. Let us suppose that we The distortion term needs no explana- have available a driver tube that can Table II lists not only the final Figure tion. If, because of the magnitudes of supply 88 volts rms with low distortion, of Merit but also the component terms the various terms, our figure ends up as say one per cent. Are we justified in which go to make up that figure. The a decimal, we may multiply the result by using 2A3's in the output, or could we ratio of the first factors is also given some arbitrary number. In this case final do better with 6V6's and how? separately as the power sensitivity (col- results have been multiplied by 1000. The 6V6 requires 26 volts drive. Let umn headed P/E), a sort of sub -figure - us apply negative voltage feedback of -merit. Effect of Feedback around the 6V6 until it requires 88 volts Type 2A3, an obsolescent filamentary drive. Its power sensitivity will then be Let's see how feedback affects this fig- type triode, has been deliberately in- equal to that of the 2A3. This requires ure. If enough voltage feedback (6 db) is cluded in Table I since it helps demon- a feedback of 3.4 or 10.6 db. This appli- a applied (around the output tubes only) strate particular point. The point is cation of feedback will reduce the dis - to increase the required driving voltage that the value of a Figure of Merit de - (Continued on page 99)

TABLE IV TABLE III ADDITIONAL CHARACTERISTICS FOR TABLE III

COMPLETE FIGURE OF MERIT PLATE PH OVERALL TYPE BIAS Po pin Rg EFF. EFF.

TYPE BIAS F1 EFFICIENCY F2 COST F3 2A3 FIXED 15 44 .34 50 K 6.25 .30 x Rg (Megs) (Relative to 6V6) 2A3 SELF 10 30 .33 500 K 6.25 .275 6V6 FIXED 11.1 .039 0.434 1.00 0.434 6V6 FIXED 14 30 .467 100K 5.65 .393 1.81 EL84 FIXED 23.4 .116 2.72 1,50 1.11 2.45 6L6 SELF 24.5 40.6 .604 500 K 11.3 .473

6L6 SELF 40.4 .236 9.55 2.00 4.77 5881 SELF 24.5 40.6 .604 500 K 11.3 .473

6L6 FIXED 58.0 .042 2.44 2.00 1.22 6L6 FIXED 26.5 5155 .514 100 K 11.3 .422

5881 FIXED 58.0 .042 2.44 3.50 0.7 5881 FIXED 26.5 51.55 .514 100 K 11.3 .422

KT66 SELF 17.7 .215 3.8 3.50 1.08 KT66 SELF 30 53.7 .56 500 K 16.0 .43

4.3 1.22 EL34 SELF 15.7 .274 3.50 6550 FIXED 55 120.0 .46 50K 22.6 .386

1.10 EL34 FIXED 19.0 .203 3.85 3.50 6550 SELF 41 88 .465 250K 22.6 .370

6550 SELF 19.0 .092 1.75 5.50 0.32 EL34 SELF 35 71 .495 700 K 18.9 .390

6550 FIXED 50.7 .019 0.98 5.50 0.18 EL34 FIXED 55 116.0 .475 500K 18.9 .407

2A3 SELF 56.5 .1375 7.77 2.55 3.05 EL84 SELF 17 34.2 .497 1000 K 9.6 .388

2A3 FIXED 127.0 .015 1.9 2.55 0.75 EL84 FIXED 17 34.2 .497 300 K 9.6 .388

6CZ5 FIXED 65.0 .0475 3.1 1.27 2.45 6CZ5 FIXED 21.5 39.6 .543 100K 5.65 .475

42 AUDIO NOVEMBER, 1959

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www.americanradiohistory.comAmericanRadioHistory.Com FACILITIES SPECIFICATIONS Mode Selector: 6 positions including Stereo, Stereo Power Requirements:. 117 VAC; 35 watts Reverse, Left channel on left speaker only, Right channel on right speaker Input Sensitivity Auxiliary, Tape, and 2 Tuner 0.25 V only. Left channel on both speakers, and Impedance: at 470K or Right channel on both speakers. 2 Phono, Low: 2.5 MV at 47K Monophonic: Internally parallels and decouples a High: 12.5 MV at 47K stereo phono cartridge to offer best XTa1: 0.1 V. very high quality reproduction from mono- 2 Tape Head, Low: 1.25 MV at 47K phonic records. High: 6.25 MV at 270K Tape Monitor: 0.25 V at 130K Tone Controls: Treble: boost 13 db at 20 KC attenuate 18 db at 20 KC Frequency Response: ±0.5 db 20 to 20,000 cycles Bass: boost 16 db at 20 cycles attenuate 20 db at 20 cycles Distortion: Less than 0.2% at rated output, 20 Trim Controls: Separate channel back panel con- to 20,000 cycles trols to balance the frequency re- Hum and Noise: High level inputs: 85 db below rated sponse of the system independent of output front panel controls. Low level inputs: less than 2 micro- Equalization: Separate bass and treble 6 position volts at input terminals (-115 dbm) switches, including NAB tape and flat for any low level flat source. Outputs: Main: 2.5 V with rated input Aural Compensator: Fletcher-Munsen compensation, con- Tape: 0.25 V with rated input tinuously variable. Gain: Low level inputs: 1000-1 Main Out- Rumble Filter: Rolloff to reject low frequency dis- put turbances such as rumble. Low level inputs: 100-1 Tape Out- High Frequency Two positions, 9 KC and 5 KC to put Cutoff: suppress hiss and noise. High level inputs: 10-1 Main Out- Phase: 180° phase reversal to phase speak- put ers or source material. High level inputs: 1-1 Tape Out- Balance: Attenuates alternate sides of center put 40 db each channel to balance for unequal source material. A.C. Aux. Outlets: 1 unswitched for tape machine or Tape: Front panel jacks, push button turntable and 3 switched controlled, to permit the use of a Size: Chassis: 14%2 inches wide; 41/4 inches portable tape recorder without dis- high; 12 inches deep rupting installed equip- permanently Front panel: 143/4 inches wide; 41/4 ment. inches high Tape Monitor: To permit instantaneous monitoring of tape while recording. Weight: 17 pounds

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www.americanradiohistory.comAmericanRadioHistory.Com Visual Stereo Monitoring

BURWELL GRAHAM and GEORGE L. FOSTER

The oscilloscope can be used to tell you more about a stereo recording than ears and meters will, provided you know how to interpret the in- dications. The author tells you what to look for and what it all means.

WHEN A WELL-ESTAhI.1SnED IL;DtiS- at home, in a quiet place free from dis- TRY is faced with a basic change turbance and technical problems. _Each in its product as a result of a new person gets a slightly different effect idea or by modification of some old one, due to his own particular hearing. -With many problems are hound to arise. some programs the phasing is very diffi- The recording and associated indus- cult to detect, particularly with instru- this in middle 1940's mental music. What is needed is a visual tries, faced the SET FOR with the introduction of the LP and 45 45° TRACE device with which vVV can monitor pro - rpm records. A number of years were grains, and check equipment. required before the manufacturers of HOE. Use of the Oscilloscope WITH INPUTS both the records and the playing equip- GAIN r0 CONNECTED While designing sinne ment were able to gain full advantage AS SHOWN playing equipment, a solution was found to of these developments. VERT. GAIN this prob- .At present, we face a, similar situa- -o- lem. The cathode ray oscilloscope was tion with regard to stereo. Stereophonic originally developed as a sensitive ideas-. Q HOR. INPUT sound is not new; it has been used on uring device to Measure position and filin and tape for many years. However, phase. Based on the old principle of the equipment used was somewhat lim- producing Lissa jour figures, it can be ited. Manufacturing, installing, and ad- r r adapted to shoIV all the information TO LEFT TO RIGHT necessary to judge stereo equipment and justing of such egtupoemit was more or CHANNEL CHANNEL less on a custom-made scale and with programming and thus serve as a win- experienced personnel. Fig. 1. Arrangement of connections to dow into the somewhat obscure stereo Stereo records, on the other hand, en- "scope." picture. he on a general The application is simple; rosy rea- abled the art to placed Other exhibitions are more polite, the availability of sonable 'scope can he used provided it usage level requiring only one channel speaks at a time. in price ranges. has adjustable amplifiers on both the X playing equipment all True stereo should result from an in- l t also resulted in the production, on a and 1` axes and access to each of them. finite number of sound sources, not just basis, of stereo records by all We have used a 43 -in. IIea.thkit model quantity two. With our present two -channel major companies. with quite satisfactory results, as well stereo we can actually point at five _Many of involved in the as several more elaborate types. the persons sound sources. retail hi-fi business have only a limited The first step is to equalize the verti- knowledge of the art. .lodging from Five Sources of Sound cal and horizontal gain of the X and Y many demonstrations and discussions, V irst, we have that resulting from channels on the scope. Set the horizon- there is little general agreement as to monophonic, in -phase (lateral cutting) tal control to horizontal input (or exter- the sound of good stereo. Normal moni- recording. This is one sound voice. We nal), connect ground terminals of both toring equipment also fails as a gunge have been listening to this for years. if horizontal and vertical to ground il' re- to judge a stereo program, or as a we reverse the phase of oiie speaker iii quired (on some 'scopes the lower ter- means to judge good stereo. a two -speaker monophonic system, the minals are grounded on the front To the average listener, so-called sound now appears to come from two panel). Connect the two upper termi- stereo is usually demonstrated by hav- points, one on each side of the pair of nals together and apply a signal, either ing a program broken into two distinct speakers, or two sound sources. This from an audio oscillator, or from one channels, earls playing into a separate same effect can he heard on a stereo output channel on a stereo amplifier. speaker system, the two being some dis- system, two signals equal and out of Figure 1 shows how to connect the tance apart. In many deoiotistralions, phase. 'scope. Now, play a record of any type the speakers are located as inch as '31l Then there is sound from the left Laving Si more or less steady volume. feet apart. The program chosen usually channel and sound from the right chan- _Adjust the vertical and horirontial shows the two -channel effect, such as a nel, five apparent sound sources. But amplifier gain controls to give a trace group of performers, where some are only five? Remember the "center" sound at 45 deg. on the 'scope. To he of any heard on one channel only, some on the was produced by combining the two use, the 'scope should adjust to this po-

other. This is easy to demonstrate. The signals in phase : the "outside" sounds sition. Allow the 'scope to warns up and effect is something like watching a ten- by combining signals out of phase by stabilize when this adjustment is wade. nis thatch. The demonstration shows only 180 deg. Other signals with varying After the 'scope is stable, again check that it is possible to put two channels phase difference are present as well re- the angle of the trace, readjust if neces- of monophonic information on one sulting in a range of sound source. This sary to the 45 deg. When the gain -con- phonograph record and get both of them gives the true stereo effect where the trol setting has been established do not with one stylus, but it is not stereo. music appears to have depth and dimen- touch these controls without again paral- sion, rather than a single source. leling the two inputs and rechecking. * Spartan Of Canada, London, Ontario. The effect can be noted much better Remove the jumper from the two in -

AUDIO NOVEMBER, 1959 45

www.americanradiohistory.comAmericanRadioHistory.Com Magnetic pickups very often deterio- rate in quality- (hie to dirt hemming lodged in the pole pieces. Very small magnetic, particles can so effect magnetic pickups that there is no difference bet wept' vertical and lateral, that is. zero ;ration. To check recording equipment, studio amplifiers, and microphones, the alive tests should be made using a small directional sound source. This ('an he posi- Fig. 2. 'Scope patterns: (A) 45 -deg. trace which should appear when amplifier inputs tioned at five places representing each are paralleled and the gains are equal. A monophonic disc will also give the same side, the center, and the interi»edinte trace when played a on stereo system, although pattern may appear more like (C) in within the large of the Fig. microphone 3 because of pinch effect, which is actually vertical modulation. (B) 315 -deg. used. trace, obtained by playing a vertical -cut record. It will sound like a monophonic record with one speaker out of phase. (C) 0 -deg. trace, left channel only. (D) 90 -deg. Going tluough these stages will, no trace, right channel only. doubt, show numerous pulhlemis with the equipment. When the equipment has puts and connect each input to one chan- 'scope with the amplifier inputs paral- been corrected, you have an excellent nel of the stereo system. The best point leled. True stereo gives an elliptical or device with which to monitor stereo in the amplifier is on the output trans- circular tract'. Any non -uniform phase recordings. former secondary of each amplifier. The shifts ill the amplifiers cana cause can- As mentioned earlier, true stereo re- voice coils could 1w used but on sonne cellation or distortion of the stereo ef- sults from audio information with all speaker systems there are dividing net- fect. Each amplifier in a stereo system phase differences. In other words, a cir- works ahead of the voice (oils. We re- should have a gain -setting control. cular trace on the 'scope! This is only quire the full range output of each Turn the input switch on the ampli- occasionally seen. More generally, how- amplifier. fiers to stereo still playing the lateral ever, the display is a sunburst effect, as The next step is to balance the gain or nmmwphomie recording. If the pickup at (A) in Fig. 3, fairly uniform in of the two amplifiers. Play a lateral re- and record are perfect. no change should shape. "Directional" stereo shows up as cording (a frequency record is pre- he noticed. Usually, however, many a pattern in the vertical or horizontal. ferred). For tape equipment, parallel changes occur. Hum nul rumble will This is desirable in some programs but the inputs as before and play mono- cause a widening of the trace. It* your listening becomes boring when the selec- phonic tape. Turn the amplifier input to amplifier has a bass reduction control, tion always appears this way. monophonic or standard. This should eut down the low response. The trace Too little stereo shows as a 45 -deg. give the same trace as when the 'scope should if the widening is due pattern (the saute as monophonic) while was set as above. if the trace is not at hum or rumble. If it does. turn up the too much out -of -phase information gives 45 deg. adjust the gain of the individual hass control and lift the pickup from a 315 -deg. pattern. This generally re- nmplifiers to make it as at (A) in Fig. record. Huma usually remains. but the sults in apparent loss of lows and, if '_'. if the trace is not a thin line but rumble should disappear. It may take the trace in this plane is too long, shows instead is a wide pattern (dotted line), some intensive work to reduce the huai a rec'or'ding with too notch vertical cut- there are soute non -uniform phase shifts and tunable to practical limits. ting. Indeed by watching the 'scope as in the amplifiers. Stereo amplifiers well as listening to the speakers, one cau Use with Test Records should be identical. Note particularly the monitor the cutting and achieve a better grid, plate, and cathode resistors and If you have the two Westrex stereo balanced recording. the coupling capacitors. Any wide di- test records, these can mow he used to With a little experience, one can get vergence between amplifiers results in a check the system. Play the lateral side, a vast amom it of information from( the non -uniform phase shift. This is very im- #714. This should give the character- trace pattern on the 'scope. ßy listening portant when the amplifier is compen- istic 45 -deg. monophonic trace. ]'lay the and watching -the 'scope at the satin' sated with negative feedback from the vertical side, #713, which will give a time, good stereo eau be recognized more audio transformer secondaries. Ampli- trace at 313 deg. The left channel, #715, easily than by listening alone. fiers having resistance -capacitance feed- will give a horizontal trace. The right This system can he used as a continual back networks can have considerable channel, #716, will give a vertical trace. visual monitor of the programs material phase differences. It is important that Poor separation in the pickup will re- during recording and particularly dur- the amplifiers are so corrected :nul ad- sult in a wide pattern on either or both ing cutting. Too long a trace at 315 deg. justed to give a thin 45 -deg trace on the vertical and horizontal traces. indicates too much vertical component with the damage of overcuttimg. When making stereo recordings, it is advisable to keep the program( balanced for at least 75 per cent of the time. This shows up as a "sunburst" type trace. This is an important feature when the recording is played on low-priced equipment. Many of the small stereo record players have only limited output on any one channel and thus need program material on both channels for full volume. The conventional monitor which uses two db or VU meters only the Fig. 3. (A) Sunburst effect, good stereo, with many sound sources. (B) Mostly vertical; shows output program might sound "thin." (C) Mostly lateral or monophonic; sound source should from each ehannel and will not show appear to be midway between speakers. (D) One channel only; can be caused by sum and difference values which result magnetic pickup with stylus off center. Trace may appear at 0 deg. instead. from vertical and lateral cutting. Æ

46 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com patented sheathed conductors flexible, foam -treated suspension

micro -thin rigid cast diaphragm aluminum frame

molded - styrene frame

light -mass cone weighted at apex

Cone Woofer for the lows The Model 350 woofer is specif- Push-pull action for ically designed to match the effi- precise control of ciency, low distortion, and excel- diaphragm of Electrostatic for the raids and highs lent transient characteristics JansZen push-pull electrostatics, Wide -range transparent treble brilliantly re- created by each JansZen Electrostatic element. The 176 push-pull sheathed conductors give precise control over diaphragm movement. worth KNOWING the difference. .. worth HEARING the difference

The Z-300 console and the new Z-400 shelf speaker the clarity of the original recording or broadcast. systems are definitely not for those who've been lis- The secret is the sonic mating of the remarkable tening to shrilling trebles and booming basses for so JansZen Electrostatic mid -high range speaker with long they've forgotten what "live" music is really the Model 350 cone woofer - the low frequency like. speaker designed specifically to match the efficiency, For whatever the program-velvety strings, the low distortion, and excellent transient character- human voice, percussion, full organ-the Z-300 and istics of an electrostatic. Z-400 reproduce with measurable precision the full Listen to these compact integrated speaker sys- audio spectrum from 30 to 30,000 cycles. Nothing tems ... singly, or in pairs for stereo ... at leading escapes them ... nothing is added by them to mar high fidelity dealers.

Z-300 Model 65 Electrostatic Two - Model 130 Electrostatic Four - Model 350 Cone Woofer Model Z-400 Shelf Speaker Model Console Speaker element Mid/High Range element Mid/High Range designed specifically for small System combines Model 65 System combines Model 65 Tweeter gives absolutely Tweeter for those who demand enclosures ... undistorted electrostatic with Model 350 electrostatic with Model 350 clean response to the ultimate in widely-dis- bass to 30 cycles. woofer ... ideal for stereo woofer ... exceptionally response 30,000 cycles. persed sound ... ideal for vertical or horizontal compact ... uniform multiwoofer systems ... placement on shelf or floor. from 30 to 30,000 cycles. response to 30,000 cycles at less than 0.5% harmonic distortion. Write for descriptive literature and prices.

JansZ* incorporating designs by Arthur A. Janszen made exclusively by en NESHAMINY ELECTRONIC CORP. Neshaminy, Penna.

AUDIO NOVEMBER, 1959 47

www.americanradiohistory.comAmericanRadioHistory.Com Series -Tuned Push -Pull Oscillator

A description of a novel push-pull oscillator using a series - tuned circuit as the frequency determining element.

E. J. CUDDY::

THL SERIFS -TUNED CIRCUIT as a fre- the most stability is ascertained. quency -determining element in an Output signal can be taken across R,; , oscillator has been used from time with little effect on the circuit as long to time and found to have certain ad- as it is fed into a high impedance vantages. In most eases, it is in the form through a capacitor, or the output may of a piezo-electric crystal and requires be taken off at the junction of Rk2 and an additional parallel -tuned tank. Other 1', and about twice as much voltage ob- applications are restricted to frequen- tained. Almost any pair of triodes may cies close to the self -resonant frequency be used, except at the higher frequen- of the tube used; still others are ac- cies where tubes designed for this use tually as a variable element in a paral- and in separate envelopes will be found lel -tuned circuit. It would appear that superior. something more flexible such as the arrangement shown in Fig. 1 would be Applications welcome addition to those now in use. Fig. 2. Equivalent circuit of the schematic 1. The equivalent circuit, Fig. 2, shows lt seems likely that this type of os- more clearly that the T, has, as a load, other causes a reversal of the action and cillator will he found more useful when the cathode resistor (R42) of tube T. a build up in the other direction. Since used with a crystal as the series -tuned plus the series resonant circuit repre- the series circuit is common to the out- circuit. As it stands (Fig. 1) it is in- sented by r; and that tube T2 has Ilk,and puts of both the tubes, it will determine convenient to use an ordinary grounded r for a load. Going to Fig. 1, it can the frequency of operation, yet re- tuning capacitor and permeability tun- be seen that due to the method of con- nouni fairly independent of the phase ing is indicated. However, where a sep- necting the grids, a slight rise in the shift between the grid and plate of each arate oscillator power supply is used, voltage at the grid of T will cause a tube. the cathode of T, may he grounded so current flow through R,,.2 in such a di- In addition to the fact that the series that a regular capacitor with its rection as to drive the grid of T2 nega- resonant circuit is not as onuh affected grounded plates connected to this point tive. This negative swing of the grid of by a change in shunt capacitance as is will do for tuning. Of course, in this T,2 will in turn drive R,,., so as to make a parallel cireuit, Fig. 3 shows that a. case, the negative lead of the supply is the grid of T, more positive. Hence, we balancing action takes place in this returned to the bottom of R11. have a build up in one direction until oscillator. Since the grid -to -cathode ca- While these factors (plus the fact saturation in one tube or cut-off in the pacitance of eaeh tube is in series with that two tubes, or a duo -triode, are re- the plate -to -cathode capacitance of the quired) tend to restrict the use of this + Bow i r, A....ociates, 11 Baintor St., other, a cancellation takes place in each circuit, it should prove valuable where J'npL', is, N.Y. half of the bridge and any remaining frequency stability is the prime con- unbalances will he canceled because the sideration. 1£ capacitance variation in each half will oppose that of the other.

Practical Circuit

As in other oscillators, a high -Q tuned circuit gives best frequency stability and also seems to improve wave shape. In addition, it is desirable to operate the tubes under Class A conditions for best frequency stability so Rk, and R,,.2 should be approximately the value recommended by tube manufacturers for such operation. The proper Fig 1. Basic circuit of the series -tuned plate voltage is important in this re- oscillator, which may be used for audio gard and some means of varying it Fig. 3. Presentation of the circuit in cs well as radio frequencies. should be provided until the tube giving bridge form.

48 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com General Electric's all -new VR -22 Stereo Cartridge try it in your own home

money -back guarantee!

We beliexe that once you hear General Electric's all -new The VR -22 is outstanding in all four critical areas of VR -22 in the privacy of your own home, on your own stereo cartridge performance: Channel separation- equipment. you -11 want to have this superb stereo cartridge Response-Freedom from hum-Compliance. for your very own. Were so sure of it, in fact, that we are making you an VR -22-5 with .5 mil diamond stylus for professional quality tone offer virtually without precedent in the Hi-Fi field: Try arms, $27.95*. VR -22-7 with .7 mil diamond stylus for profes- the VR -22 at home for 10 days. If you don't agree that this sional arms and record changers, $24.95*. TM -2G Tone Arm- is the stereo cartridge for you, bring it back and the full designed for use with General Electric stereo cartridges as an purchase price will be cheerfully refunded. You have integrated pickup system, $29.95*. General Electric Co., Audio nothing to lose and a whole new world of enjoyment to Components Products Section, Auburn, N. Y. gain! See your participating General Electric Hi-Fi dealer. *Manufacturer's suggested resale prices.

Acclaimed Oliver P. Ferrell Wm. A. Stocklin C. G. McProud Editor Editor Editor Hi-Fi Review Electronics World Audio as quoted as quoted as quoted by the in issue in issue in issue of Aug. 1959 of Sept. 1959 of Sept. 1959

. is its . tests not show up any even better than predecessor . the VR -227 is a tcp performer. The fre- listening did experts! quency response is as flat as any cartridge flaws. Frequency response from 30 to 15,000 with respect to output, channel separation was within 2.25 db of and extended frequency response and the two tested to date. Channel -to -channel separa- cps (limits of our test) +2 tion in the vital area between 700 cycles flat. Provides about the best channel sepa- channels balance within db to 15,000 and 8000 cycles was equal to the very best ration available of any checked with the ex- cycles. The shielding has been improved and ste-eo cartridges now offered the public." ception of [cartridge selling for 565.001 in the grounding of the shield and the method the frequency range from about 5000 to of shorting the two 'ground' terminals are 9000 cps." well thought out."

GENERAL ELECTRIC

AUDIO NOVEMBER, 1959 49

www.americanradiohistory.comAmericanRadioHistory.Com Transistorized Microphone Preamplifier

HORACE E. WEST`'

This simple, easily constructed preamp will make it possible to use a high -quality low -impedance microphone with typical high -impedance inputs on tape recorders.

Tn E WRITER has good Monte -type tape recorder, which came complete R5 10 K with a sensitive variable -reluctance, high -impedance microphone. With the recorder it is possible to make copies JI of long -play records of such quality AMPHENOL 9IPC3F that when the tapes and records are Cl 25 played back through a lu -fi set, it is -Mr"- 05 MIKE ; impossible to tell which is being played. CUT I 1 But when recordings were made with the I 0^ low-priced microphone, the quality was I I C5"50 quite inferior. To make it possible to , wake original recording of good quality, a good microphone was bought, and SHIELD J2 so as to provide flexibility in placing AMPHENOL the equipment, a low-ülpedanee micro- VOLTAGES MEASURED WITH VTVM, RIOR10 2 91-960 11 MEG. INPUT RESISTANCE phone and good -quality microphone transformer were chosen. It now became possible to make quality record- can he increased another fifty per cent the bottom edge of the Bakelite sheet. ings, and to place the microphone at by merely adding another pen -light bat- The units were mounted by drilling a any convenient distance from the re- tery to the two suggested. Current con- 1/16 -in. hole at each end of eaeh recorder. However, a new problem was sumed is only 0.25 nlilliainps, so the bat- sistor or capacitor, and pushing the encountered-the professional style mi- teries should last their normal shelf life. leads through. As the units are placed crophone was so much less sensitive Instead of a switch to turn the batteries in the order the signal reaches them, than the one supplied with the recorder on, a three contact female chassis re- wiring is at a urininlum-the only wires that for soft music or voices the volume ceptacle was used for the output con- used were the component leads them- control had to be turned all the way on, nection, and when the corresponding selves. On the underside of the board or the microphone placed too close to plug is inserted, it closes the battery these were eut to the right lengths, and the source of sound for comfort. circuit as well as making the output soldered together. Three short flexible A logical solution seemed to he a connections. leads were left at the input, and they microphone preamplifier to step the were soldered to the input connector up All in all, the preamp described has output of the microphone match after the circuit board was screwed to and to greatly increased the usefulness of the the high -impedance input of the re- the bottom of the aluminum box-with recorder, and should he of help to many corder. In the interests of portability a spacing washers holding the Board far amateurs wishing to make better record- transistor amplifier enough from the actual bottom to pre- seemed desirable. ings. Because of being battery powered, Other features indicated were: vent a short of any wiring to the metal no hum is introduced, and the unit is box. In the same way, three other flex- 1. Quality as good as that obtained completely free from all nlicrophonics. ible leads were left to be soldered to the with a good microphone transformer. output connector. A length of shielded 2. A noise level sufficiently low so as Construction Details microphone cable, with a three -prong not to he noticeable. matching cmmector on one end, and a 3. Output equal to that obtained from Construction was simple, with no eom- 'phone plug on the other, connects the variable -reluctance or crystal micro- plications. A low -noise transistor was used preamp to the microphone .lack on the phones. in the first stage. All resistors were half - recorder. Æ 4. Weight no greater than the micro- watt. .Miniature electrolytie capacitors phone transformer previously used be- were used in the interests of compact- PARTS LIST tween the end of the shielded cable and ness. A piece of Bakelite. approximately the input jack on the recorder. All this 3 x 5 in., was used as the hase -bond. Ci 25 µf, 6 -volt, Sprague Little- was achieved in the preamp developed, The pen -light holders were placed along Lytic and shown in the schematic, Fig. 1. It is the top edge. Most of the resistors and C2, C, 5µf, 6 -volt, Sprague Little-Lytic housed in an aluminum box 5 x 3 x 11/9 capacitors were put ill a single row, C, .05 µf, paper, midget type in., and weighs less than the trans- parallel to the short edges of the hake - Cs 50 µf, 6 -volt, Sprague Little- former. Powered by two pen -light bat- lite, in the order they are numbered: Lytic teries it has more output than the orig- R,, C R2, Qu R3, R0, R:;, C2, ("e, RR, .11 Microphone connector, Amphe- inal cheap microphone, and this output R,, R81 Q,,, R9, C3; the components of nol 9IPC3F the feed -hack circuit, C, and R1,,, are * 8487 Adern St., Vancouver 11, B.C. placed in an end -to -end position along (CIltillllyd o)7 t)!), ")

50 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com Genera Electric

back for more ventila- Power: 56 watts (28 watts per channel) music power. More than enough Soundly engineered: Power tubes at t1e extreme Advanced circuitry for to drive even low efficiency speakers. Response fat (±0.5 db) from 20 tion, cooler operation. Scratch and rumble filters. switch at rear. to 20,000 cycles, with less than 1% distortion. Channel separation 40 db. easy servicing, stable performance. Sp.eaker phasing

-off. Con- Inputs and outputs: Controlled quickly and functionally rith two multi- Sensitive music controls: Loudness: combined with power on lox volume. Balance: continuously purpose controls. For stereo and monaural cartridges (magnetic and tour: for automatic bass boost at channel. Bass and treble: dual concentric ceramic), tape heads. tape machines and tuners. Give- you flexible variable to ''off'' on either together or separately for non -matching speakers. command of inputs and complete selection of speaker combinations. type adjusts channels

56 watts of power, soundly engineered, a versatile beauty. From front to back, a remarkable achievement at $189.95*

Designed for beauty and value: Featuring a recessed front panel, the G-7700 comes complete in a beige vinyl case. the G-7710 in a white vinyl case. The price is a modest

$189.95*, including case. I The G-7600 delivers 40 watts. 20 watts per channel, $139.95*.) Other General Electric stereo amplifiers from $119.95. including case.

FM -AM Tuner, Series FA -10. Receives even weak signals with unusually low distortion, hum and noise level. Drift -free. Visual meter for pinpoint FM center channel tuning and optimum AM signal tuning. RF amplifier stage in both FM and AM increases sensitivity. FM multiplex jack for stereo adaptor. Built-in .Alf antenna: FM dipole included. $129.95*. Colors match all General Electric amplifiers: Saddle Brown FA -10 matches MS -4010: Willow Gray FA -12 matches MS -4000A. MS 2000A: Beige FA -15 matches G-7700; White FA -16 matches G-7710; Saddle Brown FA -17 matches G-7600. .Manufacturer's suggested resale prices. Slightly higher in the West.

See and hear General Electric Amplifiers and Tuners at your Hi-Fi dealer now. Audio Components Section, Auburn, N. Y. GENERAL ELECTRIC

AUDIO NOVEMBER, 1959 51

www.americanradiohistory.comAmericanRadioHistory.Com Speaker System for Perfectionists JAMES A. MITCHELL

Attention to detail and a thorough search for the slightest element which might detract from the quality of performance makes this unit worthy of duplication by anyone who wants good reproduction.

III E MOST SIIGNIF:('ANT trend ill speaker system design in the past JANSZEN 1-30 few years has been efforts to achieve realism or naturalness in sound. This G 8 may sound like 11 puzzling statement to the average :Indio fan since it might be PLUG TERMINAL logically assumed that all speaker sys- STRIP tems to attempted sound "real." Actually AMPLIFIER most speaker systems built ill the last G 0 DEMONSTRATION. twenty years have intentionally deviated 4 SWITCHES 0 )- 8 front theoretical perteet response to o--rwvvr- 8 produce the Most popular and pleasing 0 DPDT tone from the sound sourees available at 3 WAY the time. Distortions in records and radio have encouraged the popularity of 0 o speakers with juggled response curves 0) 2 WAY I and with "enhancing" resonances. And 0) there have been fads in brilliance, juke box bass, and overemphasized presence. oo--rvwvr- The first wide -range coaxial speaker a had a built in high frequency roll -off switeh so that when playing most of the shellac records of that day the noise and cl 50pf high -frequency distortion could be cut down to tolerable levels. As better records were made the range of sneakers was extended to reveal More highs. High frequencies because the object of high fidelity and excessive brilli:nlce became a fad in the design of many speakers. Peaks is the response eurve in the six - to ten-thousand-cl>s range IVOre easy to

* -1141 ,"i,(land Urire, 1í i>I.'port, Tenn. Fig. 1. Schematic of connections to the various elements of the author's three-way system.

achieve and when followed by :1 rapid What are the sound characteristics of roll -off above this trequeney gave the these speaker systems ? They are usually impression of tremendous highs without described as sounding "smooth and un- distortion in the very high frequency obtrusive, not brilliant but silky, not range. 'missy but solid, sharp, clean, and natu- The bass end too has been boosted, ral." The two qualities most `N. important rolled -off, and resonated in all sorts of in achieving this sound are 11 ) the se- ways to give the impression of big bass. lection of drivers with smooth wide - The open backed vibrant speaker cabi- range response and excellent transient nets which would whooulp on every loud performance and, (2), the mounting of note gave the first lu -fi thrills. True ex- the speakers in a rigid vibration -free tended range bass has been achieved only h:ille with all resonances eliminated. A with great effort and until recently, few commercially available speaker sys- large size. There has remained a ten- tems have been built on these principles dency to use resonance to extend the with eonsiderable success. There are also bass response of many systems. a number of suitable speaker compo- The latest aclvauees in the recording nents available for the audio fan who art have encouraged many speaker de- wants to build his own system. signers to try to produce speaker sys- To those with the "build it" urge there The completed loudspeaker serves as a tems with a much more truly "flat" re- may be some lessons in the construction base for the TV set as well as a source sponse and free from the resonance and of the writer's "perfectionist" speaker of excellent sound. "color" of earlier speakers. system. This unit was designed and built

52 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com General Electric presents today's

Model G-501 91/4" x 13" x 22" biggest A true bookshelf speaker system. cubic foot of sound

This dramatic new design brings you General within ±3 db over most of its frequency range Electric's famous Extended Bass performance from 45 to 16,000 cycles. in an ultra -compact one cubic foot enclosure Unusually clean low -frequency response results from the closed -type enclosure and Hear it ... and ycu'll agree that here is special high -compliance woofer. A new 3 -inch full, natural sound as good as, or better than, tweeter achieves maximum dispersion of highs many much larger and more costly systems. for full stereo effect. In walnut, ebony and wal- The G-501 offers realistic, smooth response nut, mahogany and cherry veneers. $85.00*

New General Electric 12 -inch Speaker System

The G-506 combines enclosure compactness with full, smooth response from 40 to 18,000 cycles. The complete unit - with front - mounted woofer, tweeted and crossover network - occupies only two cubic feet of space. But small size is gained through no sacrifice in sound! The Extended Bass design puts out four times the low -frequency power ( +6 db) as standard 12 -inch speakers in the same enclosure. Complete G-506 in four nost-wanted finishes. $129.95*

*Manufacturer's suggested resale prices. Slightly higher in the West.

hear both of these f ne speakers at your Hi-Fi dealer now Model G-506 Audio Components Section, Auburn, N. Y. 15" x 141/2" x 23U'

Hi GENERAL ELECTRIC

AUDIO NOVEMBER, 1959 53

www.americanradiohistory.comAmericanRadioHistory.Com to produce a natural sound. The final de- nient resonance) below this frequency. sign is the result of a number of experi- In the pursuit of perfection it was ments and comparisons, and the results therefore decided to cuver the range have been fully satisfying. Critical list- from 2000 cps down with mid- and bass - eners generally agree that other compo- range speakers. The Bozak units match nents in the reproducing chain-records, the Janszen in efficiency level, and their pickups, and so on-introduce more relative volume is easily brought to the odor than this speaker system. right balance. The B-201) midrange unit is remarkably fiat in the 2(10- to 4000 -cps Details of System range and it is highly deullped and free from resomance. This sneaker system was built around The woofers are B-199AL Models. the following components: A Janszen These differ from the standard Bozak 1-30 electrostatic speaker for the fre- B-199 woofers in that they have a quencies from mid -range to the limit of greater linear voice -coil travel, and a high -frequency hearing; a Bozak B-209 lower fundamental resonant frequency. midrange speaker for the nliildle and This allows au extension of the bass lower Middle frequencies; and two Bo- range in both frequency and power. For zak B-199AL woofers for the bass. optimum results they require, however, The Janszen electrostatic has an ex- a larger infinite baffle -12 eu. ft. as com- ceptionally smooth response, free from pared to h eu. ft. for the standard model in a two -woofer peaks and resonances. It covers the Fig. 2. The cabinet frame in early stages system. Broad -range range of from 500 eps up. It does re- of construction. slow-rolloff crossover con neetions quire carefully balanced hatching are used with these speakers. peak -free rolloff above 21)0(1 eps. A This greatly improves the blending of woofer and/or midrange speakers to gradual rolloff is best. the different units and minimizes cross- produce best results. Listening in- tests It is quite a request to expect a over transient problems. The crossover dicate that the woofer should off not fall woofer to work well in the 2000 -cap between the woofers and the Midrange at the 500 -cps point but should smoothly range. :Most units of 12- or 15 -inch di- is at 400 eps and overlap the rolloff of the mid- into the 2000-eps range with a ameter show some cone break-up (seg- (Contiauund on page 96)

33 3/8 n r\ - °----'-t 1`\\\ 51/2 iII \ D 1. 34 i , ii \ \\ , I. 131/2 i j I \\ 28 i 1; ` I Ia l0

i II 12 i 1 li 12% lI-^ ---;r--= ----^- li 32

,r II L II II 81/2 11 Z II r °

e e

° = 36 /2 39 SCALE a ° 1/16-=1.

P O

Fig. 3. Dimensions and plan for the loudspeaker cabinet described by the author.

54 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com Lesa!

.--.-- 0" Iv.

CD2/21 AUTOMATIC STEREO CHANGER $39.95 4 -speed, pre -wired for mono and stereo. Jam -proof mechanism with constant 6-second change cycle. Flutter, wow, and rumble on a par with broadcast standards. Heavy duty 4 -pole motor. Perfectly balanced no -resonance, no -feedback tone arm. 4V3/11 MANUAL STEREO PLAYER $ 23.25 Pre -wired for mono and stereo, plays all size and speed records. Automatic stop at end of record play. Precision turntable speed control accurate to 1.5%. Small space, elastic suspension mounting. .57/SA "LESAPHON" HI-FI PORTABLE PHONOGRAPH $105.95 Combines the CD2/21 with a powerful amplifier -speaker system in a handsome portable for truly full dimension sound reproduction. Beautifully styled, finished in tutone vinyl with gleaming brass trim. 11111/SA "LECOSTEREO" AMPLIFIER -SPEAKER $53.95 Custom -designed for superlative stereo, the 1/SA simply plugs into the 57/SA and you have a balanced stereo system with single -point control! ------M M M f SEND FOR FULL INFORMATION AND NAME OF NEAREST DEALER Electrophono & Parts Corp., 530 Canal St., N. Y. 13, N. Y. 3 3 Name Address ' the Tradition Custom Crafted in Renouszed Italian City Zone State of Unsurpassed Quality and Lasting Beauty! J

AUDIO NOVEMBER, 1959 55

www.americanradiohistory.comAmericanRadioHistory.Com HOW TO BUILD A STEREO CONSOLE THAT REPRODUCES MUSIC AS FAITHFULLY AS SEPARATELY MOUNTED COMPONENTS

For many years, serious music lovers have we could bring you this new kind of console. searched for a way to enclose high quality high- fidelity equipment in a cabinet that would match PROJECT #1 The first consideration was given their finest furniture. to our components. They had to have high quality Until now, there was no practical solution. You reproduction. The standards we set for them can be had to compromise. You had to sacrifice the best most simply described by the phrase "Integrity in possible music reproduction if you wanted a good Music Reproduction." If you are familiar with looking cabinet. If you insisted on high quality re- Stromberg -Carlson stereo tuners, amplifiers, turn- production, you chose components, some of which tables and speakers, we believe you will agree they may not have been quite so appealing to the eye. earn this description. If you dislike compromise, Stromberg-Carlson's PROJECT #2 Speaker systems were the next new kind of console will interest you. We call them important project. our new kind Integrity For of stereo con- Series Component Ensembles-and to an sole we needed two speaker systems of unquestion- uncompromising music lover each word in that able quality. We were fortunate here, because we name will be significant. had already devel- At the start, we faced the same problem that oped a system that every console manufacturer has tried to overcome : met the quality re- when full -range speakers were rigidly in mounted quirements, the well - the same console as high quality components, there regarded Acoustical was a serious loss of sound quality. Labyrinth" Speaker This loss-most often recognized as muddy or System. Its quarter boomy by noise-is caused "feedback." It occurs wavelength duct enclosure, properly coupled to a because sensitive components can detect the speak- low -frequency radiator, achieved a system reso- er vibrations which fed are back through the body nance lower than the unbafiied free air cone reso- of the cabinet. These vibrations are amplified with nance of the radiator itself. This is the kind of music the and reproduced as noise. quality we knew you wanted. If you own a console now, but do not hear these noises, it is not because your ears are insensitive. PROJECT #3 To reduce the size of high quality You do not hear them because we and every speaker systems so that they would fit into a stereo other console manufacturer had to eliminate them console of reasonable dimensions. We were cer- by compromising the musical reproduction of your tain that component -quality sound in a console console. You do not hear them because the sound could only be achieved with speaker systems that you hear is not complete. did not depend on the console cabinet HOW TO BUILD A CONSOLE THAT for their enclosure. This meant that we ELIMINATES FEEDBACK NOISES had to reduce the As we analyzed the problem, we realized there were size of the Acousti- seven projects that we had to accomplish before cal Labyrinth enclo-

56 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com sure so that we could fit two separate speaker en- styling. You choose from 16 basic models in these closures within a cabinet that had reasonable di- styles, in a choice of finishes. These cabinets, like mensions. It was not easy, but we did it. After a fine painting, best describe themselves. They many, many trials and tests we achieved the correct must be seen. size without sacrificing one iota of the extremely linear and extended response of the system. PROJECT #7 To give you maximum flexibility in your enjoyment of an Integrity Series Ensemble. NOW THE MOST DIFFICULT Every ensemble provides for your listening tastes PROBLEM HAD TO BE FACED and room acoustics by including the Stereo Choice Switch for precise regulation of stereo separation, eliminate feedback PROJECT #4 To effectively with or without separate matching speaker sys- the mechanical coupling by effectively eliminating tems. All ensembles provide space for adding a of treating the that allows it to occur. Instead tape deck. we the cause. We developed a symptoms, treated You may select your own Stromberg -Carlson the speaker sys- method of effectively isolating or choose a recommended com- result, stereo components tems from the sensitive components. (As a ponent complement-in any case Stromberg - Stromberg -Carlson Integrity Series Ensembles are Carlson components are always interchangeable. successful uncompromised ensembles.) the first If you now own a console or components, we in- key is what we call Iso-CoUSTIc The development vite you to exercise your critical judgment by lis- This mounting, in SPEAKER SYSTEM MOUNTING. tening to an Integrity Series Ensemble. (You will the resistance and compliance to vertical which find that the better component shops-as well as and horizontal pressures have the better department and music stores-have been carefully engineered, has chosen to feature this new kind of stereo console.) solved the problem. It allows Listen carefully. Look closely. Ask questions. Then -Carlson to create a Stromberg accept not our judgment, but your own. cabinet -within -cabinet suspension system which prevents transmission of speaker vibrations to the sensitive components. If you component owners could put your equipment into a cabinet whose speaker systems have our Iso-CousTIc Mounting, the quality of the sound you'd hear would be as good as your component system is now. In fact, the components we use are the same ones you would choose for your separately mounted component system. They are interchangeable.

INTEGRITY SERIES WILL NEVER BECOME OBSOLETE PROJECT #5 To assure the purchaser of an Integrity Ensemble that his choice would never be INTEGRITY SERIES COMPONENT ENSEMBLES obsolete, we designed the units in accordance with and fifty dollars to about six thou- concept. All of the components are com- -three hundred a modular from 16 models in can replace any com- sand dollars. You may choose pletely interchangeable. You and Period stylings, ponent in the ensemble to Traditional, Contemporary each tastefully designed by Federico. You may se- keep pace with new develop- or ever re- lect your own Stromberg-Carlson components ments-without Stromberg -Carlson com- placing your fine cabinetry. choose a recommended ponent complement-in any case Stromberg -Carl- son components are always interchangeable. For a complete color catalog of Integrity Series CABINETRY HAD TO BE Component Ensembles and components write EXCEPTIONAL, TOO STROMBERG-CARLSON, Special Products Division, 1418 N. Goodman St., Rochester 3, New York. PROJECT #6 To design cabinets with the permanent beauty of fine furniture. Federico re- "There is nothing finer than a Stromberg -Carlson" sponded to the challenge by creating cabinetry in Traditional, Contemporary, Early American, Ital- STROMBERG -CARLSON ian Provincial, French Provincial and Oriental A DIVISION OF GENERAL DYNAMICS

AUDIO NOVEMBER, 1959 57

www.americanradiohistory.comAmericanRadioHistory.Com For integrity i» iiiu.'ic... THREE NEW STROMBERG-CARLSON TUNERS ... in component systems ...in Integrity Series Ensembles

SR-455 AM -FM STEREO TUNER The SR -445 is actually two separate and complete units which have been placed together for convenience of mounting and use. They have individual circuitry in which no duplicate use of tubes or circuits is involved. Operate as an AM tuner, an FM tuner or together as an AM -FM stereo tuner. The SR -455 combines the separate AM and FM tuners described below. The specifications are exactly the same as listed for these two units. SR -455 .... $129.95' All three tuners are available in gold and white or black and brushed chrome. Top cover in white, black, tan or red available at extra cost. SR -445

FM -443 FM TUNER Exceptionally sensitive, low noise reception due to the wide peak -to -peak separation (475 kc) and long, linear slope (350 kc) of the balanced ratio detector, and the grounded grid cascode front end. Sensitivity is 2 uv for 20 db quieting, 4 uv for 30 db quieting (300 ohm). Local -Distant Switch results in 2 uv for 40 db quiet- I ing on local stations. Dial station selector and "hair-trigger" tuning eye. Temperature controlled circuits eliminate drift. Includes switched AFC circuit. Tuning Range: 88-108 mc. Bandwidth: 200 kc. Frequency Response: 20-20,000 cps. FM -443 Self -powered with auxiliary_power for AM -441 tuner. Provi- sion for multiplex adapter. FM -443 $79.95"

AM -442 AM TUNER For exceptional AM reception, this tuner has a frequency response of 20-7,000 cps, down 7 db at 7,000 cps. It features a tuned RF stage and 3 -gang variable tuning condenser. Its tuning range is 540 to 1,600 kc; Bandwidth is 9 kc. Local -Distant Switch adds 20 db quieting on local stations. Adjustable ferrite loop and external antenna. AM -442 $59.95' AM -441 AM TUNER Same as above, but without its own AM-442jAM-441 power supply $49.95'

"There is nothing finer than a Stromberg -Carlson" 'Prices audiophile net, zone 1, less cover STROMBERG -CARLSON A DIVISION OF GENERAL DYNAMICS

58 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com marked Channel A Pickup and Channel 13 Pickup; they permit one to choose on each ehannel bet \\ either of two low-level sources. EQUI PMEN'r Inputs and Outputs There are four inputs per channel: two magnetic inputs and two high-level ones, the latter marked tuner and tape. The r. magnetic inputs are intended for either ® O O magnetic phono cartridges or tape heads, aoO OO O with appropriate equalization determined by the position of the input selector. One chooses between Magnetic Input 1 or Mag- netic Input 2 by the Channel A Pickup and Channel B Pickup switches. This meets the problem of the individual desiring to operate both a changer and a transcription rk turntable, or the one desiring to accommo- PROfIlI date a tape head as well as a phono H. H SCOTT 299 initials. This reversal can be achieved on cartridge. any of the impedance taps (4, 8, and 16 Magnetic Tuput 2 has two jacks, marked STEREO AMPLIFIER ohms) because the "high" speaker terminal Low and High. The High jack is intended is connected to the desired tap by means of for cartridges with relatively high signal 'l'he Scott 299, Pig. 1, is an integrated output and feeds the signal through a amplifier (control amplifier and power a jumper, as shown ill Fig. 2. To enable the to know at a glance voltage divider to prevent the phono pre - amplifier eouabined on one chassis) for user whether the unit is operating in the true amp and succeeding stages from being stereo, rated at 17 watts per channel, and overloaded. The Low jack presents an im- offering the performance and refinement stereo mode, reverse stereo, simulated stereo, or other of the seven possible modes of pedance of 47,1100 ohms, while the High of design that may be expected these days any operation, the 299 features a set of three jack presents 147,000 ohms. These imped- of a piece of equipment intended for high lamps up in com- ances should be suitable for most pickups fidelity use. Considering everything that a pilot that light various the position of and heads. One can use either the High or stereo amplifier must do, it is relatively binations, depending upon the Stereo Selector control. Low jack on Magnetic Input 2, but not simple in appearance and straightforward both at once. in operation. The use of a substantial The 299 provides the following "conventional" controls, all of which are ganged: No specific provision is made for piezo- number of slide switches in place of the electric cartridges, which typically require rotary type helps eut down the "busy" loudness -volume switch, which converts the an input impedance of about 2 megobns look and makes for an attractive front volume control into either a straight gain - to maintain bass response. On high-level panel. control or a loudness control with auto matie bass and treble boost at low levels; inputs the input impedance is only 500,1100 rumble filter; scratch filter; input selector. ohms, which is usually too low, although Controls Ill its first three positions, the input one might correct the situation adequately The 299 has a stereo -selector control, selector accepts the signals from the mag- by turning up the bass control. Another separate bass and treble controls for each netic inputs and supplies European 7S possibility is to feed the cartridge into the channel but concentrically mounted, a phono, RIAA phono, or NAB (formerly magnetic input jack presenting a 47,000 stereo -balance control, a phase -reversing NARTB) tape equalization. In the fourth ohm load. For some piezoelectric cartridges switch, and a ganged gain control. and fifth positions it selects the high-level this will result in fairly correct equalization The stereo -selector control has seven po- inputs, respectively tuner and tape ampli- by converting the pickup into the equiva- sitions. To enable one to balance speaker fier. Intended for operation in conjunction lent of a velocity device throughout the levels, the first two settings, marked Bal- with the input selector are two slide switches audio range; in other words, by causing ance A and Balance B, combine both input signals and feed them to either Channel A or Channel B. By alternating between these positions and adjusting the stereo balance control, one can equate the speaker levels. In the third position the stereo selector combines both input signals and feeds them to both channels, which is desirable when playing mono records with a stereo pickup. The fourth position provides true stereo, and the fifth position reverse stereo. In the sixth and seventh positions, either signal A or signal B is fed to both channels. If the speakers have previously been balanced -by using identical speakers or by means of L -pads or similar devices-one can balance the input signals by alternating between positions 6 and 7 and adjusting the stereo-balance control; thus one night balance the two sections of a stereo cartridge when playing a mono record. The stereo -balance control provides equal level on both channels at mid -position. When turned fully to the left or right it eliminates one channel without affecting the level of the other. The phase reversing control is a double - pole double -throw switch that reverses the connections on Channel B between the output transformer taps and the speaker ter - Fig. 1. H. H. Scott Model 299 Stereo Amplifier.

AUDIO NOVEMBER, 1959 59

www.americanradiohistory.comAmericanRadioHistory.Com signal from the preamplifier or at high-level fidelity reproduction, litaxintuut "undis- SECONDARY OF signal goes through rumble and scratch torted" power tvas about 7 watts, slightly OUTPUT TRANSFORMER PHASE REVERSAL filters of the losser type, followed by a more than 3 db down front power at 1000 OUTPUT SWITCH stage of amplification, Baxendall-type tone cps. Considering that audio energy :it the TERMINALS JUMPER -CONNECT TO controls, another stage of amplification, frequeney extremes is ordinarily well 4, 8, OR 16m TERMINALL below and the gain control (accompanied by the the energy at mid -frequencies, and con- loudness -volume' switch). sidering that 7 watts will drive speakers Placement of the gain control at a rela- of medium and high efficiency to very loud tively late stage raises the possibility of levels, the 299 should provide adequate, overloading the earlier stages lite to ex- poror in the nits jority of situations. It may cessive signal. To illustrate, some tuners be noted 10 watts of "undistorted" power may present as much as 3 volts on peaks. wits :mailable at ln,otto cps, while :tt the The writer introduced 3 volts (lid valeut low end 16 watts were nv:lil:tide at 100 cps, Sill(' wave signal into the tuner input and 14 watts at 511 cps, and 13 watts at 40 eps. COMMON m easure:l 1.2 per cent 131 distortion at It wvas surprising to find Channel A of .i watts output (equivalent sine -wave the 299 originally producing 1.5 per cent "HIGH" (tower). But when the input signal was cut CONNECT IM distortion at 1 watt equivalent sine down to 0.5 volt, l \t distortion at 5 watts SPEAKER B wave power. 3.4 per cent at 5 watts, and output fell to the nmeh lower figure of HERE 4.2 per cent at 10 watts; these readings 0,23 per cent. The 299 lias no - input level were obtained by using ,just enough signal Fig. 2. Channel B output connections on sets, so the incoming signal be re- must input to drive the 299 to fall output Zvith the Scott 299. duced at the by source, for example means the gain control at maximum. Almost of a gain eottrol on a tester. identical results were obtained on Channel After the gain control the signal goes the signal output to rise with frequency in B. Ad justment of the d.c. balance controls into the power amplifier section, consisting the same manner as for :I magnetic car- produced virtually no change, but a radical of a phase splitter runt the push-pull out- tridge. improvement w':is obtained by adjusting put tubes. In these lilvs when the majority The speaker output terminals will ac- the a.c. balance controls. The results then of high fidelity :amplifiers appear to use commodate 4, 8, and 16 -ohm speakers. As Wen' 0.19 per Veld IMtit1 watt, 0.23per either the split-load or long-tailed phase previously discussed in connection with cent at 10 watts, 0.7 per cent. at 10 watts, splitter, it is interesting to find in the 299 Fib/. 2, connection to the desired tap of the and 1.4 per cent it 15 watts; even a reversion to one of the forets of floating output transformer is made by a juniper. (slightly) better results were obtained on paraphase inverter, which was eonuuon This arrangement makes it possible to eon- Channel B. years back. A pentode -triode is used as the nect additional sets of speakers, or possibly Front this experience it appears that the splitter. The output tubes, 7189's, are a a speaker for center -channel operation, to purchaser is well advised to have his 299 relative newcomer on the scene and are whatever terminals may be desired. thoroughly checked and aligned by a tetrode operated with fixed bias. com- The 299 features a center channel output petent technician before installing it in A full quota of adjustments is provided for feeding a third amplifier and speaker his audio systems. Of course, this is a in the power amplifier section, namely out- system. The, signal is taken front the out- rule that applies to all audio equipment; put tube bias, d.c. balance of the output itut transformer of each channel, the reviewer's experience with the 299 is tubes, and a.c. balance of the signals fed ing resistors. far from exceptional. (It may be noted liv the phase splitter to the output tubes. An output ,jack for feeding :t tape re- here that in measuring IM in Scott's Heaters of all the tubes in the control 222 corder is provided on each channel. The amplifier, reviewed below, adjustment of amplifier section are d.c. operated. The manufacturer states that the tape recorder the a.c. balance control laodtteed no im- same d.c. source is employed to provide input should have an impedance of at least provement on one channel and only slight fixed negative hits to the output tubes. 21111,000 ohms, which does not appear to improvement on the other.) raise a problem with most tape machines. With Performance gain full on and the controls at Maximum recommended capacitance of the mid-position,frequency response was rela- cable is to the recorder 200 µlit, which At 111u0 cps the reviewer measured 16 tively flat, as measured on Channel A, one to 8 limits about feet of low-eapaei- watts of power per channel on the 16 -ohm remaining within ±2 db in the 40 to 13,000 t:tuce cable (25 µµt Per foot), and to pro- tap before the waveform became noticeably cps range. Response was down 2 db at 20 portionately less other cable is used. if distorted on an oscilloscope. This is but a cps and 3 db at 20,000 cps. With the gain It may not be possible to record on some fraction of it decibel below the manufac- control at a position 6 db below maximum, tape machines if the output cable of the turer's 17 -watt rating. At 30 and 15,000 response was down 3 db at 15,000 cps and machine remains to the 299's connected cps, which ere practical bounds for high 5 dl) at 20,000. tape input jack. The 299 grounds all incoming signals other than that fed through by the input selector switch. However, some tape machines fail to disconnect the output cable from their amplifier circuitry TAPE RECORDER when the machine is in the record mode. Hence the signal is grounded before it can reaclt the reeord head, as illustrated in AMPLIFIER z INPUT O Fig. 3. Some amplifiers meet this problem COMMON TO RECORD HEAD DRIVER AND o through a tape -monitor switch arrange- RECORD AND PLAYBACK RECORD HEAD ment, which uses a special switch to accept the signal from the tape machine and Fig. 3. Example of at no tinte grounds this signal. In the a tape recorder where the input operating manual for the Scott 222 (in INPUT CABLE is TAPE MACHINE the succeeding review), there is a diagram signal grounded when used OUTPUT CABLE showing how to construct a simple external with an TAPE switching facility to meet this problem. amplifier such INPUT SCOTT 299 as the Scott 299. JACK TAPE OUTPUT Doubtless the manufacturer will furnish JACK this diagram on request to owners of the 299. '*-SHORTS UNUSED SIGNALS TO GROUND Circuitry Magnetic equalization (phono or tape) SIGNAL FROM THIS JACK IS FED THROUGH is achieved through frequency -selective feedback in the preamplifier stage. The

60 AUDIO NOVEMBER, 11959

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Balanced Stereo - edite anywhere in the room 4'44 Tb1â-2 MODEL RRL-12 12" 3 -Speaker RRL System iikeidawigemospeicffli Featuring the sensational new Sphericon Containing two complete 3 -way multi Super Tweeter for sweet, smooth highs to speaker systems in one compact enclosure inaudibility. From $114.95 net. MODEL UC -82 8" 2 -Way Diffaxial the `Trimensional' TMS-2 projects frequen -range speaker cies of both channels to the rear and side Excellent low cost wide walls of the room. Thus, one large wall area with unlimited versatility. Use mono- becomes channel A; another channel B .. . phonically, as matched stereo pair in exactly as if you had a series of widely minimum size enclosures, as second distributed speakers for each channel. channel speaker, or as stereo add-on. Response: 45-14,000 cps. $16.95 net.

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SEE AND HEAR THEM AT YOUR DEALER NOW! ... or write for new edition of "An informative guide to high fidelity stereo and monophonic speaker systems and components." Desk R-9, University Loudspeakers, Inc., White Plains, N. Y.

AUDIO s NOVEMBER, 1959 61

www.americanradiohistory.comAmericanRadioHistory.Com panel lamps to indicate mode of opera ti DU, ;and does not provide European 78 phono equalization. However, it is like the 299 in having a ganged gain control, volume -loudness switch, stereo balance control, separate bass and treble controls on each channel, a stereo selector switch providing the same .even modes of operation as the 299, a scratch filter, and a center -channel output. Circuitry is largely the same, the principal difference being the use of 613QS's instead of 7189's in the output stage. Self - bias is employed. The same kind of phase inverter is used, along with all a.c. hal ne- ing control. No means are provided for adjusting bias and i.e. I;ilance in the output stage. The operating manual for the 222 provides not only instructions and diagrams similar to those for the 299 but also has the following useful diagrams: 1. Showing the awl Wall how to con- Fig. 4. H. H. Scott Model 222 Stereo Amplifier. struct external switching facilities to crease the number of low-level inputs. 2. Showing him how to construct external switching On high-level inputs. n signal-to-noise ditiomd boost in bass or treble. facilities fur tape record - ratio of about 72 db w:a: measured, based Phono and tape equalization proved to ors that alo not disconueet the output cable on an input Of 0.5 volt at 1000 cps, suffi- be very accurate. At the high end, both from the tape amplifier in the record mode. 3. cient to drive the amplifier to rated power. were- within 1 db of the RIAA and NAB Showing him how to construct a Noise was measured with the input shorted. curves respectively. RIAA bass boost was phase reversing switch. L-31 The nuumfacturer specifies a ratio of 80 only 0.5 db below the RIAA curve at 50 db; 72 db is still very good. Excellent re- cps, while tape bass boost was only 1.5 db KOSS SP -3 STEREOPHONES sults were obtained on the magnetic inputs, below the NAB curve at 50 cps. There are Designed by the manufacturer a based on signals sufficient to drive the unit still many :amplifiers that depart sub- means for listening to two-channcI or to rated power. On RIAA phono position, stantially from the .NAB curve despite stereo programs Irinaurally, the Koss SP-3 about 7 my input was required for full their manufacturers' claims. is It a pleas- Stereophones eau be used for power output at 11100 cps, and the signal- ure to be able monitoring to report on mi amplifier, stereo recordings to considerably to-noise ratio measured 63 db. lnasnmch as the 299, that conforms accurately to stand- greater benefit. Many stereo recordings are micro - most magnetic cartridges will deliver sub- ard tape equalization and at the same time phoned so they sound .satisfactory when stantially more than 7 mv. on signal peaks, is able to maintain an excellent signal-to- reproduced binuurally, and for those in- a signal-to-noise ratio better than 63 db noise ratio, not all at easy to do Mien full stances where it is necessary or desirable can be expected. This is, however, very NAB bass boost is provided. good. On NAB tape position, the signal- to-noise ratio again measured 63 db. An Operating Manual input signal of about 8 my was required to drive the amplifier to rated power at The complexity of stereo compared with 1000 cps. Since the maximum signal de- mono equipment has heightened the im- livered by a tape head at this frequency is portance of the operating manual in as- much more likely to be around 4 my than suring proper installation und operation of 8 mv, the indicated signal-to-noise ratio for equipment. The Scott manual supplies full, tape heads is in the vicinity of 57 alb, which clear instructions and a number of helpful is still excellent. diagrams showing how to connect the vari- The master gain control provides quite ous input sources to the 299, how to con- good tracking between channels. During nect the speakers, how to use the 299 as an the first 40 db of gain reduction, the track- electronic crossover, how to place the speaking error of Channel B relative to Channel ers relative to the listener, and how to A was +2.5 db in the unit tested. Track- connect to the center channel output jack. ing error rose to 3.5 db at 45 db gain Also included are a schematic ;nul instruc- reduction and 5 db at 50 db reduction. tions for making the bias, d.r. balance, and Ideally, a rumble filter removes the ex- a.e. balance adjust lits. -11. 11. tremely low frequencies without affecting Fig. 5. Koss SP -3 Stereophones. the moderately low ones. The rumble filter in the 299 does fairly well along these lines. H. H. SCOTT 222 to listen without ali.sturbiug others the With the filter on, response at 100 cps was phones are extremely convenient. But the reduced only 2 while STEREO AMPLIFIER db, response measured real advantage of them is as a means of 5.5 db down at :ill cps and 9 db down ;it Th. 222 is ;a slightly smaller brother to monitoring stereo recordings as they are 20 cps. the 299, with the similarities greater than being made, particularly from uriero- The scratch filter is specified as having the dissimilarities. The 222 is rated at 12 phones. a cutoff frequency of 51100 cps, and meas- watts per channel instead of 17 watts, The Stereophones eousist of two head- urements bore this out. Response was down otherwise has virtually the same perform- phone units connected to a three -wire cable 3.5 dl at 5000 cps, 7.5 db at 10,0011 cps, ance specifications 299, at the and retains and plug. Each "phone" is actually a 3 - and 10 db at 15,000 cps with the filter most of the on. latter's features. inch dynamic speaker, and excellent low - The loudness switch introduces almost The 222 has one magnetic input and two frequency reiroaluction results from the as much treble boost as bass boost when high-level inputs, whereas the 299 has an close coupling between the diaphragm and level is reduced. At 30 db gain reduction, additional magnetie input, with a choice ear. Similarly, the small cones are capable bass boost reached 9 db at 50 cps and between High- and Low-level jacks. The of response up to about 15,000 cps. Im- treble boost reached 8.5 db at 10,000 cps. 222 lacks a rumble filter and a phase re- pedanee of each unit is 4 ohms, and with Further reduction in gain brought no ad- versing switch, does not have the three recorders laying two ranter amplifiers a

62 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com "The Aristocrat of stereo power amplifiers!" - HI FI REVIEW

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969.50 THE SA -300 60 -Watt Stereo Power Amplifier Music Power: 90 Watts at 0.8% Harmonic D stortion! THE FISHER In their October 1959 stereo amplifier report, the editors of HiFi Specifications Review said the following of the FISHER SA -300: "This is undoubtedly the most `sophisticated' stereo power amplifier available to the public at Guaranteed! this writing. The advertised claims of low hum and noise levels appear to in production models now on your dealers' shelves. noise less than be readily available Hum and fo:jnd of a pro- 0.00001 part of full rated This is certainly the quietest amplifier likely to be outside - output -100 db down ! fessional recording studio. The built-in `controlled -frequency -response Disiortion-free power at filter' is a quantum jump in thoughtful engineering design. It was all listening levels! especially developed to permit this amplifier to operate with electrostatic Optimum results with speakers, and may also prove immensely valuable where subsonic woofer all speakers! Wrote HiFi problems are to be encoun- Review: "Results equalled and supersonic tweeter manufacturer's highly ex- tered. All in all, the SA -300 is the Aristocrat of acting specifications." stereo power amplifiers, and is a wise investment for superlative stereophonic hi-fi." Prices Slightly Higher In The Far West WRITE TODAY FOR THE COMPLETE SA -300 STORY! FISHER RADIO CORPORATION 21-29 44TH DRIVE L. I. CITY 1, N.Y. Export: Morhan Exporting Corp.,. 458 Broadway, New York 13, N. 7.

AUDIO NOVEMBER, 1959 63

www.americanradiohistory.comAmericanRadioHistory.Com eathotivie or split -load circuit, and it is inherently balanced if the plaste and cathode resistors are of exactly equal values. .-Actually there is soute unbalance because of the capacitance between heater and cathode, but this affects only the frequency range front about 8000 cps up, and lias very little effect on listening quality. However. even though the phase sputter is perfectly lllauco,1, there may be a difference between the amplification provided by the two output tubes, .nid this (1111 nut be balanced out (in 1111y practical circuit) in the output stage itself, so users must re- sort tu tube nt;utuhiug to obtain exaet balance between tubes in the outltnt stage. The use of a variable cathode resistor in the phase sputter results in feeding different values of signal to the two output tube grills-that is, signals that are not perfectly equal in amplitude though they are exactly opposite in phase. Rut such an in- tentional change in the drive tu the output stage (tni result in extremely low over-all distortion, and in an amplifier using com- Fig. 6. Fisher Model X-101 A stereo amplifier -20 watts on each channel. paratively small tubes, it is important that every- step be taken to keep distortion to a minimum. Checking the amplifier under 3 -conductor jack eon be mounted in a con- 1 ,jaek of Channel A; the remaining two test, we found that a variation of the convenient location, with connections made to 1 cenneet to either euoxo or ttiono 2 trol (chassis mounted) from the optimum the two output transformer secondaries. .lacks of both ch;utuels for stereo use, anal position to one extreme changed the 1\I For recorders with higher output imped- provide 11A2 equalization. The mode distortion from the rated 2 per cent to as ances, adapters ore available to tuateh selector connects the output amplifiers to High as 8 per cent. The phase sputter cir- either 600 or 10,(ast ohms. either Channel A or Channel II for mono cuit, which employs one half of a 12AX7, The Stereophoues tue light and the indi- inputs, and to hoth channels for stereo and has a plate load of 100 k ohms and tu oatlt- vidual units arc troll Madded for comfort ri case -stereo positions, making it possible ode load (ousistiug of an 82 k fixed re- in wearing, even for long periods. L-32 to play mono records through both output sistor and a variable resistor of 60 k olnns. cleiiutels when desired- The tape -head input The grid resistors of the output stages are position sets tip the correct FISHER X -101A equalization for 470 k ohms. The circuit has the advantage 7,2-ip,s tapes, - STEREO AMPLIFIER while t tuna auxiliary of being inexpensive, yet capable of balanc- inputs are fed directly to the tons' -control Combining two 'uwatt power amplifiers ing the amplifier to a minimum of distor- amplifier tube sections. The AUX 2 position tion. and a complete stereo preamplifier -control has a high input impedance for use with unit into one cabinet Maximum variation of the volume-loud- always results it) an ccrantie cartridges if desired. interesting unit, and in these days of mini- uess control bet vveeu channels was muted 'l'he tube line-up in each channel is as aturization-to w-httever extent is possible at 3 db, and the toue controls were ob- follows: 12AX7 (or 7025 or 11(1'83; as shows a served as tracking within 5 (Ili throughout -it certain amount of ingenuity preaugt, with feedlett-k equalization; on the part of the the entire range. RIAA equalization manufacturer. Not that 122AX7 as tote -control amplifier; 12AX7 for it is unusual for a complete system to be phono was within 1 (lb throughout the as booster amplifier and phase .splitter; tond so compressed, but in many instances is range.ge. it two EL84's (7189 or 6111.5 as pentodes aceomptutied with such rust- and space - in the output stage. Plate power is fur- Considering the relative sintplicity of the cutting ginuuieks that the X -101A, performance nished by ;t (1231 (5AR4), with the plate together with the flexibility of may suffer as a result. This is not the case current of the four output tubes serving control operation, the over -tell design must with the Fisher X -101A, however, be for its as heater current for the two preautp tubes credited with following a system philos- performance is high up on the scale. ophy --with the double benefit of d.c. on the which is in keeping with the require- Each channel has six inputs-two for prettutp heaters and reduction of heating ments of a satisfactory-ii our opinion- phono, tiro for auxiliary devices, and one by the elimination of cathode resistors for amplifier. Among the things we believe tu each for tuner and tape b: head-making the output stages. Physically, the unit is tteeessttti iu any control amplifier are: twelve in all. Twit recorder output ,jacks a luit/s in. wide, 13 in. deep, and 413/1(i in. loudness control, separate toue controls tue provided, and a recorder -monitor .jack high in chassis fora. -Ventilated wood for each channel. and means for paralleling is furnished on Channel A for use with cabinets are an-ailttble. the output sections to either input section. monophonic tape recorders equipped with The Fisher X -101A has all these. feed -through circuitry. These connections Quality of construction on the unit tire ahead of both Performance volume -loudness und tested was tip to usual Fisher standards. toue controls. Output 4, 8, impedances of Specifications for the X- litil call for un While the lexibility of the unit is not as tond 16 ohms are provided on both 20 channels output of watts per channel it a rated great as with the Model 400, which is a for Loudspeakers. There are two level -set hrirutouie distortion of 0.; per cent taud an preautp-control unit only, it (mind hardly controls ou each channel-one in the Aux- iM distortion of 2 per veut, with the usual be expected. We would still like to see a 1 circuit, and one following the preampli- 20-20,0110 cps flat frequency response. phase -reversing switclt in the speaker rim - fier section to control phono and tape -head Measurements indicated ;in output of 21 cuit, and we believe sonie provision should inputs. The normal operating controls are: watts on one channel and 23 on the other be made to (Mange the tape -head equaliza- input selector. anode selector. balance, vol - 1 at per cent harmonic distortion. Inter- tion as needed for the common tape speeds nine -loudness eouubiuetl with the a.r. power modulation measurements were in tweord- man sud Ti., The X -101A is still a fine switch, dual bas and treble toue controls, tince with specifications. 8in(e the pclutse- unit, however, and it is not likely- that the rumble and switch, loudness contour switch. splitter circuit of each channel is provided individual iv Ito buys Fisher equipment The input -selector switch has tour posi- with a means of adjusting the drive to the would be satisfied with 3a/ -ils tape any- tions fo' magnetic phono cartridges-two output tube grids, any minor differences in how, so that is not too nitwit of a problem. for monophonic and two for stereo use. the amplification of the output tubes ritti As to the phasing switch, it could he The first two provide equalization for 78 heu compensated readily. The type of phase mounted elsewhere in the system-ecru on and LP curves, and connect to the iriioxo splitter is that eouunonly known as the one of the speakers. L-33

64 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 65

www.americanradiohistory.comAmericanRadioHistory.Com EDWARD TATNALL CANBYIi

VOICES t 'cutely high, aloi scent sounding, and to- little birds will sound pretty much alike to the gether with a baugy piano, some Stephen Foster Song Book. Robert high -power beginner, but there are always the big ones Shaw percussion and a runthly, juicy organ, they and the odd -ball fowl to keep you interested. Chorale. (Includes "Play -It -Yourself" crut get superb effects. Ti'-y last band, side 1. I;aad stuff and unique. booklet.) RCA Victor LSC 2295 stereo Voices from the Vienna Woods. Boys Moussorgsky Mélodies-enregistrement R('A's heady extravaganzas continue and Choir of Vienna. intégrale. Boris Christoff, assorted pfs., this one turns out to be a beauty, though the Omega OSL 28 stereo orch. "Do -It -Yourself" aspect is pretty feeble as a This bas been hanging :wound for months- Angel 3575 D; LX (4) ginotii -k. It's the record that counts and any- haven't had a chance to mention it, but I've thing you is, extra have to pay is well worth it. enjoyed the sweet. sealintentat, typically Vien- For lover's of Russian music this an in- Sure, everybody knows Stephen Foster. But teresting specialty. As indicated by the album what nese boys' singing a good many times. The cones through clearly- in these Foster music is mostly traceable back to Beethoven, title, it conies from France, where a good arrangements is Foster's by -now almost classi- Strauss, Schubert, Haydn, Mozart-but never many of the recordings evidently were made. cal purity of melody. The man was certainly a forget that in Austria you need merely men- These are all the loose \lomssnrgshy songs, in- first rate musician and at marvelous composer tion one of these gentry and tears well up in cluding a few with to -chest ra-they cun.si itute of fine tunes, perhaps in the Schubert class- the eyes of the lowliest peasant. Beethoven a pretty big dose for one-time listening and if Schubert had been born in 19th century and Schubert aren't highbrow. over there, you so you will want this album as a long-range America, is to be a or Foster in Vienna. It clear, I'd see. Thus- the Big Nantes on this record ooze pleasure, absorbed a bit at time. say, that an accident of circumstance led nut in the corniest style you could ask for- Christoff is good- --nn two ways about it. IIe Foster to compose only that which his back- has the right sort of big- mobile basso -baritone ground Austrian corn, of course-and there isn't so experience and training made possible much as a trace of long hair and high brow to voice to put Russian style into Moussorgsky ; -and into these songs. so limited in outward be heard. he knows the tradition to u T and is thor- scope, he put what it takes to be a really fine Jus' lovely, and beautiful in stereo, too. Try oughly at home in at medium that is all style- musician. it on your own tear glands. the songs are impossible to sing for voices What Robert Shaw and his e olleagues have trained up in a different tradition. Ile acts, done here is to treat Foster melodies with a as he sings-he bellows. grunts, heaves, sighs, classic restraint, relying on the simplest of Gilbert and Sullivan: The Pirates of Pen- groans-and this is utterly right. Ile hits per- harmonies in line with those that Foster would zance. D'Oyly Carte Opera Co. New Sym- fectly that garish, deep-Rmmuntic nightmare himself have understood, avoiding the modern phony Orch, Godfrey. quality that is the most dramatic aspect of tendency to dress up the straightforward London late -19t1í century Russian nau.siu and in par- tonnes with fancy barber shop or jazzy (rag- OSA 1202 (2) stereo ticular of Moussorgsky himself. time) coloration. I don't mean that these Shaw Here's another continuing series and I note Best of all, Christoff has an excellent ear settings are dry --they're as schmaltzy as you this recording as one of many-probably all and grasps every nuance of illoussorgsky's could wish and some of them get pretty com- of the G & S operas, sooner or latter. Note, too, often tricky harmony and tortured melody. plicated, too. But the sentiment is strictly in that there is a parallel series from England Because of this, he is able to project the line with the style of the tuelody-diatonic being issued on Angel, by the Glyndebourne grunts and the groans, the half-spoken pas- (scale -wise) harmonies for diatonic tunes; the Operas company: take sty- respectful word for sages, without ever losing the thread of musi- :otnewhnt highbrow sound of the whole actu- it that London's original D'Oyly Carte group cal line. Lesser singers make hash of it all too ally serves to bring out the siutitle beauty of is far, fair ahead in the gauze, as it has been often. the Foster songs on their own --where more for so long. They have the tradition. the style, Otte oddity-the fatuous series of Nursery zippy arrangements merely make them sound the attitude. the type of voici', that makes songs, sung in the first person by a little boy old-fatshioncd. G & S living satire rather than half-dead mostly to his nurse, are doue by Christoff en- Most of this is choral singing, with as- Victorianism. Nobody else has it quite so good. tirely in a thin, nasal semi -falsetto. Sounds a sorted solo voices intermingled ; parts are '''his one is particularly nice in stereo, what bit silly at first, but very possibly titis is the male -voice. as scents tippreipriate: the faster with the various "outdoor- scenes where proper Russian tradition, at least for a male items-"Doodah!" and the like --are touched pirates, policemen and assoried ladies are voice. I found it a bit hard to take and, per- up with a bit of banjo, just enough to keep prowling around hunting each other. Wonder- sonally, I find Jennie Tourel's soprano-voice things in perspective. Words are words and ful effects. I liked particularly the monologue approach more effective as music. But what is Foster is foster: if you don't like my de- "asides" of the male chorus. in the midst of a huge basso to do when he's supposed to act scription. try- the record and judge for your- all this. Very imaginative use of the stereo the part of a live -year -old? Mighty precocious self. You'll be bound to enjoy it unless your recording medium- English Rocca (London) little lad it would be, who could sing in a Musical auistoc:act or something. has a good edge on everybody else in this re- Christoff's natural basso! As for the Gimmick. a pretty booklet with spect, I'd say. litr had when this album was arrangements of the saute songs (for piano 'wade.) Keep your eye peeled and your purse Purcell: Welcome to all the Pleasures and voice) by Skitch Henderson, it's good propped op, n for any and all future IO)vly (Ode on St. Cecilia's e st.r Day, 1683). Blow: looking. decorative, but otherwise v.ry poor - tirí. second -best Foster. The sketchy atrangeun titer Ode of the Death of Henry Purcell (1695). (no pun intended) altogether lack the sly Voices of Afaican Birds. Recorded and Alfred Deller, John Whitworth, April Can - Of. the recorded settings and, silly idea. ,'lilt Narrated by Myles E. W. North. telo et al., Kalmar of the first verse of each song is printed! Ilnw't Orch. London. heck are you to do it yourself if you don't Cornell Univ. Records Vanguard BGS 3015 stereo ( 111 Roberts I'1.. Ithaca, N. Y.) have the other verses? '''here is probably no music more iuuuedi- a new slant to the notable Cornell atoly strange to the average modern ear than Gospel Songs. The Grace Gospel Singers, sri of bird song records; the birds are from that of Purcell. out of the 17th century: and piano organ, tambourin, traps. - u u ri- cuttiment, to begin with, :íín1 the no type of voice is more startling. too, than su -r rte -r is no longcr the familiar, slow-paced the male alto or countertenor-of which Rondo-lette SA 115 stereo there I tr. A. A. Allen, whose dry, sentimental bits are two in this recording. But Purcell doesn't Not so bald. The seven young negro irl- i-uoni and fact have g_ven continuity to la he long to get through to most of us-he (l'ut looking at their picture) have collective tuest i'1 1110 earlier Cornell offerings. Ile starts was one Of the world's true top musical gen- pretentions to higher things- hey've had tits one off, lint bows out in favor of the main iuses-and the countertenor soon loses his Training, or some of theta have. and they look from Africa, who sounds just like his name. oddity and becomes another mus`.catl instru- like a good bet for TV ur Drondtcay or some- Very British, with a .strait;,' outlander touch, ment, particularly- e'l'ective in music such as thing; but Mother Nature and good old Reli- ttua' you get used to the Senior District this where he was originally the proper per- gion win out here: though there are some Cotuuissioter's voice-be is Commissioner for former. Purcell himself was a countertenor. fancy high notes, some styled -up endings. all of Kenya --and his somewhat discuisive Ir strikes me than this is Alfred Deller's mostly the girls just can't help Iettin' go. And background accounts, you'll find the bird finest countertenor .singing to date, in Van- what a sound! Mostly. their voices are ex- sounds fascinating. Even an ordinary tyro guard's long series of 'teller recordings. His like me can till in a moment that these are voice in both of these works is stronger, * 780 Grcrtne'ieli SI., New York 74, N.Y. no yankee bird calls. As always. a lot of the steadier, better controlled than I remember

66 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 67

www.americanradiohistory.comAmericanRadioHistory.Com him in the past : !het(' are fewer yawps, less the Japanese(?) original. So it goes for a nearer to the original sounds than the fl(ssied- semi -femininity. ti ore of the human -oboe tvhole LI' side, and subjects range over the mp and thickened symphonic versions su quality that is so superbly- effective in the eternals, such as clouds in a blue sky and Widely used ill past terntorb, produeth music. He is particul:nly good, balanced by what -not, All in all, though this is a "conventional" Mr. \vhitwortl:'s similar but slightly lower Side 2 tSeurn) is outwardly the same, but big -scale Mandel effort :uul will not particu- coent'rtenor vole,, in the plow piece. the English poi-ns-iï they are poems-consist larly' pi- :Ise the musicologists. it does decid- There never was a more exquisite exact of half-sentcuees. mostly beginning with a edly bent -tit froml these new-fangled restora- musical ear than Deller's, there is no living present participle, left dangling. To para- tions of old practice, and yon will find the voice. to my knowledge. more perfectly suited phrase, I could fabricate (luo of these myself : music quite reut:ukatbly- accessible in the list- to the strange, sensuous, highly ornamented 'Sitting in a choir, the cloud,: parted." No, ening. _A booklet with comment, story, 11 Purcell melody than his. the clouds didn't sit in the chair: you are left worths is helpful. The "St. Cecilia" Ode is an early one, not with :t feeling that maybe the poet sitt in the the more familiar Ode recorded elsewhere. chair and . . well, anyhow', that's the way (Yang. 116559) It is on a nosiest scale. has it goes, and the side 2 subject magi --r has a gorgeous moments including the inevitable distinctly modern ring to it as well as a sa- Bach: Arias for Voices and Instruments. long aria on a ground bass. a pa.ssauaglia if tirical and even rather crude touch, ill a high- Bach Aria Group, Wm. S:heide. you wish-this ono strongly suggesting the brow sort of way. Things are mentioned that Decca DL 79405 stereo great lament in "I lido tool Aeneas" that was are not always considered proper in con- the first of Purcell's works to beconw world- ventional western society, though maybe in This is a if slightly zooi,. If famous in modern times. Blow's music in this new world they are felt differently. you can ima_iue old Ilerr Rack dress..I up memory of Purcell, who died young, is much What is all this gibberish about-urine in- with a Frcttclu beret on fop of his long wig, less colorful in melody and harmony but sticks cluded? Heaven knows-but 3hr. Watts is a maybe an opera Iie .jerkin or sOhtti'I ti big 'round to the same general styee of expression, en- well known leader of the new' East-West about his 01141)114' and a faded pair of blue tirely "pre-iiandelian", still very mulch the thinking, and I) great many intelligent Ameri- ,leans (u the lower extreutities, you'll have an pure English music that developed out of the cans are dabbling in Zen quite seriously these idea of the utter mixture of performance French Lully and the Italian Monteverdi. days- -it is a form of Buddhist thinking not in styles that are combined by these well kmow' If Blow seems at first less exciting, less luny mind clearly either philosophy, religion, of concert soloists. joined for "chamber music" colorful, we must take account of two reasons. aesthetics but a sort of elemental blend of in concert form : First. he was a less -great composer, though an all of theta. They ahi sing and play effectively, lout they excellent one. (An older man than Purcell, he Don't by-pass matters like this too quickly. might as well be speaking different musical outlived him by many yeas. as 111)31ín did The present:lti.uu, like most new-fangled move- languages. It isn't a urntter of "wrong" style Mozart, influenced and was inluenced in turn, ments, is self-conscious and almost deliberately this is simply It jumble of utterly unrelated as was Haydn.) Second. we have to keep in arty, or oliquey. lint the new movement. like styles. all bmucheel happily together; anti ap- mind that Blow wrote his Ode in the period the beat movement in general. may well be parently the performers don't have the faint- just before ilandel, when Purcell's land g) tying towards a very- genuine need in our est idea that blue ,leans don't go with . Monteverdi's) oarlicr, more colorful experi- hand -boiled, Madison Avenue culture. A need well, that, say, ]sigh -Italian opera singing ments in harmony and melody were already for all of us. even engineers, though maybe isn't suited It, a cottttmplalive Bach aria, nor considered out of style, crude, undesirable. ono aren't yet quite as positively aware of it is Schubert -like piano playing, however beauti- Blow wrote mere neutral non sic-for our ears: as Mr. Watts is. ful, a proper accompaniment for the same. but for his own time, it was modern, tasteful If you enjoy b:ug;ng into new' things so This is typical .\nieric:ut, alas. \\'hen will and more "advanced" than Purcell's. to sneak. hindside t'ormost, just for the heck we ever develop a pcc'tst'utlulq sense of style? You can't blame the man. And you can re- of it, you'll maybe want to try this disc. When will our artists get away from the idea flect that the slitti)' thing happened to Shakes- There's an earlier one that might be more that each and rrery 4'(e ..f them taut perform peare's style in the saute period and on into helpful called "hail:0" (31EA 1,1' 1001) that anything, iu :Illy style, nationality tar period? the 18th century. Ile w'as considered uncouth they didn't bother to send me; it "explains it all '0111es from the typical diverse Anueri- and crude; his stories were often re -written in the relation of 'Len Buddhism to Japanese cat musical training and heritage, without what seems to us a far more monotonous and ime;t-v'-Alan Watts does, I should say, any clear "classical" style amt tradition of colorless style --but which to the 18th century \laybe he also explains the relation of Alan its own. wised and borrowed from every part represented modern progress and sophistica- Watts to Zen and, incidentally, to Sumire of that European world of music that is ours tion. Hasegawa Jacults. The Director of these re- as well as Europe's. Our big musicians simply The Blow, by the way, is composed for two cordings, in th's connection, is named henry go their own way 115 a mater of course, feel - altos (countertenors) and two recorders, a Jacobs. \light be a clue. hug no stylistic pain at all. combination that is ruthless in the extreme Yes- many an "aumheilic" performance is in generating natural interntodulation tones. Handel: Judas Maccabeus. Utah Sym- musically dull and pedantic; this recording Is The two voices produce violent beats; the re- phony, anything but dull and generally It is very corders generate even stronger ones. Van- Univ. of Utah Chorus, soloists, magical. Rut Vow(' day, we'll learn to pick and guard's recording is good but my pickup had Abravanel. choos4' (1111. :ntistic ensevultles for over-all styl- it bit of trouble here and there, coping with Westminster WST 301 (3) steles istic blend ttit i npliluJe, the way We pick our these extraordinarily tough wave fronts. It's Rosiness ;Ind engineering and scientific eunt- hard to tell in such situations whether the This is another ill the current Ptah series utittees in line with the purpose in view. more audible h:1.. .z sounds are electrical dif- of Mandel worts, following upon last year's You'll hear big tastes all right, here-Eileen ference -tones or I')rt of the acoustical original. "Israel in Egypt." The two lure so different Farrell. Jan l'eerce, Paul I-lanowsl:y, Julius that a direct comparison Interesting. is perhaps beside the Itaker:m(1 Ste on. :They're all goo)1, and so their point : 1 can rattly say that I enjoyed this re- leach is good, too, even if it is very unauth- cording more Ilia n "Israel" and think that it Zen & Senryu. Alan Watts, Sumire Hase- entic (and generally wrong. I think) to eradle- is generally a b4'ttcr job, perhaps simply be- snatch any liaelu aria ual of its proper con- gawa Jacobs. Music by Vincent Delgado. cause is it more suited to the particular ag- text, where it belongs as part of a larger work. MEA LP 1002 gregation of performers on hand. The micro- Lots of pros and lots of eons here, and you (Maxim! Engineering .1.cxociates phone treatment is definitely better in some can't (lodge any of them. Ifo.r 303, Nnnnvtlit0, Calif.) respecta-notably the placement of the solo singers, who in "Israel'' pr:tctically breathed They throw things like this out at you and dorm your neck, incongruously. here they are you're supposed to know what it's all about. mostly at a distance and in modest volume, ETCETERA If you don't (and how many record reviewers more nearly in musical balance with the rest do?) then more foul you. Nevertheless, I of the ensemble. (But the harllsi,hord con- Prokofieff: Symphony #5; Symphony #7. found the exploration of this cryptic (for lie) tinuo is now unnaturally close for sod' a Paris Conservatory Orch., Martinon. disc quite interesting -1 was able to i1 it to situation.) some extent into what I'd vaguely lu-aol as to This University c'hor'us is indefatigably en- RCA Victor LSC 2272, LSC 2288, stereo the goings-on among the advanced young t hush' stio and its singers' interest in the music l'Inse 1W,) separate but complementary re- people these days, beatniks and all. is qui,I;ly- passed on to ils as listeners. The cordings are part of an interesting R('A Vic- What do you hear? No explanation of any- group is a fine "instrument- and only a more tor import series from Prance, with a french thing, of course, neither on the disc nor on disciplined sense for good phrasing and conductor. and I'mt all for this variety in the jacket, which merely gives sources fur rhythm is missing, the conductor's fault. The basic its'.\ fare. These are charaeteristically what is spoken. A jangle of oriental strings solos improve upon the standard oratorio French performances. all-out, with bout the then an American male voice with a slightly style, singing with the expected big solo voices strengths and weaknesses of the breed. British accent reads a poem. Not a long but with more animation and better musical The weaknesses arc utterly unimportant, to poem-mlerely a few words. Jangle again, fol- and text sense than is 0 0 111111 0 11 in American my ear anyhow for instance a nasal, slightly lowed by a high, intense sereetch of foreign productions of this sort. out -of -tune tone quality, especially in the we language. This should be, suppose, the lady Indeed, this recording is a rather nice illus- winds. Some people will say that this is a named Sumire Hasegawa ,Jacobs, who clearly tration of the iunpaet upon the old-line, mas- student orchestra and you can't expect it to Tier must have married outside the family. sive, heavyweight oratorio performance now play in tune; t tend to think, from long list- presentation is interesting but quite obviously being made by "authenticity" the big fuss ening experience. that this is a French quirk unintelligible if you don't know the !anguage (ver the return to the "original" ways of do- of happens too often. The French is style-it which, I'll hazard a guess. just possibly ing things. We still have here a huge chorus just 41om't mind a few "beans" here and there, ,Japanese. II honestly would not know from and a big orchestra, plus "big" soloists of between two or our,. instruments playing to be i first hand experience, though sure have characteristic modern voice -types. But we also slightly different pitches. A nice effect, in the heard a reasonable amount of Japanese fur an have a harpsichord -tend -cello continuo accom- proper c ireumstunces, timid I agree with them oldster antidatiug the present U.S.-Japanese paniment, restored to life according to the -I like it. I also enjoy that loud, forward cultural rapproachement.) The lady finishes original Eighteenth Century practice (and woodwind suied that is uniquely French, in tt breath . pause-then another male - over -amplified in the recordings. as above men- voice poem in English, more jangles, more of tioned) : we have simpler orchestration, nn1(.h (Continued on page 100)

68 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 69

www.americanradiohistory.comAmericanRadioHistory.Com I iar, and You lie l a Line acrd I'll Net 3 l'oh>. .\ former Mendier of :t 31aItalia .Jacksoui gospel belie. he includes a powerful reauliug of City /'idled IIrnrrtt. Ills ''neeptjot' of Ninintle /Tail, the ode Billy lloliday made famous, differs considerably front hers in ils masculinity. :nul the theme is amplified ou t'hnit, kung. and l'rison 11 -nil Rlurx, Mliekt'v Raker, a guitarist who marl,- his reputation in the popular field. is autoug the accompanying /owes of Erntst haves, Ilayw'uod Henry. 1,10v,l 'l'rotamu amt I'auaua Francis. Any lapses nu his nil I-1 :il',' vonipensated by his work on I/ru'tlut l:lrrr.v, where ht approaches the agonized oufury of Entier t Johnson, who was without p''e'r 11 Wong blues gttittu'ists. The sound on prey ions \':utguard and London re- rordiugs made Sellers luckier than /Host of his rnufreres, and his good fortune continues here un.ler the supervisinu tuf I(ati' Il:uuuck.

Count Basie: One More Time Roulette SR52024 CHARLES A. ROBERTSON* Thad Jones: Motor City Scene United Artists UA55025

i tait the deeper fluid' of the blues. Ills STEREOPHONIC .\nwug the pre:deuas besetting :1 h'_ trumpet echoes the yearning lament of a Imlay is the uecessily of pia ying fur dauo.ers Mahalia Jackson: Great Up Morn- Libby Holman ou /'rt d,lir Eret t PM(' f"1", where Gettin' in a spaclous ballroom out week, and then \\yutuu sits in its pianist. ing Columbia CS8153 Iíelly -.fier Evans enlettaMing the wore sednto inlu;rt es of a st iltrs an intern:I inua1 note on the liner by supper t/ainey Nat Cole: Every Time I Feel The Spirit hotel club the next, ,Tones, eon. paring' This t>pr of iuipruv kill ion tu a lc It,, is cool idol iug plans fit!' a band of his Capitol SW 1249 mend,- o1' ,tit seen,- ones.. painting. the shifts nwu, shows :III ,nytueness of this .sit tint ion to Prato,-,- :nul Spain on -I1/ and Victory Baptist Choir: Sunday Meeting /:lors. Flu- Ilan should stand him in good stead when he teearr, .cuti trhrst, Those. patrons of sitntttler Warner Bros. WS1270 heads out off fhe rood as a leader. In filling festivals who felt slighted because Davis a commis .iou from (.01 111( Earle, ho delivers "Thai the immense of neglected vitality sited singing to auuonnce his numbers may tance Ill' Conti usitiuns which exploit ill turn ear.. and its inereasiig effect on popular music some. consolation in the filet that lie seems fully graduated section work or the full voice have become et:u:illy forces able to attract the nt- diflidett Iovvard Culinubia, 'l'hese Iwo of the band. II' the emphasis is on the polished lentinu of the larger companies is d lesion - tilles, tire' ou tit least, revers,d the label. iut'ee!iun. remember where Basle is working. str:tted by Hies:. Upon recordings. Columbia has sorting then) out. you \vill find tenor these days and be happy the hilts are being tiered Ibe ea reef. of sa furl \lahalia .lacksott in an Nisi .lohn felt r:itie nobly shouldering the paid. Solos by Pittill: Wess, Tillie, and Joe attractive series, 11111 is her the sorrows of :1 ont', presenting for I{ttcquel Metier ou /ulule Newman, Playing muted trumpet, tit the sub- first time, amazingly enough, in the rnntpauy Ilttcis extracts Ilid. Ityptinlit. lust ensily of on dued textures well, :1141 \I:ushttll Royal's alto of :t gospel choir. Ilor precious choral support Edith the swirl a bal Piaf front of ntnxeth' sax is suitably melting on 7'/re Jl Willi' c 1111 was drafted bent more worldly on the other. 'l'he groups and meuliers of the rin'tlttn .\-err, s'rl.a. 'l'he lender's Matto encourages a sang from arrangements. It seems likely that section are well riblted in stereo. list hearty unison shout on Rat Racy. and -1/ att. her attcmhtuce at .Toe Bost ii-s niaraihou l'i:af ni/it's di I opportn11ity to Prolong this gospel sing Square Garden. tinned, sending on a at Madison last ttong 1'apilol dozen songs .loues, joined by Spr'itng, resulted in the selection of the recorded Yogis. ttill l'had mostly former De- lively ill stauding are The truiters, salutes his native city at the head corps of songsters assembled around her. As Crowd, her last e;tsn11's hcstseller in France, of :I sestet. Ills fellows in the front with Mildred Falls, her regular Pianist, their tutu Until the t: mi of 'I'iulr, one of four prepay line, however. :ne ills,, Bnsieites usually tus- assigned task is to anticipate the numbers seletted front score of singer's the the flint .ociatrQ as soluisls with the driving side of every clian_e of tempo and expression. while Les -1 retools de ltrtunin. There is no stereo to the band. liven a ,-have,' lo stretch out on she molds an impassinntd panegyric. The divide ber nititt,\ odd pounds, but voie,- iter four themes provided hy .pones, they demon- same kind of improvisation is eommon is imw'erfnl entesah to extend group to lite utmost strate. the finer points eif interplay and to jazz, hot no jazz singer alive call tut orchestra condneled Robert group Match by Chauvigny. an ability to curate uuauees of their own. Miss .1m l:stta's singing of 1 l'r,oats the .1 tisi,'rr, Jones alternates between cornet and tlnegel or God Put a Kninhoti' in the .sky, 'l'he gait:n Brownie McGhee And Sonny Terry: Pick hot u, lülly Tiitehell solos fluently on playing of .Iiulnty It:tney is exceptional, and while tenor sax, Trombonist .\1 Grey, an interloper the stereo picture is well proportioned. A Bale Of Cotton Janus Stereo FST2012 from \'irginita, splines on both sets, meander- Sat Cole makes no effort to equal this in- Brother John Sellers: Big Boat Up The ing a toothaouo blues tensity of feeling but his voice carries more through for River Monitor Stereo MPS6002 'Pommy Flanagan, Paul Chambers and Elvin sincerity and conviction than even he imparts ,Jones comprise the rhythm section, tuid stereo to a ballad. his ambitions wore to Country (dues 'ingiug a 1.11 prin. ;lit c re- If soar to centers soloists nicely. greater heights, the arrangements and con- cording techniques kept such steady company the ducting of Gordon Jenkins would keep hint at one time that the terms seemed almost earthbound. 'I'M. choir of Chicago's first sy nunymous. Of recent years they drifted Charles Mingus Jazz Workshop: Jazz Church of Deliver:anco, whose pastor the Rev, apart and on these two stereo discs the divorce is Portraits United Artists UAS5036 Ralph God dpasten1. wrote tt song on Tliss coinplet'. There. is a simple gr.. Mien r to Jtackson's program, To 1/c It's Fu 11'ottdcrfal, hhe art of Itrowui,' McGhee and Sonny 'ferry Most of the hazards of recording before a helps out admirably on a dozen older spirit- w -hielt the iliadequtte suaud t.1 twenty years lice mullein, ;tre overcuuie is I his concert by uals, giving each an appropriate gospel beat. ago failed to rnuceah and records made when the Charles Tlinges Jazz \Vorlesleoli at the The Victory Baptist Choir of Los Angeles they first met are still prized. Their consistent Nonagon .\rt Gallery. where it series of .Tazz was recorded ou lolat itt and consists of two admirers may easily possess several yersious Profiles brightened tee New York season last hundred voices, with stereo allowing ample of the dozen songs Olt the r1111.1lnt program. winter. Rather ha it follow the custuui of host of folk room for all, .1 typical church meeting in- these enthusiasts have heard the presenting assorted tu'tis's, vault program pair in convert :utti cludes a short sermon by the Rev. .Arthur are aware of how much is focused on t1 single group. in this instant... clang on Peters, traditional hymns, and recent com- la nenntlthouie records. 'rimy will be oii,' whose leader feels his hesi work is done positions by Itoberta Martin delighted to litd the guitar and lead voice of outside a studio. 'faking op the slunk ,':rased and Virginia Met:lire Davis. each selection to a on one channel. while 'ferry fills out by Ile need to hind to substitute pianist at Shepherding mov- other ing climax is an inspired org:nnist, with the with harmonica and vocal ibligattos. the last minute, which has Itichtud \Vyands elements in his playing thin could only come Stereo placement duplicates exactly like posi- silting in for Boren, Pierian, may also have. tions assumed on :and from knowledge of a riv.rhoal 'tillio1e. the sl age the 111uault placed hint on his mettle. Whatever the reason, of separation is just right for a lifelike per- Mingus has never recorded to greater advan- formance. Late comers clot find uo better Miles Davis: Kind Of Blue in- tage and his bass playing is nothing short of troduction to the title song, lrn red ad I/ole, spertarul:n. As the sole accompanist for John Columbia CS8163 flu sr a Kurkttx 'l'r,rt nib t, and It'ru'rled Life Il:uuly, alto sax, ;it the beginning of I ('utt'! Edith Piaf: Piaf! Capitol T10210 mono It rs. 'l'he titles on the $econd side :Ili' nil - Get ,storied. he weaves guitar and bass figures printed rather aimlessly on the label and together so expertly that an impression of _A vent:mnt:1i touch flavor: this apitearanoe liner, being played at once is con- of a revamped Miles Davis Sextet, which can two instruments Brother John Sellers. by runaparison a more veyed, Beeause of his extreme facility and now boast of the presence of pianist Bill contemporary singer, begins with the country dramatic use of a strumming effect, at times Evans, plus a new drummer in ,Jimmy Cobb, blues and brandies out in several directions. Mingus setuta lie plucking a lingo Whether the increased subtlety and finesse With the hacking of an instrumental quintet, to guitar. Besides a full bass tone, be obtains sounds are due to these additions or to the nature he endeavors to relate each number to his of the leader's five originals must be left to ex lerienee in ti context ranging from spirited which other musicians can accomplish only the future to determine, for his thence here ha elelaps on Huddle Ledbettee's 1I'ß r, 111"ax through tleutruni,' aids. is the azure plaint of the torah singer rather n I,iI le Rep, to the rhythm and blurs impetus Out .No l'rirate Income Blues, fervid ex- given 7'rortlth' is a il' on, an. Boyhood nteno- changes between Handy and tenor saxist * 732. The Parkway, Mamaroneck, N. P. ries fill the title tune, )l'atrrvurluu on the Booker Ervin build to H shatter... climax.

70 AUDIO NOVEMBER, 1959

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AUDIO NOVEMBER, 1959 71

www.americanradiohistory.comAmericanRadioHistory.Com 'l'wo other out posts inns by Mingus are the suuntl.reviltilized uu l'lu itvrgu Li t n/11o4tru, and result of his scoring for Rlnuluwx, a film pro- K. ant uif. A studio. rather than the New CONFIDENTIAL duced by John i'assa vi -lis. Handy's playing York bistro where Murphy recently appeared, makes his recording debut something of an is the scene of the recording. evert. and drummer liauuie Richmond's use ilex Stewart and Dickie. \Veils collaborate of linger cymbals is :I IliiiI- The engineering on ti dozen ut' the light. swinging eonversa- INFORMATION by ]holy Van Gelder has depth and presence. ttuns so popular in clubs tif this type. With with emphasis on the fttl, scope of the bass each tissiglied a channel, Ilu stereo interplay flights. The room is adequate for the group is pretty well described by the leadoff tune, Not so long ago the mahatmas of hi fi and holds all attentive and inintrusive au- Little die Echo, although the responses are were solemnly treuchiug anent loud- dience. rottradirtury on (t luit itt' it Little Kixs, 117 ill speaker enclosures that "the bigger the lui, hour. St u'svunI reivases Inured st atenletits six, the better the sound." Since the un cornet. drawing replies from the trom- Duke Ellington: At The Bal advent if stereo, this catch -phrase is no Masque bonist that range anywhere hunt exclamatory longer heard. The reason. obviously, is Columbia CS8098 disclaimer to soothing assurance. A rhythm purely iouunerchit. The monaural nruket Shorty Rogers: The Wizard Of Oz section of John Brunch. Leonard c:askit and was Charlie Alasterpaolui able to swallow one big box. lint the RCA Victor LSP1997 encourage the spirited stereo market couldn't swallow two. runletnking on S e . Tnyctitcr, and These eshibilion bouts feature two heavy- 'Trou- Ile turc hall tu flu houri. Since necessity is the mother of in- weight vention, leaders and arrangers trying out their this situation created a galaxy fanciest footwork on ,unir lightweight nnt- of new geniuses. Jerry Shard: Vibe -Rations ')'hough they had never Irrial. -At etgagrunvit at the Poll Masque, thought of it before stereo. or even said situated in the .Amerle:Inar Hotel at Miami Urania Stereo USD2023 be it couldn't lento. there suddenly ap- Urach. prompted Luke Ellington to bring lais Joe Glover: That Ragtime Sound! peared a rash of small hoses. even piano tu the fore in interludes styled after Epic Stereo BN536 "shell' -size." all with the most astonish- Carmen l';nalier°. \\'hen the rest of the hand ing attributes. They were "even better" recovered its equililuiion. the response was A hit of ragtime. swing and a number of than their big brothers. .\ctnally. they in kind lavish with expression :lint copias stereo ideas are cheerfully combined on these were nothing tube, titan smaller versions ill hnuor. Clark 'ferry, trumpet. and tenor items. .Jerry Shard and his trio piny in a of the same old bass -reflexes and folded - saxist fool (iult7.atlVis huff tun) pull' on Who's room till Broadway, tutti' calletl the l'iradilly horns with their inevitable boom and .I /raid tif I/t' di/t /und o11i' to blow it into Circus purr that has featured a smooth, inti- distortion. swinging shape. in Itotrke/t ,S'e rt. rndt, i/nentin mate type of swing shoe .\tlrian itulliti intro- .1aclison's solo, duced it there in the guys, As the Itollini Some time before this stereo -forced Iromlont soulfully shaded stilb lilituger mute, formula is still going strong. Shard adheres miniaturization. an entirely new. defini- will stop any of the 1'our- ltgged lu it closely. unhtili ,us vibes or a tive and compact loudspeaker enclosure friends in its trades. AVitte the piano playing centered in stereo, the tart continents of the tuneful set of Alines. In stereo, they are was invented . all invention such of band around it spotlighted between hill Suyker's guitar and outstanding novelty and merit that are especially cogent. Siam, 7'n/rr..,: n Iloliihi . as prodded ley Dirk Itunutt9's bass. and the arrangements are fifteen claims ill that were asked along Harry i':rney's baritone sax, is a tightened tip to permit a total of fifteen tunes. were allowed ley the otflce. treat for any Patent sound system. Joe ):lover, who was pianist with Milt Equally valnalble foreign patents were Shorty Rogers Shaw and his Iletroiters back in the 11's. also grliadult. 'l'he principle was likes the score Darold .Arlenwrote in- allots four tunes to a big hand wills twee genious. logical and scient ilic. anti should wrotefor the .Judy Garland filth because of its "cute, merry pianos. then assigns a single pianisi to quar- appeal al tttce to attyotv who has per- quality," and designs his swtiugs necurelitgly. flee tet or small band on four ltmtibers emrh. Must reptto enough to grasp the idea. an Aflo-Cuban overture lu hrgiu the safari, he shifts the effective in stereo is the larger group, with The best loudspeaker enclosure is. burden between large and small units within pianists Iry Brodsky and \lilt Kraus tilling obviously. the totally enclosed cabinet the bald. creating effects that are well real- bout channels ten /,iltic Knrk (elttirn//, black Because it is entirely central autl neither ized in stereo on LC/ 'x frill in Lori'. and Litre and 1174 it. . and Lon -r4 11444n Kay/. Most re- adds to. nor takes from. her perform- Ilona The. II'ifelt ix head. fete dolly's piano warding musically is the septet. with drum- ance. Unfortunately. it ntnsl be large sparkles uu Orer llie /titittbnu, and the as- mer Ch;uiucry Jlurehnnse helping out Charlie Shavers. trumpet. and (_p ruble feet I or the enclosed air acts sembled triants include Barney Kessel, Bud clarinetist .Bonny i.y- as a cushion tiptoe cone movement. Shank, Larry Bunker. Jimmy Giuffre moi Mel tell on r,4 ',lino shout, and llurrirnIle 'My. thereby impairing reproduction.lt. í.e \yis. Fire other Arlen songs serve as all Bradford (Battle, by its patented pressure ruron,. Boll' discs :Up easy In ti tree to, anti Franck Pourcel: Viennese Waltzes In relief valve. eliminates would make excellent presents for recent this air pres- Stereo Capitol sure, and can. therefore. be made cont- graduates of rouf: and roll. ST10214 poet . only a few itches larger than The Melachrino Strings: Rendezvous In the speaker itself . . wwittout sacrific- Rome RCA Victor LSP1955 ing any of the performance values in- Dave Brubeck: Gone With The Wind herent in the large infinite baffle. Cur. Columbia CS8156 Continental strings cavort in gay al:uulon there is no cabinet resou;utce, ou ilmwe tlbnnis. Most collections iiuIu 1:n,Íuyiug a brief respite from the boom or distortion. For these reasons, concerts, Strauss, Lehar, und Ivanovici waltzes festivals and world tours. the Dave Brubech by the Bradford Bantle was and is the programmed Frank Pourcel, but doubtless i /nautet relaxes and wanders only compact cabinet fully equal to. or footloose in versions whose origins are Austrian, Hun- better than, the large through a set of tunes that lit like au old garian. .\uoriu:ut. or any country other than enclosures. either pair of shoes. 'Plie before or after stereo. leader's tempos fur slues Franke. So what better way to tempt the :nid rrs11'111 doll Georgia INt .flat 1/iad, and stereo purchaser, (rand this recording will be Totally enclosed "arouslic suspeusiou^ Lonexuoinu Knoll. while the sound of his piano released in stereo Duly.) than to offer them systems have )1eroin pnpulan. 'Plie is deep :nad full. doe Morello on 11ruuas. with in arrangements that are characteristically ford Baffle \vas the original "aeemstie the assistance of bassist Gene Wright. leads French'! Pourcel complies wills saucy Gallic suspension," only limier. for the degree the way on two versions of Cam ptntrta Hansi', aoeeuts. and the fine recording was made in of "suspension" is automatically self- ont Tieing Wafted along by breezy \\'est In- the lathe-AInrefoil studios in Parris. adjusting. dian rhythms. IIe takes over rottpletely on George. \lelarhrito conveys his personal im- ,shorl'nin' it/Tod. compounding at heady ntix- pressions of Rome in four original 'Fite Bradford Battle is made in Iwo composi- titre from melodic 711111 pemnssi oe ingredients. tions sizes one. for ss. fns. and one that include views of the Colosseum. ... for 12s Paul Desmond varies the of and lbs. in all popular h,rdwoods. tone his auto sax street srtnes. train noises, bells of the basil- to accommodate either a wtn111 and Vital ica. und the Vatican. Ills settings of priced from $34.7tu to se m. in. Made and familiar l:n..ia situ t l Rlurx, or a magnolia -scented melodies list a nu11ther of stereo effects. none finished better than most expensive, Gone Wino custom furniture. 'l'Ire 11-imt. The hitintite stereo of \stitch interferes with a penchant for lilting unil:in:: is uttenti... to each soloist in turn. strings or the sound of Leon Gossens' oboe. Sold separately, for only $85.00. is I On re. 'j'ui'ce ('oins in turc fountain, and the Bakers Ultra 12" speaker. For those Turk Murphy: At The Roundtable ,Irri red erci. Roqua are all desiaited for danc- who appreciate natural facsimile instead ing. of calculated artificiality, this is the Roulette SR25076 lìuest suera ken Rex Stewart And Dickie tvit Milli'. Its superiority Wells: Chatter Harry Belafonte: At Carnegie Hall is accomplished by ingenious cone de- Jazz RCA Victor LSP2025 sign, plastic foutu surround, 1s,umll gauss RCA Victor 1506006 magnet. and other exclusive features, The revivalist hand of the redoubtable The Kingston Trio: At Large 'fork Murphy now carries not only a without which ullinute reproduction is drum- Capitol ST1199 impossible. mer. but a girl singer whom the leader engages in vocal duets. inn her own, Pat Yankrc Two benefit performances, held on success- If you love music, unalloyed : if boum sings oh noddy. and -\-ohod// Hyena ti' l'un ive evenings last Spring and taped on the anti distortion shock your nervous sys- II hen ïu,ii're Itou -u and llul, in a style remi- scene, account for the two -record album of a tem; and if you have ever stopped tu niscent of the estimable Claire Austin. Two Harry Belafonte concert at Carnegie Hall. The wonder how the "Bigger the box, the migit:11s make this set noteworthy. Fed identical programs are combined by tacking better the sound" advocates catl now l'Io)utcl Kee//, written by Murphy. feartures the best of each, but without iilersiilicitug any promote -size." bass -re `shelf Ilexes and lutistpia feue 11113 do. while etarinetist Bob selection. Many who are familiar with his folded -horns that :ire even better than Ilehut contributes Ua//break ti es, Thad studio recording of these folk songs will find ever," write for literai ti ri-. Bradford \Vilkersuu. the drummer, is reinforced by then vividly recharged by the electricity Audio Corporation, 27 East 3Sth St., tuba sorties from Bill Stanley. After doing which flows between the singer and a Iive New York 16, N. Y. without tt percussionist for so long, the audience. The tempos are slower, climaxes 111Ï t'i'ff ixe iii t u f Itmdtr's trombone and Bob Short's trumpet reach a greater intensity, and the awesome

72 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com New Stereo Tape Recorder Cybernetically engineered for intuitive operation

Fluid smooth, whisper quiet...with feather - mixing controls on both channels for com- ganged volume control. Head cover removes, light touch you control tape movement bining "mike" and "line:' The SM -310 re- giving direct access to tape for easy editing. with the central joystick of your Newcomb cords and plays back half-track monaural The Newcomb SM -310 is a sleek, rugged, SM -310. This exciting new stereophonic also. So versatile is the machine that you compact machine, discreetly styled by an record -playback tape machine has been may record and playback on either or both eminent industrial designer in easy -to -live. cybernetically engineered to fit you. channels in the same direction. with shades of warm gray and satin alumi- Intuitively, you sense how to operate this The SM -310 is a truly portable unit which num...a gratifying, precision instrument for handsome instrument. The natural move- combines the features required by the pro- the creative individual who is deep in the ment, you find, is the correct movement. fessional and desired by the amateur for on - art of Cape recording. Eight, tightly -spaced Loading is utterly simple. It is almost impos- location making of master stereo tapes. For pages are required in a new brochure to sible to make a mistake. The transport han- example, the SM -310 takes reels up to 10", describe the SM -310 in detail: send for your dles tape with remarkable gentleness, avoids has two lighted recording level meters ar- free copy. stretch and spilling. ranged pointer-to -pointer for ready compari- Advance showings in New York and Los The Newcomb SM -310 records stereo- son, has a 4 digit counter to pinpoint position Angeles proves an unprecedented demand phonically live from microphones or from without repeating on any size reel. For play- for this instrument. We urge those who de- broadcast or recorded material. There are back there are a "balance" control and a sire early delivery to place their orders now.

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www.americanradiohistory.comAmericanRadioHistory.Com hush before :1 number is a greater tribute to his command of :at audience than the thou- (lerous applause It the end. Each receivers :at extended treatment, with the greater part .Ì one silo devoted to an 11 Malt .Ilatildn. Stem is works its wonders well. not missing a whisper front the singer as he is accompanied by a l'irtysevet piece orchestra. con- behind ducted by Robert I'ormati. or a small group seated downstage. But when the voices of a t'h0111S o stage. of the members of the "reh;s- every ti:t. and the nudienee are joined together at Isis behest, some readjustment if the control settings may he desirable. Bogen '1'11, l ings1on Trio draws from sources best known to folklorists to offer an enlarged repertoire on their current release. The custom component of revising mark -riot to fit their spirited and witty style is followed. with the usual enter- taining result. on a 11021.11 songs. In addition stands a In .11.T. .I., which hurtled tip the hit list faster than the Itost>u subway, there are Ill 1111 Non- notra. (trim! .\ntra, The I.wI!1 /Hark liiIle, and guarantee lín)ut'oiDty Tlrc .{/curt), On of their first stereo album. they charmed a coueert audience with the skill of a e. Bela font The result .f con - satisfaction trollud studio conditions, their second affords a close and dynamically expressive lout: at the group's methods of putting varied material taget her.

Buck Clayton: Songs For Swingers Columbia CS8123 Two happy results of Stanley Il:ulce's main- stream series. begun .0 the Feisted Ethel last Spring. :u1. a British concert tour for liai']: Clayton and this recording date with the musicians who are making the trip. lu prepat- ration. I'layton supplies four originals and arrangements oÍ fier standards. The troupe carries an extra trumpet player in Emmett Perry. who employs a dill. ope11 one on this cession to contrast with the leader's muted embellishments. That this practice works in stereo is a cotniidenee, Lut a very pleasant one. It ads. Wo; 511 Clay I. two blue: themes. where Iheir disparate styles scent Io 1111 (to in a single lyric expression. so well do they complement each it her. lu addition to alto sax, E:u'I \C,ure plays lurid via ['Biel. and Buddy 'l'ale is on tenor sax. 'l'rout bon ist Dick i1. \Cells furnishes the atmospheric effects ni \-igbt 7'reirr. The rhythm could do with a guitar. hut perhaps the chaire Isly between that and the spare trumpet. MONOPHONIC

Music Of New Orleans: The Birth Of Jazz, Vol. IV Folkways FA2464 The story of the lira reei'nl,t u: rlurus is too well known to beau' rep,IiG,. tint too often it is retold as though Louis .\ !lust rong originated :i nosa style of singing on the spur of the HültleiI sclieu the lyries if a song eluded him back iu 1tr25. \lusieitins have always used the vocal imitation of instru- HE'S ADMIRING TWO INVEST- Amplifier and you have versatility and ments in practice to clarify written passages. ments well -made; investments malting it second unto.... for Armstrong to engineering excellence that assure the iwerionle tempor,ny 11is'ress aiIII it aorilicss which guarantee him-and you-a world ultimate in faithful sound reproduction. item Iatloll. Its eoi11ner,(tul proper tics proved magicaI and en:o urged a host of imitators of unending listening pleasure. The Bogen's B61 Turntable can add even of varying degrees of sensibility. iiad they Hot Let;:eta prepare 1111 unsuspecting lilblic. it ST442 Stereo FM -AM Tuner gives you further to your complete musical enjoy- is dunl'ttul that symphony conductors would put aside their sensitivity and freedom from distortion ment. too, dignity today and allow a It's wonderful, that Bogen microphone tit rnvcstlr.p 011 therlr warbled that are unequaled at its remarkable components look j ust as handsome as they 111sirurtions to a rehearsing orehesirr.. Arm- strong's antecedents for Ibis form of ex- price. It also includes a tuning meter, sound. Hear them at your favorite hi-fi pression are found in the New Orleans style of ens. mild, playing. primarily as interpreted provision for multiplex adapter and au- dealer now. by the second line of aspiring musicians who followed the tadyphoia' tomatic volume control on each channel, for Dept. AO -119, of the nut] citing lands Write information to: withiul henelit of notorious Evidence of how features usually found only in units cost- BOGEN -PRESTO, Paramus, N. J. thoroughly it beeame a part of the Language o:' these youngsters is eonttiuull nu the fourth ing much more. A Division of The Siegler Corporation. volume of the series in which Samuel B. ('barters is recapturing much of the city's Combine the ST442 with the DB212 jazz history. Louis Koplin is Stereo Control Center /Dual 12 -Watt rd heard recoils I rind ilg the BOGEN sound of a 1910 blind as it played Bucket's the sound way to better stereo Gat a /to!r Iie It, aoeaIiziug all the different etclì nliam parts with rare accuracy and ingenuity. The style harks hark to the days when he worked ST442. sensitivity: FM: 1.úµv - 30 dh quieting at 75 ohm input. AM: 3µv :outer. 20 db S/N. Frequency Itespouse: its guitarist with his younger and more FM: 20 to 18,000 to cps 20.2 dh; AM: 20 1.500 cps 1. db. Antennas: FM: built-in line antenna; AM: built-in ferrite fatuous brut her Freddie. whose cornet loopstiek. Tubes: 9 (plus ;t man- diodes). Controls: Selector, AFC out, AM, FM Tuning. Power. ]'rice: $I49.50. Enclosure nerisms are affect ion:tlely ILlplicnted. and legs: $7.50. DB212. tower: SI watts (two 12 -watt channels). Response: 20 to 20,000 cps ±1 db. Distortion: lean That :a member of a than 15t.. Controls: Selector, Function, Speaker Inversion, Volume. Balance. Bass, Treble. Ili Filler Lo Filter. Speaker rhythm sertiuH should remem- leer so well the Phasing, flower. ]'rice: $119.35. Enclosure I legs: $7.50. All prices slightly higher in the west. tonality and i u'i'uliaTities

74 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com hi. ,on, pa u,iou, l' nearly half a ,ruler}' ago is astonishing. There is no better proof that this knowledge is basic In the traditional ensemble and a source f its strength. Harrison hnntrs es,hang,. riot iiiscense, of 1:nd,ly holden with \.o111.cornetist 1 'II arli, Luce, w110 lead, a quintet on 1/"plc /,caf Reg. The ha lame of the ,-until installtueet is allotted to I1. .F. Rousses' a con of ragtime wits .Dent his }'neiger ,lays trailing tunes with cabaret pia utsts. Before allowing a . melody lì, now beneath bis lingers, he talks Fairchild is design .. lisaniingly about the enVironutent whiten ere,l it. giving vivil impressions of the Irish Channel, Tom .\u,lerson's. and the bur- le.gm questi who inspired Red lime Ray. G nie of the material MIS taped as long as .even year, hug,,, ail the sound suffers tic- cordiielc.

Mose Allison: Creek Bank Prestige 7152 For a voting Matt 1st Io aattaiu his f 1.1' in a period of slightly hutoll' than a year IS quite :in arthi,cenmut. eceu ill these days of an amply .lipid., of jazz albums. Where \lose .\Bison i, concerned. it is ail the more remarkable ber:uuse ni uell of his work consists or original .ketches. Stem iniag l'nun titi' country bless lu:n4 tin ring a shil,lhool in Mississippi. they art crue nad g,ttuiao bits f .\mtri,:out. Four rurreul pille, lepitt la oast. l'a I o-,etm ill chill the no poi oser a rttatr' latte, a rural genii'. the :attics of a si rte. and a visit to the swimming boll' indl- rate,l ou lle titi.. l7e sings on If on Lire, it poire somber vehicle in which conditional t,,'omises are made aga inst the drummer's steady ha,-kheat. I1 is elm raotsrislit' Iwang Is :I ISO heard ou \V ill i, Maahon's tale tif a sooth- sayer, '/'lo ..'e e, ti/h ."titi, \Chen plu}iag the works of other composer., Allison iacu rpo ra tes noadertt elements is leis style to tt greater degree, astin 7 Oldta't rare, und t'nbi in the ,.'k!,. Esthautges bet tcetn Adàisun }atnnr% bass, ttnd Bonnie Free. drums, enliven l'auker's Fan/bird ,mitt', ail lìllington's l4'elntle ln tr K

Cannonball Adderley: Jump For Joy Mercury MG36146 In arranging the score of Duke 1-iliugtou's ".lump For .14,3 .. Bill Russo siceessfelly evades all the el lenient jazz eattgories. Al- though strings :t re rm played, the ulcers re of Julia Adl,rhy. alto sax, and tent peter Emmett Berry bra's a chamber jazz classifica- tion. While the composer rrcised the 1941 show in i951, Russo adds enough origiuttI ideas of his own to remove it from tit, slued, The all new Model SA -12 I;lliugtun domuiu. Chet be sloes ttccuplpli.h exemplifies the design for is the first tom pie t, preset] athut of a tyori, which Fairchild is famous. that should blue been recorlel long ago, fuel Examine the SA -12. Start with taut. dry writing for strings that lits the base soloists the one -hole mounted and provides considerable interest. .\ level. Move regular rhythm sect inn tit' Milt 11inton, hill and built-in spirit next to the arm itself a Evans, Barry I:atlbraitli and .1 hinny l'ubb ... contrasts admirably with the four strings. sleek satin curve comple- which are .mined on I,treussice figures by mented by the balancing Hinton. Berry's mated flights are beautifully weight. Pause along the arm framed. and Adderl,r slams with fluency and and note Fairchild's "Cue- the req-::red variety of pne. ing" device. This controls gentle, precise setting down Barney Kessel Plays "Carmen of stylus in groove. At arm's Contemporary M3563 length is the universal cartridge slide. Permits inter- lu s't,lip,_ "I':nuou'' lo,yu to El' size. change of 2, 3 or 4 -pin mon- Barney Ke..el 1,111 iris as eertatin amount of operator scope 1 'Ii riding his ntudern jazz aural and stereo cartridges cer.ion of the s art bet wets hyu bnsi,' groups. without re -wiring, tools, or tine follows the con vent bola l small -hand soldering. Write for complete setup, and th'' other highlights his guitar specifications or seethe SA -12 aiming five wood ind, nn rhythm. while two at your Fairchild dealer. You'll yeses are piayer as imDrovisrd duets with want it for your installation. cubist Vic faa FsWtnaap. The toil iau airs are The cost $34.95. helot from being .ubnurge,l ter long by as- ... signing, coral lime, to Buddy Collet le, Ray height, 31/4" Linn. Andre Prey in, sloe Mond ragon. and dimensions: Shelly Marine, who does etl'rythiug brit lull maximum; length, 121/4"; dis- Ca rmei's tigauretie "u his druhups. Surely rte tance required from turntable lift,- lived out West long enough to manage center to arm pivot, 82742"; thaat too. .\, Bizet 's music was considered re. rear overhang, 23/e". ma at the tint, for the use of Ilnle and harp, he won hl probably enjoy hearing Lis themes trups;,osel for I',tllette's flute and EQUIPMENT CORPORATION Keasel's guitau'. Ile would like the recorded FAIRCHILD RECORDING sound, at least. Vernon hike's iuformatire 10-40 45th Avenue, Long Island City 1, N. Y., Dept. A119 liner notes fail to credit the far-out brain behind the new title,. Æ

AUDIO NOVEMBER, 1959 75

www.americanradiohistory.comAmericanRadioHistory.Com AUDIO ETC.

(j1YN01 paie 11, STEREOPHONIC MONOPHONIC / 11e won't ever have reason to if he buys :1 tape cartridge machine. So, you see, I think that RCA in its persistent way has its mind and eye on :1 long-range objective that is uncommonly hard-headed, whether you may like it for yourself or not. The cartridge in these terms is not only a good idea-it is the ottlti idea. To sell tape to a Mtge market yo t have to get rid of lite tape, in effert. Put it inside, make it automatic. That's an almost terrifyingly sure kind of thinking in this fine country of Ours and the sooner we understand that it applies right here ,lust as much as it does elsewhere, the better for all of us.

Instant Sound And thus, onwards to the machine itself, which is generally less iutport:lilt than the big principle of the tape cartridge. RCA's SUP -2 is just One embodiment of the ideal; :utybotly tool his brother can see that others are possible and probable. Let me proceed eraltwise and make ph}-sisal distinction between the basic Pt'A Victor tale cartridge chassis, the THE STANDARD THAT SAVES DOLLARS mechanical tape desk with pushbuttons, heals, motor drive, etc.. and the surround- Since its introduction, the Ampex 351 Series has been acknowl- ing "package" of anil:iti rs, controls, fur- edged as the standard of excellence in profsional recorders for niture, speakers. These latter wit: vary the broadcast industry. Broadcasters-and ,other users with widely; the:leek itself, :It least in the highly critical recording requirements, such as recording studios RCA linos, looks to be fairly standardized'. and educational institutions-will find that the purchase of an It is a dawned ingenious little package, a faults Ampex 351 is further justified by these important facts: let me tell you, in spite of fete T can find with it. The tape deck lifts right The recognized precision and engineering skill which go into out of this first cartridge machine, as it each Ampex 351 guarantees unsurpassed durability and reliability doubtless will lift out of other models to for a long, dependable life. As a result ... on a cost -per -operating - come; it is self-contained, very economi- hour basis. Ampex is the most economical of any recorder made. cal in space (it could he slightly smaller perhaps, in a pinch, lint not much), it is PERFORMANCE SPECIFICATIONS mechanically efficient, quiet, steady, and in Note: As professional equipment, the Ampex 351 specifications listed are surprisingly foolproof ordinary opera- accurate measurements required by NAB standards and do not incorporate tion. It really works. any exaggerated sales claims. These are the guaranteed minimum performance Thus, for example, the automatic in- specifications the customer can expect in long-range operation. stantaneous stop at either end of the tape motion is astonishingly simple and com- Frequency Response: 15 ips ±2db 30 to 15,000 cps pletely reliable. Push either the fast for- 7's ips ±4db 30 to 15,000 cps ward or fast rewind button and at the ± 2db 40 to 10,000 cps end of the tape the stop is instantaneous, Flutter and Wow: 15 ips-well below 0.15% RMS on a dime, and never fails. The action 73Z ips-well below 0.2% RMS depends ou a small lever that is moved Timing Accuracy: Within ±0.2% (±3.6 sec. in a 30 min. recording) over by the sudden increase of tape ten- Starting Time: Full speed in less than 1/10 sec. sion and locks things tight, instantly. No At 15 ips, tape moves less pressing Stopping Time: than 2" after slow braking, 110 electrical contacts. no "Stop" button. tape inserts, no relays, told the tape is

: Half track, full track, 2 track Models stereo (separate erase fastened on its hub by nothing more 1.0111- to each track). Console, portable and rack mount. ples than an ordinary loop. It works because there isn't any inertial FULL REMOTE CONTROL mass to keep things spiraling, as in the The Ampex 351 Series can be operated in mush heavier tape reel :mid mounting- Vt3dsGe, the relay -solenoid tape motion control unit just the tiny lightweight center spindle, for Start, Stop, Fast Forward, Rewind and without side pieces, and the small roll of Record modes from any remote location. tape itself. 'Tricky, and a most ingenious mechanical solution of one of the major There are 185 Ampex dealers to serve you. Check the inertial problems in the handling of all Recording Equipment listing in the yellow pages of tape. metropolitan area directories, or write Dept. 304 for AMPEX There isn't ally doubt that this car- the name of your nearest dealer. CORPUS FION tridge, in its own way, is mechanically good and very effective in the one major intent 934 CHARTER STREET REDWOOD CITY, CALIFORNIA professional construction-slip-ill, no - Offices and representatives in principal cities throughout the world. of its whole products division thread, instant sound. It is a pleasure to

76 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com slip one recording in, slip it out, put in another, flip sides, each in one easy motion taking a second or so. All you need to do its to try it for a day or so to find Traditional Serving a that it really is a far cry from threading OLD WORLD NEW WORLD tape by hand, even in the most ingeniously Craftsmanship ERCONA of Sound ! designed reel-to-reel machine. (A far cry, that is, for people who want this sort of thing, who value it highly. It may mean nothing at all to you, just as the record changer and the "all -groove" needle may be your favorite anathema, and mine.) I can't make this point too clearly, be- TURNTABLE cause it is the basic point of all, the crux for the discriminating who demand the ultimate in of the whole cartridge argument. All other e NEW drefred Ire matters are secondary. MODEL To continue with one more virtue, the s MADE IN ENGLAND a Created by skilled hands of English fool -proof approach is carried even into craftsmen working to tolerances of the ingenious "trip" that keeps you from .0001", the Connoisseur turntable is erasing tape when you don't intend to. constructed to assure you of remarkable silent operation. The hys- It's just a small lever on a spring mount Newly teresis synchronous motor -driven that is situated under the rear flange turntable is non-magnetic and where the cartridge goes in. Two little Developed' equipped with an illuminated strobe Automatic control arm and diamond disc to insure speed perfection. Wow holes in the cartridge itself, one for each stereo pickup must be seen and heard to is less than .15% and Rumble is 50 direction of play, allow the lever to re- be appreciated. Just one touch lifts or db down (7 cmisec. at 500 cps). lowers arm with perfect precision. Superb main undisturbed ill normal playing Oper- stereo! Only $59.50 net. Mounting size: 15%" x 131/2". Only ation. Try to record and a solenoid prac- $119.50 net. tically grabs the control out of your hand, won't let it turn, along with the above - mentioned loud squawk. Your recording is protected-though the first time I tried this I almost jumped out of my skin at the loud noise. STUZZI magnette To "defeat" this gadget and allow for recording and erase, no more than a piece Portable of freezer tape or anything similar that Tape covers up the holes in the cartridge, wilt Recorder STUDIO force the lever back and break the pro- MICROPHONES tective circuit as the cartridge is inserted. ltl England's most honored You can fix it Fully line of microphones to as- separately for each "side." Transistorized! sure the highest broadcast- This protection is in line with those useful ing quality standards. Professional performance packed into a automatic double -exposure preventers in mere eight pounds! Hand-crafted in Vienna Of rugged, compact design, to highest Continental it's the 1.Ar-4 each features a dural ribbon most modern small cameras (even those standards, 4 . cartridge weighing 1.2 mg ideal travelling companidn for dictation, (1/960 oz.) and triple have a "defeat," in the better models) conference recording, interviews or record- screen protected. Imped- ing fine music to broadcast standards. 100 for home and you must admit 4 ances available professional or that RCA is techni- hours on flashlight batteries. Dual track, recording equipment. Three models: Sym- cally one up on anybody else right here. dual speed, it will operate in any position phony, Celeste (with switch) or Avon super- . on land, sea and air. Vibration -proof. cardioid. From $59.50 net. Positive, automatic erase protection, so Velvet touch push button controls. Only $269.50 net. you can't record even if you go so far as to try to move the recording control. Incidentally, and as a further point of good thinking, the actual record knob is nicely tied in with this safety feature via the solenoid that will not allow it to be moved. This knob is spring loaded and High priced snaps out of "record" position when the speakers a time for STOP button is pressed. must? listening I had only minor difficulties with the coo cartridge deck's mechanical ' operation, MADE Series mostly not too ENGLAND Ìì Mark Ill important. On one of the IN VOTAVOX "Cig" speakers don't have to have big machines the rewind wouldn't work-a MADE IN ENGLAND price tags. Not with the famous R 8 Al brake that didn't let go. It was OK on Here are speakers that bring true high When superlatives pall ... and specifications the other. Annoying, but superficial. fidelity and luxury listening-yet at a no longer impress ... it's time to listen- Another small problem was more impor- price unbelievably lower than expected long and carefully. In this most exacting of for such excellent performance. Your audio tests, the Vitavox DU120 Duplex Co- tant and also more interesting. There's an stereo speaker investment can be mini- axial Speaker emerges triumphant! Here's odd halfway point of resistance as you mized without sacrificing quality if you full range reproduction free of distortion add an it & A to your present speaker and peaks. For proof, ask for a demonstra- insert the cartridge into the deck that caul system. Coaxial construction in 8", 10" tion of the new Vitavox Hallmark System fool you, you and 12" models. Aleomax III Anisotrop- which employs the DU120. You'll hear the if aren't paying close at- difference and tention, into ic Magnetic systems of 12,900 Gauss want either the DU120 or thinking it is seated all the Flux density. As low as $13.95 net. Hallmark as part of your own system. way, when in fact it is not, by a small $89.10 net fraction of an inch. Unfortunately, the machine will operato in this position, with at selected Hi-Fi Dealers some strange results. One night, alt it folk singing party, I got a fine stereo record- Specific literature on request ing that plays backwards but won't play frontwards. Imagine my surprise! (Im- ERCONA CORPORATION agine the fury of a purchaser who rain (Electronic Iliei.aion) into this trouble.) The cartridge evidently Dept. 53 16 West 46th Street, New York 36, New York wasn't quite seal! ; the heads recorded on

AUDIO NOVEMBER, 1959 77

www.americanradiohistory.comAmericanRadioHistory.Com the wrong area of tape, hitting a channel that properly runs in the other direction. t4te That's how I figured it out, anyhow. grsk Trctd,tLosi! RCA would squirm if it heard my backwards stereo, but all that is needed is a In these days of factory mechan- bit of finagling that would insure more isation on the grand scale- positive seating, and would prevent the where success so often is mea- machine from operating until the line-up was exact. It's possible that my halfway sured only in terms of ever- point involved warpage of the cartridge expanding output-people tell itself. which I hear has caused some early us that it is refreshing to meet a troulil, - now probably cleared up. manufacturer imbued with the Abnormal Operations quaint idea of refusing to grow big. I said something about normal operation. As you can now imagine, the tape But it is quite true. The success cartridge is intended for vast quantities of the Ferrograph of normal, operation-and very little else, during the especially such abnormal procedure, in- past ten years has been due volving manual handling of the tape, as entirely to our deliberate decision editing, or adding and removing tape from to make quality rather than the cartridge's insides. Quite right and within the clearly directed philosophy of quantity our sole objective. Not the cartridge design. for us models to suit all pockets I)o I know. I tried, and found out very, or Tape Recorders built down very quickly that to do anything at all with the tape itself, once the is to a price to compete in world cartridge laid open in its two halves, is fiendishly markets. Instead, to maintain our high those who use the Ferrograph pro- difficult. No reels, just the little plastic standards without compromise we have fessionally in scientific and industrial hubs that sit loosely in their holes like chosen to restrict our output. research, in the teaching of music, tiny flanged manhole covers-they slip drama and languages, in the manu- completely out of place if you look at We believe that a Tape Recorder, being them, tape and all; and to manipulate facture of gramophone records, in the an instrument of high mechanical pre- therm you must somehow manage to hold exploration of far -away places, in bark the spring brake that keeps tape cision, needs a great deal of critical and radio and home entertainment-know from unwinding, thereby using up extra unhurried supervision at every stage of fingers. A turn or so by hand, winding that Ferrograph equipment is the best its manufacture which it would be or unwinding, and before you know it that money can buy. your tape is off the roll ill a spiral snarl difficult to carry out in a factory geared that takes hours to untangle. Everything to large scale production. Ferrograph Series 4A just falls apart; the plastic sheath slithers away, the hubs pop out of their sockets. This then is the Ferrograph tradition. Fitted with three independent motors, including synchronous main drive to capstan, with record- When you do try winding on tape, you It is based upon a policy of utilising ing level meter and interchangeable plug-in find that it won't lie evenly, there being to the full the wealth of technical heads. Two speeds (3tt/74 or 74/IS i.p.s.) with auto- no reel flanges, so that the cartridge halves matic changeover to correct compensation net- knowledge and craftsmanship that is won't fit over the uneven roll, or it scrapes work. Fitted with Brief Stop, gear -driven Turns and sticks after reassembly. All in all, I still part of Britain's heritage. Counter and with provision for additional stacked Head for stereo playback conversion. know of no quicker way to get into a sweat than to dicker with this cartridge's in- Today all who are seriously 24 watts of undistorted output through high interested quality elliptical speaker. Auto Stop instantly sides! I had to; I wanted to play a piece in tape recording-and this includes stops motor drive when spool of 4 -track tape that I had made on my is empty or tape breaks. $399.50 other recorder, the Tandberg, and so I started by patching it onto the short RCA Ferrograph Stereo 808 cartridge demo tape I had on hand. An all-purpose instrument permitting full Ferrograph Stereo 808/4 that stereophonic recording and playback together Model 808/4 records two -track stereo and mono- I never did get to play it that way and with conventional half track monophonic record- phonic tapes and plays four -track stereo, two - only managed to rescue my tape from dis- ing and playback. The output of all channels track stereo and monophonic tapes. As with aster by using my big Ampex 350 as a (stereo and mono) ends at low level so that Model 808 the output of all channels ends at template, slipping the cartridge hub over owner can conveniently make use of his existing low level thus permitting existing high fidelity one of its spindles, and reeling very hi-fi amplifiers and loud speaker systems. amplifiers and loud speaker systems to be used. care- General specification and mechanical General specification and mechanical fully, back onto the conventional plastic features similar to Ferrograph Series 4A. $595 features as Ferrograph Series 4A above. reel. I also wound too much tape into the cartridge. It's hard to judge when to stop; if you put on too much, the rolls bind against each other halfway through the '7Zc run, and you spend the next hour painfully reversing them inch by inch, until they are free to move. (The trick is that the bigger roll gets bigger faster than the smaller roll gets smaller, as you'll figure out if you can visualize the cartridge. ervap Thus they get closer and closer, until- the fatal jam-up.) Manufactured in England by No, the cartridge is not for manual BRITISH FERROGRAPH RECORDER CO. LTD handling. But I do think that in the future somebody could market a simple edit - 131 SLOANE STREET, S.W.I and SHIELDS, ENGLAND LONDON, SOUTH rewind accessory that would hold the hubs U.S. DISTRIBUTORS: Ercona Corporation, 16 West 46th Street, New York 36, N.Y. and tape in line, something on the order handle 8 CANADIAN DISTRIBUTORS: Astral Electric Co. Ltd, 44 Denforth Road, Toronto 13 of those editing gadgets that and

78 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com 16mm movie film. It would be great for new madison fielding 440 those of us who will insist on opening up series our cartridges, to tinker with the insides. But please don't ever forget that you aren't supposed to be messing around opening up your cartridges, any more than you are supposed to play with the insides of your dial telephone! (Not even for broken tape. You fish out the loose ends and splice the tape outside the cartridge.) If the tape doesn't play, you take it to your dealer, just like any other home appliance. And pray.

The SCP-2 "Package"

.\1y final words are going to be somewhat blunt. I am still all for the cartridge it'll do itself and its potentialities in sound as well as its physical convenience and reliability. I admire RCA's basic tape deck no everything but end. But this particular embodiment of the cartridge principle, the SCP-2 stereo recorder, seems to me a disappointment and I do not like it. It is disappointingly mediocre in performance and conventional in construction just where, in this crucial And if you're one to be transported on wings of song, then situation, it should shine out as a splendid this is truly hi-fi to fly by. All puns aside, though, Madison example. It will do RCA's cause no very Fielding's new Series 440 is a triumph of stereophonic com- great good, I think, and is likely to component design. A powerful AM tuner and a high sensitivity FM tuner are combined on the same chassis with a dual pound the general misunderstanding con- channel 40 -watt stereo preamp-amplifier. The result? cerning the cartridge itself by its slightly Amazing flexibility! And the knowledge that there is nothing unspectacular operation. I can say this be- in high fidelity reproduction that will stymie this fabulous cause it is my disappointment, as a pro- piece of equipment. of is in- ponent the cartridge system, that Item: Automatic third channel stereo. A true mixing of both volved here. In basic respects I'm on RCA's channels. Perfect for a three channel system or for stereo side. in one room and a monaural source in other rooms. Again let me categorize. There are the Item: Output for stereo headset. Just plug in and listen in bugs, first, those assorted minor failures complete privacy. we usually expect in new that production Item: Push buttons and lights. Mix from six program sources of any model, which often vary from in- on each channel with push button selectors. Jewelled indica- dividual machine to machine. And then tor lights eliminate any possible ambiguity. there are the inherent troubles, faults, Item: Aural Zero Null (AZN) Circuit. Push a button and tune weaknesses, that are part of the design, for silence. When the sound disappears both channels are common to all models or apparently so. in perfect electronic stereo balance. The two merge, but I can cite clear ex- Item: Separate bass, treble and volume controls for each amples of both that had me discouraged. channel. Nulling, phasing, noise, rumble, tape monitor and Bugs are less important, except when loudness switches. Other controls include FM tuning, AM there are too many of them, or they are tuning, master volume, stereo / monaural switch and stereo of the careless sort-like the STOP push- reverse. Power switch is push / push button. Permits all buuton that just fell off when I pushed dial settings to remain untouched while set is not in use. it. Unglued. Or, a more serious one, the Item: The Series 440 is fully described in a specifications maladjusted level indicator on my second brochure we have prepared. Write for it or see your Madison machine-when it flashed to indicate cor- Fielding dealer for a comprehensive demonstration. rect recording level I got a grossly overloaded and very distorted playback signal; when their was no flash at all, the level turned out just right. The first machine was OK in this respect; but it had something wrong in one amplifier circuit which let out horrid squawks, every so -_.--9.o9 9-.. flb..,._ often, that stopped only when I gave the machine a good slap on its sides. As mentioned, a rewind didn't work on one of the machines. On the other, the playback was unaccountably muffled on all material, and i: II `111 adjustment of the tone control had nothing to do with it, as far as I could tell. Could have been head alignment-but this Series 440 $325.00 machine had just been especially checked Matching cabinet $30.00 out by RCA. By a most unfortunate pure PRICES SLIGHTLY III ".TIER 1H THE WEST. coincidence I had a Columbia Records executive in the house the day I tried out this second example of the SCP-2, with its life- madison fielding less high end. 11e gave one snort and that was that, but he should have heard the by Crosby Electronics, Inc. first one, which sounded really fine on ©BRAND PRODUCTS, INC. playback of RCA's recorded tapes. Why Dept. AU -119, 39 West 55th St., N. Y. 19, N.Y. such a difference? RCA has had a lot of Marketing organization for Madison Fielding

AUDIO NOVEMBER, 1959 79

www.americanradiohistory.comAmericanRadioHistory.Com time to get this machine's production in hand and stabilized. These things and other small, petty items of the sort aren't the kind you can excuse because of an ex- cess of zeal-a "green" promotor so enthusiastic about his new product he doesn't have time to check it out properly. RCA Victor is hardly that kind of outfit. The inherent difficulties, characteristic of the whole production, are less easy to pinpoint but still they weigh out cumula- ;L_... STEREO tively. Sure, this is an "ordinary" home machine in a field where performance standards haven't always been of the highest. But, for example, why do these am- THE SOUND 'THAT OUTMODES plifiers-of all amplifiers, you might think -turn out to be so noisy? At full volume the hiss is positively steamy; there is generally an impression of background dis- CONVENTIONAL STEREO! turbance in all the playing through the machine's own power plant that is most unfortunate, right here where it will be assumed by so many listeners to be inherent in the cartridge system itself. It isn't, but a lot of folks will jump to eon - elusions that cannot possibly be to RCA's advantage. The problem can be summed up, I think, it' I suggest that we have here a standard, run-of-the-mill home machine, unimagina- tively put together, unnecessarily bulky and clumsy, but probably no worse than, nor better than many others of the general type. This is exactly the trouble-for to incorporate the crucial tape cartridge deck inside such an ordinary package is incredibly unwise, in view of the present hot situation! For once, there should have been a really imaginative, enthusiastically designed, outstanding package built around the cartridge, even if it meant a loss in cash for awhile. Common sense, for goodness' sake! Instead. . . . Well, I do have one more item to mention specifically, that hit me especially hard-the two-ehannel recording feature. The best I can say is that it is adequate for superficial home entertainment, on voice -quality. It works, it plays back, it'll give you stereo or binaural effects according to your material and mike technique, more or less. But as I've already suggested, I am enthusiastic about the new possibilities for home use of two -channel recording, and I want more than mediocre sound. That's just what I got. First, the ceramic mikes, nattily squared off in good looking eases, are strictly inferior in tone quality -I tried them against the ceramics furnished by Tandberg and the difference was It took the engineering know-how of Weathers to discover this revolutionary astonishing, in favor of Tandberg. The electronic advancement in sound and size! TrioPhonic Stereo introduces the Tandberg cermies are darned near profes- listener for the first time to "Equalized Sound." Now you can sit anywhere in sional in the quality of sound they give. the room and experience the same magnificent tonal realism and fidelity of The RCA mikes seemed to use painfully full -range stereo. "Equalized Sound" is produced by two book -size full range ordinary. AVliv ? no cir- stereo speakers and a unique, non-dlirectional hideaway bass. Then the recording itself. I'm cuit -man and I'll make no technical criti- Ask your dealer today for a demonstration of Weathers startling new audio cism; I only know that the recorded play- dimension-TRIOPHONIC STEREO with "Equalized Sound." You must see it, back sound, of all types, was uniformly hear it, compare it, to believe it! inferior to the input signal, the noise was high, it seemed impossible to get a really Weathers For the ultimate in TrioPhonic stereo listening, select the matched healthy level on the tape (comparable to synchronous turntable with StereoRamic pickup system. RCA's own, on the excellent recorded commercial cartridges). the sound was generally unconvincing. The quality from the .4UD For more information of TrioPhonic Stereo write for FREE booklet, Dept. mikes is, for anyone who knows what can be done, just plain weak-kneed. No highs, WEATHERS INDUSTRIES, 66 E. Gloucester Pike, Barrington, N.J. Division of Advance Industries, Inc. no presence . . . phooey! A real disap- Export: Joseph Plasencia, Inc., 401 Broadway, New York 13,1,1.Y. pointment.

80 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com I followed RCA's suggestion that you may copy off your old half-track tapes Outperforms Costliest Speaker Systems onto cartridges, or tape your (lise records into cartridges and I found that the resulting playback quality was not remotely ENJOY THE BEST AT GREATEST SAVINGS comparable to the original. That's a fair test. Even a low-priced home tape recorder should be able to reproduce a disc record from its tape with sound that is pretty EXCLUSIVE nearly equivalent to the input sound heard through the same system. Why not? All I A PRODUCT OF ALLIED RADIO can say is things didn't work out that way .í- here-and I tried two machines. It's really me say why. I'm just a simu- I High -Compliance not up to to man.i. =N lated customer, after all. iiiiii 1111111111.11111111N Electrostatic Speaker System Cartridge Disc AB í. m ONLY Comparable to speaker systems selling at 50% more! This whole business is tantalizing be- ... $12950 Here's an Allied exclusive- cause there are such big silver linings to ARTHUR JANSZEN DESIGN pat- $5 Down the hi-fi speaker sensation of these bleak clouds. Let me say quickly that ented dual ..electrostatic radia- the year-combining patented Arthur the playback of the commercial cartridges tors ...rated the best again and Built-in power supply; Janszen design dual electrostatic tweeters on my first RCA Victor SCP-2, by-passing again. ve.vet-smooth response to be- with a new and revolutionary high -compli- the built-in power and feeding the pre - yond 25,000 cps. ance woofer. The results are amazing: Dis- amps direct into my outside system, was tortion is held to a mere 0.5% at full 50 excellent, and absolutely all that could be watts input. Response is clean and level, asked for. I must say again, the cartridge EXCLUSIVE 30-25,000 cps. You have to hear it to be- is inherently good. HIGH -COMPLIANCE lieve it-transparent high frequencies to Just -to prove it for myself, I did a long 12" woofer featur- beyond audible honest AB test on an RCA Victor LP stereo disc ing weighted cone limits-smooth, KN enclosure, of 3/4" wood versus the very same recording in a tape in solid cast -alumi- bass. The -3000 num alloy frame... throughout, is finished on 4 sides; 14 x cartridge-it was the Mendelssohn "Refor- with heavy-duty mation" Symphony with the Boston Sym- sintered ceramic 261/2 x 13"; available in mahogany, limed magnet for ex- oak or walnut. Impedance, 8 ohms. U. L. phony under Munch, one of my favorite tremely dense flux. recent records, I got the two going in sync Approved. Shpg. wt., 50 lbs. (after I had slowed down my too -fast EXCLUSIVE: Acoustically correct KN -3000. Only $5.00 Down. NET $129.50 enclosure of choice hardwoods, changer turntable with a careful finger) finished on 4 sides... and switched back and forth from one to the other. Let me tell you, the AB was very nearly a draw, with the cartridge sound clearly a bit ahead on over -an impact. The cartridge noise level was a bit lower, or at least smoother and less noticeable, the sound perhaps a shade cleaner than that of the dise, the cartridge bass definitely richer and the dynamic range as good or maybe better. (The bass could have been a matter of equalization, of course, and/or perhaps a slight attenuation of the bottom end on the stereo disc in order to accommodate a long playing time. Has been done.) Definitely, the cartridge could match the dise on every important count, and perhaps surpass it. My ears won't tell me whether the very high highs were more audible on the dise than on the tape hut know well enough that the ultra -top 15 -Day Trial & Moneyback Guarantee. Try the I KN -3000 Speaker System in your home for 15 range is insignificant in musical impor- days; if you are not completely satisfied, your tance compared to the over-all quality of SEE YOUR ALLIED purchase price will be refunded by Allied upon sound and the presence of clean middle 1960 CATALOG return of the equipment. and medium -high highs, to 10,000 cps or so. for a detailed de- You are certainly free to argue that last scription of the order from point to suit your own preferences, and you remarkable new can judge the cartridge performance, ac- KN -600 HC high - ALLIED RADIO compliance 2 - cordingly, from your own angle. Give me way speaker, with the sensa- clean response to 10,000 and you can have tional 4.6 lb. ceramic magnet ALLIED RADIO, Dept. 34-1.9 100 N. Western Ave., Chicago BO, III. the rest, that tiny fraction of a per cent and 1/2" thick polystyrene cone. of the whole of the music that is 'way, See hundreds of other top Ship me KN -3000 Speaker Mahog. D Oak. Wal. way up. Naturally, each of us must fit buys on everything in Hi-Fi in System(s). D these things inter .our own listening pat- the 1960 Allied Catalog. Write $ enti. (Shipped F.O.B. Chicago) FREE terns. I can only pass- on my own reac- for your copy today. I am interested in saving money on everything tions, and sugge,st.that they do apply to in Hi-Fi. Send me your FREE 1960 Catalog. 1 Only $5 down many thousands of other musical listeners New Easy Terms: (or less) on orders up to $200. Name as well as myself.) Up to 24 months to pay. Address 1

That's it, for the moment. It is clear City Zone State (Continued on page 104) L --J

AUDIO NOVEMBER, 1959 81

www.americanradiohistory.comAmericanRadioHistory.Com NEW PRODUCTS

Noie'.co Stereo Recorder. Engineered net and ., nt:atching crossover network. each of which is entirely independent of and ,nanufactued by Philips of the Assembly consists only of mounting the the others. Both models have three op- Netherlands, the Norelco "400" features speakers, constructing the crossover net- erating speeds --17/s, 3) and 7a/ ips-with 4 -track stereo and monophonic record and work, and lining the cabinet with fiber a frequency range at the latter speed cif playback for tape economy; three speeds, glass which is supplied with the kit. For 30 to 16,000 cps within 2.0 db. Channel 7112, 3:1, and 1 T/,4 ips, for versatility; and full details write Heath Company, Benton separation is better that Ell db at 1000 simple piano -type keyboard controls for harbor, Mich. L-2 cps. Among' features of the recorder is ease of operation. It will also play back a selective erase switcl, which permits conventional 2 -track stereo tapes. Housed Fisher Integrated Tuner. Audio Control erasure of any one track without affect- in a high -fashion carrying case, the "400" C_nter. This unit is Fisher's ;newer to ing the other three. T:uufberg of America, consists of tape -drive mechanism, two the discerning music lover's demand .for Inc., 5 Third Ave., Pelham, V.Y. L-4 preamplifiers with controls, two 4 -watt maximum operating eflicieu'y and flexi- potter amplifiers, and a Norelco wide - bility, wtih minimum installation and Transistorized P.A. Amplifier. Engi- range speaker. Also furnished is a Norelco maintenance consideration. The new neered essentially for mobile operation, dynamie stereo (dual elements) micro- model 100-T is an ultra -sensitive stereo- the Bogen Model It'l'27i c:na be operated phone. All that is needed for stereo play- phonic FM -AM tuner and a flexible master front any 5- to 14 -colt d.c. source, includ- back is a second speaker. The machine audio control center mounted on a single ing 6- or 12 -volt automotive electrical sys- has inputs for recording from micro- integrated chassis. It is designed for tems. It will supply n full iii watts ,f phone(s), tuner and phonograph, with fa- every type of stereo and monophonic op- output power 1'1,111 a I2 -volt battery with cilities for mixing microphone with either eration. All types of record players, tape a current drain of three amperes. Maxi - tuner or phone. An output jack for moni- recorders, :nul external tuners crut be muta over -:all gain is I il dh. The unit has readily eounected for the reproduction of two separate inputs, one for a microphone any stereo or monophonic program ma- and the other for tuner, phone, or tape terial. It will also accommodate, directly recorder. Each input is individually con- on the chassis, the Fisher M1'X-20 FM trolled, permitting mixing of the two multiplex adaptor. F. dirt een front -panel

a 6 ('p se -

controls and switches, plus five on the t, i'ing with stereo headphones is also in- rear, afford an unlimited selection of pro- corporated in the unit. Because of the gram source and the highest possible de- Philips magnetic head with gap gree of control. A center -channel output of only 0.0001 in., extended high -frequency jack permits the connection of a third response is possible even at the lower amplifier and speaker for a more uniform spc, d Frequency ranges are stated by spread of the stereo sound pattern. The the manufacturer to be: 50 to 18,000 cps FM and AM sections of the 100-T are at 7 t/ ips; 50 to 14,000 cps at 3% ips, and wholly independent in operation and can 50 to 7000 cps at 1T/s ips. Signal-to-noise be used individually for monophonic re- rain is better than 55 db. Wow and flutter ception or simultaneously for FM -AM con'ent is under 0.2 per cent at 7% ips. stereo. The preamplifier is virtually with- An automatic stop is actuated by metal- out noise or distortion. Frequency re- lized tape end after wind, rewind, record, sponse is 20 to 20,000 cps within ± 1.0 db. channels. Respite its high power rating, and playback. This is a remarkably fine Distortion is less than 0.2 per cent at the BT25 is remarkably small and light, rated output of 5 volts. Hum recorder for the discerning home record- and noise are measuring but 6% x 33/4 x ins. ist. held to a minimum by fila- 4% and For further information, write: North d.c.-powered weighing only 3 lbs. It will fit in the glove American Philips Company, Inc., High ments. The 100-T may be used with any compartment of most cars. The output Fidelity Products Division, 230 Duffy high -quality dual -channel power ampli- receptacle on the amplifier is internally Ave., Hicksville, N.Y. L-1 fier, such as the Fisher Model SA -300. Engineered wired to match an S -ohm speaker, but to provide top performance taps are provided on the output trans- Heathkit Acoustic -Suspension Speaker. without compromise, this unit will satisfy former for handling impedances As a the most discriminative ranging result of a recent licensing agree- user. Fisher from 2 to 16 ohms. This is an ideal unit ment, Heathkit becomes the sole kit li- Radio Corporation, 21-21 44th Drive, Long for fire department or police use, or Island 1, fur censee of Acoustic itesearch, Inc., and is City N.Y. L-3 any general application where a small now offering' the AR acoustic suspension high-powered p.a. amplifier is required. principle in kit -form speaker systems. The Tandberg Four -Track Recorder. ttevel- oped prin::,rily for Roger -Presto, P.O. Box 500, Paramus, first Heathkit to use the system is the educational and in- ..J. L-5 AS -2, a kit version of the AR -2. The 10 dustrial usus, the new T:,o,lberg four - -in. track :acoustic -suspension woofer and a two - loou::l,honic tape recorder affords Transistorized Harmonic Generator. In- speaker "cross -fired" tweeter assembly tended primarily to simplify and speed up the servicing of transistor radios and other types of transistor circuits, the HG - 104 is ideal for trouble -shooting high fi-

provide frequency range of 42 to 14,000 maximum recording and playing time on cps within + 5.0 db. Harmonic distortion quarter -inch tape. The Model 4 which is at 10 watts input is less than 2.0 per cent mutually operated, and the Model 4F delity components and other audio cir- above 60 cps. The AS -2 is furnished with which is a remote -control machine, will cuits. The instrument provides :audio, i.f., a completely assembled, pre -finished cabi- record, play, or erase four separate tracks, and r.f. signals simultaneously, thus Mina -

82 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com 3 NEW TUNERS FROM :tlntinc set -tip tinte and frequency selection. lise of the 11U-104 also eliminates the nerd for unsoldering transistors fir test until the faulty one has been discovered. Seni nre, Addison, 111. L-6

A.V.C. Amplifier. l àvel.,ped for broad- 'mst and public-address application, this H. H. SCOTT a111Rtliti.r will maintain n eotist;nit output within ± 1.0 db with input changes ais great as 30 db. Exteedingly rapid automatic gain reduction prevents syllable slipping, and .shit a utomalie rain increase ;ivoi Is auttontatie control ;.t syllabic frequencies. For broadcast application, the gain t:un'ol feature automat'. -ally keeps modulation ait peak levels tvithoatt 1'Sceed- ing modulation limits and eliminates the element of human error. For p.a. :nid

330 D Stereo _ittO s ystem atppliotiti inns, nutniaaii mnopens tion is made within very iv ÍII AM -FM Tuner 51811111 1 11 11 I volt- 1111111 1:10 (lb, or 0 lit in $?24,95' .( to Set p the output level . oust;11tt icilltiu 9.11 dh. Fretluenty response is _)1 to 20,000 cps ivithiu I.ti db. 1tviv.-1111 gain is 35 to :l0 dl, tvitlt ;t signal-to-noise ratio

of 60 dt . (hated power output ismilli- ivatts lit '.n per cent total dislortiou. Ait rtdjustaible gain -reduction ;11111 ,rain-itt- Wide -Band FM...Wide-Range AM Make These tease speed eontrol enables variation iu attack and release tinting. The unit has a Most Sensitive, Most Selective Tuners! self-, mit:tined ttoivt'r supply, and is housed World's 1111(1 eabinel de- in a ventilated shielded radically new H. H. Scott 330D signed for standard ratek-patnel mounting. The completely separate FM section of the e'outpletë teclniie;al stlecitientions may be stereo tuner utilizes H. H. Scott's exclusive Wide -Band FM circuitry to assure obtained by writing to Amplifier Corp. of reception in even the weakest signal .\meriea, :190 hroanlWaty, New York 13, absolutely drift -free and interference -free . 1'. L-7 areas. Wide-Band design also lets you separate stations so close together on Audio Delay Line. This devise is now the dial that ordinary tuners would pass them by. The separate AM section being produced by The I tatou company, unique Wide -Range detector so that, for the first time, Livingston, N.J., for use in the iontpaitiltl:' utilizes H. H. Scott's stereo broadcat.sting system developed by- you can receive full range AM broadcasts with fidelity and frequency response l" loyd K. Becktr of Bell Telephone Labora- adaptor facilities let you convert to tories, and first revealed to the engineer- comparable to FM. Special multiplex ing fraternity in ;nt .article by Mr. tot multiplex at any time. in the Abty, 1959, issue of :l'I->Itt. At pres- 320 AM -FM TUNER ent the system is being used successfully The many fine fea- by the National I;roadeasting i't'nitrnty. built into this 9'51, the tures The Itatven delay line, Sp,''. has superlative tuner, h.1I,.ieili l'lia11'ate te rist ics' total delay lu including Wide - Range AM and Wide -Band FM, have never been avai able before for less than $200. This tuner is ideal where AM -FM stereo reception is not available. $139.95* 310C FM TUNER This professional tuner is the most sensitive and selective available. Its outstanding performance and sensitivity have made it the choice universities and laboratories throughout the ;...,.'irF for maxi- of 1. Separate FM front-end, silver plated world. Sensitivity 1.5 µv for 20 db of quieting. ." mum sensitivity. 2. Separate AM front-end. (IHFM rating 2µv) $174.95* 3. Separate AM and FM professional tuning con- s1w °Slightly higher West of Rockies. Accessory case extra. trols. 4. Wide -Band FM detector for distortion -free reception on all signals. 5. Highly selective FM IF stages permit separation of stations close together on dial. 6. Wide -range AM detector. 7. Selector H.H. SCOTT ee switch. 8. Band switch with these positions: FM, AM Wide, AM Normal, AM Distant. 9. Illuminated Mass. H.N. Scott, Inc. Ill Powdermill Road, Dept. ' - Maynard, tuning meter. 10. Stereo output jacks. 11. Jack ]chase linearity . 1.0 per spe- milliseconds: instant connection of multiplex adaptor. Rush me new catalog and complete technical -o :I.n per 1e - for cent, I n)1 to 111,11)1)1 cps, components. recorder output jacks.13. AM Ferrite cifications on all new H. H. Scott 10W 11111 cps; fretlueney response - '.0 tlb, 12. Stereo tape impedance Mitt Antenna. 14. Chassis constructed of heavy 311 to 111,000 cps: input Loop Name ohms ;1t normal level of 4.0 rllrtn: output copper bonded to aluminum tc insure reliability. itnt itnpedaner 000 ohms: h;11nio0ie distort 15. 10 KC whistle filter. Specifications: FM sensi- Address d less LO per crut ; insert ion lit dbnt than tivity 2 microvolts for 20db of quieting; (IHFM 11/SS zet'.,; hunt and noise level is d'nvn City State rating 2.5 sv); FM detector bandwidth 2 mega- r,0 intorutatiun db. -Requests for further Export: Telesco International, 36 W. 40th St., N.Y.C. should be directed to the intention of cycles. E. L. Grayson at the address shown al,,v.. L-8 HEAR THE FABULOUS LONDONSCC TT INTEGRATED STEREO ARM AND CARTRIDGE

AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com Aluminum Component Slides. These mum extension is 14 ins. Equipment 21/4 "d. Argonne Electronics Mfg. Corp., slides are int,nded for use with record slides smoothly on precision changers, ball bearings. 165-11 South Road, Jamaica 33, N.Y. turntables, amplifiers, tuners, A special silencer spring eliminates vibra- L-10 tion and resultant distortion. Robins In- dustries Corp., 36-27 Prince St., Flushing 54, N.Y. L-9 Illuminated VU Met.er. Encased in clear plastic, this instrument utilizes a precision jeweled -bearing D'Arsonval m"ve- 'cent and provides 2.0 -per cent accuracy for full-scale meter deflection. The 3900 - ohm "A" scale indicator is calibrated and damped in accordance with standard FU meter practice. The upper scale of the large 3 -in. meter reads -20 to + 3 db, while the lower calibration reads 0-100 per cent m"dulation, with 0 db corresponding to 100 per cent. Useful frequency range is or similar -i cabinet ialosed equipment 20 to 20,000 cps. The meter will reach 99 which must be moved t iitviud for acces- per cent of steady state reading within sibility. Designated ,':<-I:tll, the slides 0.3 sec. when a sine wave is suddenly have a load c1 ap- capacity :hi lbs. and maxi- plied. Dimensions are 31/2"w x 3-1/16"h x

GRADO NEW LITERATURE Semiconductor and Materials Division, "Truly Radio Corporation of America, Somerville, the world's finest..." N. J., announces availability of the "RCA Semiconductor Products Handbook HB - 10," devoted exclusively to data on RCA semiconductor devices including transist- Master Stereo Cartridge $49.50 ors and silicon rectifiers. A companion to Custom Stereo the "RCA Tube Handbook HB -3," the new Cartridge $32.50 publication is available in conjunction Micro Balance Tone Arrr $29.95 with the HB -3, or separately. The new handbook has been compiled to meet the requirements of electronic equipment design engineers primarily, but will prove useful to all who have need for up-to-date technical information on semiconductor devices. Convenient loose-leaf form permits revision of data on existing types and the addition of data on new types as they are made available. Subscription to the handbook HB -10 is $5.00 domestic ($5.50 foreign), and includes one binder, data sheets, and service for one year.

Allied Radio Corporation, 100 N. West- ern Ave., Chicago 80, I11., is now distribut- ing its new I Iwo catalog. Consisting of 444 pages, of uchich 232 are in color rotogravure, this biggest of all Allied catalogs lists more than 40,000 items. Featuring extensive listings of stereo components, it also includes a wide selection of complete systems. In addition, the catalog lists several do-it-yourself stereo systems featuring Allied's own Knight -Kits. Do- it-yourself enthusiasts will find a bigger - than -ever selection of hi-fi amplifier, tuner, and preamplifier kits, plus expanded listings of custom cabinet kits for speakers and other components. Music lovers who desire the finest in record entertain- Skilled watchmakers working to almost ment will find listed a wealth of specially unbelievable toler- selected stereo records from which to ances, handcraft each GRADO Stereo Cartridge to a degree choose. Latest 16% -rpm "talking book" of performance which has become a universal standard of records are also included. Your copy of this great catalog will be mailed free upon quality. written request. L-13 Extremely low surface noise due to phenomenally wide frequency response, coupled with extremely low CBS Electronics, Information Services, distortion and 100 Endicott St., Danvers, Mass., will mail excellent channel separation, achieve uncompromising realism. free Bulletin E-355 which gives complete Full bodied sound technical data on the first in a series of alive with delicate timbres, combined with complementary NPN-PNP power -trans- wide dynamic range, will thrill you with the impact of a live istor lines. These complementary pairs performance. of transistors permit new circuit design economies. The planned line of five NPN- PNP pairs is the result of a customer application survey made by CBS Electronics. GRADO LABORATORIES, INC. The pairs feature high voltage-up to 100 volts-and proved reliability (exceeding 4614 Seventh Ave., Brooklyn 20, N. Y.-Export-Simontrice, MIL -T -19500A) for audio, control, voltage 25 Warren St., N.Y.C. regulation, servo and computer applications. L-14 Audio Fidelity Professional Products Inc., 770 11th Ave., New York 19, N.Y.,

84 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com will mail without charge an attractive folder listing the complete line of Tele- funken microphones as well as a number of professional audio components and accessories. Of particular interest to TV, stage, and motion -picture producers is the "Microport," a small FM receiver and transmitter assembly of the "wireless microphone" type which has a range of approximately 1700 yards. Users of professional audio equipment have a distinct need for this publication. Write for it. L-15 General Electric Company, Semicon- why ductor Products Department, Charles Building, Liverpool, N.Y., is now publishing a new edition, the fourth, of the "Transistor Manual," which contains 227 pages of information on transistors and ruin their uses in electronic circuits. Included in the 20 chapters is information on basic semiconductor theory, transistor construction techniques, biasing, switching characteristics, transistor servicing techniques, your and several articles on circuitry. In addition, the book contains a revised and up- to-date listing of all American JEDEC- registered transistor types with their valuable basic specifications and interchangeability information. The "Transistor Manual," fourth edition, is priced at one dollar. records? Allied Radio Corporation, 100 N. West- ern Ave., Chicago 80, Ill., has just published "Understanding Transistors," a 64 - page handbook which not only serves as an excellent introduction to transistors, but also as a helpful reference for those already acquainted with the subject. Writ- ten by Milton S. Kiver, well-known author of many volumes on electronics, the book opens with a concise discussion of the properties of germanium. Opening sections of the book clarify basic theory and provide a solid foundation for the succeeding chapters. Many transistorized circuits, with a detailed explanation of each, included. than 50 grams and illustrations. Price of "Under- standing Transistors" is fifty cents.

CBS Electronics, Danvers, Mass., has available for dealers a new phono cartridge cross-reference chart. It lists both CBS-Ronette and Columbia CD cartridges for exact replacement of more than six million cartridges now in use in the U.S.A., and provides a convenient tabulation of technical specifications. Exact -size silhouettes for each cartridge TONFARM CONTROL provide a quick identification of model number, and a handy table illustrates and If the tonearm slips out of your fingers and describes various bracket installations. bounces over the record -the record is The 8 -page catalog, Bulletin PF -285, is available free to independent service deal- lowers the ruined! If you're unlucky, you will also ers throng their distributors. need a new stylus and possibly a new cartridge. Radio Shack Corporation, 730 Common- Why take a chance? DEXTRAFIX® TONE- wealth Ave., Boston, Mass., has just an- tonearm nounced publication of its annual elec- ARM CONTROL prevents such accidents! It tronic parts and equipment catalog, "1960 places the stylus in the lead-in groove Guide to Electronic Buying." The publica- - tion scores a number of firsts for a parts gently and accurately. Then, at the end distributor's catalog. It is printed entirely into the of play or at any point on the record, it in rotogravure on 8x/2" x 11" magazine -size paper stock, contains paid display adver- lifts the stylus from the record. And the tising and articles written by leading au- stylus cannot touch the record until the thorities, and features a handbook for the is again lowered for next engineer and the hobbyist. The catalog lead-in lift bar the play. lists some 40,000 electronic items. Net, The DESTRAFIX® TONEARM CONTROL also as opposed to list, prices are shown. It facilitates "cueing" at any point on the includes over 100 pages of hi-fi products, and some 200 pages of industrial and serv- groove. record. ice items. Price of the catalog is thirty- A must for turntables-and record five cents postpaid to consumers; it will be mailed free to industrial concerns re- changers with manual operation! questing copies on a company letterhead. lifts it $4.95 Sylvania Electric Products Inc., 1100 Main St., Buffalo 9, N.Y., has available a Another quality product new characteristics and replacement guide by the manufacturers of for semiconductor diodes. Included in the after play! 12 -page booklet are complete data on the LEKTROSTAT® ratings and electrical characteristics of Record Cleaning Kit all Sylvania types as well as a replacement guide to virtually all EIA registered diodes. Copy will be mailed upon written request. L-16 dexter chemical corp. consumer products div. 845 Edgewater Rd.. N.Y. 59

AUDIO NOVEMBER, 1959 85

www.americanradiohistory.comAmericanRadioHistory.Com NEW! sensatIon of

TWO HAROLD LAWRENCE'

Encore! Bin! Altra Volta! The subject tion. Obviously unsatisfied with the meager h° fl of encores again came into the news applause that greeted the première perfor- this past summer when Russian critics mance of a modern orchestral work at a scolded Leonard Bernstein, on tour with Boston Symphony program, Serge Kous- sh ws the New York Philharmonic, for impos- sevitzky spoke to the audience: "I can see ing a repetition of Charles Ives's The that you didn't understand this piece. We'll

If you're a stereo connoisseur Unanswered Question upon his Muscovite play it again to give you another chance to with a limited budget, you deserve audience. Last year New York critics filed appreciate it." the sensation the New York a similar complaint against Yehudi Menu- of Between Movements and Chicago high fidelity shows: hin for playing a Bach solo encore at a the superb new ESL C-99 New York Philharmonic concert. Both these Applause between movements of a con- Micro/flex stereo cartridge. performers struck back at the critics- tinuous musical composition is generally Bernstein in statements to the press and frowned upon by experienced concert goers. Years of advanced transducer Menuhin in an article for the Saturday When it occurs, the performer pretends to technology have in culminated a Review-and attributed their actions to ignore it, averts his eyes from the direction cartridge which equals the what Menuhin calls, "the collective heart of the hall, and waits for the right mo- performance astonishing specifi- and spirit of a friendly crowd." But just ment to resume the performance. The late cations of the international as reporters and politicians differ on the Hans Kindler, on tour with the National stereo standard, the ESL C-100 size and sympathies of a street rally, critics Symphony, once encountered between -move- Gyro/jewel. and artists differ likewise on the volume ments applause during a rendition of and of a Like the world -famed C-100, the intensity applause at concert. Tchaikovsky's Pathétique Symphony in This disagreement is one of the many new C-99 utilizes two patented fac- Springfield, Massachusetts. He waited dis- made, D'Arsonval generating assemblies tors that have and continue to make, creetly for it to stop; instead, it seemed to the encore issue in -the most linear transducer an often controversial gain momentum. Several times, the con- public music -making. elements known. Instead of the ductor raised his arms to give the down- There is no mistaking the spontaneous C -100's jeweled separating beat, but the audience simply would not be outburst of applause, with elements, the C-99 pioneers the shot through quiet. So he turned around, and gently follows a out- exclusive new Micro/flex cries of "bravo," that truly reprimanded the listeners: "You really frictionless molded coupling standing performance. Everyone present shouldn't do that, you know. All the same, expects the to his system. artist favor audience thank you very much. And since you seem with an encore or two. In the ease of such to like this movement so well, I'll play it a performer as Wilhelm Backhaus, this for you again." could be a lengthy affair, lasting until the Encores of this variety, however, con- house management turns on all the lights, stitute rare events in the concert hall. The drops the curtain, or rings bells in an effort Springfield audience in that incident had to drive out the musical squatters on both the first movement repeated, but usually sides of the stage. The encore, however, is it is the scherzo or allegro finale that is not always as simple a matter as this. A encored, as in the ease of the first perform- musical -sociological study of the encore - ance of Roussel's Symphony No. 4, for taker should include the following cate- example. gories: manner, motive, time, place, and In the history of orchestral encores, choice of repertoire. surely Leopold Stokowski surpassed all When you come right down to it, every other conductors in terms of the duration performer fully intends to take encores at of Isis post -concert offerings. As guest con- the conclusion of his recital, and indeed ductor of the N.B.C. Symphony, lie once conies well prepared with a number of directed performances which were broad- additional pieces. Less predictable is the cast from the Cosmopolitan Opera House manner in which he proceeds to take the (now the New York City Center). The encores. The ever -ready encore -taker is public was invited and the price of admis- never too sure of his reception and rushes sion was $1. Because the radio program The resulting cartridge is back on stage after only a smattering of lasted one hour, Stokowski felt that the distinctly superior to everything applause, hoping to intercept the audience's public was not getting its money's worth. the ESL except C-100 and P-100, move for the exits. The short intervals be- Accordingly, he scheduled encores after the yet costs only half the price.* At tween bows and the rapid succession of show went off the air, solely for the bene- a mere $49.50, the new C-99 is pieces soon make it perfectly clear that the fit of the studio audience. On one occasion, the lowest price ever for authentic artist is performing "unilateral" encores, the orchestra was deployed in the usual ESL stereo superiority. based not on the public's enthusiasm, but Stokowskian manner; that is, in a highly on its mere presence. unorthodox arrangement. No section was The reluctant encore -taker, on the other place; furthermore, a FOR LISTENING AT ITS BEST in its traditional hand, appears never to have heard of cluster of brass players was located behind Electro-Sonic encores. He beams at the audience, bows the podium, along the apron of the stage. elegantly, but will only perform when the At no time during the program did the Laboratories, Inc. public becomes explicit in its demand and brass sound. But after the announcer had Dept A 35-54 36th Street begins to shout, "encore," or calls out titles signed off, Stokowski informed the audi- Long Island City 6, NY of favorite pieces. ence that they were about to hear their Encores are sometimes dictated by a cool "encore": Shostakovitch's Symphony No. 6. reception rather than by a heartfelt ova- The work began, and still the brass re- *Net price for the C-100 is now $100, and the P-100 is $110, mained silent. Finally, after half an hour including transformers. * !6 W. Ninth St., Neu- York 11. N. Y. of Shostakovitch had elapsed, the players

86 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com received their cue-and what a cue it was! Stokowski suddenly spun around on the podium, his snowy inane and famous profile caught in the spotlight, and pointed a THORENS TD -124 lets you well -manicured hand in their direction. The effect was startling. In the realui of symphonic, chamber, or solo instrumental concerts, interruptions of concentrate on music a symphony, quartet, or sonata for encore purposes is largely a thing of the past. The same might he said for operatic en- not on cores, though vestiges of this tasteless practice still exist. No less a renowned artist than soprano Renata Tehaldi indulged in mechanics an encore during a San Francisco performance of Tosea less than five years ago. Re- sponding to an especially noisy ovation (reinforced by a claque), she stepped out of character to acknowledge the applause and cheers, and then signalled the conductor to repeat the aria, "Vissi d'Arte," thereby making an artistic shambles of the opera's dramatic continuity. Tebaldi's encore annoyed not only the critics but also the opera buffs who like their Puccini straight. The same critics would have been far more annoyed at the behavior of certain earlier singers who in- terpolated totally unrelated songs or arias into the operas they sang. In his entertain- ing book, The Music Goes Round, the late recording impresario, Fred Gaisherg, tells of two such vocal sinners. The first, Miguel Pieta, "would respond to a bis with encore after encore of popular songs which had nothing to do with opera," while the second, Jan Kiepura, "would make sure that a piano was ready in the wings for accompanying him as he rushed out to take his encores-all, of course, irrelevant to the opera." While one cannot wholly agree with Artur Sehnabel, who once said, "Applause is a receipt not a bill," there are times when it might be a good idea to dispense with the encore and adopt the ancient Russian custom of applauding the applaud- ers. Finest Swiss -precision craftsmanship, famous for generations, is embodird in the Thorens TD -1.24. It's the one turntable that lets you forget COMING HI-FI SHOWS technical problems-rumble, wow, flutter, _Nov. 6-8-Seattle, NVash., New Washing- incorrect speed and consequent ton Hotel. (Rigo ) "off -pitch" reproduction ...all Nov. 8-15-Mexico City: Fifth Higln Fi- the rest of them, as if they never delity Fair, 300 Insurgentes Avenue existed. Relax. Concentrate solely Building. Gala inauguration ceremonies, Nov. 7, 5:00 p.m. Also in the same week, on music as it was meant to be heard. First International Symposium on Audio, See, hear this world-renowned tran- Hotel Plaza Vista Hermosa, a meeting scription turntable at your Thorens fran- of audio engineers. For information, chised dealer's today. 9.17 write or phone Miguel Augusto :Aranda, $99.75 net. President, Asociaeion Mexicana de Im- Thorens TD -124. Finer craftsmanship, more features, pulsores de Alta Fidelidad, A.C., Genova than any other turntable anywhere. Acclaimed by criticu. throughout the world. 16-2, Mexico, D.F., Mexico. Telephone 11-24-57. AND THESE OUTSTANDING VALUES COMPLETE THE "TD" FAMILY OF FINE TURNTABLES: Nov. 13-15-Portland, Ore., New Heath -

man Hotel. (Rigo ) Thorens TD -184, $75.00 net. A Thorens TD -134, $60.00 net, A Thorens TDK-101, $47.50 net. Nov. 20-22-Philadelphia, Pa., Benjamin "TD" transcription table with manually -operated transcrip- "TD" precision in kit form. Franklin Hotel. (Rigo) integral arm, "Dial -o- rratic" tion table with stereo -wired arm Simple to assemble with no Dee. 4-6-Minneapolis, Minn., Hotel Leam- operation. Arm wired for any gives you superlative quality special tools for superlative rec- ington. (Audio Div., Paul Runyon Chap- standard stereo pickup. with minimum expense. ord reproduction. ter, ERA) Sold only through carefully selected franchised dealers Jan 13-17-Los Angeles, Pan Pacifie Audi- torium. (H/FM) SWISS MADE PRODUCTS Jan. 23-26-San Francisco, Cow Palace. HI-FI COMPONENTS LIGHTERS (MR1A) SPRING -POWERED SHAVERS Jan. 27-30-Vancouver, B. C'.. Canada, HOREj5 MUSIC BOXES Hotel Georgia. (IMF A) NEW HYDE PARK, NEW YORE

AUDIO NOVEMBER, 1959 87

www.americanradiohistory.comAmericanRadioHistory.Com Ns>, tise.s.:-..:.:1`.\1 AMPLIFIERS (from page HI.FI Sit li" An alternative approach is the twin - AMPLIH' coupled amplifier referred to previously. This uses completely separate transformers but employs large capacitance from screen to cathode to achieve tight coupling at the higher frequencies. The double transformer achieves sufficiently close coupling for the low frequencies, which is not difficult. The Circlotron circuit utilizes a com- paratively ordinary output transformer and only needs one of them. Its disadvantage is the fact that it needs two high -voltage suppliers. While this may STEREO AMP. not be any more expensive (probably is SM -88 Possible to combine with any pick-up or tape -recorder. Most less expensive, in fact) than using two suitable for home or business use. Power Output: 20 Watts or a more expensive (10W each channel) output transformers There are only a few knobs, like in an ordinary single stereo single one, it does have the disadvantage Frequency Response: amplifier, enabling any member of the family to handle it easily. 1 db 20 to 40,000 cps. that the high -voltage suppliers are vir- Output Impedance: 8.16 When two amplifiers are combined by means of an output tually attached to the plates and cath- and 32 ohms terminal, they become an ordinary amplifier of 20W output. Sensitivity: for 10W out- Speaker performance is possible. odes of the output stage. This means in the supply circuit put each channel TAPE By means of a MODE switch, it can be operated four ways. that capacitances 2mV, MAG 5mV, X -TAL This makes it very convenient to use as it eliminates changing and the power transformer are effec- 100mV, AUX 0.2V the wire connections each time. tively in the audio circuit of the amplifier which can introduce complications MODE SWITCH in that direction. MASTER VOLUME So each circuit has its critical factors BASS CONTROL and it is only by taking careful account in each TREBLE CONTROL ' of the various critical factors circuit, watching out for the possibilities BALANCE of blocking, or other spurious conditions SELECTOR 460, IZUMI-CHO, SUGINAMI-KU, TOKYO, JAPAN -the things that can happen due to the difference between practical program material and the kind of signals used for measuring amplifier performance- STATEMENT REQUIRED BY THE ACT OF AUGUST 24, 1912, AS that a satisfactory amplifier can be pro- AMENDED BY THE ACTS OF MARCH 3, 1933, AND JULY 2, 1946 duced. Using any basic circuit as a (Title 39, United States Code, Section 233) SHOWING THE starting point it is possible to design OWNERSHIP, MANAGEMENT, AND CIRCULATION OF out the various bugs that spoil amplifier performance. AUDIO, published Monthly at Lancaster, Pa., for October 1, 1959 So, rather than saying that any one 1. The names and addresses of the publisher, editor, managing editor, and busi- particular circuit is basically the best ness managers are: Publisher: Charles G. McProud, 204 Front St., Mineola, N. Y.; circuit, it is better to look a little closer Editor: Charles G. McProud, 204 Front St., Mineola, N. Y.; Managing editor: none; and see how well the circuit has been Business manager: Henry A. Schober, 204 Front St., Mineola, N. Y. designed as regards avoiding some of the spurious things that can happen in am- 2. The owner is: Radio Magazines, Inc., 204 Front St., Mineola, N. Y.; Henry A. plifiers. PE Schober, 204 Front St., Mineola, N. Y.; Charles G. McProud, 204 Front St.. Mineola, N. Y. PREAMP 3. The known bondholders, mortgagees, and other security holders owning or hold- MICROPHONE (frotta page 50) ing 1 per cent or more of total amount of bonds, mortgages, or other securities are: none. J« Output connector, Amphenol 91- 860 4. Paragraphs 2 and 3 include, in cases where the stockholder or security holder Q, 2N133 transistor appears upon the books of the company as trustee or in any other fiduciary relation, Q: 2N132 transistor the name of the person or corporation for whom such trustee is acting; also the R, 5600 ohms, 1/z watt statements in the two paragraphs show the affiant's full knowledge and belief as to Ref Rs 120k ohms, 1/2 watt the circumstances and conditions under which stockholders and security holders who R3 560k ohms, 1/2 watt do not appear upon the books of the company as trustees, hold stock and securities in R,, R8 100 ohms, 1/2 watt a capacity other than that of a bona fide owner. Rs, R9 10,000 ohms, 1/2 watt R7 1/2 (Signed) HENRY A. SCHOBER, Business Manager. 390k ohms, watt 20,000 ohms, 1/2 Sworn to and subscribed before me this 9th day of September, 1959. Rlo watt (Seal) Donald F. Mattone, Notary Public. 2 Penlite batteries Miscellaneous hardware State of New York. No. 30-7766600. Qualified in Nassau County. Term expires Insulated mounting board, 3 x 5 March 30, 1960. in. Aluminum box, 5 x 3 x 11/2 in.

88 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com UNIVERSAL STEREOPHONIC CONTROL CENTER (f rom page ;21) aeterizes the extremely quiet perform- over-all clean sound of the control unit. cartridges used were the Fairchild XP -4 ance of the control unit. Transient re- Further, its excellent low -frequency ,>'e- and 232 magnetic cartridges and the sponse is excellent, as shown by the sponse really shows up on strong bass Eleetro-Voice 21-D ceramic cartridge. square -wave photographs of Fig. 2, with passages, such as organ pedal notes. Dis- All cartridges tested performed excel- no signs of ringing or overshoot. The tortion is low, as shown by Fig. 4, and lently in conjunction with the control frequency response is flat and smooth RIAA equalization exact, as shown by center. The control center had gain to as shown by the response curve of Fig. Fig. 5. spare, even with the low -output Fair- 3. This smooth response leads to the Extensive listening tests and measure- child cartridges -5 millivolts for 7 ments have been conducted using repre- em/sec deflection. Using the standard sentative samples of both magnetic and Nestrex 1-A stereo test recording, both ceramic stereo phono cartridges. The types of cartridges showed flat, smooth

+20

BASS FULL C W. I TREBLE FULL C. W. +10 I. I. Fig. 3. Frequency II _/.... 3 response curves, 7 o ,.... showing tone -con- BASS AND TREBLE SET FLAT

trol performance. 51 10 BASS FULL C. C. W. I â ,NMI

20 1 -- 1111 TREBLE FULL C.C.W."III

I 20 3 20000 100 1000 , , 10000 Fig. 2. Square -wave responses of the FREQUENCY IN CYCLES PER SECOND amplifier. Upper, 2000 cps; lower, 60 cps. ONY The Famous SONY C37A Condenser Microphone Professional acceptance of the Sony C -37A microphone is due to its trouble -free, static -free performance. Perfectly matched with the CP-2 power supply, the C -37A microphone features an exceptionally smooth frequency response from 20-20,000 cps.

U.S. DISTRIBUTOR: SUPERSCOPE, INC. SUN VALLEY, CALIF.

TOKYO .. ONY C ORE ORATION JAPAN

AUDIO NOVEMBER, 1959 89

www.americanradiohistory.comAmericanRadioHistory.Com tion he used for easiest construction. Tise Separate channel construction also has 0.7 the advantage of keeping the left Z .1.11...1.... -right 0 ...... c DUAL R 0.6 channels physically separated thereby -1006 PHONO" X333333.%1/3U.w2I/! 0 BMINPUT... reducing interchannel crosstalk. Because G 0.5 11...3werAI... of ó .p'01__....r.. the outstanding hum and noise per- satisfies Z 0.4 II...pL.. formance of the control unit it is im- 0 1r/..5. 0.3 ...3333. portant, regardless of what type of con- â 31I11.131C du.- TUNER ..... INPUT 111111 struction is adopted, that the every need ./13311111G113 entire con- 0.2 31 33311. ó /IY .1113 trol unit be encased in a metal enclo- RATED 0.1 iiuruu1 ..313.3... sure so as to shield it from unnecessary MOM OUTPUT 3333333333 ..as both a professional z o 73131M1uuuu hum pickup. single play turntable 0 0.5 1.0 15 2.0 25 The phono preamplifier stages (V, OUTPUT LEVEL-VOLTS RMS and V5) should be shock-mounted to and superior prevent Tnicrophonics. Shock mounting Fig. 4. Distortion vs. output curve. of these tubes can be easily done by record changer placing a small rubber grommet on each frequency response. Mounting screw between the tube socket Using the Fairchild Tracks-and operates automatically 232 stereo cart- and the chassis and allowing the tube ridge, a comparative listening test be- socket to float on these grommets. -with stylus pressure as low 11/2 as tween stereo disc and tape was con- All grams! Minimizes all leads carrying a.c. to the control wear. ducted. Using RCA Victor's "Hi-Fi unit should be shielded to minimize hum. Fiedler" (disc LSC-2100 and tape Use two -conductor shielded cable for BCS-41) an audience was asked to note DUAL -1006 connections to the pilot light (PL,) , the difference between stereo disc and power -switch section of S, (S,0), and Built-in direct reading stylus pres- tape on an A -B basis. Most listeners a.e. heater wiring for Vs, V4, V7 and sure gauge. Easy to use, weight ad- could not note any difference. Those Vs. Do not use shielded cable anywhere justment conveniently located. that did identified the disc primarily by else in the control unit as the high ca- the surface noise of the disc. pacitance of shielded cable will cut down the high -frequency response of the DUAL -1006 Construction control unit. Instead, use twisted -pair Big, heavy 105/s" turntable is lami- 1)o not he frightened by the seem- wiring for all connections between input nated and concentrically girded. ingly complicated circuit schematic of and output jacks to the amplifier, and Can't warp or become eccentric. Fig. 1. All stereophonic control units between the amplifiers and all controls. must look complicated for they contain Twisted -pair can be easily made by twice as touch circuitry as their mono- tightly wrapping together two pieces of DUAL -1006 phonic equivalents. A quick glance at hookup wire. One wire should be used this schematic will show that both chan- as a shield and connected to common Rumble -free motor is so powerful nels are almost identical and that con- ground and the other wire used as the turntable reaches full RPM from struction is a matter of building two signal conductor. There is only one ex- dead start in less than 14 turn! control units within a single housing. ception to this twisted -pair rule. When The only place where differences between wiring between the amplifiers and the DUAL -1006 the two channels exist is in the vertical - tone controls, use twisted -pair but also lateral mixing circuit ( V26 and V6B) cover the bundle of twisted -pair cables All drive gears disengage automati- However, the difference here is in the running to each tone control with a cally-no "neutral" position to re- resistive mixing and these components loosely fitting shield of braided copper, member, no flat spot thump. can he mounted on the TYPE switch (S,) and ground the copper braid. This ad- directly. This makes both channels iden- ditional shielding is necessary because tical in construction. the tone controls are particularly sensi- DUAL -1006 As can be seen in the photographs, tive to hum pick-up. Be sure to keep all Obsolescence -proof intermix for all the author used two identical wiring twisted -pair cables from one channel present or future record sizes. Stack hoards for the main circuitry. It is sug- well separated from the twisted -pair in any sequence. gested that a similar type of construe - cables of the other channel. DUAL -1006 Elevator Action changer -spindle prevents damage to record grooves and center holes. Truly gentle! .lo Fig. 5. Curve of RIAA equalization I 5 DUAL -1006 compared to the 6 o resultant curve of 5 For the full story, write... the amplifier. 0 > to

''..°5; united udio -20 20 PRODUCTS OF DISTINCTION l.0 1000 1=0 ° 202-4 East 19th St., N. Y.3, N.Y. FREQUENCY IN CYCLES PER SECOND

90 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com in Fig. 1. This Grounds for each channel should not 000 ohms, only that they match each of this tube as shown c: insures a low return imped- be connected directly to the chassis, but other. pacitor to ground the d.c. heater sup- should he connected to a separate The BALANCE control is a two -gang ance for pick-up of the ground wire connected to the chassis 500,000 -ohm linear potentiometer that ply and lowers the hum only at the input phono jack. Connect should he wired so that the resistance cascode preamplifier. the left ground wire bus to the chassis in the left channel increases and the at J, and the right ground wire bus to i -sistance in the right channel decreases Power Supply the chassis at .I,. The power supply as the control is rotated clockwise, and is a The power supply (shown schemati- ground return lead (pin P of P, ) vice versa. The GAIN control also cally in Fig. 7) should not be built on should be grounded to the chassis with a two -gang potentiometer, 250,000 -ohm, control unit, but ground lug at the power plug, P,. audio -taper type. It should he wired so the same chassis as the separately and placed Low -noise deposited -carbon resistors that the output of both channels in- should be built five away from the main con- are liberally used in the phono pream- creases as the control is rotated clock- about feet supply was de- plifier section of the control unit. 1)o not wise. trol unit. The power with the con- substitute conventional carbon types. A 25-µf, 150 -volt electrolytic capaci- signed especially for use unit it is not suggested that The use of deposited -carbon or wire - tor, C'R, should he connected front the trol and supplies be substituted. As wound resistors in this critical circuit heater of the right cascode phono pre- other power earlier, it is essential that d.c. is well worth the additional cost in terms amplifier, Vs, to ground at the socket noted of the superior low thermal -noise performance that results. Keep all leads in the phono preamplifier as short as possible. As a matter of fact, all leads should be kept short to minimize huai pick-up and cross -talk. If a ceramic or crystal stereo phone cartridge is to be used, the Aux input should be converted to a piezo-electric cartridge input. Break the "x" connections shown on switch sections S,_( and S,_o and add the dotted connections shown in Fig. 1. This modification allows the vertical -lateral TYPE switch, function when the selector switch, S1, is set to AUX. A ceramic or crystal cartridge should be used only in the Aux input because the 5-megohm level controls (1?,, and R56) in the Al x position form a proper load for these cartridges. The control unit can be constructed to handle tape inputs either from a tape preamplifier or directly from the tape head itself. If you already own a tape head preamp, the control unit should be built as shown and the tape preampli- California fier output connected to the tape input Outside of Redwood City, of the control unit. However, if you de- most complete display of sire to drive the control unit from a the stereo tape head directly, it will he necessary for you to include a tape -head preamplifier in the control unit. In this AMPEX ease, break the "X's" shown on the tape input leads in Fig. 1 and add the tape to be found anywhere is at the head preamplifier shown in Fig. 6. Try to shock -mount the two additions! 12,AX7's and be sure to use low -noise types such as Mullard or Telefunken. HARVEY In order to insure symmetry of mixing PROFESSIONAL SHOWROOM in the vertical -lateral mixing circuit. plate and cathode resistors of the phase - inverters (R,o, Rio, R.:o, and Ro) should World's largest inventory of be matched to within 1 per cent. The simplest way to match resistors is to Ampex equipment, take an ohmmeter with you to the supply house and measure 22,000 -ohm, accessories, and parts 1 -watt resistors until you find four that match within 1 per cent.2 It is not necessary these resistors be exactly '_'''.- that HARVEY RADIO CO., INC. 2 This is sure to make you popular with 1123 Avenue of the Americas (6th Ave. of 43rd St.) New York 36, N. Y. the store personnel. Better still, buy a dozen resistors and select in:itrhed pairs t Block from Times Square JUdson 2-1500 after you get them home.

AUDIO NOVEMBER, 1959 91

www.americanradiohistory.comAmericanRadioHistory.Com RECORD DUPLICATE PLAY STEREO TAPES heaters be used for the cascode preamplifier to prevent hum. The power supply shown in Fig. 7 provides d.c. for the heaters of the cascode and other .a stages without the use of a special power transformer. This is done by placing the 6.3 -volt and 5.0 -volt heater windings in series -aiding and using this 11.3 -volt source for the heater rectifier diode. Unless the windings are placed in series - aiding, the voltages will subtract and only about 1.3 volts will be available for the heater rectifier. Before permanently soldering together the two leads from the 5.0 -volt and 6.3 -volt windings, measure the total available voltage .e across the two windings with an a.c. e 1.:0 QY voltmeter and, if necessary, reverse one .'j 0 0it r z O e set of windings so that the total voltage f340.50 RECORDING is about 11.3 volts a.c. The two wires STEREO RECORDER AMPLIFIER 11149 50 may then be soldered together and the power supply completed. The d.c. heater supply has sufficient current capacity for four tubes only, so do not attempt THE STEREO SYSTEM to supply the heaters of the entire control unit with d.c. If the tape head pre - amp of Fig. 6 is incorporated, it is sug- achieves the full, true potential of stereophonic sound. gested that these two 12AX7's (V, and Roberts' superbly designed transport mechanism, with its V2 of Fig. 6) be powered by the d.c. hysteresis synchronous drive motor, provides perfection in heater supply and tubes V2 and Vs pitch-and timing accuracy of 0.2%. This, with Roberts' exclusive of Multirase Head, gives you professional recording quality. the control unit be switched over to the Send 25e for Complete Stereo Information Kit. a.c. heater supply (pins K and L of P1), Complete Stereo System $499 - Four -Track $509 Control -Unit ROBERTS ELECTRONICS Inc. 1045 N. SYCAMORE AVE., HOLLYWOOD 38, CALIF. Adjustments Connect the control unit to its power supply. Before turning the power on be The First Book of its Kind-No Other Like It! sure that all tubes are in place and that the power supply d.c. heater adjustment resistor (R10 in Fig. 7) is at its maximum resistance. Unless this is done, the SOUND in the THEATRE d.c. heater voltage may be too high and by Harold Burris -Meyer and Vincent Mallory burn out several filaments. Allow the unit to warm up for about fifteen min- Nothing like SOUND in the THEATRE rived systems and equipment specifications. utes then adjust the heater voltage at has ever been published. It is the first Complete procedures are given for: Planning, the socket of the right cascode pream- book to set forth in authoritative detail what assembling, and testing sound control installa- you can plifier (pins 5 and 9, V5) to 6.3 volts do with saüwd by electronic control, tions-Articulating sound control with other and how d.c. by to do it whenever the source (singer, elements of production-Rehearsals and means of the heater adjustment musician, per- speaker, etc.) and the audience are formances - Operation and maintenance of resistor (R10 in Fig. 7). present together. The book develops the re- sound control equipment. If you have included quirements for a tapehead pre- electronic sound control from amplifier, this the necessities of the performance, the char- THE AUTHORS must now be adjusted to acteristics the NARTB of the audience (hearing and psy- During the past thirty years, the authors have developed tape playback character- choacoustics), and the way sound is modified the techniques of sound control in opera, open-air amphi- istic. To do this, connect your tape head by environment, theatres, theatres on Broadway, hall, and scenery. Sound theatres on -the -road and to the control unit and insert a 10 -ohm sources are considered for their susceptibility off-Broadway, in concert halls and night clubs, in Holly- wood of control and need for it, and the many and in the laboratory. Some of their techniques are tech- used in broadcast niques for applying electronic sound control and recording as well as in perform- TABLE II ances where an audience is present. From their laboratory are described and illustrated in thirty-two spe- have come notably successful applications of sound con- STANDARD PLAYBACK cific problems. From these problems are de - trol to psychological warfare and psychological screening. EQUALIZATION (Values given in volts rmsl Frequency NARTB R IAA cps Tape Disc RADIO 20 2.00 0.92 MAGAZINES, INC. 50 1.40 0.71 Dept. 2 An re 100 0.90 0.45 Post Office invaluable erenre an in- Box 629 - 1 dispensable guide for anyone 200 0.50 0.26 working in the theatre a com- Mineola, New York s, 500 0.20 0.14 plete technologic I thesaurrs for the engineer, arc itect. designer. 1000 0.10 0.10 I am enclosing my remittance for $10.00 technician. student. and teacher 2000 0.060 0.074 Send my copy of ` concerned with th reinforcement SOUND in the THEATRE postpaid. of sound and speech. 5000 0.038 0.039 10000 0.032 0.020 ;No C.O.D., all books sent postpaid in U.S.A.` ,.w 1000 -cps input signal set at value required to and possessions, Canada, and Mexico. nroduce output of 0.10 volts; input signal then held Add 50c for Foreign orders.) at this value for all other frequencies.

Name AUDIO NOVEMBER, 1959 \ddress

www.americanradiohistory.comAmericanRadioHistory.Com INSERT BETWEEN X', V1

SHOWN IN NOTE 1, FIG. 1 LOW -NOISE 12AX7

B+ 2

... .--s.y...711.16...-, C5 ;"..í 0.1 ^->ie'.u..w>. TO LEVEL y. t.<::,4 CONTROL ,,...-.-'. ---s.. TAPE HEAD-L R2 +-J

C I 2200

0.1 a0 Fig. 6. J2 Schematic (ON FIGURE Il z of tape -head pre- O amplifier which .

...-e....' GND BU5 L may be incorpo- \ ---,..2,., rated into the amplifier. ( f1rt. 4 -1.--GND BUS R ),...... - GND BU5 R 0 oc O, CZ nc \ C8 a' > TAPE HEAD- R 51 PNf vY, LL C7 yN RIO Ce I o 2200 J8 (H.,«,_ TO LEVEL (ON FIGURE 1) CII CONTROL 0.

'LOW -NOISE DEPOSITED CARBON RESISTORS

B+I V2 B+2 LOW -NOISE 12AX7 resistor in the ground lead, as shown queueies listed in Table II and by ad- in Fig. 8. Adjust the equalization first justing the left tape -equalization con- for the left channel. Set the SELECTOR trol, R8 in Fig. 6, set the outputs to switch, S to TAPE. Connect an audio match those listed for NARTB equali- generator to the 10 -ohm resistor through zation in Table II. Each time the equali- THE a 1000 -ohm resistor as shown. Connect zation control is adjusted, return the an a.c. VTVM to the left TAPE OUT jack, generator to 1000 cps and re -adjust its FINEST 15 in Fig. 1, and turn the left tape output for 0.1 volts rms. IN HI -F1 level -set control, R14, all the way up. Set Repeat this same procedure for the the SELECTOR switch, S, to TAPE. Set the right channel. Connect the a.c. VTVM USE THE generator to 1000 cps and adjust the to the right TAPE OUT jack, J in Fig output so that the VTVM indicates 0.1 1. R54 is the right tape level -set contro FINEST volts rms. and R16 in Fig. 6 is the right tape Set the audio generator to the fre- equalization control. The tape -head pre IN AUDIO R3r_ TUBES 110 K +45 VI 2W 9-JVV1Mry R4 Tl = 110 K 6X4 - 2 W TRIAD R -9A R2 B+l RED A The design and engineering of Tung-Sol 10 50mo51ÿ,r g+2 YELLOW 5881 and 6550 Audio Amplifier TRIAD C3X JI Tubes RI 85 R6 B+3 ORANGE voice 14 PIN give to the true meaning of Hi-Fi. 9100 CHI 47K 2W 4300 2 W > AMPHENOL 0 2 W The ratings and uniformity of these tubes + 40 + 40 + 40 + Y FEMALE CI C2A""T C2B aT- (165-30) provide the performance characteristics d 1450 V V 45400 V 600 V CT 150 V 1450 lj1g } ^ required by the exacting Hi-Fi circuitry. 50 ma 11 a BROWN 5881 Vl HUM I L K BALANCE Beam Power Amplifier provides the

I 1 ultimate in reliability where the 6L6 is J2 0 BROWN normally called for. YII C6 6550 A. C. CR -1 81 SARKES TARZIAN Beam Power Amplifier first in the 100 RECE PT. _ J3 5N26 watt RIO GREY power range designed specifically 10 W TO for audio service. 181 + -AS . 4000 1. ; 2000 PREAMP OPT. a 5V C4 C5. i0 15V 15V

1 H GREY .022 N C7 200 V

BLACK - 6 FT. CABLE

Fig. 7. Schematic of the power supply. Tung -Sol Electric Inc.,Newark 4, New Jersey

AUDIO NOVEMBER, 1959 93

www.americanradiohistory.comAmericanRadioHistory.Com u l plifier is now adjusted to the stand- TAPE ard NARTB playback curve. HEAD ONLY the ACRD Stereo The remaining two adjustments are PREAMP A. C. made with the control unit connected to IN TAPE pre -amplifier gives you VTVM a !magnetic phono cartridge and a pair POSITION BREAK these years ahead design of power amplifiers and speakers. Set GROUND the SELECTOR switch to PHONO, the TYPE LEAD features 'wit.di to 45/45 the GAIN and and turn 1000 lwn level -set controls (R,, and 1153) AUDIO CHECK THESE EXTRAS for maximum volume. Adjust the power GENERATOR INSERT leu RESISTOR IN GROUND LEAD hums (Rs in Fig. that no other kit gives: supply baan:e control, (SEE TEXT) 7), far minimum hum. 1. Selective Rumble 5. Input Level Place an older monophonic LP on & Scratch Filters Controls Fig. 8. Method of connecting an oscilla- your turntable. With the FUNCTION tor into the tape -head circuit to make 6. Exclusive Panel 2. 3rd Channel swit:h (S3) in the forward stereo posi- Output Light Matrix adjustments. tion (position 2) and the GAIN control C.,, C,, .068 200 v., 3. Exclusive Mike 7. Lowest Hum with set at midrange, adjust the phono level - C,S, C,,, µf, paper D.C. C, 0.22 µf, 200 v., paper Dub Switch Filament Supply set controls to a C comfortable listening C,;. C.,N 2700 µµf, mica Plus many level. With the BALANCE control cen- C, 2200 µµf, mica 4. Phasing Switch other features tered, adjust the level -set controls so C ,.,C,t 220 µµf, mica that the sound level is equal in both C 40 µf, 25 v., electrolytic C,6 25 µf, 150 v., electroly- speakers. tic With the FUNCTION switch still set in ,I thru J,, Chassis -mount phono the forward stereo position, switch the jacks P, TYPE switch to VERTICAL -LATERAL. The 14 terminal male plug, Amphenol 165-31 left speaker will have the lateral signal PL, 6.3 -volt pilot light component and the right speaker will R R f, 51,000 ohms, low noise, have the vertical distortion component. deposited carbon Temporarily turn off the left amplifier R,, R,e 1800 ohms, 4 watt 2000 ohms, watt and turn up the volume. Listen to the R R, R,,, R 510 k ohms, # watt distortion component in the right RS, R,6, Ro,. RSo 100 k ohms, low noise. ACRO'S STEREO speaker and adjust the right phono deposited carbon level -set control for minimum distortion. R,;, R,,, 4711 k ohms, low noise, deposited carbon The vertical is now -lateral mixing eircuit R;, R 2.2 megs, watt PREAMPUFIER balanced. R R,,; 33,000 ohms, watt This completes the construction and R9, R49 1500 ohms, low noise, ng of your versatile stereophonic deposited carbon EASY TO ASSEMBLE KIT R,u R5, 10 megs, 4 watt , n i t col center. If properly constructed, R,.,, R,,, R,;, R5:, Unequaled Versatility; Logical planning; - Pre ou have built a fine piece of high-fidel- R, R, 500 k ohms, audio -taper assembled, tested, printed circuit board ity having potentiometer makes construction simple. A PERFECT equipment excellent response MATE FOR characteristics and control facilities that R,:, R 5 megohms, audio -taper ACRO'S STEREO 20 AND ULTRA potentiometer LINEAR II AMPLIFIERS. will not he soon obsoleted. . . . Unless R,,, R.:,. R:;, R7.. 1 meg, I watt mass is SPECIFICATIONS three -channel stereo around the (R194 R,9 ) corner! (R.;i, Rc6) 22,000 ohms, snatched INPUTS each channel pairs, 1 watt Magnetic (Turntable & Changer) R:,, R,;,, R,;, 75(1 k ohms, watt, Equalized 78, LP. RIAA R,., PARTS LIST 10% Crystal/ceramic (switched in mag. input) R,.., R,;.,, R,;, 360 k ohms, 1 watt, Sensitivity for 1.5V out Low Level 5 MV. R For Figure 1 High Level 30 MV. 10% C2, 40 Tape Head Equalized NARTB Sensitivity 2 MV C C24, C,., if, 30 v., electrolytic R,., 1500 ohms, 4 watt FM AM FM Multiplex Tape Head C., Cn, CY6, C4, .(122 µf, 400 v., paper R,,, R,,6 39,000 ohms, I watt Microphone (switched into one channel for announcing, CC,,C Cxv 4.7 µµf, ceramic R R,;7 91,000 ohms, watt faded in or out with balance control) :;, C9, C15, C21, CeB, RYA, RSz, R68, R7, 2.5 megs, linear -taper C,,,. 0.1 400 OUTPUTS 2 Ampl., 2 Tape, 3rd Channel C,, C4, µf, v., paper potentiometer CG, C ,,, ,,Cm;C. R,9, R,.9, R69, R7, 150 k ohms, 1 watt INPUT SELECTOR (8 position) 78, LP, RIAAI, RIAA2, C:f, C.96 0.1 µf, 200 v., paper Rna, 10,000 ohms,} watt Tape Head, FM -AM, FM Multiplex & Aux. R78 C C,6 240 µµf, mica R,,, R 100 k ohms, watt OUTPUT SELECTOR 7 MODES (Check -A, Check -B. C9, C 560 µµf, mica R.,s, R7, 3300 ohms, } watt Stereo, Stereo Reverse, Monaural A- B, Monaural A, Monaural B.) 6 panel light Matrix provides selection Mode at a glance. CONTROLS Gauged Volume/Loudness, Balance, In- dividual Bass & Treble for each channel SWITCHED EXTRAS effective each channel. Filters, scratch and rumble loudness phasing tape Input/ monitor mike dub

AC OUTLETS 2 switched 2 direct TUBES (4) Type 7199 low noise pentode/triode Over-all view of DIMENSIONS 4-1/2H x 13-3/4L x 6-3/8D the author's pre- PRICE: Kit $69.50 Self powered kit $79.50 amplifier - control Write today for free folder unit.

ACRO PRODUCTS COMPANY KIT DIV.

410 SHURS LANE, Dept. HF 11 Philadelphia 28, Pa. ACRO, THE FIRST NAME IN AUDIO!

94 !'.UE2PO e NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com R:S, Rr 220 k ohms, watt C5, ,a .033 µf, 300 v., paper 0.1 µf, 100 v., paper R,6, Rre 500 k ohms, ütear- C5, C 0.1 µf, 300 v., paper C, .022 µf, 200 v., paper taper ganged poten- C6, C,P .022 µf, 400 v., paper Cl?, Selenium rectifier tiometer R,, R, 10 megs, low noise, de- Sarkes-Tarzian 5N26 Rs Rn 250 k ohms, audio -taper posited earbon J, 12 -pin female plug, ganged potentiometer R<, Rm 220 ohms, watt Amphenol 165-30 R:s, R,, 2200 ohms, -watt R.r, R,, 200 ohms, watt J, J, A.c. receptacle R,,, Reh 47,000 ohms, 1 watt Ra, R,: 200 k, low noise, de- L, 10 Hy., 50 ma, Triad s, 4 -pole, 4 -position ce - posited carbon C3X ramie rotary switch, R5, R,5 2.2 mega, low noise, de- R, 47,000 ohms, 2 watts shorting type (SELEC- posited carbon R. 51,000 ohms, 2 watts TOR) RR,a 5600 ohms, watt R,, R, 110 k ohms, 2 watts 8: 2 -pole, 2 -position ce- R R,5 200 k, watt R. 4300 ohms, 2 watts ramic rotary switch, R,, R,, 10,000 ohms, linear - R.; 9100 ohms, 2 watts shorting, (TYPE) taper potentiometer, R, 510 k ohms, watt ,35 3 pole, 4 -position ce- (equalization) R, 250 ohms, 2 watts, po- ramic rotary switch, VHF, 12AX7 tube, low noise tentiometer, wire - shorting, (FUJNCTION) For Figure 7 wound F F5 12AY7 tube Ft, F:, 12AX7 tube C, 40 µf, 450 y., electro- R 300 k ohms, watt r5, Fe 6C4 tube lytic R, 5 ohms, 10 w., adjust- C,, C, 40-40 µf, 450 v., electro- able lytic T, Power transformer, For Figure 6 C, 4000 µf, 15 v., electro- 300-0-300 v. at 50 C Cr 19.1 µf, 100 y., paper lytic ma; 5 v. at 2 a.; 6.3 C,, C8 51 µµf, mica C5 2000 µf, 15 y., electro- v. at 3 a. Triad R -9A C,, C: 40 µf, 25 y., electrolytic lytic Fr 6X4 tube

This is a KLH coil, held by a KLH hand. The quality of the coil contributes to " ... A patient search for the quality of KLH speaker systems. extremely high quality" The quality of the coil depends on the skill and patience of the hand. KLH has good hands.

1 Research and Development Corp. ZEZN Cambridge, Massachusetts

AUDIO NOVEMBER, 1959 95

www.americanradiohistory.comAmericanRadioHistory.Com than 1 -inch plywood. Why not use these SYSTEM surfaces and gain volume? It was only "PERFECTIONIST" necessary to solve the problem of getting (frorol. page .l) a good tight seal and to devise a logical method of assembling the system. range unit starts at about 1600 cps. No crossover element is added to the Jans - Construction zen. It has its own built in 500 -cps high- pass filter. The bass speakers actually This was accomplished by building the contribute sound in the 30- to 1800 -cps frame shown in Figs. 2 and 4. The cor- range, the midrange speaker in the 200 ner was square enough that no special

THE N.V. PHIL. to 2800, and the high -frequency speaker cutting was required. A template cutout ORCH., from 500 to 30,000 cps. The speakers for the floor moulding was used to cop- L. BERNSTEIN, COND. are driven by a 50 -watt high -quality ing saw the bottom rear of the cabinet. I. STERN, amplifier. Both the 4- and 8-ohnl output Sponge rubber weather stripping was VIOLIN taps are used for matching and channel attached to the inside of the cabinet AT COLUMBIA RECORDS balancing. The midrange unit and the along all floor and wall intersections. electrostatic can be connected to either The cabinet was firmly attached to the the 4- or 8 -ohm taps. This allows the wall with angle brackets as shown in

Fig. 4. Another view of the frame. Having no back, it must be firmly NEUMANN attached to the M -49b walls. SELECTED EVERY TIME... FOR QUALITY &

DEPENDABILITY mid- and high -range volume to he ad- Fig. 5, two to the floor board and two justed by several decibels to allow for on the top inside to the wall studs. Soft room acoustics. The has an ad- can be Frequency range: 30-20,000 cps Janszen putty applied around the mould- Output impedance: 50/200 switchable ditional adjustment control on the hack ing or at any points of had fit, however Field pattern: Continuously for this same purpose. The crossover air tightness is not required and leaks variable through all characteristics- networks and speaker control circuits of a few square inches are insignificant. omni-directional, cardioid and. figure -eight and all intermediate pattern configurations used are shown in Fig. 1. Firm, vibration -free mounting of the Non-linear distortion: less than 0.3% entire range to 110 dB absolute. For best listening, the optimum height of the electrostatic tweeter is about at Dimensions: Microphone: 3" dia.; 61/4" length. Power supply: ear level when seated. The midrange 61/2" x 4" x 43/4" unit should he close to it and the woof- Weight: Microphone: 13/4 lbs. Power supply: 51/2 lbs. ers about half way between them and the floor. These requirements, plus a NOW $495.00 desired corner location, led to the general design of the speaker cabinet. The need for 12 eu. ft. of spawe in the infinite baffle without it oppearing too large led to one innovation in the de- Audiootham sign. The cabinet was built without a sales co. inc. hack. That is, it was planned to fit flush with the wall and carpeted floor. The 2 West 46th Street, N. Y. 36, N. Y. corner wall was found to he extremely Fig. 5. Detail showing method of attach- rigid and acoustically dead. More so ing the cabinet frame to the wall.

96 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com volts was also installed at this point to power the Janszen. This circuit was run from an auxiliary outlet on the control preamp, so that the power was on only Bó when the hi-fi system was being used. A I rum demonstration switch panel was installed on the left side of the speaker cabinet. The switches allow any combination of STEREODYNE II the speakers to be heard. There is also a switch changing the speakers from a PHONO PICKUP three-way system to a two-way system. There is sufficieint room on the shelf to mount the crossover components, the terminal strip and switches and still install the Janszen. The Bozak speakers were bolted to the speaker mounting board and wired. Cinch -Jones plugs were used to connect the speakers on the mounting board with the proper leads in the cabinet for ease in installation. New, hum free push pull magnetic stereo pickup of superb Fig. 6. Before attaching the loudspeaker Damping the Cabinet cha-acteristics. True stereo mounting board, the entire interior is The acoustic insulation of the interior reproduction because of wide filled with pieces of fiber glass. of of the cabinet was the subject several channel separation. Smooth experiments. Proper damping of space light tracking cabinet frame is essential, however. resonances and minimization of the fun- response and The dimensions and general plan of damental resonance of the woofers are combine to give clean natural the cabinet are given in Fig. 3. The cor- the main objectives. The best results sound from both stereo and ner shape makes possible an extremely were obtained with the following proce- monophonic recordings. rugged frame for the speaker mounting dure : 120 sq. ft. of Gustin-Bacon Ultra - Mounts in all standard arms. board. The perpendicular sides and the lite fiber glass, a lb. per cu. ft., 1 inch box frame for the Janszen utility model thick was procured. All interior frame With replaceable diamond speaker makes a box girder type of con- surfaces were lined with the 1 inch ma- stylus-$29.95` net. struction. Additional braces and stiffen- terial. Then the entire interior volume ers are glued and screwed to the top and was with of fiber glass sides as shown. A 2 x 4 built-up plywood triangularly cut in sections of about 4 cross brace is used, and a brace post is inch size, as seen in Fig. 6. The mounted Bó TONE ARM installed between the cross brace and the speakers were covered with two layers center of the speaker mounting board. of tightly stretched cheesecloth, with The speaker board is made up of two holes cut out for the magnet covers, 'integrated g -in. plywood panels screwed and glued stapled to the mounting board. Over this Arm and together to form a rigid 11 -in. speaker was placed at 16 -in. circle of fiber glass Cartridge support. The design of the cabinet is with an X cut in -the center to slip over such that the finished frame can be at- the magnet cover, as shown in Fig. 7. tached to the corner, then the speaker The edges of the circle were stapled to mounting board with speakers attached the mounting board. The midrange unit is fitted into the front of the frame was similarly treated, then a V shaped against a 1 x 1 moulding. The moulding pocket of 1 -in. fiber glass was formed contains a series of 2 x in. carriage around the mid range unit to isolate bolts spaced every six inches around the it partially from the woofers. The pocket MODELL TA -12 edge. The bolts fit through counter-bored was also filled with fiber glass cuttings. matching holes around the edge of the You might fear that all this filling speaker mounting board and by attach- with fiber glass would use up a large ing washers and nuts, the mounting portion of the interior volume. Actually Combined arm and. Stereodyne board can be securely fixed to the frame. II Cartridge for optimum A finished moulding with grill cloth is itesu;ts. Dynamically balanced, the then attached to the frame covering gimbal -pivoted a -m permits entire front and held in place by fric- 2 gram tracking. Simple to tion fit pins. When the frame is constructed it mount, handsome appearance, should be painted or wood finished and and outstanding in perfor- then attached to the wall. The necessary mance. Only $49.95' net. wiring should then be installed in the cabinet. An eight -terminal strip was 'Slightly higher in the West of the shelf installed at the left front Available from leading high for making all connections to speakers fidelity dealers everywhere and crossover network components. Since this was easily accessible by just DYNACO, INC. front moulding and grill Fig. 7. Woofer and midrange units are removing the Powelton Ave., Phila. 4, Pa. thoroughly surrounded with fiber glass 3916 cloth it greatly simplified comparative Cable address Dynaco, Phila., Pa., U.S.A. listening tests. A plug outlet for 110 after installing mounting board.

AUDIO NOVEMBER, 1959 97

www.americanradiohistory.comAmericanRadioHistory.Com BALANCE YOUR the very fine fiber glass takes up less than 1 per cent of the total volume. It STEREO SYSTEM- effectively increases the volume because it slightly lowers the resonant frequency ONCE- of the speakers in the cabinet. More important is its effect of virtually elimi- SO IT SOUNDS nating all interior cabinet resonances. The effect of RIGHT. the fiber glass baffling di- reetly on the back of the woofers is CENTER THE NEEDLE noticed only in the range of the fundamental speaker resonance. (A bout 40 OF THE NEW cps in this case). It has the effect of increasing the damping in this range, I«seele ems abti which causes the output at the resonant frequency to he reduced, but it produces STEREO BALANCE METER a broader and smoother response in this region. WITH SIMPLE The speaker plugs were connected and the speaker mounting panel fitted into Fig. 8. Approaching the final stages- CONTROLS ON BACK- the fiber -glass -packed frame and the the loudspeaker mounting board in place nuts securely ONCE- tightened, resulting in the awaits only the grille -clothe in its frame. appearance shown in Fig. 8. The Jans - zen utility model THEN YOUR SYSTEM 1-30 was then put in the speaker in other acoustic surround- the shelf k and rested on a inch pad ings this may not he observed, hut the of felt. The ALWAYS front panel was painted a fiber glass hacking seemed to smooth out flat black. This matches the color on the response. SOUNDS THE SAME- the Janszen and nothing is visible The transient behavior of the system through the SOUNDS RIGHT speaker grill cloth. The is judged to be excellent. Microphone finished front moulding with attached oscilloscope studies with square waves FOR THE ROOM IT'S IN- grill cloth is then attached by the fric- and pulses have shown the presence of tion fit pins and the unit is complete. no resonance save the fundamental res- WHENEVER YOU The finish on the cabinet is a soft gray onance of the woofers. This has always which matches the walls and nearby been small in magnitude and damped CENTER THE NEEDLE. hook shelves. The grill cloth is an open out within two cycles. The Cook Chro- weave drapery SIMPLE? material dyed a match- matic test record has two good transient ing gray. A TV receiver is built in on tests. The first is for the bass range. It YES! top of the speaker, and its audio output consists of three trains of short tone can be played through the entire sys- bursts followed by the steady tone of EFFECTIVE? tem. There is virtually no vibration of the pitch used in making the short the speaker cabinet at wide open vol- bursts. DECIDEDLY! The first train of bursts is a ume levels. series of sine -wave tones of 62 cps but The circuit connections of the speak- only 2 cycles in duration. The second ers allow considerable leeway for bah train is the same but the bursts are 4 a acing the loudness of the three channels cycles in duration. The third consists for optimum listening in rooms of vary- of bursts of 8 cycles duration. The ob- ing acoustics and for listeners with dif- ject of the test is to determine the short- ferent preferences. While the unit has est bursts in which the tone can be rec- not been measured in an auechoic cham- ognized. Perceptive listeners can defi- ber, it apparently has a flat response nitely identify the tone of the 2 -cycle from 35 cps to the upper limits of hear- bursts on this system. This is rather un- ing. Even more important, it produces usual. a very natural sound almost entirely The second transient test on the Cook free of artificial coloring of any kind. record involves very short tone bursts On the Cook Chromatic Scale Test rec- in the 1000- to 2000 -cps range. This is ord there is a series of tones on the the range in which many cone speakers musical scale recorded from 32.7 to 8372 show resonances. On some speakers the $1495 at Better HI-FI Suppliers cps. They are recorded with a Fletcher tone can not be recognized from the Munson characteristic and when played short burst or the burst will sound a back low Sound choice for a Hi-Fi Christmas! at a very level they should all half tone or so different from the refer- sound equally loud. All listeners have ence tone which follows. There is no con- agreed that no loudness difference is de- INFORMATION AVAILABLE. WRITE: fusion in recognizing the tones on this tectable on any of the tones. system. ki,, matiX,,. Frequency sweeps with an oscillator, The completed system has been very microphone, and an oscilloscope show satisfactory. In addition to being quite extended range and good wave form to accurate theoretically, it reproduces above the limits of hearing. They also music pleasantly. When the sound source show no resonances or peaks or dips calls for it, it can be highly impressive. throughout the range. Before the fiber We have found differences in records glass backing was used on the woofers, not previously noted and we are looking 1616 North Damen Avenue there was a tendency to rate the tones forward to greater improvement in the Chicago 22, Illinois around 40 cps as slightly too loud. With recording art. 'E

98 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com WHERE

OUTPUT TUBES THERE'S (front prim A FINE tortioi from 3.5 percent to 1.0 percent. TAPE It will also increase the damping factor from 0:072 to 2.65. The new Figure of RECORDER... Merit for the 6V6 is 450. This figure implies that the 6ß'6 with 10.6 db of feedback is 3.5 times better than the 2A3 without feedback. Note, however, that the relative values of the Figures of Merit again depend very much on thi' damping factor and the importance which we assign to it. The foregoing shows how we may re- compute our basic Figure of Merit for a tube with feedback (around output stage only). Our Figure may also be used to determine the result of placing tubes in parallel to achieve more desirable per- /rote to MAGNECORD owners formance. For example, if we want an output To insure optimum recording quality stage capable of 35 watts, we may wish with your excellent machine, the to determine whether a pair of tubes in recommended tape is irish #211.. . push-pull is best, or whether two pairs and for uninterrupted recording, push -pull -parallel of a different type in irish #602 gives 50% more playing time will be still better. For a single pair we tape on any given reel size. could use the EL34 which has a Figure than standard of 15.7 in fixed bias. A smaller tube Send for technical bulletin. which could deliver adequate output in push-pull parallel is the EL84. It has a ORR INDUSTRIES INC. Figure of 23.4. In paralleling tubes we Opelika, Alabama double the power output, but the voltage Circle 99A input remains the same. The power sensitivity is therefore doubled. The distortion at full remains the same for 4 output .1111111111111111111 each tube. The damping factor remains tube plate resist- IMOMii the same since both the have been = ance and the load resistance emirrmiumr!I/' halved, keeping their ratio constant. The r'^. basic Figure of Merit is therefore doubled by putting tubes in parallel. As a result of the above discussion we see that we may obtain 35 watts from a The only recorder pair of EL34 tubes with a Figure of at any price that Merit of 15.7, or that we may achieve INTRODUCING: does everything it with four EL84 tubes and a Figure of 46.8 (See Table III). This is quite a BETTER.' substantial increase over 15.7, and leads us to wonder whether a high Figure of Merit is not to be obtained merely by paralleling enough tubes. The answer is yes, if we confine our- selves only to the basic Figure of Merit, and choose to disregard other factors, among them the cost. Even the most devoted purist, however, would pause to think before putting twenty or thirty small tubes in parallel in order to achieve Records stereo what just two large tubes can do. NAL" Plays back either Aside from the cost, there is another turc or four track danger in putting too many tubes in stereo tapes. parallel. This is the effect which paralleling has on the driver tube. Each time a sold only thru franchised tube is added in parallel, the input im- dealers. For more information agn e cord pedance goes down. As the number of and the name of your dealer P. O. BOX 7186 / TULSA, OKLA. tubes in parallel grows large, the input write Dept. 200. capacitance may easily become large enough to affect the high -frequency DIVISION of MIDWESTERN INSTRUMENTS manufacturers of ele ironic data acqu,sition instruments response of the driver stage, particularly Circle 99B

AUDIO NOVEMBER, 1959 99

www.americanradiohistory.comAmericanRadioHistory.Com if the output tubes are triodes. There is includes the factors that went into mak- the matter of grid -circuit resistance, ing up the first Figure of Merit (F1). however, which may be of considerable The following are the formulas used: importance when adding only one additional pair in parallel. F5= Eff xR9mamXF1 F3= F2 x Cf SAVE where Grid -circuit Resistance Eff = Efficiency Maximum grid -circuit resistance The data on every output tube always Rnmax = Cf = Cost factor 25% includes a characteristic called Maximum Permissible Grid -No. 1 Circuit Resist- Table IV lists the additional charac- ance. This characteristic, as its name im- teristics used to make Table III from plies, shows the highest value of resist- Table II. ance which may be placed in the grid cir- With these tables at hand the de- This is our cuit. The valise varies over a range of as signer is now able to snake a logical and GROUP SUBSCRIPTION PLAN much as five to one for a given tube, de- systematic choice of output tubes. And pending on whether fixed or cathode bias if he chooses to omit certain factors it Now you, your friends and co-workers is used. Fixed bias always requires a will not he from ignorance, but because can save $1.00 on each subscription lower value of resistor. he chose to give that factor an arbitrary to AUDIO. If you send 6 or more sub- If a tube has a relatively low value of value of 1. (Note that multiplying (or scriptions for the U.S., Possessions and Canada, they will cost each subscriber permissible grid -circuit resistance, than dividing) any Figure of Merit by one $3.00 each, t/a less than the regular severe limitations are placed on the will not change its value.) one year subscription price. Present driver stage. The a.c. load resistance As new tubes are brought out they subscriptions may be renewed or ex- seen by the driver cannot be large. This can be appraised by this method, and if tended as part of a group. Remittance will limit the gain or increase the dis- to accompany orders. new factors are considered important tortion of the driver and often does they can be added conveniently to the both. Paralleling tubes always makes framework already established. 1E AUDIO is still the only publication this problem worse, since as tubes are devoted entirely to paralleled the permissible grid -circuit resistance is greatly reduced. (Halved Audio RECORDS Broadcasting equipment for two pairs, divided by three for three (from page 68) Acoustics pairs, and so on.) It may be greatly to our advantage Home music systems then to include the maxi- though the relatively less potent string play- Recording mum permissible grid circuit resistance ing is, I suppose, also French, and negatively PA systems as a factor in our Figure of Merit. In so. Negative or no, the emphasis here on forward brass and woodwinds is Record Revues interesting after addition there are several other charac- our own stress, in the l'. S. A., on big, opulent teristics which we may wish to use. string sound. whether it may he the Phila- ( Please print) delphia, the Boston, or Morton Gould and André Kostela net z. (He's American, now.) Name Efficiency As for I'rokutieff, these are his two most Address ingratiating symphonies. The Fifth is his best known, a big. melodic work of a The of is im- conservative efficiency the tube type cast : the Seventh is to my mind Just as good, New n Renewal portant. A good tube is one which con- though it is his last and exhibits a certain verts a large percentage of the d.c. sup- tired, disillusioned end -of -an -era effect. It is Name wonderfully melodic, too, full of superb or- ply power into a.c. power. It would cer- chestration anit some of the best satire on the Address tainly be poor design if we added more modern Russian school of sabre -dance symphony that you'll ever run into. Hidden satire, cost and complexity to the power supply of course, but it's there. New Renewal than we saved on the output stage. Let Excellent stereo and excellent sound, too, us then include plate -circuit efficiency and the French playing avoids the big -string Name schmaltz that too often gets thrown into the Address as one of our factors. more sentimental tunes in Prokofleff. Again, a The power required by the filament pleasant and welcome change of em ph a sis. ri circuit may influence our opinion of n New Renewal Moscow Nights-Popular Russian Hits. tube considerably. Tube A may appear Monitor MP 590 Name to have a much higher efficiency than Ugh. I Address was momentarily curions about this tube B, until we see that A's heater -what do the Russian young people dance, power more than makes up the difference to, in Moscow? That's what we have here, a fJ New Renewal in plate circuit efficiency. This is ad- quick look via your own ears, so to speak, into current Moscow night life. Nice cover, young mittedly of minor interest to the holne a Name people in Russian dance hall. constructor, but as before he may omit The ugh refers to everything but one rather Address mild blues, slightly American in flavor (as far this factor from his Figure of Merit if as is now allowed, i suppose)-the St. Louis he so desires. Blues, with guitar. Sounds odd. very odd. and New Renewal The final factor is that of cost. This rather pleasant. The rest is just the sort of sleazy semi -Russian dance stuff you might ex- Name may be taken care of easily by giving pect. about as exciting as Muzak, if I may use a trade Address the cost of the lowest priced tube (6V6) name. Main difference is that Russian the pops singers don't croon ; they sing like opera arbitrary value of 1, and then ex- or "folk song," with hig. wobbly voices. pressing the cost New Li Renewal of any other tube as its If you want background music in Russian, ratio to the 6V6 cost. this is it. U. S., Possessions, and Canada only A new table taking these factors into Sibelius: Symphony #5; Pohjola's Daugh- consideration is Table III. Table III has RADIO MAGAZINES, INC. ter. The B.B.C. Symphony, Sargent. two Figure of Merit columns. The col- Capitol -EMI SG 7181 stereo P. 0. Box 629, Mineola, N. Y. umn headed F2 does not include cost It's been a long time since I listened to tins while F, does. Each of the new Figures old-time war-horse of early symphonic mod -

100 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com entity, and I'm impressed both by the music how-, the electrical originality of Schubert's and by the up -dating of performance, that in extraordinary harmonies - they were extra- this version makes it sound remarkably newer ordinarily daring in his day and were so in- BUY IT? I can't than it used to. tended - are not projected, not particularly ... The British have always been the leading heard by the players. Similarly, the superb non -Finn promotors of Sibelius. who tends to bits of melody, the familiar major -minor play sound old-fashioned and over-Romantic to us of sunlight and shadow, are all treated in Americans. Sir Malcolm Sargent has kept the what I might call a Brahmsian style, solidly, even pronounce it! old man's music thoroughly fluid and alive authoritatively, musically, but not with ex- over there, just as Sir Thomas Beecham keeps citement. another British favorite, Delius, going stronger Who knows? Maybe Serkin is dead -wrong than ever. and these players more nearly right in terms The Fourth and Fifth are decidedly the best of Schubert's own day. But if performance of the Sibelius symphonies, I'd say. One is today means interpreting the basic sense of sunny and full of craggy melody, the other is the music in ways we can understand, then remarkably bleak and strikingly modern in this falls down for my ear. In the Twentieth structure, all things considered. But the Fifth, Century we need a super high voltage to con- the sunnier one, was subject-twenty years vey an electrical effect. ago or more-to ultraschmaltzy Romantic in- terpretation. That's what we used to get, from Music of Delius. Royal Philharmonic, such as Stokowsky and many another. But here, surprisingly (to me, anyhow), the Beecham. schmaltz is more modest, the inner structures Capitol -EMI G-7116 and sonorities more lively, the music much less Tchaikowsky: The Nutcracker Ballet. Phil- banal than I would have thought possible. It's a matter of hi-fi (wide -range stereo harmonia, Kurtz. sound does wonders to bring out the masterful Capitol -EMI SG -7149 stereo Sibelius orchestration) and a re-evaluation of imports the musical elements. For instance, when the Here are two nice brown Capitol inevitable great, big pretentious Sibelius tune (both covers are brown) and you can doubt- comes along, ü la "Finlandia," this orchestra less get them both in either stereo or mono ; I doesn't fall for the old schmaltz-the tune happened to hit one of each. gets played fairly and It's getting so that there's only one conduc- squarely but without tor who can get away with Delius (and who blowing the roof clean off, thank goodness ! helps, plays him at all regularly) and that is old It it really does. Tommy. He is an man and when Of course, Sibelius' famed wandering con- Sir obstinate progressing he thinks something is good he will continue struction, amiably from one idea to promote it come H and high water. So we to another without visible or audible shape except have more Delius-and after floating aurally for a occasional return, is as loosely two of disc I'm in- unsymphonic. But nowadays it doesn't seem through the sides this to matter particularly. Who said clined to thank Sir T. for the experience. "ah!" a sym- Delius, you see, is out of date in a big way. phony had to be rigidly structural in the Ger- man of He represents a more or less dated British style musical architecture? I think Impressionism, of a very saccharine sort (the ELECTROSTATIC that, now, Sibelius can be taken by most of lots us without fuss pretention English stand more musical sugar than or just as he is, we do), his harmonies are drippy and thick, TRANSDUCER... out of an earlier period that already has the he is starry-eyed, writes for big, lush orchestra nostalgia and quaintness of a vanished way -generally speaking, most moderns just don't of thinking. Fun, and very sonic in stereo. dig this sort of thing. Delius, it appears, falls the 2 -in -1 mid -range and super tweeter between stools ; he's also too subtle, too icky, that brings out "hidden sound" Rimsky-Korsakoff: Scheherezade. New for the mood music people and the worshippers of Rachmaninoff or the "Warsaw Concerto." your present cone or piston -type York Philharmonic, Bernstein. But when Sir Thomas gets to work on an speaker cannot capture! Columbia MS 6069 stereo orchestra with Delius in hand, so to speak, the music comes through. It sounds right, na- I can characterize this recording very Make it easy on yourself. Just ask for tural, expressive, unforced ; it is good music, quickly. It is now getting to be fairly obvious when Beecham is there to bring out its best the AH! Speaker and we promise you'll that Lennie Bernstein, who does up a modern points in impeccable style. hear sounds you never believed possible piece (particularly a one with bit of jazz or Whichever side you play first, you'll like with your present Hi-fi set-up. Your Broadway in it) with a superb modern verve, best. Two sides in a row, maybe, are too much. when he tackles a solid late -Romantic opus Just play one at a conventional tweeter cannot and does goes time. It all sounds much all-out to make it even more so. alike, but you can choose from Brigg Fair, A not give you complete high frequency Thus, this is no snazzy, zippy, modern Song Before Sunrise, Marche Caprice, On response, due to its inability "Scheherezade" at all. Instead, it goes to recover all-out Hearing the First Cuckoo, Summer Night on quickly enough from abrupt frequency for big, pompous, super -Romantic effect. And, the River, Sleigh Ride, Intermezzo, most of by golly, it works. Old Rirnsky was hardly a change. The AH! electrostatic trans- these being items from larger groups of works ; satirist; on the contrary, his somewhat over- the Intermezzo is from an opera. ducer, of course, is based on a completely blown works were conceived in deadly earnest The Tchaikowsky "Nutcracker" is that new - and, to him at least, seemed not at all super- new electronic principle and reacts style sort of ballet suite that is less than instantaneously to frequency ficial. To treat this or any other Rirnsky to the whole ballet but much, much more than all change a humorous or apologetic modernizing is a the old-time short suites which most of us -no matter how abrupt-so, areas of deadly sin. grew up thinking were all the music fit to "Hidden Sound" are revealed with the So-you'll find this big, impressive, weighty print in the various familiar scores of the Dr. "AH!". Just one minute of your listen- "Scheherezade" just what Rirnsky ordered, sort. I like Kurtz ; his playing is lean, eco- and incidentally-it's just what your new nomical, easy and naturally musical. That's ing time at your dealer's will convince you. stereo outfit needs, ton, Cahgeous. enough for most of us, though ballet people will always be counting leaps and jumps and The 2 -in -1 AH! is a mid -range and figuring whether the music is fast super tweeter to give you full response Schubert: Trio, Op. 99. David Oistrakh too or too slow. I wouldn't know-and for home listen- from 600 cps to past the limit of audibil- Trio. Angel S35713 stereo ing minus ballet the actual dancing speed is not necessarily required. This is an excellent ity. And, the AH! is complete. Nothing Russian -played recordings reach us now in listening record. else to buy-R/C crossover network and a double al ream, one source direct from Russia itself and the other in recordings made by AC power are built in. To prove our traveling Russian virtuosos, mainly in Eng- confidence in AH's superior quality we land and in the U. S. The Russian school of IF YOU ARE MOVING guarantee the elements for 5 full years. performance, in either situation, is now getting to be well known on its own, and it stands Please notify our Circulation Department out rather remarkably-still-from those in- at least 5 weeks in advance. The Post Office does not forward magazines sent to wrong 4-9. terlocking ways and means of music -making Only that we lump together as "Western." Mainly, destinations unless you pay additional post- it tends to be high-tension for contemporary age, and we can NOT duplicate copies sent 49.95 Russian music but low-tension for all other to you once. To save yourself, us, and the kinds. That includes Schubert. Post Office a headache, won't you please cooperate? When notifying us, please give Here you have three big, lumpy players Send for FREE your old address and your new address. booklet "8 unusual (physically speaking) giving a powerful but Hi-Fi and stereo arrangements with relatively low -voltage performance, quite Ro- the AHI" Complete with schematic mantic in an old-style way, strikingly without Circulation Department diagrams and wiring instructions. the enormous excitement and tension that, RADIO MAGAZINES, INC. say, a trio with Rudolph Serkin would inject P. 0. Box 629, Mineola, N. Y. into this music. It is all done here on a very Cosmos Industries, Inc. high plane, but I can't help feeling that, some- 31-28 Queens Blvd., Long Island City I, N.Y.

AUDIO NOVEMBER, 1959 101

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No. 115 No. 112 McPROUD HIGH FIDELITY OMNIBOOK TAPE RECORDERS AND TAPE RECORDING Prepared and edited by C. G. McProud, by Harold D. Weiler publisher of Audio and noted authority A complete book on home recording by the author of and pioneer in the field of high fidelity. Contains a wealth of ideas, how to's, High Fidelity Simplified. Easy to read and learn the what to's and when to's, written so techniques required for professional results with home plainly that both engineer and layman recorders. Covers room acoustics, microphone tech- can appreciate its valuable context. niques, sound effects, editing and splicing, etc. Invalu- Covers planning, problems with decora- SfD>

HANDBOOK OF SOUND REPRODUCTION No. 110 by Edgar M. Villchur You save 55% with this combination of valuable audio and high fidelity books. The Handbook of Sound Re- Right up to date, a complete course on NOVEMBER sound reproduction. Covers everything production ($6.50) ; the best of AUDIO ($2.00) ; Tape Recorder, and Tape Recording ($2.951. from the basic elements to individual SPECIAL! chapters of each of the important TOTAL VALUE OF ALL THREE $11.45 components of a high fidelity system. Regularly $6.50... offered for a limited SAVE Your cost ONLY $5.00 POSTPAID time at only $3.75. This offer expires November 30, 1959 $6.45! Good only on direct sale from publisher. SPECIAL! You pay only $2.75 for this Order #OS10 book when you order it with any other book on this page.

AUDIO Bookshelf RADIO MAGAZINES, INC., Dept. J P.O. Box 629, Mineola, New York . r ! Please send me the books I have circled below. I am enclosing the full remittance of $ (No. C.O.D.) All U.S.A. and CANADIAN orders shipped postpaid. Add 50(/ for Foreign orders (sent at buyer's risk). BOOKS: 110 112 115 120 123 124 0S10

NAME ADDRESS

CITY ZONE STATE

www.americanradiohistory.comAmericanRadioHistory.Com DEFENSE & HI F! BACHELORS ll yuayc 3n9 anything imhrer-o e in comparison with chestra and chorus but as well t'\ rc New the aooustically well-nigh perfect sound minute detail of choral, instrunten t a l the audience would hear during the live and solo accents; not as things domi- concert? The audiofans decided to try. nant but as one sees the beauty of indi- The entire installation, minus turn- vidual flowers in the foreground of the PROFESSIONAL 55 tables and tuner, was set up at King deep, rieh field. That is what makes the Hall, the recorders and amplifiers in the symphony, the concerto, the rhapsody, the Ultimate wings, the three speaker systems on the overture. stage, placed quite as they had been in The system had indeed proved itself. STEREO CARTRIDGE the BOQ room, but with, of course, That, no one contested. Quite to the con- greater distances between them. Test trary, this product of the science of our tapes sounded fine, more alive than in day combined with a rich heritage of Ç..--BIAOi;-M ,: the small room. art, evoked, for many of those present, F£SSflNAk GS Altec time of this concert The three M-20 microphone sys- again the curtain c,ie tems were now installed, two of the a significant time of drama, for here r._. , r mikes suspended high at curtain point, were the contrasts of man's achieve- equidistant from the center, the third at ments. Slowly, with a suspenseful hiss, center, on the stage, for solo work, the the electrically operated drapes on the three systems being then fed into the side walls slid back, revealing expanses "series" recorders as in the BOQ room of glass and varnished, slotted wood. On installation. stage, the conduetor's baton came up, The results were fabulous. The live stood poised, then came down. Outside, concert over, soloists, chorus and mem- beyond the glass, twisting trunks of bers of the orchestra had an opportu- giant oak trees stood gaunt in the night nity to hear themselves. As the audience while between them, incongruous in a had heard them? Yes-but better. In faint fluorescence, passed the figure of COLUMBIA many respects, fax better; for without an armed, uniformed sentry in brisk sound -reinforcing for the live concert military stride, but perhaps knowing, Professional 55 . there are always things that are not feeling, that inside the edifice beside Cost $28.95 heard as they should be in all parts of him Brahms, a man long dead, had taken an auditorium, and this applies even to over by proxy-the inexhaustible pre- This new transparent cartridge is , the professional's version of the those of the best acoustic design. With rogative of the immortal-while hun- popular Columbia CD. A high -com- the three -speaker stereo playback on, dreds sat exposed to his dreams. pliance modlel with excellent transient response, it uses a .5 -mil dia-. there was nothing of the performance And what about the future of this mond stylus and is designed for that could not be heard in all parts of hi-fi system? transcription turntables. Comes hall, Ville, the BOQ's complete with 4 miniaturized plug- the in every seat and aisle and rear "Well," says Lt. St. in equalizing networks fo- low- and area. Those of the audience who had re- chief audiofan, "for my permanent high-level inputs. mained to hear the demonstration were shoreside system I'm now planning an- lavish in their praise. Here, in stereo, other Hartsfield, for the left channel, or CURVES, FACTS AND FIGURES PROVE' IT was not only the ttal richness of or- maybe a Paragon and a 7£

STEREO MONO 1 T. T. PREAMP -4 AMP

Ask for Bulletin E-331. Check tlhe Professionai 55's superiority in: linearity - .. separation .... needle AM -FM 1-4 ELEC. PREAMP t --s point i'apedance .. , low mass .. . TUNER MIXER 41-111-- -1- freedom from sum and distortion ... output level ...and ruggedness.

YOUR OWN EARS PROVE IT Better still. Your own ears will convince you the Professional 55 is your best investment. Ass to see and hear it at your distributor's e> today! > STEREO STEREO TAPE TAPE PREAMP '1 /7 1 CBS ELECTRONICS - ). A Division of Cotumb a Broadcasting System, Inc. r Danvers. Massachusetts Distributed in Canada by CANADIAN GENERAL ELECTRIC CO., LTD., TORCNiTD Block schematic of recording -reproducing system.

AUDIO NOVEMBER, 1959 103

www.americanradiohistory.comAmericanRadioHistory.Com TYPE STEREO -FAX BOOST-0-12 db AUDIO ETC 251-A Provides Stereo Realism CUT -0-16 db groin page 81) From Monaural Source 2 -db steps that RCA's tape heads (and even the tape preamps AT in this model, SCP-2) are as good as they come and can do an excellent job 40 or 60 cps on four -track tape at 3% ips. Since the basic RCA tape deck includes this sound AND quality, the last word is far from said as 3, 5, 10, and to what can be produced out of this ex- celled little chassis. 15 kc Yep, of course, it costs money to put out good sound. Tandberg's four -track recorder, minus stereo speakers, costs a good Hear new depth and brilliance from your deal more than RCA's SCP-2 with speak- monaural tape and record collection by installing the STEREO -FAX in your high fidel- PROGRAM ers; its quality should be higher. But RCA ity stereo system. This network component has too much at stake; RCA has infinitely permits you to take full advantage of your stereo system with all monaural program EQUALIZER great resources. It seems clear that RCA material by introducing phase displace- can easily give us optimum cartridge sound ment between amplifiers. The result is extraordinary realism. Get new enjoyment whenever it has a mind to. I'm from ALL radio broadcasts. Written up in The 251-A Equalizer is a passive LCR waiting. Short P.S. Note Hi-Fi Directory and other leading publica bridged -T network with two sliding levers that other companies tions. Unit comprises a passive RLC circuit for attenuation and equalization, one for are moving into cartridge tape, notably requiring no power source. Easily installed without disruption of existing hook-up. low frequencies and one for high. This Bell. If you're interested, it might be good type of equalizer has long been the to take a look in Bell's direction. I haven't DISC AMP I .4 standard for corrective equalization in had a chance yet. STEREO -FAX sound recording. TAPE H SPKRS RADIO AMI421 Impedance: 600 ohms Level: - 70 to + 20 dbm MORE PRESS STUFF - Insertion loss: 14 rib Power required: none Available only by mail, postpaid if cash with Panel size: 3''2" x l' _" Net price: $260.00 Last April, you may remember, I ran a order, or C.O.D. plus postage. (Calif. residents add 4% tax.) Shipping weight little piece in this department which I approx. 11/2 lbs. for either model. Complete ELECTRODYNE called Press Stuff; it was all about the technical data, simple installation instruc- state tions, and schematic included with each CORPORATION of mind into which I was being order. Satisfaction guaranteed driven by too much public relations, via AUDIOPHILE MODEL U -3A $19.95 503 South McClay St., Santa Ana, Calif. the mail and in multiple doses. Also, on STANDARD MODEL U -4B $16.95 New York City: Robert Marcy and Assoc., 1776 Sway. the side, I spoke of those hundred -word ORDER NOW or write for full information :trod for lateat catalog telegram invitations that wake me up at Gaylor Products Co. sG-De11pt. 9 Circle 104A seven in the morning. . . . Well, I felt a lot better after getting that piece off my 11100 Cumpston St., No. Hollywood, Calif. chest and I note that it has been setting Circle 104C off small explosions here and there, ever the only since. OK by me! The Billboard, that august and influen- tial sheet, was one of those I mentioned- CHECK OUT YOUR the Billboard had been insisting for months that I was a record dealer and plastering me with special 10 -day offers, for more CARTRIDGE way to continue getting $tereo Profit$. Well, after awhile a very nice letter came in from that source and it began in these very words: "This IS a Sweep Frequency personal letter and only one copy or it will be mailed to you." It was the Circulation Transcription $HURE Director himself and, pleasantly enough, o performance from your he approved of my "Rules for Publicizing RIAA CURVE 1 DB Publicists," believed that publishers should 33-1 3 LATERAL "see and heed them." Not a tomato in the For Microgroove and Stereo whole letter, which just goes to show. But as for taking my name off the dunning list-I mean the mailing list-that might high fidelity stereo not be too easy; I was to understand that sEcartridge is to be the filing system for such lists was very complex . . . something about looking for me under my postal zone number ... but, anyhow, he would do what he could to de- record-dealerize me. That was June 3rd. I sent him the very your replacement stylus next Billboard 10 -day special offer that is a genuine came my way, mailing plate and all. The Photo of Variable Reluctance Cartridge latest? In late got a September I fat letter TYPE 102M from The Billboard. It was a special 10 - day offer, for more $tereo Profit$. I haven't 60 - 10 KC given up hope yet. 100-13.5 KC SHU As for those enormously impressive tele- $6.60 Net (Quantity Discount) precision made stereo grams that invite you to some lavish press party or other and invariably arrive in the WAYNE R. JOHNSON wee hours, presaging doom, I groused in April that they either came three weeks LABORATORIES ahead of time (at seven a.m.) or at the BOX 27678 LOS ANGELES 27, CALIF. s Circle 104B very last possible minute. One had actually Circle 104D

104 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com arrived the day after the big shindig. I ran do more than quote you the following, AUDIO FIDELITY which came before the fall Hi Fi BEL CANTO just CONCE RTA PE S shows, with amusement on my part: DOT EDWARD TATTNAL CANBY 780 GCH ST NYK ELEKTRA A HERE AT LAST! LONG WAITED ... NOW PRESS CONFERENCE TOMORROW TUESDAY EVEREST the Arkay/Harting MS -5 HOTEL SHERATON EAST GOLD SUITE 11 AM HIFITAPES Record LUNCHEON TO FOLLOW DEMONSTRATE NEW KAPP Playback STEREO CONCEPT IN HIGH FIDELITY STEREOPHONIC M -G -M MERCURY COMPONENT . . . SORRY THIS 1S SO LATE TAPE DECK 0M EGATAPE Professional qualify et a AS NEWLY APPOINTED PUBLIC RELA- BUT ROULETTE popular price .. . TIONS FOR THIS COMPANY WE ARE JUST only $129.95 S -M -S DEVELOPING OUR PRESS LISTS TRIED PHON- VANGUARD A supreme achievement In tape deck design and performance. the ARKAY/HARTING records your favorite ING YOU WITHOUT SUCCESS. VERVE music with the same superb performance of tape recorders VOX costing many times more. No other tape deck-regardless Apology accepted with pleasure-the of price- offers so many Important features. Here's just a only trouble was, I had another luncheon WARNER BROS few: WESTMINSTER Dual -Ira& combination bead for All -metal tape fingers. drop-in date. (Let's not bother about which (om- two speeds loading WORLD PACIFIC 30-16,000 cp. ± 2 db. All -metal tape guards pany it was. Very reputable and very fa- Flutter and wow: O of 1% Large (S " diem.) capstan Fine -button oper wn Sise: Inn" s 14/0" s 65 " miliar.) - SS db. S/1V a deep. You a copy or Beethoven in stereo... now on 4 -track tape AVAILABLE SOON, NEW ARKAY Stereo Record and Playback P.S. can probably dig up PREAMPLIFIER in Kit or Pre -Wired form, specifically two of the April Aunio at the office, if for less than the identical recordings on hi the Tape Deck. deàgoe AItKAY/IIARTING you're lucky. stereo discs...a complete Beethoven con- ARKAY CS -28 cert: Symphony No. 3 (Eroica), Symphony STEREO AMP/PRE-AMP No. 5, plus the Egmont and Coriolan Over- COMPLETE THE OOMCHA COMMODE tures, with Sir Adrian Boult conducting CONTROL CENTER Somehow, when I get to grousing about the Philharmonic Promenade Orchestra the stuff I like to call ooneclia music-that of London on one reel of 4 -track, 71/2 ips Full 28 watts stereo or monaural, 60 watts peak 14 watts tarsi gain channel reverse stereo balance control two-channel sticky sound they dole out in restaurants stereo tape offering permanent master control lull range bass and treble controls IM distortion, 4 2V via wire and FM multi- to 1 harmonic distortion, 1% 30-20,000 cps dual pre -amp and banks and recording fidelity... just one example of output jacks speaker outputs, 4, 8, 16, 32 ohms response, plex to supermarkets and what-have-you- 20-20.000 cps push-pull EL84 Williamson circuit. what is in store for you among the more I don't really feel I'm carrying my AUDIO Wired and tested $99.95 Easyto-build Kit 6495 than 300 4 -track tapes now available Write today for complete, detailed illustrated literature and specifications audience along with me a full 100 per from recording companies. For See and hear ARKAY Kits at your dealer. cent. After all, why should a large col- 19 leading FREE! Stereo booklet and catalog. Write Dept. A. lection of engineers and technicians col- complete list of tapes and dealers in your All prices 5% hie Mr west of Mississippi lectively dislike a product that uses so area, write 1032 Kifer Road, Sunnyvale, much of their own know-how and stock in Calif. UNITED STEREO TAPES 88.06 Van Wyck Expressway Richmond Hill 18 N.Y. tradef Circle 1 05 A In my blacker moods I can imagine each Circle IQ5C one of you with complete wired music pur- ring softly in your private office, not to mention the bathroom and the front par- lor. I can just see thousands and thousands of AUDIO readers basking happily in the sounds I hate, tingling with subconscious ELECTRONIC pleasure to the gentle, munching massage ORGAN upon the ears. Makes nie want to get up for your and run. Well, I'm not such a snob as I thought. HOME! I positively treasure a letter from a cer- BUILD -IT - tain Paul Davis, AUDIO reader from Lawn - dale, Calif., that renewed my pristine faith YOURSELF in the old-fashioned ear, the kind that looks music straight in the face and takes it full force. I gotta quote from him or SAVE! I'll bust. .. You hit the nail on the head, about Now you can own a professional electronic organ and save up to 50% on an easy that oomcha music. . . . The other day I pay -as -you -build plan . .. The world famous into a store to buy a new 1171O *aid it couldn't be done? went plumbers ARTISAN ORGAN-in 14 models from the commode. He had mocha music on, play- popular 2 -manual Home entertainment style ing it thru a 6 -in. speaker of about 80 to the majestic 4 -manual Theatre and Church per cent distortion. I should have suspected style is now available in kit form. Simple step- anyone that likes dishwater music as a by-step instructions, pictorial diagrams and ideal spare PRONOUNCE IT WEEOO phoney. I was ready to go stark, raving schematics make this an -time project for anyone. mad, I had to bear this for a full 10 minutes. Anyway, his prices were flukey. I FREE LITERATURE on REQUEST DID IT! went to the place that didn't play this dis- Get the Artisan Story before you purchase ... solved your speaker problem by putting torted honkey-tmlk hotel music. any Organ, Kit or commercial model. engineering integrity ahead of mere appearance "People call it hi-fi I hear it in the den- ARTISAN New . relating prices to actual costs, not to "what Home of tists, doctors, supermarkets-I can scream. MUSIC HALL ARTISAN ORGANS the traffic will bear"... relying on your good Why can't they play classical music once judgment of real quality and value. For litera- in a while. Lucky I have many records at ture. write ... re KITSORGAN and can get away from it all." home K` RR' That's what happens, you see, when you COMPONENTS udio push this oo,n.cha business too far. The united technical term for it is consumer resist- O F DISTINCTION PRODUCTS I'd call it justifiable mayhem. ELECTRONIC Sr.,N.Y.3.N.Y. ance-but 202-4 East 19th Moral: If you want to sell a good commode, DON'T wire it for sound. Circle 1058 Circle 105D

AUDIO NOVEMBER, 1959 105

www.americanradiohistory.comAmericanRadioHistory.Com fridge being loose in the touearm. To rec- tuAtyte tify this condition, merely tighten the two -ret, holding screws. CLASSIFIED The chatter tends to show up more on ed`I 100 -fly the outside of the disc in contrast to the Rates: per word per insertion for noncommercial advertisements; 250 per word for commercial adver- center. The reason for this is that the angle tisements. Rates are net, and no discounts will be Amazing DeWALD of the tone:lrnt with respect to the lateral allowed. Copy must be accompanied by remittance In full, and must reach the New York office by the STEREO & MONOPHONIC Is vibration of the groove walls of the record first of the month preceding the date of issue. HI-FI COMPONENTS is more favorable to the transmission of vibrations to the loose parts at this time. Since many 78 -rpm records are over - l'tIt SA LE recorded, the arm and cartridge may be Ilroc iner Transcendent, Mah, $390. Klipschorn Tv!e K377-7, Mah, $400. unable to cope with the excursion thus Marantz('otsttlette 1-l' (old), $75. prtobic. tl. Marantz Constdette 1-C (new), $105. E -V Horn 8-2X4, Driver T24A, $60. Stephens Horn 82311, Driver 216, $60. 16- and 8 -ohm Speakers Concertone 1501, stereo head, $275. only Q. In fil rt auytltirtp about All fully guaranteed. Now 50 Watts ... the construc- Audio Exchange, 153-21 Hillside Ave. Jamaica 100 Watt Peak $139.95 tion of an ,v -akin speak, r which would make 32, N.T. audiophile net it superior to a 1tî-ollt., speaker? Howard HIWI FIDELITY SPEAKERS REPAIRED N-2200 "CLASSICAL" ,1. Murray, Philadelphia, Pa. Stereo Aulprite Speaker Service Contol Amplifier with separate equaliza- A. 70 Vesey St. New York 7, N. T. BA tion, selector and mode controls Individual Because the 8 -ohm speaker uses less 7-2580 tone and loudness controls High output low wire on its voice coil than does the 16 -ohm for d:stortion I.M. under 1°,,. WRITE confidential money -saving distortion speaker, and is therefore likely to be prices on your Ili -Fidelity amplifiers, tuners, N-1200.8 speakers, tape recorders. Individual quota- N -1000-B lighter, the 8 -ohm unit might possibly re- N -803-B "CONCERTO" tions only ; no catalogs. Classified IIi-Fi Ex- 'AMBASSADOR" spond slightly to change, AR, 2:175 "IMPERIAL" 30 Watt better highs. However, a East 65th St., Brooklyn 34. AM -FM Stereo 16 -ohm N. Y. AM -FM Tuner Stereo Control speaker has an advantage that the Tuner $77.95 Amplifier voice coil can be made quite long. If com- INDUCTORS for crossover networks. 118 $99.95 in $99.95 pliances and magnetic circuits types stock. Send for brochure. C. & M. are care- ('oils. 3016 %V., fully Holmes Ave., N. Huntsville, OVER 35 YEARS OF KNOW-HOW! designed, such a unit will have Ala. greater cone excursion. ['NI'SVAI. VALUES Hi-Fi components, Such a speaker may have an additional tapes. and tape recorders. Send for package advantage: A 16 -ohm speaker quotations. Stereo Center. 18 W. 37th St., usually N. Y. C. makes use of the full secondary winding of the output transformer of the conven- RENT STEREO TAPES-over 800 different-all major labels-free catalog. Stereo- A DIVISION OF tional power amplifiers, which means that l'arti. 1608-H Centinela Ave., Inglewood 3, UNITED SCIENTIFIC LABORATORIES, Inc. the leakage inductance will be reduced and California. 35-09 37th Ave., Long island City 1, N. Y. the efficiency of the output transformer HI-FI DOCTOR- Will solve your hi-fi u will therefore increase slightly. Since the problems on -the -spot. Acoustic, audio, radio u u feedback engineer. Stereo designing. Professional vis- Circle 106A is taken across the 16 -ohm tap its, Clay. evening. New York area. William in most instances, the peculiarities of a Bohn, Plaza 7-8569, weekdays. BRITISH PRECISION WORKMANSHIP particular speaker system can be more SALI]: 78 rpm recordings, 1900-1950. Free Guarantees finest Hi-Fi Reproduction fully taken into account in terms of the lists. Collections bought. P. O. Box 155 (AU), over-all system. Verona, N. J. I realize that these points may well be DISKINS-Shaped polythene slipovers to challenged, and advance protect your LI"s from dust and abrasion. I these possibili- Packets of 12: 7"-50f, 10"-75t. 12"-$l, post- %7 [/i v` -r `/ l ties for whatever interest may be created. free from SWAINS Papercraft Ltd., Buck - Actually, the impedance should not hurst 11111, Essex, England. Agents required. OUTPUT have any effect of performance in any well - MAJOR BRAND RECORDING TAPE. Man- TRANSFORMERS designed speaker. ufactured and nationally advertised by one of Æ the four major U. S. companies. 1800 ft. genu- POWER RATINGS ine DuPont Mylar. First quality, no splices, 60 watts at 25 c.p.s. for less than brand new. Full refund if unsatisfied. Not to 1°, total harmonic distortion. EMPLOYMENT he confused with inferior tapes. $1.89 each. 10 100 watts at 35 c. p.s. for less than for $18.00, 100 for $170.00. Include postage. 19;, total harmonic distortion. S & F Electronics, 7959 Melrose Ave., Los Angeles 46, California. FREQUENCY RESPONSE Three outstanding opportunities with :l Flat within . } dB from 20 c.o.s. young, dynamic firm with technicnllt- FOR SALE: Shure M-16 Studio Dynetie to 30 Kc/s. traincd management located in metropoli- integrated cartridge -arm assembly- original SECONDARY LOAD tan Boston. factory carton, $65 ; Heathkit BC-lA tuner, Secondary in four separate sec- wired, $20: Heathkit FM -3A tuner, wired, tions which may be connected ELECTROACOUSTICAL ENGINEER $20; all units its top condition and perform- in series or parallel to match Minimum two years design and produc- ance. Write J. Itorrevik. 400 Memorial Drive, speaker impedances of 0.95, 3.8, tion experience required. Top Cambridge, Mass. P6000 8.5 and 15 ohms. opportunity Model Plate to Plate Load for growth -oriented engineer. For{ SALE : Bogen microphone mixer, Shure Tap :.I jthone, P6001 6-8 K ohms 43" mit'' amplifiers, Heathkits. Johnnie, INSTRUMENT DEVELOPMENT ENGINEER cl Seth Road. Forest N.Y. P6002 4-5 K ohms 20" $49.50 NET Hills, P6003 3-4 K ohms 200 Design and package audit frequency in- P6004 2-3 K ohms 20 struments. Minimum SELL: Ampex 400A 5 -track. Two Altec three years design and M-11 mike systems: 21-B and 21-C mikes. Here is port specification of P6000 thePartridge Series production experience required. "Ground - Shure model 300 mike. Reasonably priced. of Output Transformer. For complete specification B. and floor" opportunity. Peter \Veston, 4743 Westminster Place, St. other information on this and other Partridge Louis S, Mo. Transformers complete and return the coupon. RADIO COMMUNICATION ENGINEER PARTRIDGE TRANSFORMERS LTD. llesigu and package multiban(1 radio 4-TRACK United Stereo Tapes, $3.9.5 up. Sole U.S. Rep. M. Bob's Tape Service, Box 13325, Ft. Worth 18, SWEDGAL cenununications equipment. Minimum three Texas. 258 Broadway, New York 7, N.Y. c:ns design and production expe.rienee re- Telephone: WOrth 2-5485 quirt'ti. Fine opportunity for outstanding ENJOY PLEASANT SI'IiPRISES? Then personal professional write UN before you purchase any hi-fi. You'll r71. Swedgal A II I development. be glad you did. Unusual savings. Key Elec- Broadway, New York 7, N.Y. For further information, write William tronics, 120 Liberty St.. New York 6, N. Y. '258Please send your 1959 60 Catalogue containing I Evergreen 4-6071. complete technical data on Partridge Output Glaser, H. H. Scott, Inc., Maynard, Mass. Transformers. EXt'ELLENT QUALITY recording tape _..._ I 7" reels. 30-15.000 cps - 'NameAddress guaranteed. City HI-FI TECHNICIANS WANTED 1200' Acetate, 3/$3.90-6/$7.50 Zone State i 1800' Acetate. 3/$5.10-6/$10.00 My jobber would like information too One fully experieneell tuners, tapes, 1200' Mylar, 3/$4.80-6/$9.00 He is _ I photos. Another, trainee, able to mount 1800' Mylar, 3/$6.60-6/$13.00 Address ]hangers, turntables, and eager to learn 2400' Mylar, 3/$9.60-6/$19.00 LCity Zone StateJ hi-fi servicing. Driver's license Add $.15 PP and handling per reel, FOTO- required. SOUND, 88 Harbor Road, Port Washington, Circle 1068 Audio Exchange, AX 7-7577. N.Y.

106 AUDIO NOVEMBER, 1959

www.americanradiohistory.comAmericanRadioHistory.Com TAPE GUIDE BEST IN HI-FI VALUES! (from page 38i NO All orders rushed to you 4. Metal storage cans and storage DELAY in factory -sealed cartons. chests are also available. Some Cans are SERVICE Write for free catalog. made of special material to shield the 25-A Oxford Road tape from magnetic fields produced by audion Massapequa, New York motors, transformers, and so on. 5. The Tape -Time Ruler is manufac- Circle 107C CHECK OUT tured by Ferrodynamics Corp., Lodi, New Jersey and is available-at least at YOUR TAPE RECORDER the tinte of writing-free of charge. ON THE SPOT: FgQ, Not all tape machines contain footage counters or clear and accurate markings Soundcraft's MAGNA -SEE Kit lets you under the reel to indicate elapsed time ANTENNAE see the sound on your tape Get more FM stations with the world's most and thereby help the operator locate :1 powerful FM Yagi Antenna systems. desired passage on the tape. The Taltc- Checks for: Head Alignment Head Send 250 for booklet "Thorne And Varle- Time Ruler is placed on the supply reel tions" containing FM Station Directory. wear Track placement and balance spindle. and a reading is taken at the APPARATUS DEVELOPMENT CO. Contains: 1/s pint outermost layer of tape to indicate the Magna -See Solution Wethersfield 9, Connecticut number of feet and playing time left. Plastic bath Circle 107D While the foregoing has sought to e Eye -piece magnifier 'nntprehensive account of the ac .es- Pressure -sensitive tape 5 glass slides ,,,rit's available to the operator of a for permanent copies CANADA tape machine, it is quite possible that High Fidelity Equipment of your developed some have been inadvertently omitted. track, and complete Complete Lines Complete Service instructions. I l' so, the writer asks the indulgenTe of Hi-Fi Records - Components Makes editing easier and Accessories the manufacturers of such items and will ...more exact. attempt to correct the omission in the For free MAGNA -SEE &LECTRO-i)O1C,E near future. brochure, write SOUND SYSTEMS 141 RUNDAS ST, WEST. TORONTO, CANADA REEVES SOUNDCRAFTCORP. Circle 107E GREAT PASTURE ROAD, DANBURY, CONNECTICUT special N'est Coast: 342 N. La Brea., Los Angeles 36, Calif. Canada: 700 Weston Road, Toronto 9, Ont. Canada recording tape Circle 107A RENT $1.19 1200 ft.; 7"-guaranteed splice -free 1800 ft.; 7" ... $1.89. Enclose 100 for ICELeLgil_ tapes reel cover postage and handling. stereo each to over 800 different albums Superior to European & American Products all major labels Sold profitably everywhere no deposits on tapes rented Extended range 3 -way Speaker postpaid to and from your home kieruiff SOUND CORPORATION n20 W OLYMPIC BLVD., LOS ANGELES 15, CALIF. Free calalo'j 12TX-1 stereo-parti Circle 107K 1608-C CE!ITINELA AVE.. INGLEAGOD. CAUF. Circle 107F Low, medium and very efficient high tone speaker LOOK mounted on a no further . if you're searching for hi-fi savings. single axis, Write us your requirements now. forming a coaxi- Key Electronics Company al sound source 120 -lt Liberty St., N.Y. 6, N.Y. EV 4-6071 system. Circle 107G

In addition, high tone can easily be ad- Time Tested STAT -SIL Static SI.O Now! Hear lancer inhibits dust and static noise. justed with an attached brilliance control RECORDS Get rid of "pops" and "crackles" for high-fidelity that interfere with ideal sound re. we deliver "Scotch" postpaid to your door exceptional reproduction. AT THEIR production - spoil your listening pleasure. Use STAT -SIL that in- (recording tape, that is) Complete Hi-Fi speaker catalog upon BEST! hibits airborne dust attracted to the. request. record by electro-static charges Prices???? O -e keeps records cleaner, longer. Easy. send for catalog ... you'll be glad you did! MANUFACTURER GENEX to apply. Money back guarantee. e Complete STAT -SIL kit only $1.50 Corp. nostpaid. FUKUYO SOUND CO., LTD. Dept. A, G.P.O Box 1124, New York 1, N. Y. 'Ma,pe t) 25-2, HORIFUNE, KITA -KU, TOKYO, JAPAN 1608-C CENTINELA AVE . I Slit EWOOD Cable Address: CORALFUKUYO Circle 107H Circle 107F Circle 1078

AUDIO NOVEMBER, 1959 107

www.americanradiohistory.comAmericanRadioHistory.Com cz âje#e Superior Quality Hi-Fi Kit ADVERTISING INDEX OUTSTANDING DESIGN - INCOMPARABLE PERFORMANCE

Acoustic Research, Inc. . 28 KT -250 50 WATT INTE- Acro Products Company 94 Allied Radio Corp. 81 Altec Lansing Corporation 65 GRATED STEREO AMPLIFIER American Electronics, Inc., American Concertone Division 39 Amperex Electronics Corporation 6 A completely new stereo high fidelity amplifier Ampex with a Corporation 33, 34, 76 high quality of reproduction, versatility of Apparatus operation, and distinctive styling. Development Corporation ... 107 Arkay 105 A full range of controls enables you to enjoy the utmost in listening Audio Bookshelf 102 pleasure in any situation. De- Audio Fidelity Inc. luxe features include: unique "Blend" control 67 KT -250 LA -250 for continuously variable channel separation- Audiogersh Corp. Cov. 111 from full monaural to Audion 107 IN KIT FORM COMPLETELY WIRED full stereo, 4 -position Selector, Mode, Loudness and Phase switches. Bell Telephone Laboratories 18 89.50 Also provided are outputs for 4, 8 and 16 ohm Bogen -Presto 74 64.50 speakers. Hum -free operation is insured by the Bradford Audio Corp. 72 use of DC on all preamp and tone control tubes. British Ferrograph Recorders Co., Ltd. 78 50 WATTS MONAURALLY 25 Harmonic distortion, less than 0.25%. IM distor- British Industries Corporation 3 - WATTS tion, less than 1%. Hum and noise, 74 db below CBS Electronics, A Division EACH STEREO CHANNEL full output. of Columbia RESPONSE 17- Designed with the kit builder in Broadcasting Systems, Inc. 103 21,000 CPS ±1 DB (at normal listening mind, assembly is simple-no special skills or Classified tools required. 106 Level) UNIQUE Complete with deluxe cabinet and Connoisseur 77 "BLEND" CONTROL legs, all tubes and parts, detailed instruction Cosmos Industries, Inc. 101 PREMIUM EL86 OUTPUT TUBES SEPA- manual. Shpg. Wt., 26 lbs. lATE BASS AND TREBLE KT -250 Stereo Amplifier Kit 6.45 Down DeWald, A Division of United Scientific CONTROLS Laboratories, Inc. 106 CLUTCH -OPERATED VOLUME CONTROL Net 64.50 LA -250 Stereo Amplifier, wired 8.95 Down Dexter Chemical Corp. 85 3rd CHANNEL OUT Net 89,50 Dynaco, Inc. 97 EICO 15 Electrodvne Corporation 104 Electrophono G Parts Corp. (LESA) .. 55 KT -500 FM -AM Electro-Sonic Laboratories, Inc. 86 Electronic Organs Arts 105 STEREO Electro-Voice, Inc. Coy. IV TUNER KIT Electro-Voice Sound Systems, Inc. .... 107 Ercona Corporation 77 More than a year of research, planning and en- Fairchild Recording Equipment Co. 75 gineering went into the making of the Lafayette Fisher Stereo Tuner. FM Radio Corp. 63 specifications include grounded- Fukuin Electric (Pioneer) 69 grid triode low noise front end with triode mixer, Fukuyo Scund Co. Ltd. (Coral) 107 double -tuned dual limiters with Foster -Seeley dis- criminator, less than 1% harmonic distortion, full Gaylor Products Co. 104 200 kc bandwidth and sensitivity of 2 microvolts General Electric 49, 51, 53 KT -500 i LT -50 for 30 db quieting with full limiting at one mi- Genex Corp. 107 Gotham IN KIT FORM I COMPLETELY WIRED crovolt. Audio Sales Co., Inc. 96 The AM and FM sections have separate 3 -gang Grado Laboratories, Inc. 84 74.50 124.50 tuning condenser, separate flywheel tuning and Harman Kardon 27 separate volume control. Automatic frequency Harvey Radio Co., Inc. 91 control "locks in" FM signal permanently. Two Heath Company 7-9 separate printed circuit boards make construction Multiplex Output for New Stereo FM JansZen 47 and wiring simple. Complete kit includes all parts Loudspeakers 11 Johnson, R., Tubes (including 4 dual-purpose) -}- and metal cover, a step-by-step instruction man- Wayne Laboratories 104 Laing Eye 1- Selenium rectifier Provide 17 ual, schematic and pictorial diagrams. Size is Key Electronics 107 lobe Performance Pre -aligned IF's 131/4" W x 101/4" D x 41/2" H. Shpg. wt., 22 lbs. Kierulff Sound Corporation 107 KT -500 7.45 Down Kinematix, Inc. 98 Tuned Cascade FM Dual Net 74.50 Cathode LT -50. Same as above, completely factory wired Kingdom Products, Ltd. 5 Follower Output and tested 12.45 Down Net 124.50 KLH Research Cr Development Corporat ion 95 Lafayette Radio 108 KT Lansing, James B., Sound, Inc. 13 -600 PROFESSIONAL Madison Fielding 79 Magnecord, Division of Midwestern STEREO CONTROL Instruments 99 CENTER Marantz Company 12 Solves Every Stereo/Monaural McIntosh Laboratory, Inc. 43, 44 Neshaminy Electronic Corp. 47 Control Problem! Newccmb Audio Products Co. 73 Provides such unusual features as a Bridge Con- ORR Industries, Inc. 99 trol, for variable cross -channel signal feed for Paco elimination Electronics Co., Inc. 41 of "ping-pong" (exaggerated separa- Partridge Transformers 106 tion) effects. Also has full input mixing of monau- Pickering G Company 17 ral program sources, special "null" stereo bal- Pilot 31 ancing and calibrating Radio Corporation KT -600 ; LA -600 system. Also has 24 equal- Professional D:rectcry 107 ization positions, all -concentric controls, rumble IN KIT FORM L COMPLETELY WIRED and scratch filters, loudness switch. Clutch type R Cr A 77 volume controls Radio Corp. of America Cov. II i for balancing or as 1 Master 79.50 134.50 Volume Control. Has channel reverse, electronic Radio Shack Corporation 71 phasing, input level controls. Sensitivity 2.2 mil- Reeves Soundcraft Corp. 107 livolts for 1 volt out. Dual low -impedance out- Reslo 77 A REVOLUTIONARY DEVELOPMENT puts (plate followers), 1500 ohms. Response 5- Rigo Enterprises, Inc. 4 IN STEREO HIGH FIDELITY. 40,000 cps ± 1 db. Less than .03% IM distor- Roberts Electronics, Inc. 92 tion. Uses UNIQUE STEREO & MONAURAL CONTROL 7 new 7025 low -noise dual triodes. Rockbar Corporation 11 Size 14" x 41/2" x 101/4". Shpg. wt., 16 lbs. FI4TURES AMAZING NEW BRIDGE Sansui 88 CIR- Complete with printed circuit board, cage, pro- Scott, H. H., l'--. 83 CUITRY FOR VARIABLE 3d CHANNEL fusely illustrated instructions, all necessary OUTPUT parts. Sherwood Electronics Laboratories 1 CROSS -CHANNEL FEED PRECISE "NULL" LAFAYETTE KT-600-Stereo Preamplifier kit - Shure Brothers, Inc. 104 7.95 Down Net 79.50 3RLANC!NG SYSTEM RESPONSE 5-40,000 Sony Corporation 89 LAFAYETTE LA-600-Stereo Preamplifier, Wired Stereo -Parti 107 C -S -±- 1 DB -13.45 Down Net 134.50 Strombcrg-Carlson, A Division of General Dynamics 56-58 Stuzz i 77 P.D. 807. 222 :3'PT AK -9 Tandberg of America, Inc. 2 -et& JAMAICA 31, N. Y. 107 W Tapeco Send FREE LAFAYETTE Thorens 87 Catalog 600 Tung -Sol Electric Inc. 93 CUT OUT Uher 37 l Name AND United Audio 90, 105 United Stereo Tapes 105 PASTE ON University Loudspeakers, Inc 61 I Address POSTCARD V itavox 77 Weathers Industries 80 City Zone.... State Weiss, Warren 37

108 AUDIO NOVEMBER, 1959