~Free Aóarei4 /%14- ./ from the LINE MOST WIDELY USED by PROFESSIONALS

...lie o ~free aóarei4 /%14- ./ FROM THE LINE MOST WIDELY USED BY PROFESSIONALS... I TO High- Fideli urntables for Home Installations

PRESTO 7 -2 A crowning achievement in engineering design -the T -2 For over 20 years, Presto transcription turntables have two speed model offers superb high -fidelity- performance at been the choice of broadcast- station and sound- studio en- modest cost. Its heavy, balanced aluminum turntable and gineers. Today, more are in professional use than any rugged drive system eliminate wow. flutter and rumble. The make. interchangeable idler wheels disengage in the "off" position other to prevent flats. Heavy- duty. 4 -pole motor insures accurate Now, Presto offers the audiophile three precision turn- speeds. Shift mechanism permits quick change from 33's incorporating many of to 45 r.p.m. while table is spinning. Comes equipped with tables for high -fidelity installations, built -in strobe disc. 45 r.p.m. adapter. and rubber record the design features that have made our transcription turn- mat. Only $59.50 tables famous. See them at your local high- fidelity shop-or PRESTO T -18AH for full details and specifications, write for catalog to Undoubtedly the finest high -fidelity turntable for home use Dept. G12, Presto Recording Corp., Paramus, N. J. that money can buy-. Three speeds; precision -made throughout: wow, flutter and rumble are virtually non -existent. Employs 12 ", cast -aluminum turntable and constant -speed hysteresis motor. Speed selector has five positions: 45 oiT 33',4- off - 78. Only $1.77.nn PRESTO T-18A Has all the features of the T -18A11 (above) except that it 1 /P/n/ssr( TURNTABLES TAPE RECORDERS DISC RECORDERS is equipped with a heavy- duty. 4 -pole induction motor. Only $75.00 DISCS STYLI AND HIGH FIDELITY CABINETRY A SUBSIDIARY OF THE EIEDLER CORPORATION THE BRITISH INDUSTRIES

MODEL 301 7 e P,rojeslCa «af" TRANSCRIPTION TURNTABLE 114,*!: q WORLD'S FINEST!

A simple explanation of the thinking behind this great turntable!

N any transcription turntable, there are two potential sources of c noise which produce the effect commonly termed "rumble'. These are the motor ... and the spindle on which the turntable itself re- volves. Since any turntable and motor rotate on bearings which create heat and noise, the problem is to reduce the noise to a point of in- o audibility, first by minimizing the source and then by isolating it.

The motor used in the Garrard Model 301 is a precision -engineered, dynamically -balanced 4 -pole unit, encased in a heavy die -cast frame. o Designed by Garrard, it is also built in Garrard's own plant. This guarantees its quality. However, in any motor, some vibration may be evident. Therefore, the 301 motor is completely isolated from the I unit plate, suspended by three tension and three compression springs, so that it is actually isolated in a 360° sphere. This method of sus - I pension is unique, and it is one major reason why the Garrard 301 is

I so remarkably free of vibration.

In addition, the one lever which connects the motor to the unit plate (the speed control lever) is also ingeniously suspended within three springs, rather than by using a conventional bushing or pivot. The Garrard 301 is the only unit wherein the motor is entirely suspended by springs from ever) lever and even from the unit frame itself! (OVER

The ìui turntable weighs a full 61/2 lbs. and it is made of precision - machined cast aluminum. Being heavy and dynamically balanced as well, it imparts flywheel action, which tends to override a variation in speed.

The all- important turntable spindle is polished to mirror finish. This minimizes any turning noise. Then, by setting the spindle in a die - cast housing which is completely filled with a special lubricant under pressure, even that minimum of noise which remains is isolated and prevented from reaching the turntable or unit plate. This, in turn. also prevents vibration from reaching the pickup. In order to insure that the spindle is at all times under the influence of strong damping pressure, a reservoir for the lubricant is built into the housing. By simply turning a knurled knob, a new supply of WIMP'grease is forced into the housing whenever required.

Another 301 feature is the method of setting the precise speed. After the major speed selection has been made, a control knob on the top of the unit can provide an additional 21/2% variation, plus or minus. This magnetic speed control operates as an eddy current brake. Two permanent magnets are set on either side of a rotating disc, which is attached to the motor arma- ture. By increasing or decreasing the distance of the magnets from the center of the discs, the field strength of the magnets is varied and reflects in the speed of the motor. The eddy current method of control is instantaneous, precise, permanent and fool -proof. The wow, flutter and rumble specifications of the 301 are well below those required by the NARTB. The 301 was developed in conjunction with the highly critical British Broadcasting Corporation, and it is used in their broadcasting work. This great product meets all the qualifications which are desirable in a turntable. It is quiet, precise, rugged and proven through count- ,1.,u less hours of use under the most ^ » ^ r "'" arduous conditions.

The performance of every Garrard t - r- 301 unit is checked exhaustively _.. by the factory and appears on an 1 individual test card supplied to the purchaser.

For literature write Dept. 6X17S. GARRARD SALES CORPORATION PORT WASHINGTON, N. V. DECEMBER, 1957 VOL. 41, \.,. Successor to RADIO, Est. 1917. for Ultimate Fidelity

AU D Io 1.Nr :INF.F.RINC. MUSIC SOUND REPRODUCTIO,

C. G. McProud, Editor and Publish.. Henry A. Schober, Business Manager Barrie K. Richardson, Associate Editor Marie Caspe. tssistant Editor outatandin9 hon- M. Durgin, Production ora bestowed, un Janet Manager soil:ited, by most recconixed testing Edgar E. Newman, Circulation Director or lenirations.

Sanford L. Cahn, Advertising Director Special Representative - H. Thorpe Covington, 814 Lincoln St., Evanston, Ill., DAvis 8-8874 .01 Mid West Representative - Sanford R. Cowan, 300 W. 43rd St., INC' New York 36, N. Y. West Coast Representative - James C. Galloway 6535 Wilshire Boulevard, Los Angeles 48, Cali!. CONTENTS No matter what your source of music Atuliocliitie-Joseph Giornaclli -FM, your own discs, or tape -you

Letters _ 6 will enjoy it at its best coming from Sherwood's complete home About lnsir -I! troi/ Low re rnee 12 music center ... most honored of them a l!Sherwood Coming Events 14 tuners for example .. .

Editor', Review . 16 The Stereo Recorder -.\ Recitation and an Education-Joseph E. /'re,I,, 14 First to achieve under one microvolt Ilote To Platt Your Ili -1'i System -C. R. T'ie,i,no 2-1 sensitivity for 20 db FM quieting increases station range to over 100 miles. Lnpcdanee und Feedback iii . \tulio Circuits -I1, rfun li,u.4ei :nid Mens'', C. /'allok 26 Other important features include the new "Feather -Ray" tuning eye, auto- The Sad of a \Watt Resistor lase Ilall'- - Walther Birbl, r :Ili matic frequency control, flywheel tun- Loudness, Its Definition, Measurement and Calculation, l'art II- 11arref ing output level control aid cathode - Fletcher and W. .1. Manson tll follower output. 1:lfaipuunt Review -//W,u ¡,real /, mol llrn,dI ;it III, (,.nerd' /sleelrie CR-I/. and traa..eriptirn, 511 Fairchild I,,rut,,hlr arm. the Garrard line Model S -2000 FM -AM Tuner S139.50 net 1(ee ird Revue -Edward Tatwall ('ant l 56 Model S-3000 FM (only) Tuner S99.S0 net Audio ETC- Kelward Tat null Canby 112 New Literature 69 For complete specifications, write De. t. Jazz and All That- ('hdrl,:. .1. Bob, it ,on 711 New Products 7, SHERWOOD Industry Notes and Peuple 93 ELECTRONIC LABORATORIES. INC. Annual Indes 94 2802 West Cullom Avenue, Chicago 18, Illinois Advertising Indes 96

COVER I'!I()'l'O Prout "Down Muter colors this attlaeticc nrrallnlcut ereate,l The "complete high fidelity home music center." by : \. E. II i -don '.1 IIavili n \ 'Wright. Ltd., Radio & . \udiu I :ngincers, of I \ "ietoria Slrel t \Weir, . \nckl:nul, N. Z. The equipment consists of a Philips . \I tuner, 1'\c :naiIliicr. I ;:nrard changer with 'l'anuov cartridge, a Tauuuv lai' dual 1L9 ('oneeutrie speaker ton opposite wall) and a Philips tarp. recorder- removable for pmtable use. 'Plie taule trame at the lover right. ventilates the rupin amplifier. AUDIO trifle registered It. S. Pat. 00.1 Is published monthly by Radio Magazines. Inc., henry A. Schober, President: 11 C. G. Merroltd, Secretary. Executive and Editorial Offices. 204 Front St., Mineola, N. Y. Suhsrription rate -U. S. Possessions, Canada and Mexico. $4.00 for one year. $7.00 for two years, all other countries. $5.00 per year. Single copies 50C. Printed in U. S. A. at Lancaster. Pa. All rights reserved. Entire contents copyright 1957 by Radio Magazines, In Ne.,, York hear "Accent on Sound" with Sklp Weshner, WBAI -FM, week nights, P.M. In inc. Entered as Seeond Class Matter February 9, 1950 at the Post Office. Lancaster. Pa. under the Act of March 3. 1879, 9 Loa Angeles. NRHMFM, 10 P. M. RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y.

AUDIO DECEMBER. 1957 1 AUDIOCLINIC ??

JOSEPH GIOVANELLI

Note: One of the results of the al Ono. :oplitiers as ti. scribed, be sure that the recent high fidelity shows is that we have amplifiers are identical. Should one have gained numerous new subscribers. For one more stage than the other, the output James Melton their benefit, let me state that it is the signals would be 180 deg. out of phase, makes his tape recordings on function of this column to answer any causing a cancellation rather than a re- anti all inquiries put to it, regardless of inforcement of the signal. Even if the their suitability for use in the column amplifiers have the same number of stages, itself. Write to nie at the address shown but are of different circuit design, there and not to Avow magazine, anal please en- is likely to be enough phase difference be- close a stamped, self -addressed envelope. tween their output voltages so that at least Because all letters are answered by mail, partial cancellation will result. irish it is obvious that your help in this regard will save me considerable time in getting Cabinet Dimensions ferro-sheen the answers to you. Should you prefer not to have your name appear in the column, Q. I am thinking of building a large recording please so indicate in your letter. Unless bass reflex cabinet of approximately these tape we receive word to the contrary. we shall dimensions: 2t/j ft. x 2% ft. x 6 ft. I assume that we may use your name. would like to know whether these dimensions are suitable, provided that the port Tape Direction i:: properly tuned. IV. A. Long, Akron, Ohio. Q. in AUDIOCI.INIC in September, 1957, A. In theory, the optimum ratios for discussing conversion to stereo, you say the dimensions for a bass -reflex enclosure that with the shiny side of the tape facing are 1:2:3. Therefore, assuming the largest the viewer, is intended for the upper half dimension of your cabinet to be 6 ft., the the speaker. Which way is the tape left others should be 2 ft. and 4 ft., respec- renniny: from left to right or from right tively. Because of the large volume of to left.' Paul V. Gerhard, Beverly, Vass. such a cabinet, it will probably be neces- A. The upper channel always feeds the sary to scale down all dimensions, keeping left speaker as the listener faces the their ratio intact. speakers in listening position, and it is assumed that the nape is travelling from Balance 11f1 to right. Q. I hare a fine amplifier in most re- .peets, bill 1 do notice that, as the gain is rwo Amplifiers reduced, the balance between highs and Q. Not. I-On l connect two 40 -wall am- lows is not of the same proportion as when plifiers to drive one 4 -ohm speaker sys- the gain is turned up. There seems to be Here's why you should use tem' Both are to be fed from the same a very definite point at which the fre- preamplifier. Frank A. Cappi, Chicago, quency becomes good. What is this con- Illinois. dition and how can it be corrected? Naine !f"itheld, Lake Worth, Fla. A. I do not advise connecting your two amplifiers to one speaker system unless A. This sounds as though it might be an you are sure that the speaker system can advanced case of Fletcher -Munson trouble, Ìhandle their combined power. One of your and the effect is due to the lowered sensi- :uuplifiers has more than enough power tivity of the human ear to low frequencies output to overload the speaker system. The as level is reduced. On a perfectly flat re- only value of so connecting your amplifiers producing system, music will appear to would be that of obtaining slightly less have the proper balance only when the distortion. Although the decrease in dis- reproduction level is identical with that of tortion could be measured by laboratory performance. If this is the problem in your methods, it is doubtful that it could be ease, you might find a solution in installing detected aurally. Should you still wish to a compensated type of volume control in try this, proceed as follows: place of the "flat" or uncompensated control now in use. There are other causes It's the best -engineered tape 1. Connect the output of the preamplifier directly to the input of each of the which could result in a loss of highs as in the world ... power amplifiers. the volume is lowered, the most common 2. Connect together the common, or of which is due to high stray capacitance ground, terminals of the power amplifiers. in a grid circuit. As capacitive reactance 3. Join the two four -ohm taps. This at the higher audio frequencies approaches ...gives you better highs... better lows... will provide the necessary futur ohms to the input impedance of the amplifier, the better sound all around! Saves your tape operate the speaker. amplitude of the high frequencies is di- more minished with respect to middle and lower recorder, too because the irish FERRO - By so conneet.ing the equipment, - obtained than could be frequencies. One form of such capacitance SHEEN process results in smoother tape power output is had from a single :mplifier. It should be is that between the resistance element of ...tape that can't sand down your mag- remembered, however, that the internal a volume control and its case. This varies netic heads or shed oxide powder into your impedance of the output circuit has been with the setting of the control, so that machine. Price? Same as ordinary tape! halved, which is the reason that the 4 -ohm when the control is in the most advanced speaker had to be connected to what had position, the effects of the shunt capaci- been, for each unit, the 4 -ohm takeoff. tance are at a minimum. The larger the Since the output of most preamplifiers resistance of the control, the smaller will is terminated in a cathode follower (hav- be the shunt capacitance needed to cause ing low output impedance), two or more this high- frequency loss. To minimize this high -impedance circuits may be directly effect, replace the present volume control bridged across its output terminals with- with one whose resistance is no more than out significantly affecting the perform half that of your present control. By Available wherever quality lape is sold. alive of the sw-tcau. \\'hen connecting power whatever amount this resistance has been ORRadio Industries, Inc., Opelika, Alabama decreased, the value of the coupling ca- Kr port: Mohan Er porting Corp., Nra l'ori:, N. P. pacitor feeding this control should be in-

Canada : :l etas Radio Corp., Ltd.. Toronto. On la rio - . \, a 1.v I. . I re., Ih-ookiyu 3, creased, so as not to impair the low -fre-

2 AUDIO DECEMBER, 1957 J Ile who is fortunate enough to own the Garrard 301 Transcription Turntable and the Garrard TPA /10 Tone Arm can enjoy the unique pleasure of knowing that bis is the finest ... the handsomest ... record -playing combination in the entire high fidelity galaxy. A pair of great products... great because they reflect 35 years of skill and the standards of leadership. No gadgets. .. no compromises.. . only the time - proven features which guarantee continuing, undeviating excellence.

ORLD'S FINEST RECORD PLAYING EQUIPMENT

Model PROFESSIONAL Model RC98 4 -SPEED SUPER TRANSCRIPTIONTION TURNTABLE AUTO -MANUAL CHANGER Each speed variable! Continuous I- or - variable Each unit with its own control on all speeds. $87.50 -" report. performance test There's a Garrard $85.00 - a- for every Model TPA /10 TRANSCRIPTION TONE ARM Model RC88 4-SPEED DELUXE high fidelity system -Professional performance. AUTO -MANUAL CHANGER jewellike construction Exclusive pusher platform and exceptional protects your records. $54.50 versatility. $24.50 -+ Model T Mark II Model RC121 4 -SPEED MIXER 4 -SPEED MANUAL PUTER AUTO -MANUAL CHANGER A superior unit for quality Fire performance with economy budget systems. $32.50 and compactness. $42.50

For Information, write, Dept. GA-17 GARRARD SALES CORPORATION, PORT WASHINGTON, N. Y. quency performance of the amplifier. 1f the value of the coupling capacitor is not increased to meet the decreased control resistance, losses will occur because of the voltage divider formed by the reactance of the capacitor and the resistance of the COMING control. As frequency decreases, the reactance of the capacitor increases until finally there comes a point where that of the capacitor equals that of the volume control. As frequency proceeds below this point, it is obvious that more voltage will be lost across the capacitor than across To Your City . the control. From this point on, low frequencies will be attenuated at the rate of ti db per octave.

Power Output HIGH FIDELITY Q. 1 have been checking the power output of my Williamson -type amplifier and hare had some disappointing results. 1 am using 6L6 -GB tubes as power output stages, driving a UTC LS63 output trans former, right into an 8-ohm speaker. The tube manual states that these tubes, operated with cathode bias with 360 volts on their plates and 370 rolls on their screens. SEE and HEAR the latest in HIGH FIDELITY from would delirer d4.5 watts in class AB. I'm operating the tubes at 340 volts on the leading high fidelity manufacturers .. . plates and 350 colts on the screens, and with a 350 -ohm cathode resistor, bypassed with 330 p-f. The grids are wirer/ with 470,000-ohnt resistors. If 1 disconnect the driver stags from the 6L6 !rids and feed it into separate 470,000 -ohm resistors, I can obtain 15 -16 volts RMS to drive the Don't miss these public showings `Amplifiers - Pre -Amplifiers - grids of the 6L6's. This waveform is clean as seen on a 'scope. However, as soon as 1 of Hi -Fi Equipment . . . from FM-AM Tuners - Turntables connect the driver to the 6L6 grids can only the most economical units for the and Record Changers - Phono drive thent to 10 volts RMS. Beyond this budget- minded to spectacular Cartridges Microphones point, the waveform flattens off. At this - - point 1 can get only about 10 watts out. home music theatres ... com- Music Control Centers - Can you explain ,,1ty 1 cannot approach at least the 3r1 -teal1 level with the above pare and enjoy them all. Speakers. parameters.-' W. R. Henry, Albuquerque, *Speaker Enclosures and Equip- New 'Mexico. ment Cabinets - Finished and A. It is logical to expect that, when the 'Complete Hi -Fi Systems and Assembled Do- Yourself output of your driver stage is connected or It- to a dummy load, more output would be Cbmponents. Kits. obtained than when the same driver was connected to its proper grid load, with the remainder of the circuit made operative. This is because the output stage is designed to feed back a certain amount of its energy is such a direction as to cancel a portion of THREE FULL DAYS OF CONTINUOUS DEMONSTRATIONS the driver's output voltage. A driver stage of higher capacity would have to be used FROM 1 P.M. TO 10 P.M. FOR EACH SHOW to overcome this difficulty. Such a stage might take the form of a push -pull parallel configuration. Think back to the original Williamson circuit, in which 807's were used. In some Rigo Shows 1958 circuit arrangements as these tubes are easily capable of delivering 40 -50 watts output, and hams use them as Class B linear amplifiers and easily obtain 100 .Jan. Ill. 11, 12 Minne ;y,uli- hotel Dyekman watts from them. Williamson got 8 watts out, using them as triodes, but with very Jan. 17, 18, 19 Indiunapoli Hotel Antlers low distortion. Jan. 24, 25, 26 Buffalo Hotel Statler Feb. 7, 8, 9 Denver Hotel Cosmopolitan Speaker Demonstrations March 7, 8. 9 Pittsburgh Hotel Penn -Sheraton V. I u-i..h t, ,I, mon.trale the frequency March 21, 22, 23 Newark llotel Itobert Treat range of the various speakers in my three- way system, both singly and collectively, isolating them one from the other, using one, two or three. Can you suggest a ADMISSION 50t means which will permit this sort of thing? No MC Il ilbrld. Lake Worth, Fla. A. When renwwing a speaker from your crossover network as you plan doing for demonstration purposes, a resistor whose value equals that of the impedance of the 500 N. Dearborn, Chicago 10, III. speaker which it replaces must he used. RIGO S Inc. I /'ton fin uref nu IMO,' S..'I

4 AUDIO DECEMBER. 1957 NEWEST achievements in High Frequency reproduction!

NEW HYPERSONIC NEW RECIPROCATING- FLAREi T-50 DRIVER H -600 HORN Smooth, distortion -free sound repro- Uniform, wide -angle dispersion of duction from 600 cps to inaudibility! sound over the entire operating range!

T -50 THE ONLY TWEETER IN THE WORLD WITH er Hypsonic H -soo NO HIGH FREQUENCY PHASE CANCELLATION

TOP CUTAWAY

BOTTOM CUTAWAY

Exclusive features of the T -50 Exclusive features of the H -600 Q Special type aluminum voice coil for high fidelity and long life O © Initial expansion vertical di- The only known "front concave" hypersonic diaphragm with abso- O O Horn contours'"' in horizontal ©p rection lutely uniform path lengths O O Ultimate expansion in horizontal O O The only hypersonic acoustic head with "radial slots" to achieve direction absolutely no high frequency cancellation O Front plane equalizer "" O The only one piece integral hypersonic mixing chamber available O Uniform front wave pattern Exclusive with Un i rcrei tp super precision close tolerances today for SPECIFICATIONS: Air column: 73/ "; Horn Cut- O Rim -centering for long life off: 600 cps; Recommended crossover: 700 cps; Dispersion: 125` horiz. x 55 sert.; Bell mouth: Response: 600 cps to inaudibility; Recommended crossover: 700 cps: Power 83/4" 43/4" overall; Depth (less driver): 734"; SPECIFICATIONS: net capacity: 50 watts, integrated program; Diameter: 4% ; Depth: 41/4"; Throat: 11/4" -18; $49.50 net Throat: 1% "-18 thread; $18.00 °Patent pending t U.S. patent $j2,690,2á1 More University tweeters, mid-range horns and drivers ... for maximum bay of application and flexibility of operation

HF-206 H le Tw . Response to inaudibility. Crossover 5000 cps. Wide angle "reciprocating flare" die -cast aluminum horn. 8 ohms 533.00 net. UXT5 Super Tweeter. Crossover 5000 cps up. Wide -angle response to 17.510 cps. 8 ohms. 521.00 net 4401 Tw . Crossover 2500 cps up. Wide-angle response to 15,000 cps. 8 ohms. 518.00 net. T -30 High Frequency Driver. As tweeter with H-600 in 2 -way system: as mid-range with H-600 or Cohreflex in 3 or 4-way. Response: 200- 15.000 cps. 8 ohms. $30.00 net. LISTEN aiiveitsí`'y svuitaS óeia Cobreflea Horn. Crossover 350 cps up. Exclusive twin - flared 27" exponential air column. Dispersion: 120° x 60° 1 Heavy precision aluminum die casting. $23.10 net. UNIVERSITY LOUDSPEAKERS. INC., RO SOUTH KENSICO AVE.. WHITE PLAINS. N. Y.

AUDIO DECEMBER, 1957 5 LETTERS Etaoin Shrdlu SIR: Thank you for the splendid presentation of the writer's article "Stereo-Monaural Conversion Amplifier" in your November issue. I am very grateful for your en- couragement which made the whole thing possible. That "ol' debbil" Etaoin Shrdlu let only t couple of small errors creep in on you the Preamp diagram: 1. The resistor in series with the tape can head input (shunted by 200 µµf) should be 100 R rather than 10,000 ohms. enjoy 2. The Radio input voltage divider is 270 R and 27 R instead of 27,000 and 2700 the ohms. Do you have any plans for a double Pre - amp with balance control and ganged best volume controls/ This might be an item which would interest your readers. in Hi -Fi LoutsBOUROF.T, 3996 McKinley Blvd., Sacramento 19, California (Answer to last paragraph: it's on the way be sure your system includes and should arrive about March. En.) SIR: We were, of course, pleased with the review of the new Wharfedale 3-way Speaker System which appeared in the November issue. THE ONLY 2 -IN -1 FULLY AUTOMATI However, I should like to point out a tactual error which was contained in the CHANGER AND AUTOMATIC MANU L PLAYER review concerning the speaker placements. You state that in one of the systems the 3 -in. cone faces forward and that in the Deluxe model it faces upward. This is not so. Both of these speaker systems are identical as far as the speaker placement is concerned and both have the 3 -in. speaker facing upward. The only difference the two systems is the framing of the cabinet on the more expensive model. FRANK HOFFMAN, British Industries Corporation. MIRACORD XA -100 is the 4 speed 80 Shore Road, Port Washington, N. Y. record changer that makes Hi -Fi easy ( Thanks for the correction. We occaston- everyone. It does everything automatically, at the push of a but- ollq make some that aren't noticed, too. for On the Philips Tape Recorder review in ton ... starts, stops, repeats, pauses, filters! It intermixes 10" and 12" the November issue n -e said that when the microphone was plugged in it cut off the records! It changes from automatic to manual in a moment. And it radio input. This ain't so either. Actually, when the microphone is plugged in along has the unique "free- wheeling" tone arm that can't jam! No other with a radio input, they are mixed. The volume control has all these features! So get a MIRACORD XA -100, if on the recorder controls record -player both in, uts, while the :.:dio signal level you're assembling your own system ... or having your may be adjusted independently by the $ 50 volume control on the tuner. We trust this dealer hook -up a system for you! 67 will not have influenced anyone unduly. En.) (Incidentally, we wonder if it has ever been explained ,n readers who are not in ...and for transcription quality the graphie arts why the peculiar combination of letters, ETAOIN SHRIMP, is often in a 4 -speed manual player... .wen in typeset material. Anybody want to 1.now? Er.)

MIRAPHON Stereo Discs

XM-11OA (The following is an excerpt from a letter by Ruben E. Carlson, rice -president at only $3750 of Fairchild Recording Equipment Com- pany to its dealers and representatives. It complete with every feature to does such a clear job of describing the two satisfy the most critical listener! methods of cutting stereo (list's that it is believed that readers will find it instructive and interesting. En.) ask your dealer for a demonstration . . . There are two systems at present competing: the first of these is the WEST -

F AI,) 111E r !NE :,T 111' rAa REX so- ealled 45 -45 system, and the second is the LONDON Vertical -Lateral system. AUDIOGERSH CORP. 514 BROADWAY. NEW YORK 12, N. V. We were privileged to attend demonstrations of both of these and to inspect very WORTH 6.0800 IN CANADA: Atlas Radio Corp.. Ltd.. Toronto closely all aspects of both.

6 AUDIO DECEMBER, 1957 It is encouraging to note that everyone seems determined not to make any stereo records before adopting an industry -wide standard method, since all are anxious to MIRATWIN avoid the errors of the past in connection with LP's and 45's. This is the attitude of both Westrex and London, and we know of very few new developments which have been approached so sanely. In the LONDON system of recording, the two channels are fed to a specially de- world famous quality cartridge brings out signed cutter in which the cutting stylus moves vertically for one channel and laterally for the other. The groove is therefore a complex engraving in three dimensions. THE BEST IN ANY having vertical and lateral components representing each individual channel, and the record has a most peculiar appearance because of the shape of the modulation. HI -FI SYSTEM! The playback cartridge (their experimental model was a variable reluctance type) is so designed that a lateral component affects one of two separate pickup coils, and a vertical component affects the other coil. There are, therefore, three leads from the pickup, one being a common ground. The two signals are fed through two independent amplifier and speaker systems. Of the two demonstrations, the London system exhibited slightly better sound. It was the general opinion that this was not inherent in the system but was rather due to a better MIRATWIN prototype pickup in the case of the London system. There are certain inherent disad- mst-1 single vantages in vertical recording which are well known (pertaining to distortion and with diamond stylus for LP dynamic range in particular) which would seem to he an argument against this system. or standard diamond stylus \\-e must say, though, that the London sound was excellent. Formerly $34.50 NOW 1126.60 The WESTREX system is a little harder to understand without actually seeing and handling a model of the cutter, as we were privileged to do. The idea is, however, that the cutter is designed so that there are two driving rods attached to the cutting stylus, each of these coming down to an angle of 45° from the vertical and forming a " V " with 90° included in the "V". These driv- MIRATWIN ing rods are attached to moving coils set »tst -2 turnover higher up in the cutter, and the stylus is supported on a rather long cylindrical tube running horizontally (and perpendicular to with sapphire stylus the plane of the driving rods). Either moving coil alone will therefore move the for standard and diamond stylus up and down along a slanted line stylus for microgroove at 45° to the verticle. If both coils operate together and in phase, the stylus will be Formerly $45.00 NOW pushed equally and will move up and down $31.50 vertically. If both coils operate together but out of phase, the stylus will be pushed only sidewise or laterally. Since each coil is connected to a separate channel, a 45° or slantwise motion corresponds to one o channel, and either vertical or lateral motion has information for both channels. For AS this reason, the 45 -45 system achieves com- NSW NEW If you have plete compatibility for standard micro- a hi- fideliy system, bring out groove records and this is felt to be very its finest tonal values with MIRATWIN. important. That is, the WESTREX sys- Because MIRATWIN is as smooth and sensitive a cartridge as man can tem enables playing of stereo discs monaur- make ... faithfully transmits the complete recorded sound! Acclaimed ally with a standard LP cartridge, or by audio engineers and music appreciation enthusiasts alike, MIRATWIN binaurally with a stereo cartridge; also, fits all standard tone arms, has instant stylus replacement. Enjoy it in the stereo pickup will play standard LP your hi- fidelity system for the best in recorded music! Recommended as well as stereo discs discs monaurally, tracking force when used in separate tone arms 4 to 8 grams; in record binaurally. The user can make the transfer partially or completely and without mak- changers 6 to 8 grams. Ask your dealer to give you an A -B Test today. ing obsolete any of his present records or equipment. MIRATWIN CARTRIDGES REPLACEMENT STYLI system, in Of course with any stereo jus l - -lU Aired. Diannn+I 526.50 D ?1 -2 .\lima- INaa,ond 516.50 eluding the Westrex, two amplifiers and MST -IS Single Sapphire 10.00 DN -2 Standard Diamond_ 16.50 preamplifiers, and two speakers are needed MST -2D Dual -1 Sapph., 1 Diam.-_ 31.50 SM -2 Micro- Sapphire_ 5.00 for stereo results. The Westrex cutter is MST -2A Dual Sapphire 15.00 SN -2 Standard Sapphire_ 3.00 also compatible and will cut either 45 -45, vertical- lateral, or regular LP records, so FAR :\IIEAI, TIIF. FIN'F:ST 111' FAR we are in the fortunate position that both are willing to adopt the principal parties AUDIOGERSH CORP. 514 Broadway, New York 12, N. Y. .aloe best suited to the public 's need. RUMEN E. CARISON WORTH 6 -0800 IN ('. \N: \II- \: : \tl:u Radio Corp., Ltd., Toronto

AUDIO DECEMBER, 1957 7 treat your family to all the fun and enjoyment of fine high fidelity at one -half the price you would expect to pay

HERE'S ALL YOU NEED

to build your own HI-FI

HEATHKIT HIGH FIDELITY FM TUNER KIT This FM tuner is your least expensive source of high fidelity material! Stabilized oscillator circuit assures negligible drift after initial warmup. Broadband IF circuits assure full fidelity, and 10 microvolt sensitivity pulls in stations with full volume. High -gain cascode RF amplifier, and automatic gain control. Ratio detector gives high- efficiency demodulation. All tunable components prealigned. Edge -illuminated dial for easy tuning. Here is FM for your home at a price you can afford. Shpg. Wt. 7 lbs. FM TUNER MODEL FM -3A $25.95 (with cabinet) HEATHKIT BROADBAND AM TUNER KIT T his tuner differs from an ordinary AM radio in that it has been designed especially for high fidelity. The detector uses crystal diodes, and the IF circuits are "broadbanded" for low signal distortion. Sensitivity and selectivity are excellent. Ouiet performance is assured by 6 db signal -to -noise ratio at 2.5 uv. All tunable components prealigned. Incorporates AVC. two outputs, and two antenna inputs. Edge -lighted glass slide rule AM TUNER dial for easy tuning. Your "best buy" in an AM tuner. Shpg. Wt. 8 lbs. MODEL BC -1A $25.95 (with cabinet) HEATHKIT "MASTER CONTROL" PREAMPLIFIER KIT This unit is designed to operate as the "master control" for any of the Heathkit Williamson -type amplifiers, and includes features that will do justice to the finest program material. Frequency response within :1% db PREAMPLIFIER from 15 to 35,000 CPS. Full equalization for LP, RIAA, AES, and early 78's. Five switch -selected inputs with separate level controls. Bass and treble control, and volume control, on front panel. Very attractively styled. and an exceptional dollar value. Shpg. Wt. 7 lbs. MODEL WA -P2 $19.75 (with cabinet)

8 AUDIO DECEMBER, 1957 HEATHKIT "BASIC RANGE" HIGH FIDELITY SPEAKER SYSTEM KIT

The very popular model SS -1 Speaker System provides amazing high fidelity performance for its size because it uses high -quality speakers, in an enclosure especially designed to receive them. It features an 8" mid -range- woofer to cover from 50 to 1600 CPS, and a compression -type tweeter with flared horn to cover from 1600 to 12,000 CPS. Both speakers are by Jensen. The enclosure itself is a ducted -port bass- reflex unit, measuring 11%" H x 23" W x 11?<" D and is constructed of veneer -

surfaced plywood, '/," thick. All parts are precut and pre - drilled for quick assembly. Total frequency range is 50 to 12,000 CPS, within *5 db. Impedance is 16 ohms. Operates with the "Range Extending" "BASIC" SPEAKER SYSTEM (SS -1B) speaker system kit later, if greater frequency range is desired. Shpg. Wt. 30 Ihs. MODEL SS -1 $39.95

HEATHKIT "RANGE EXTENDING" HIGH FIDELITY SPEAKER SYSTEM KIT The SS -1B uses a 15" woofer and a small super -tweeter. to supply very high and very low frequencies and fill out the response of the "Basic" (SS -1) speaker system at each end of the audio spectrum. The SS -1 and SS-1B, combined, provide an overall response of *5 db from 35 to 16,000 CPS. Kit includes circuit for crossover at 600, 1600 and 4000 CPS. Impedance is 16 ohms, and power rating is 35 watts. Measures 29" H x 23" W x 17'/.," D, and is constructed of veneer -surfaced plywood. ?%" thick. Easy to build! Shpg. Wt. 80 lbs. MODEL SS -1B $99.95 ...and save! RANGE EXTENDER

HEATHKIT "LEGATO" HIGH FIDELITY SPEAKER SYSTEM KIT The fine quality of the Legato Speaker System Kit is matched HEATHKITS only in the most expensive speaker systems available. The listening experience it can bring to you approaches the ultimate in esthetic satisfaction. Frequency response is *5 db 25 to 20,000 CPS. Two 15" theater -type Altec Lansing speakers cover 25 to 500 CPS, and World's finest an Altec Lansing high frequency driver with sectoral horn covers 500 to 20,000 CPS. A precise amount of phase shift in electronic equipment the crossover network brings the high- frequency channel into phase with the low- frequency channel to eliminate peaks in kit form... or valleys at the crossover point. This is one reason for the mid -range "presence" so evident in this system design. The attractively styled "contemporary" enclosure empha- sizes simplicity of line and form to blend with all furnishings.

Cabinet parts are precut and predrilled from ?;" veneer - surfaced plywood for easy assembly at home. Impedance is 16 ohms. Power rating is 50 watts for program material. Full, smooth frequency response assures you of outstanding high fidelity performance, and an unforgettable listening experience. Order FIH -1 -C (birch) for light finishes, or HH -1 -CM (mahogany) for dark finishes. Shpg. Vit. 195 lbs. MODELS HH -1 -C or HH -1 -CM $325.00 each

Pioneer in "do-it-yourself" electronics

HEATH COMPANY "LEGATO" SPEAKER SYSTEM

A subsidiary of Daystrom, Inc. Benton Harbor 25, Mich.

AUDIO DECEMBER, 1957 9 25 -WATT AMPLIFIER

70-WATT AMPLIFIER

ELECTRONIC CROSS-OVER easy -to -build designs by insure

HEATHKIT 25 -WATT HEATHKIT W -3AM You get more comprehensive HIGH FIDELITY AMPLIFIER KIT HIGH FIDELITY AMPLIFIER KIT assembly instructions, higher T 25 -watt Heathkit model W -5M is rated Features of this fine Williamson type ample quality circuit components, and "best buy" in its power class by indepen- fier include the famous Acrosound model more advanced design features, dent critics! Faithful sound reproductión is TO.300' ultralinear" transformer, and 5881 assured with response of :1 db from 5 to tubes for broad frequency response, low when you buy HEATH hi -fi! 160,000 CPS at 1 watt, and harmonic distor- distortion, and low hum level. Response is

tion below 1% at 25 watts, and IM distortion .1 db from 6 CPS to 150 KC at 1 watt. below 1% at 20 watts. Hum and noise are Harmonic distortion is below 1% and IM 99 rated quiet, 1.3°%, 20 watts. HEATHKIT 70 -WATT db below output, assuring distortion below at Hum and hum.free 20 HIGH FIDELITY AMPLIFIER KIT operation. Output taps are 4, 8 noise are 88 db below watts. Provides and 16 ohms. Employs KT66 tubes and output taps of 4, 8 or 16 ohms impedance. This new amplifier features extra power Peerless output transformer. Designed to Designed to use WA -P2 preamplifier. Shpg. reserve, metered balance circuit. variable use WAP2 preamplifier. Express only. Wt. 29 lbs. MODEL W -3AM $49.75 damping, and silicon -diode rectifiers, re- Shpg. Wt. 31 lbs MODEL W -5M $59.75 placing vacuum tube rectifiers. A pair of HEATHKIT W-4AM 6550 tubes produce full 70 -watt output with HEATHKIT HIGH FIDELITY AMPLIFIER KIT a special- design Peerless output trans- ELECTRONIC CROSS -OVER KIT former. A quick -change plug selects 4, 8 A true Williamson-type circuit. featuring and 16 ohm or 70 volt output, and the This device separates high and low fre- extended frequency response, low distor- correct feedback resistance. Variable damp. quencies electronically, so they may be fed tion, and low hum levels, this amplifier can ing optimizes performance for the speaker through two separate amplifiers driving give you fine listening enjoyment with a system of your choice. Frequency response separate speakers. The XO-1 is used be- minimum investment. Uses 5881 tubes and at 1 watt is :1 db from 5 CPS to 80 KC with tween the preamplifier and the main ampli- a Chicago-standard output transformer. controlled HF rolloff above 100 KC. Har- fiers. Separate amplification of high and Frequency response is .1 db from 10 CPS monic distortion at full output less than 2°% low frequencies minimizes IM distortion. to 100 KC at 1 watt. Less than 1.5°%, har- 20 to 20,000 CPS. and intermodulation dis- Crossover frequencies are selectable at 100. monic distortion and 2.7°%, intermodulation tortion below 1% at this same level. Hum 200, 400, 700, 1200, 2000, and 3500 CPS. at full 20 watt output. Hum and noise are and noise are 88 db below full output. Separate level controls for high and low 95 db below full output. Transformer tapped Variable damping from .5 to 10. Designed frequency channels. Attenuation is 12 db at 4, 8 or 16 ohms. Designed to use WA -P2 to use WA -P2 preamplifier. Express only. per octave. Shpg. Wt. 6 lbs. preamplifier. Shipped express only. Shpg. Shpg. Wt. 50 lbs. MODEL W -6M $109.95 MODEL XO -1 $18.95 Wt. 28 lbs. MODEL W -4AM $39.75

10 AUDIO DECEMBER, 1957 W -4AM 20 -WATT AMPLIFIER W -3AM 20 -WATT AMPLIFIER

A-7D 7-WATT AMPLIFLr'.

A -9C 20 -WATT AMPLIFIER HEATHKITS

IVorld's finest electronic equipment ...top HI -FI performance in kit form ...

HEATHKIT A -9C HIGH FIDELITY AMPLIFIER KIT This amplifier incorporates its own preampli- HOW TO ORDER ... fier for self -contained operation. Provides 20 Just iii. ntúy n, kit you desire watt output using push -pull 6L6 tubes. True by its model number and send check or high fidelity for the home, or for PA applica- money order to address bolo:,. Don't hesitate tions. Four separate inputs -separate bass and to ask about HEATH TIME treble controls -and volume control. Covers 20 PAYMENT PLAN. to 20,000 CPS within *1 db. Output transformer tapped at 4, 8, 16 and 500 ohms. Har- monic distortion less than 1°%, at 3 db below rated output. High quality sound at low cost! Piorrrrr in Shpg. Wt. 23 lbs. MODEL A -9C $35.50 "do-it-yourself" rlrrirorice HEATHKIT A -7D HIGH FIDELITY AMPLIFIER KIT This is a true high fidelity amplifier even HEATH COMPANY though its power is somewhat limited. Built -in A subsidiary of Daystrom, Inc. preamplifier has separate bass and treble con- Benton Harbor 25, Mich. trols, and volume control. Frequency response is t 1% db from 20 to 20,000 CPS, and distortion is held to surprisingly low level. Output transformer tapped at 4, 8 or 16 ohms. Easy to build, and a fine 7-watt performer for one just becoming interested in high fidelity. Shpg. Wt. ADDRESS 10 lbs. MODEL A -7D $17.95 Model A -7E: Same as the above except with extra tube stage for added proamplificalion. CITY & STATE Two switch -selected inputs, RIAA compensation, and plenty of gain for low-level cartridgres. P /ease send FREE Heathkit Catalog Shpg. Wt. 10 lbs. $19.95

AUDIO DECEMBER. 1957 11 DEPENDABLE! VERSATILE!

PRICED 1 Notes on Request 1

1 RIGHT! HAROLD LAWRENCE 1 1 / \ 11 OLD IT .\ MINUTE! " cries the con rheduled not only for the performance, poser, hurrying toward the po- but to ascertain whether all the notes I had dium, score in hand. The con- been correctly copied. In the case of the I ductor raps his baton and the music stops. Milanese copyist, only a single correction After a brief conference, the latter says: had to be made at the recitative rehearsal, I "Let's have it from Number 22, please." and that was not a musical one, but a let- I After the repetition, the composer ex- ter change from della to dalla. changes a meaningful glance with the eon - in the middle of the 18th century, some duetor who turns to his right: "Violas, 301) years after the appearance of the first your first note at 22 should be A flat, not printed music, printing activities came to I A natural. Please write in the correction." a virtual standstill in Europe. Manuscripts The work in question was being played outnumbered printed copies in the Breit - from manuscript parts and a copyist's mis- kopf catalogue of 1755, and most people take had been responsible for the offend- found it more convenient to obtain music _ ing note. In the laborious process of copy- from a copyist than to wait for its pub- ing out orchestral parts, errors are bound lication. For this reason, publishing houses / to crop up. In some cases, the fault may employed staffs of copyists to handle business 1 I) with the composer who neglected to in- of this sort. LGa z_C[L dicate the right transposition, or it may Naturally more printed music is rela- simply he that his manuscripts are well - tively available today than 200 years ago. nigh indecipherable. In other respects, however, the situation Although a handwritten copy can he remains basically the same. Successful DECADE perfectly legible, musicians prefer the composers see their works printed at the printed page. Yet, apart from the stand- time of their premières, but most contem- ard repertoire and certain moderns, large porary music is played from manuscript. INDUCTOR segments of the libraries of symphony or- Orchestral parts for a half -hour symphony chestras all over the world are still in man- amount to approximately $1000. Profes- uscript form. Contemporary works head sional copies of the full orchestral score UNITS i the list, of course, but a surprising number being somewhat of a luxury (the copyist's 1 / of well known pieces of pre Nuclear Age fee equals that for all the parts together), vintage may also be found here. The first the conductor usually has to cope with the examples that come to mind are Offen- composer's squiggles. And the precise and bach 's I:ailé Parisienne (arr. Rosenthal), crystal clear musical calligraphy of Igor Here's vital help for your design I'a Tenter 's Advents/ow in a Perambulator Stravinsky is a rare exception. Besides, and experimental work on audio filters, (rev. 1941), and quantities of Strauss the latter's works are generally available equalizers and tuned cir- waltzes in print. cuits at frequencies between 150 and polkas. Outside of the concert and 20,000 cycles. hall, orchestral scores for musical come- All munitions who have had to squint at dies, TV spectaculars, popular singers and blotchy manuscripts, or who have strug- Four units available in ranges the movies go imprinted for obvious rea- gled with recalcitrant music quills, can from 10 x .001 Henry to 10 x 1.0 sons -all of which provides the copyist now take heart. Two years ago, a com- Henry. When all four units are with a steady stream of assignments. poser-inventor named Cecil Effinger (as- connecting in series, 11,110 steps sociate professor of music at the Univer- from .001 .Henry to 11.11 Henries The copyist has been an important part are obtained. of the musical scene for centuries. Before sity of Colorado) brought forth his ''Mu- the application of the printing press to siewriter " -a music typewriter that may Excellent stability vs. current and music in the late 15th century, he was the eventually replace finished handwritten temperature changes. Reasonable source of all available music copies. Since copies of music just as surely as the al- amount of D.C. may be run printing could not keep up with the flood phabet typewriter made handwritten let- through the units with little effect business world. on inductance. of composition that poured from the pens ters obsolete in the The of musicians from that time on, his liveli- Musicwriter was some ten years in the Write for Bulletin D -2, describing hood was far from threatened. In fact, the making. After numerous experiments and this low- priced line of high quality copyist was in a position to make more prototypes, Effinger finally evolved his 79- HYCOR Decade Inductor Units. money from a work than the composer him- character, free -moving carriage, device Dimensions: 5%" L. x 3" W. x self. After the first rehearsal of Mozart's that can produce results comparable with 2%" H. opera, .1/ithridafr, in Milan on December that of a printed score. Resembling an of- 12, 1770. father Leopold wrote home to his fice typewriter in shape and design, the wife: "The copyist is absolutely de- Musiewriter is the final step in a century - lighted, which is a good omen in Italy, and-a- quarter attempt to bypass pen and where, if the music is a success, the copy- ink for finished copies. Dozens of patents ist can earn more from the sale of arias for music typewriters have been issued in INTERNATIONAL RESISTANCE CO. than the composer does from the entire this country and abroad since the 1880's, HYCOR DIVISION opera." Rehearsals in those days were reports Effinger, but they were all either 12970 Bradley Ave., Sylmar, California impractical or impossibly complicated. 'fi U'. Ninth St., New York 11, N. F. History is replete with examples of in-

12 AUDIO DECEMBER, 1957 Ys s41Its friy sU99esfióh eveyf4e!

What is? will soon tell you. But to make a long story short Norelco Full Response Speakers. -These Norelco people have been in the sound As your choice for true high business for years. They designed these twin -cone fidelity reproduction, Norelco's speakers to accurately register highs through the twin-cone speakers will bring you smaller cone and lows through the larger cone. a new dimension in musical en- Both are operated from the same voice coil and joyment for a long time to come. the same magnet- producing a flat response with They make a perfect family treat exceptional reproduction of transients. On low at Christmas time. loudness levels, relative tonal balance is clearly bass, Yes, but money gets tight at this time of year. maintained with clean smooth middle tones and clean, sharp highs from undesirable Why, that should be no problem. -free harmonics and spurious effects ... Need I say How's that? more? Simple, penny for penny, note for note, Norelco In what sizes are they supplied? FRS speakers reproduce sound more faithfully Five, eight, ten and twelve inch models, and there than any other sound radiator anywhere near its are specially built Norelco enclosures available price range. for them too. They are obtainable at better What makes Norelco speakers so much better? dealers everywhere. They all produce real sound, I always say, listen to be convinced -your ears brother ... real sound!

N /CCO cGrc.d Speakers are available in 5", 8" or 12" sizes in standard impedances. Priced from $6.75 to $59.98. Blueprints are available for the do- it- yourself enclosure builder. Norelco Enclosures are available in three sizes, priced from $33.75 to $119.95.

ADD TO and improve any sound system with fiore%o1 FULL RESPONSE SPEAKERS.

vrte today to Dept. Al2 for brochure and prices of these unique speakers.

NORTH AMERICAN PHILIPS CO., INC., High Fidelity Products Division, 230 Duffy Ave., Hicksville, L. I., N. Y,

AUDIO DECEMBER, 1957 13 veutions anti discoveries being made simultaneously in different parts of the world. In London, an ea- music -hall entertainer who used to have special musical numbers written for her, often thought of the problem The T R C of music copying. After she retired, she quietly began work on her own music type- triple -duty microphone writer. This year, she finally came out with a prototype of a machine which differs in by certain basic respects from Effinger 's model. The operator of the Musicwriter oust type with his right hand while he manipulates the carriage with his left. The English machine's carriage can be moved Icy means of keys so that the writer can p with both hands, thereby turning out larger quantities of music. Each invention was developed independently of the other. In view of these developments, the copyist can soon put aside his traditional quill and adopt the slogan: "Have amachine, will copy." A

COMING EVENTS

HI -FI SHOWS

.I :non :n;y le I_ -\lünoapolis: Hotel Dyck -

man (11;,r .

.I:niu:n 17 IfI-Indi:mtapolis: Hotel Ant- lers (Ifiqni-

,i:nuiary _-I 24I-L'ulTalu: Hotel Statler (Ilipgi.

February 7 9-Ifencer: llutel t'osuropulitau (llülol.

I'vlumm 1- 1- Itl -S :ni Francisco: Whitcuntb it's versatile... Hotel iIIII.1/ lightweight... Feb. _II -Jl:m. _ Los Angeles: ltiltumre low cost, too! Hotel (///I'.1/ .

Elgin's new TRC dynamic microphone \I:uch 7 9-Pittsburgh: lintel l'enn-Rhern offers faithful audio reproduction in the ton (Big.). 80 -8500 cps range, yet lists from $11.50. It is designed for use with tape re- March I 1 IG-\\'ashiugtmi, 11l'.: Nhureh:mu corders ... yet has the versatility to 11,0,1 i led, in nil, nl r. perform ideally at meetings and assem- blies, wherever p.a. systems are used. \larch 21- ^_.,- -Newark: llutel Rubrt Tree.t The TRC is less than five inches long, (Riau weighs only nine ounces, has a pol- Sept. :N1 (h-t. ished, chromeplated case. It is omni- 4--NEW YORK High Fidel- ity show. New York Trade Show directional and picks up voices within Build- ing f ///F.I/ a radius of ten feet under average conditions. or lavalier The TRC is also available in crystal OTHER EVENTS and ceramic types. lay, I Eastern Joint Computer Con - Get the facts on this new addition to Elgin's I- t,mnee. Park Sheraton Hotel, Washing- complete line of "American" microphones. Write today for specifications and complete ton, P.C. WE- A I E E- \('\l. descriptive literature. February _n 21-l'nnfereuce on Transistor and Solid State Circuits. I'Itilndelphia, l'a. I Itl:-.\IEE- Univ. of l'a.

April 14 -17-Radio Component Show, org:utised by the ltmlio and Eleetronic ELECTRONICS DIVISION Component Manufacturers Association: ELGIN NATIONAL WATC H COMPANY 11 rusvenur [louse :nul Park banne Mouse, 107 National Street. Elgin, Illinois London. \larch :I -S7- Institute of Radio Engineers National Convention. New York Pity.

14 AUDIO DECEMBER, 1957 A new standard in HYSTERESIS MOTOR DESIGN

Uniform Speed To Meet Exacting Requirements. Low Noise Level approaching Inaudibility. High Starting Torque for instantaneous efficient operation.

SPECIFICATIONS* A new era of electronic enterprise continues to place greater and WC2913H WC2913H -1 greater emphasis upon engineering design and creative production. Turntable Tape Recorder New tape recorder and turntable applications have required hys- Volts 115 115 teresis motors unusually precise in their performance, rugged con- CPS 60 60 withstand continued use, built within smaller and 24 struction to Watts Input 21 all this to meet the competitive price require- .25 .22 smaller frames ... Amperes end product. Number of Poles 4 4 ments of the RPM 1800 1800 A large order- but Induction Motors has done just that in its line 1 125 H.P. 1 150 of hysteresis motors -compact in size, precision manufacture with T.P.I. (oz. in.) 3.0 4.5 Typical of these design achievements are the in.) 3.5 5.0 assured reliability. T.P.O. (oz. find themselves in such fine recorders as those T.ST. (oz. in.) 2.3 4.0 types which today Capacitor (mfd) made by Ampex. 1 2.5 220 Volts A. C. Induction Motor's reputation of quality has been proven over the Weight l lb. l lb. years in their manufacture of a complete line of precision sub - fractional horsepower motors.

AI1 specifications are relative to frame For complete information on IMC hysteresis and torque motors size. The hysteresis series is available in for tape recorders and turntables, write for catalogue HT. seven frame sizes from ?d" diameter to 4!z ". "Can be supplied with magnetic shielding (Mu- Metal) Induction Motors Corp. 570 Main St., Westbury, L. I., N. Y. Phone EDgewood 4.7070 6058 Walker Avenue, Maywood, Calif. (iihrthtmati anb iin ijrar 6reeting,s trillI! t1ir 1itturti anb 'taff of Atüìtu

EDITOR'S REVIEW

STEREO COMMENTS are eouepletely satisfied with the results an that particular tape. We then get some more tapes, and some WITII THE Al. ?n)ST CERTAIN CONVERSION of 1111111" sound good and some sound horrible. with little or no thousands of home systems to stereo within stereo effect. Naturally, we would first blame the Manu- the next year -both with existing tape equip - faeturer for the poor tape finality. tilent and with the reining stereo discs, %ye feel that On the other hand. it is likely that any record or sonic pertinent observations alight be Made. To date, tape wannfactirer -and more and more of the former we do not recall having seen any treatment Of the are beroueing also the latter -who was trying to turn importance of speaker phasing, yet the over -all quality out good quality would have been satisfied as to his of stereo 1'eproduetion depends ;neatly on this one quality in his own studio and on his own system. condition. Ilowever, he may be using two different types of To best observe this for oneself, it is only neeessary amplifiers, one having one more stage of amplification to connect two speakers to a singly amplifier. placing than the other. and even though his inputs were the speakers at a separation which would be normal properly phased (for twi identical systems) his out- for the listening room. Such a separation. We feel, wits would be out of phase. ('an we assume that every would be sonmwhete in the vicinity of one -half the Manufacturer will make sure of his phasing by play- length of the shorter wall of the room, speakers being ing a full-track recording aeross the two heads when- placed about one -fourth of the distance fulfill each of ever he sets up a new system? ('an qtr be sure that the the two adjoining walls. 'Chen reproduce sonic well phasing Nvill remain constant through the various known selection through the two speakers. with the systems used in making Multiple copies of the Master acoustic outputs adjusted to as near the same level as tape? possible -by weans of a pad ill the more ellicient of Let us consider another possibility. Suppose we have speakers. the iwo a system which we set up ( without being aware of the When you listen to an arrangement of this sort, the possible pitfalls in phasing) with a specific pair of sound should appear to coule from a virtual speaker amplifiers and speakers. ')'hen we change amplifiers or located halt' way between the two --in tact. we once speakers. and we find 0111 that nothing sounds right 1111 an exhibitor at a Aluntreal show that Ave would after the change. if we are aware of this problem. take the speaker in the center because it was so .Mall. we eati ehango speaker connections and everything If you seem to hear both speakers when you are stand- will be satisfactory again. On the other hand, there is ing in front of then), it is almost certain that the nothing we van do to ensure that every stereo tape Or speakers are out of phase. Then simply reVersc 11 le record is pleased exactly right for our (wit particular two leads to gnu of the speakers, not both. The sound system. should then appear to come front the center. There is a cure, however -not automatic, to 1)0 sire. ')'his solution would serve perfectly well if we were Wit certainly one which will allow ns to slake a cheek to use a single amplifier to drive the two speakers whenever we hear a tape or disc that doesnot sound always, or even if we were to reproduce a monaural .just right. We feel that EVERY stereo system should he tape or disc through two amplifiers and speakers -- set up with it reversing switch on one of the speakers once we had tbent couneeted properly We ('011111 assume 'Phis would make it possible to 1hec1: every time we that they would stay that way. were not satisfied with the sound. Chat happens, however. when we go to stereo tapes All that is required is a simple double -pole, double- or discs. I P'or a description Of the two stereo dise throw switch. In our own installation this is mounted systems now being considered by record manufac- on the back of the speaker housing. readily awrssible turers, we suggest you read Mr. ('arlson's letter on from the top. It is likely that there will be some page 7.'t Let its assume that we set up onr system standardization of phasing at some future (late, but using a tape from a given manufacturer. and that we until then we find the phasing switch most useful.

16 AUDIO DECEMBER, 1957 NO FINCERNAIL FUMBLINC1

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BELL TELEPHONE LABORATORIES WORLD CENTER OF COMMUNICATIONS RESEARCH AND DEVELOPMENT The Stereo Recorder- A Revelation and an Education

JOSEPH E. FREDA

Unlike most other products, the stereo tape recorder is often sold to us without a complete treatise of how it can be used for many purposes other than simply for the reproduction of music. The author tells his experiences in several areas of application.

THE WRITER is a confirmed don't-do -it- rclatiuo to French and English speech yourselfer to whom a terns like "cath- practice. ode follower output" means nothing I got so wrapped up in the problem more than some object a salesman thinks of what to do that I even took to reading one ought to love. So it was with some educational journals, and it was thus diffidence that this article was submitted that I came across descriptions of col- to a magazine whose writers, and pre- lege language laboratories with their ex- sumably a fair proportion of its readers, tensive use of tape recorders, and also are highly competent technicians. INPUT OUTPUT INPUT OUTPUT descriptions of how recorders are used CHANNEL 1 CHANNEL 2 On the other hand, what I really have in the music and speech departments. to tell is a story that I think might be NORMAL of some interest to both audio techni- CHI CH 2 OUTPUT OUTPUT The Starting Step cians and to non -technical users of audio TO / TO CH 2 CH I equipment. It concerns the search for a INPUT INPUT \I \ first impulse was to go right out special -purpose tape recorder that ended ' and buy one of the common home varie- up with the arrival in our home of a ties of tape recorders. Such a machine stereo recorder (not playback only) can indeed be very useful, and much which has wrought dramatic changes in material can be found on its educational many of our family activities and which applications in books, articles, and is only incidentally used for stereo- magazine departments. Farther on in phonic music reproduction. The Channel Integrator. With the switch this article I will offer some suggestions The moral of the story, for us at in the position shown, the output of for owners of these recorders. But by least, is that a stereo tape recorder with Channel 1 is switched to the input of this time I had become completely fas- provis'on for both single and two -track Channel 2 without the need for disturb- cinated with the highly specialized tech- recording is probably the most useful ing connections at the rear of the re- niques developed in the language and and satisfying piece of audio equipment corder. music departments of schools, and I one can have around the house. for by hours of home practice in which wanted to apply them, even improve I have no desire to make a special dis- we become involved in one way or an- upon them, in the home. After weeks of play of my initial ignorance about the ether. Again, his school activities hardly having my ears dinned in hi -fi show- construction and operation of tape re- ,justify any optimism about his ever rooms while examining. all types of tape corders, but that is part of the story. learning to speak the French language recorders, and after further reading on Just incidentally, the reader should not without extra -curricular activity. Finally, the subject of educational recorders, I be surprised if he also meets a few he could obviously stand some extra work became reluctantly convinced that no baffled technicians in the course of ad- outside of school on good English speech. monaural recorder used alone could pos- ventures in equipment selection. tow objective has been to arrange ac- sibly meet all my requirements. Like many parents, my wife and I are tivities at home in these three fields It was in C. J. Le Bel's book "How to intensely interested in the education of which are pleasant for us and fun for _Bake Good Tape Recordings "' that I our son, Larry. We are prepared to par- Larry. i4ing before the tape recorder found the best short description of spe- ticipate, when necessary. iu home activi- came into the house, I think we aecoin- cial educational techniques and why they ties.associated with his studies to plan plished something. We often play to- require a stereo recorder: programs we know will interest him, and gether, Larry on his clarinet and dad on "A binaural (stereo) tape recorder can be used in any to provide him with fascinating and un- the flute. And who always made mistakes of the following ways: usual types of instruments and equip- before the tape recorder recorded them? a) Recording on channel 1 in one direction and channel 2 ment as well as the more common types. Parents will know well enough what in the opposite direction Most his studies are taken care of (dual -track recording). of Larry thought about that. And, of course, b) Recording the same signal on both adequately through his school activity he had the most difficult lessons down tracks simultaneously (single -track re- and somewhat routine homework. There pat after the first couple of hours of cording). are, however, dramatic exceptions. The e) Recording separate signals from sepa- practice. It was clear that in some way rate most these is music. The once - microphones on each channel simul- obvious of Larry (and dad, too) had to be made to taneously (binaural recording). a -week lesson period must be prepared listen to himself in an entirely new way, 44-10 Ketcham St., Elmhurst, L.1., quite different from the way he listened I Published by Audio Devices, Inc., 444 N.Y. as he played. The same thing was true in Madison Ave., New York 22, N.Y.

AUDIO DECEMBER, 1957 19 the other and for channel -to- channel sound -on -sound recording. But by this time I had learned not to make easy assumptions, and nowhere in Berlant's descriptive literature did I or anyone else find specific reference to these last two techniques or to the "recording selector" switch which makes them possible. So I presented to a number of salesmen handling Beriact equipment what appeared to them a formidable list of requirements -\L. LeBel's five points. I was invariably told "it couldn't be done." One salesman reported that he got the saune answer from the regional Berlant representative. For salesmen and others whose experience with tape recorders has been primarily limited to music repro - dnetion, those aspects of stereo recording having to do with techniques like sound -on -sound are evidently not quite so obvious as the writers of Berlant pro- motional literature apparently think they ought to be.

The Realization Making a Live French Recording. Allen Counteraud reads French expressions into the It Was only in the operator's microphone under Larry's direction to introduce pauses of the proper length in the manual recording. which came after purchase and delivery of the recorder that we really got final .1) Recording on channel I while listening nay prohlenis Were milt' beginning. When answers to umr questions. The Concertone to playback of channel _. . particu- \I r. Lo Bel referred a binaural 23 comes equipped with four heads larly valuable in educational work and to re- has led to the fairly widespread use of corder I had taken him to mean any (upper -track erase, lower -track erase, specialized two channel recorders in binaural recorder. Su the description ul' stacked record. stacked playback) and schools and colleges. . . . student can the :\niprx stereo tnudel S -5290 as having. space for a fifth. I had ordered a modi- listen to pre- recorded instructional ma- full -track terns. tWU -track record a1111 tied 23 with an additional (half- track) terial or language drills on channel 2, head and I :and during panses provided, record his tWU -ttuk IiIsyhack" Wutdd Hot by itselt had a perfectly valid, almost own responses or oral repletion on rh :nt- have discouraged) Hu' fruw ordering dui! brilliant, scheme for sound -on -sound uel I. operation. umehire. Ihd 1111 1 I examined the Am- To my great embarrassment e) Recording the playback from channel I pex and tried to plot out ill some (h4ail the manual not only showed how to get onto channel 2 while simultaneously add- channel -to- ing n microphone recording of channel hone it. %%multi handle each of the item - channel sound -on -sound with no 2 (sound -on -sound recording). This fea- listed by \l r. l,( Ifel I loud that item, modification whatever, but also de- ture is particularly valuable to music d) and (e). the Heusi important of all. scribed an accessory switch, which they students who wish to practice vocal or NI re quite itupos.ih:le. Sieve the fttll- hid trader the function-obscuring name instrumental solo parts with recorded of "channel accompaniment. The original "accom- linek erase is going to %rase both tarL- integrator," that enables paniment" track is not destroyed in .icutltaceumly whenever any recording the operator to get the sound -on -sound the process and if any mistakes are is in process, the erase of recorded ma- without even pulling a plug. The key made, the student can simply rewind terial on channel 2 before it even reaches features were, of course, the combina- the tape and give it another try." the 1!; h:uck head effectively precludes tion of upper and lower track erase While it is not the ease, as ilr. Le Bel either recording on one channel While leads and a "recording selector" switch unintentionally seems to suggest, that listcnin_ to playback on the other, or permitting recording on just one chan- every stereo recorder has all these fea- sound-ou- sound recording from oily nel, simultaneously with playback (only) on tures, this is a brilliant summary of the d hannel Iu the other. Since the \lagne- the other. features a tape recorder shoald provide cord stereo recorder has the saute head There is nothing unusual about our if it is to be n truly flexible educational eontiguratioll as the Ampex, it too could installation of the recorder and associ- instrument. not be used without special modification. ated equipment, but since reference will ')'hat settled it-or so I thought. 111e desrriptiuH of the Be l:uit :;:t and be made from time to time to our special In a tape recorder directory I found l'uueertuee 2 :1 recorders. on the other equipment it may be well to briefly de- a few specialized two-channel educa- hand, showed separate upper and lower scribe the entire set -up at this point. tional recorders. ')'heir claimed fidelity track erase heads as :t staldtnd feature. For recording on a single track from was low enough to curl your hair if you which dhviumsly makes it possible to re- phonograph or radio and for playing also expected to use the recorder as a cord on one channel without erasing on back a single track. a Marantz consolette part of a music reproductiuu system, as the other by the simple expedient of is used as a control center. All the RCA we did. So I holiest to the only three operating only one of the two pretuups output and input jacks at the back of stereo recorders known for good music tthilt. recording. I suppose it sldutdld have this instrument which might be useful reproduction- Ampex. Berlaat- Coneer- bceu etitiallx. obvious that sorb a nut - with the tape recorder are extended to tone, and Magnecord. Xuee of them was chine would also be designed to provide a telephone jack panel at the front of cheap, but since my only other alterna- for recording on either chancel alone the cabinet housing the audio equipment. tive was two tape recorders it would With Goth pre:Imps in operation, which An old, slim 10-wntt amplifier, modified have to be one of these. is what is required, in addition to sepa- to operate as a straight power amplifier, At this point, whets everything seemed rate erase heads. for recording on one ryas installed in the ease housing the two to be nicely resolving itself, i discovered channel While listening to playback at recorder preamps, and is used for tnon-

20 AUDIO DECEMBER. 1957 aural playback outside the house or as a second amplifier for stereo music playback at home. Larry has a Viking 75SÚ tape player as a part of his own music set -up in his room, and this player is sometimes used in conjunction with the Concertone for copying and editing tapes. More detailed description of specific features of the recorder and associated equipment, and of the mechanics of the all -important sound-on-sound recording technique, will he found in the succeeding parts of this discussion, dealing with the application of the stereo recorder for niusie and speech training in the hume. First for mnsie.

The Recorder as a Music Coach It is a rare music student who can evaluate his playing at the time he is practicing, and our son is not one of the exceptions. Simply recording his practice at intervals and listening to the playback gives him a new insight into his weaknesses and suggests what to con- centrate on in further practice. For this we can use one channel of the Concertone 23 as monaural recorder. For anything beyond this we must use API the two tracks of the stereo recorder in Inserting Pauses in Continuous Speech Records. Output of Viking goes to Channel 1 various ways. input of Concertone; latter runs continuously, while Viking is stopped at the end of We often use them to provide a rapid each sentence or phrase for the desired pause. A -B comparison between Larry's playing and that of a competent professional, ting precise aattaek. They will not accept 'l'Ire same procedure is followed in playing the same piece of music. On the statement of an observer that this is practicing with the "Music minus one" channel 1 we make a live recording of not so, and ntay not even recognize their records wIiieh provide ,just the symphonic his routine practice material as played failings when listening to the playback or dumber aeeuntpauintent to a concerto by an instructor, or we transfer from a of a monaural recording they have or provide chamber works minus one of phonograph record to this tape track a themselves made. But they ean't argue the instruments played in the standard portion of a well -known work. Larry with a tape of a duet. trio ur quartet chamber group. records his playing of the same material which they have made. .t no vrel , nrcept- What is required for are -man enscnt- onto channel 2, timing his start by listenable result nrquires an a INlately steady bles and for playing with recorded ae- ing through earphones, though for this beat and extreme precision of attack. eampaniments :und duet parts is some purpose precise timing of the two chan- Any failure is immediately obvious. sort of sound -on- sound, and this is a nels is not critical. He may then continue Larry found this out as soon as he at- good plumee to pause for a general dis- on his own without listening to channel tempted a duet and has .since worked cussion of s -o -s techniques. one or he may attempt to play right hard at developing the precision re- along with the professional musician. quired for trios and quartets. Ile is hav- Two -Recorder Operation When the tape is played back the two ing a barrel of fun, hut more important recorder outputs are connected to the is the fact, that th:s special type of prae- Two separate recorders provide a TV and EXTRA inputs of the Marantz pre - tice has resulted in greatly improved sound -on -sound procedure which, while amp. Setting the recorder playback con- performance on his instrument. not as elegant and convenient as that trols at the proper level, he can alter- A useful variant of this procedure offered by the Concertone 23, will never- nate between the two charnels by simply applies only to duets. The instructor's theless make possible all the special ap- flicking the selector switch. Since the playing of one part of a duet is re- plications described. Each recorder must material on chnnel 1 is not erased during corded on channel 1. Larry rereco'ds this have a two -input mixer and an earphone recording on channel 2, Larry may re- part simultaneously with his own uniero ,jack that automatically disconnects the peat his own recording as often as he phone recording of the other part on recorder's speaker when the phones are wishes. channel 2. I sometimes transpose for plugged in. There are inexpensive mix- But nothing has so faseivated Larry flute one part of a clarinet duet and re.- ers on the market for recorders that do or so fired him into activity as has the cord this on channel 1, giving Larry an not have them, and the installation of a possibility of emulating those highly - opportunity to make duets with it when phone jack is a simple matter. Duet and publicized popular singers and musicians I am not around. accompaniment parts are recorded on who make duets, trios and quartets in When he is preparing for a student machine A. When the tape is played back which they sing or play all the parts concert, the piano accompaniment part the student will listen with earphones to themselves. At first sight this might seem may be recorded on channel 1 by his the output of machine A and will record to be mere doodling, but it does in fact accompanist, giving hint a chance to this output simultaneously with his own serve an extremely useful purpose. practice with the accompaniment at microphone recording on machine B. Young music students often think they tome, recording himself and the accom- Since the first tape is not erased, this are holding a steady beat and are get- paniment simultaneously on channel 2. may he repeated as often as the student

AUDIO DECEMBER, 1957 21 tages or disadvantages of an instructor and class. As students, we have to dig up our own material, getting it from records and recorded tapes, taking it off the air, and finding native French speakers to record material for us. Also, as a family, we are even less homogeneous with respect to interest in learning a foreign language and willingness to put serious effort into it than is an average high school or college class. The machine means something different and contributes something different to each member of the family. For his own private reasons, which probably would not make much sense to anyone else, pop has become determined that he is going to read French literature in the original language, that he is going to comprehend French spoken at normal conversational speed (which is fast), and that he is going to speak French as well as he can in spite of the great handicap that he has little or no opportunity to converse in the language. So the recorder doesn't need to "moti- Ih vate" him, merely provide the materials for learning and the opportunity to Making a Duet. Larry plays the second part of a duet along with the first part practice. recorded previously by his instructor or by himself on Channel 1. Both parts are recorded together on Channel 2. Mother is terribly eager to learn the French she never did learn in seven wishes. For one-man ensembles the first record selector switch is set fou -channel years of school courses. But with so part is recorded on machine A. then 2 only" to avoid erasure ou channel 1. many other interests and duties she this with the second part on machine B. After balancing the output level of chan- wants to get it by sonic forni of Osmosis. and so on ad infinitum. nel 1 tutti the two input levels of channel And she is convinced that, being literally An example of a monaural s -o -s re- 2. simultaneous recording is made of enveloped in tape recorder French from corder using a single tape transport is channel 1 output and tnicrophoue. The time to time, she is succeeding in this the Concertone 24. The stanmlard three same procedure is followed for combin- utterly painless method of learning the heads (erase, record, playback) are pre- ing the first part of a one -man ensemble language. ceded by an extra playback head con- recorded on channel 1 with the second Larry's problems are something else nected to a playback -only preamp. We part. To add the third part simply plug again. From about six to nine, he was have, in effect, a tape player and a taupe output of ehatuu1 2 into line input of terribly interested in learning a lan- recorder sharing a single transport. channel 1. And so on. guage. Unfortunately I could not then do When the player output is connected to While the nuplugging and ropluggimg anything about it and the New York the recorder input the recorded signal is of the inputs and outputs is not at all City school he attended had no language rerecorded a little farther along on the difficult. it does require accessibility to program for the elementary grades. Now same tape, from which the recorded ma- the back of the recorder and is at best that he is in Junior High School and is terial that has already passed the first something of a nuisance. `o Berlalit has required to learn a foreign language, playback head has been erased. Since provided a special t hree -I n.itioo stench, he semis to be past the stage of active the output of the tape player and a the channel integrator to earlier. interest and is a somewhat reluctant microphone can be recorded siund- All recorder inputs and outputs pass learner. But we do not want him to learn taneously on the recorder section, we through this snitch. lu the center posi- a foreign language, and it is already have a form of s -o -s in which the origi- tion all lire left in their normal position. pretty clear that we can't depend on his nal recorded material is destroyed. This I it a second position the output of chan- school class to develop his interest and is all right for one -man ensembles, but nel 1 is connected to the input of channel do an adequate job of teaching. if our it is disastrous for playing with duet 2. Iu a third position the output of chan- private language laboratory is to do any and accompaniment parts or when using nel 2 is connected to the input of chan- better it must revive his interest and put mil 1. the recorder for learning n foreign lan- some real fun into the learning process. guage. In all these cases it is necessary The planning of this private language to conserve the pre -recorded material for Our Private Language Laboratory laboratory and the mechanics of its further practice. After reading reports about the great operation have in themselves been im- The Concertone 23 combines the con- etiectiveuess with which taupe recorders portant elements in the effectiveness of venience and high quality of the mon- Lree beta used for language instruction the recorder for language learning in our aural s -o -s Concertone with the greater iu schools, I expected a great deal from home. Like utmost twelve -year -olds, he flexibility of two separate recorders. An or stereo recorder in this area and have gets a big wallop out of using the ma- accompaniment or duet part is, for in- not been disappointed. chine -what with its numerous knobs, stance, recorded on channel 1. When this We have had a great deal of fun set- switches, meters, reels, microphone, pro- tape is re -run the output of channel 1 ting up our own language laboratory. vision for recording from the air, from is plugged into the line input of channel obviously it could not be simply a copy records and from other tapes, and -par- 2, the microphone is plugged into the of the kind of laboratory set up in the ticularly-sound -on -sound recording. He niike input of the smue channel, and the colleges. We don't have either the advan- is both willing and anxious to undertake

22 AUDIO DECEMBER, 1957 projects from which he will absorb a and the most important bit of doing in all I could say was "Ugh!" However, great deal of the French language, and this field is speaking. Speech practice is while I am still far from satisfied, I can I don't hesitate for a moment to plan obviously essential for the development see real improvement through practice some pretty insidious gimmicks to keep of good pronunciation and fluent expres- with the recorder. the excitement at a high pitch. He takes sion, and the contention of many experts For those with the usual home tape programs off the air for the family, he that one must speak the language in recorders who want to use this technique dubs records onto tape for later sound - order to comprehend native speakers is the machine will have to be equipped on- sound use, and he assists me in a certainly supported by our experience with a two -input mixer and a phone tricky technique for inserting silent with records and radio. We had listened jack if it does not already have these spaces in continuous speech material. to continuous speech records and radio features. For this last he is paid a modest but broadcasts for some time before we be- Sometimes we want to practice inten- well-earnedned sum and has been promised gan to work with records containing sively just a portion of a record, but an increased fee when he can handle the pauses and with the tape recorder. Dur- don't want to ruin it by constantly pick- whole thing by himself (he'll have to ing that period our progress in aural ing up and putting down the stylus. learn a lot of French to do that). We comprehension was slow. It picked up Then we take advantage of the sound - recently met a French fancily ,just ar- quite rapidly as soon as we began to use on -sound feature of the Concertone 23, rived from France and they have enthu- these special records and developed even even though we are not actually blend- siastieally agreed to record for us. Larry more rapidly after we got the stereo re- ing sounds as we did with music. The is, of course. the s,amul engineer on all corder. I would say that our ability to record is dubbed "as is" on channel 1. projects, and learn- more French from comprehend rapidly spoken French has When the tape is replayed the output the record ing -i ii- than he realizes. improved in almost direct proportion to of channel 1 is recorded on channel 2 our own ability to speak at approxi- while the learner records his repetitions mately the same speed. Even our ability cm the same channel during the pauses. The Laboratory in Operation to rend French has improved with speech Any portion of the recording may be As I pointed out earlier, the home lan- practice. selected for practice, and a single short guage laboratory does not have a corps For fun and for specialized practice section may be practiced over and over of instructors to record precisely the in aural comprehension we do use many again, without damage to the tape or to material the laboratory needs, and we continuous speech records from the the disk from which channel 1 was re- have to dig up material from any source wonderful variety of dramatic, poetry, corded. For home learning this would we can. At least for the language we are and literary records produced in France appear to he a much more convenient learning and the area in which we live. and distributed by such companies as procedure than that followed in many there is plenty available. London International and Period Rec- college laboratories where the student The most available source of material ords. records his repetitions on channel 2 is phonograph records. And I would to while listening to playback on channel 1, like to start off the discussion of records then must use binaural phones to hear Using Language Records with sonic conelusions. I know that. the the French speaker in one ear and his word `learning" can he given nmiiv While the record with pauses is, we own repetition in the other. meanings, but I don't think any of them think, superior to the continuous speech It should be clear from the above de- can he stretched far enough to justify record, when used alone it has one seri- scription why it is that when we have a the claims made by some makers of lan- ous drawback. You can repeat the choice of the saine learning material on guage records that you can learn the rhrases and sentences immediately after either records or recorded tapes we al- language by listening to records for x they are spoken, but it is not possible to ways choose the records. Almost every minutes a day. Believe me, you won't evaluate how well you have performed owner of a tape recorder also owns a rec- learn a language in x minutes or x hours and what progress you are making. The ord player and is thus fully prepared a day solely through the use of records. great value of the tape recorder is that for at least the record- plus -microphone- You will rind some of then tremendously it permits such evaluation. to -tape technique, while the use of a useful in improving your pronunciation For speech practice, as for music. we recorded tape for the same procedure and your ability to comprehend the sometimes use the Coneertone 23 as a would necessitate a second tape recorder Spoken language. Von will not. get the single- channel recorder. If Larry is or player. Besides, the records are fluency that comes from extensive con- going to practice straight through an cheaper. versation with French -speaking people. entire record containing pauses, he feeds We do, incidentally, find a valuable We have, incidentally, found the records the output of the phonograph into the use for Larry's Viking tape player as an for which the wildest claims have Iie,n line input of the recorder and connects occasional part of our language labora- made to he the least useful of all those a microphone into the mike input. He tory. We sometimes cone across a con- we have obtained. starts the record going, listens with ear- tinuous speech record -such as RCA's There arc roughly three types of lan- phones to the input monitor, and repeats Modern French By Sound -which con- guage -teaching records and tapes avail- cash phrase or sentence into the micro- tains wonderful practice material, if able : phone immediately after he hears it. only it had the pauses to permit imme- .(1) Those which consist entirely of non - His own repetition is thus recorded in diate repetition! Well, we put them in. tiimous speech, in the form of phrases, the pause during which the French The records are first transferred to tape. sentences, dialogues, or a story. speaker is silent.. When the completed This tape is then played on the (2) Those which consist largely of phrases Viking, is played and sentences, each followed by a record through the loud with its output connected to the line in- pause which gives the listener time to speaker we will hear each sentence put of channel 1 of the Coneertone, repeat the speech unit immediately spoken by the native French speaker which is allowed to run continuously after hearing it. followed immediately by Larry's version. with the recording (3) selector switch set Those which consist of a mixture of My own these two forms. first experiment with this tech - for channel 1. The operator listens 1,ique was a shattering experience. While through earphones to the input monitor I am amazed to find that there is some I had been using these records without amplifier of the Concertone. He stops debate as to the comparative usefulness the tape recorder I was under the happy the Viking at the end of each sentence of the first two types. Language learning impression that I was doing just fine - for a period of time long enough to per- is one field where the educational dogma not perfect, mind you, but pretty good. mit repetition of the sentence. Since the "you learn by doing" seems unassailable. After I heard myself for the first time (Continued on page 89)

AUDIO DECEMBER, 1957 23 How to Plan Your Hi -Fi System

C. R. TIEMAN

The author offers a method for making comparative listening tests in order to evaluate performance of audio equipment on a quantitative basis as a logical means for choosing components.

WII EN ONE'S INTERESTS turn toward the acquisition of a high fidelity THRESHOLD OF FEELING 4 LOWNESS LEVF.L audio system, he is to ,zo æo introduced ru___ _. _PAU a comparatively new world of elusive w1n1il1,_ values, and he most likely will find that ; HMI 11YrD gu to lay a sound plan for either construct- f "3° M11111 Fig. 1. The Fletch- $ 1 ing or assembling his system is a very i interesting but involved task. er- Munson curves eM:n. Il© of equal loudness Aside from the barrage of claims and ;: :EMr111:1" at the listener's counter -claims of the equipment manu- .D IMUSIEtCic11111.D ear. facturers, advice from all quarters is `ú!\\l11N1 likely to appear to be in serious conflict. C'ìiCsi1111E7,'crj% The beginner may be unable to plan ef- - `° Ì1ÌÌ1.._1111..i.IÄ fectively because the values of which so 111111 `.\'Ii:!11l:':í11IJ many speak glibly are subjective in na- § IIIIIIC\`\I:!!11ME=fliínIN ture and depend upon personal tastes 2 o 11 III and interests. Naturally, these different ALE PRESSURE/10`M interests as expressed by different ad- I. visors can he mutually conflicting, and FREQUENCY IN CYCLES PEN SECOND he has not been able to establish his own standards or recognize his own particu- could be grouped about as follows: tlu feels that the symphony euueert must be lar needs. The measures of system ef- "sound engineer," the "music critic," duplicated in the home in both tonal fectiveness are related to personal tastes. and the "interested listener." The s111III range and volume. Ile requires the 30- to The purpose of a plan is to provide engineer" is the fellow who, above all, 511 -watt system, while the average single the system which most nearly satisfies needs a variety of gadgets so that he can speaker home system will be well served exercise complete control over the signal the listener's interests at a minimum cost. with a 10- to 20-watt system. and compensate for We all have heard of the fellow who. any situation. In ad- The "interested listener" is the one dition, he may require a multiplicity of after spending much time, effort, and who aspires to have a musical system of inputs to his amplifier to give him flexi- money to acquire a suitable system some- a quality that is 11111eh better than is bility in changing from tuners to micro- how fails to be satisfied; and after a afforded by the average commercial radio phones, or to any one of several record- while, has actually acquired enough and TV equipment, ers. He enjoys the thrill of being but he borrows from equipment to assemble several systems. able the "sound engineer" to shape or modify the musical output and the "music If your aim is not to "tinker," then some critic" what they can contribute to to taste. Individuals in this category tend for time spent in planning a system will pay his listening pleasure. wishes to emphasize the importance the He to use off handsomely in the long nun. of amplifier, preamplifier, and the auxiliary his system to satisfy his personal needs Regardless, whether we wish to design which may range from a dance party or circuits; but so far as listening is con- circuits or assemble a system from com- background music, to occasional serious cerned, frequently their needs pleted components, we first must estab- are satisfied with attention to musical masterpieces. lish some planning objectives an 8 -inch speaker of moderate or goals quality. toward which to work. The second step Importance of Individual Taste The second fellow is the perfectionist is to choose individual components which who demands the ultimate in perform- Because high fidelity means different will satisfy these objectives at n mini- ance and scrutinizes each things to different people, the first thing mum of cost. The first and most impor- individual unit to make sure that it is the best available that a hi -fi sales agent will want to distant step is to set one's sights: if you within the state of the These cover when you visit his shop, is what aim too high, the budget suffers directly; art. people emphasize the importance of hearing your individual tastes are. and what you and if you aim too low, the results will every last note and overtone the music expect to do with the proposed system. ultimately be unsatisfactory. Within the offers. The are impatient with the slight- Naturally, he will get to the point re- confines of the space here, we will spend est noticeable distortion, and ask for ac- garding the size of your proposed most attention on the first step in plan- curate compensation for both the record- budget, for he can cite systems that can ning, that of getting the objectives or ing and the ear; some are concerned be assembled for less than $100, as well goals outlined to satisfy personal tastes. with the effects of the temperature and as those which will cost over $1,000. High fidelity means different things to humidity of the room in which the music To the salesman, one may quite inno- different people, and a "good" system is played. Occasionally a few perfec- cently state that he would just like to for one person may be a "bad" system tionists tend to join a cult of "fanatics" have a simple system that accurately re- for another. We may all have seen at who demand improvements beyond what produces what the microphone picked up least three kinds of enthusiasts which the ear is able to hear. Another subclass in the first place. To this remark, an ex- 34 °ó N. Randolph St., Arlington 7, Va. of the "music critic" is the person who perienced hi -fi "expert" may present a

24 AUDIO DECEMBER, 1957 and son of different systems against each disquisition on why this is very difficult, step in understanding one's needs some- other. The facilities of several hi -fi shops not impossible. In addition, one expert planning objectives is to learn if hears. are such as to allow one to synthesize a proclaimed that some persons do not thing about what the ear actually the aver- wide variety of systems simply by throw- want to hear music as it originally The hearing characteristic of ing a few switches. With such a facility, sounded, but they prefer the modifica- age listener is shown in Fig. 1. These one may listen to systems ranging from tions that are afforded by the electronic curves are called the Fletcher -Munson the least to the most expensive. The guiding principle, they say, curves of equal loudness, and they illus- system. the purpose of planning, we is: `let your ear be the judge," and if trate how the ear -the physical termina- For various recommend that one should approach the you the impression that the original tion of the hi -fi system -acts for get first series of listening tests in such a is present as the recording is sound levels and various frequencies. orchestra to establish his own preferences system is "good" -this Note particularly that as the loudness way as played, then the to make a selection "presence." Some ex- level of sound is decreased, the sensi- rather than attempt is the feeling of This author believes that perts further assert that accurate quan- tivity of the ear at low frequencies of equipment. component selection should be deferred titative analysis of sound reproduction changes with respect to the mid -fre- until one has firmly in mind the stand- is futile, because the list- quency range : a sound at 0 db at 1000 for the listener he feels are worth derived from the sound cps is just as loud to the ear as a sound ards of performance ening pleasure time and money. Only when largely subjective, and is at 30 cps having an intensity 60 db the cost in system is an idea of the performance he of personal taste. greater. This is a factor of 1,000,000 in one has purely a matter a system in which practice for evaluating sys- terms of acoustic power. However, the seeks can he assemble Standard components make their full contri- performance is to make a series of same two frequencies at the 100 db level the tem bution and are still held to the minimum listening tests to ascertain the differences both have the same loudness insofar as cost. in the ways in which the same recording as the ear is concerned. As a practical matter one is usually can sound from different systems. If the This characteristic of hearing plays a well acquainted with what might be local hi -fi shop does not have some ar- very important part in the hi -fi system, railed the "lower level" of performance rangement whereby different systems for it means that at a reduced level of because of familiarity with TV and may be compared, then the beginner sound a given musical selection will ap- radio. Based on this starting point, the would be faced with some rather diffi- pear to lose its low tones; conversely, tests described here were initiated to de- cult choices, for it is virtually impos- boosting the volume will increase the ap- termine the best system performance the final analysis to evaluate parent intensity of the lower tones. sible in available, and how various high fidelity performance from advertising For high fidelity reproduction we wish listening systems compared with the best. Wide literature. to maintain a balance between the highs of price and performance were After a few listening tests, one can and lows so that the sound resembles the ranges and technique was sought to readily appreciate the advantages as original production to get the feeling of found, place them in a suitable line of succes- well as the limitations of the subjective "presence." But the original, such as a sion for comparison. Assembled ampli- method of measuring listening pleasure symphony orchestra, may in the concert fiers ranging from $100 to $150 gave system performance. Qualities seem hall be at a level of 80 to 90 db. In the or very high quality performance; speakers to be present in some systems that are home, the level is normally reduced to a and their enclosures ranged from less not described by the specifi- range from 60 to 70 db; hence, the home adequately to over $700, and the tonal cations. I found it virtually impossible system must accentuate the lows by a than $40 range and generally pleasing quality of at the outset to make any judgments on substantial amount-almost 20 db for a the sound varied widely. Turntables, on the basis of a few isolated demonstra- 35 -cps note -to compensate for the ear's the other hand were almost universally tions and without some coaching regard- characteristics. of make and model in the places ing what features were good or bad. The Accentuating this loss of low, tones one so there was no particular choice untrained ear can overlook a variety of with reduced volume is the reduction in visited, avilable in this item. desirable as well as undesirable features performance of many components at low to determine per- a system. Without some experience, frequencies, and the difficulty of radi- The techniques used in commensurate with the one can readily become confused when ating such waves from speakers and their sonal preference make use of the sev- system performance by play- enclosures. Some speakers, for instance, pocketbook was to evaluating as by music because one is ex- may have a characteristic drop in power eral amplifiers recommended best ing recorded substitute speak- posed to a myriad of sounds in rapid radiated below 100 cps, so that by the the salesman, and then successive that cover a wide range of time the signal gets to 35 cps the radi- ers and enclosures to make up succession speakers displayed and volumes, and a wide ated power is off by 10 to 20 db. systems, because the frequencies and perform- range of waveforms. Certainly, peculi- The rule "let your ear by the judge" the widest range of price We are, in effect, attempting to arities or idiosynchrasies of the speaker, is a fundamental one, but one that should ance. to the ear at amplifier, or turntable could he exercised with considerable caution match the hi -fi equipment enclosure, restrictions. by the beginner; and poor per- and understanding of the way the ear best we can within budget be missed listening tests, formance could be judged as adequate. reacts. Stressing the need for of technical specifica- Experience and some instruction are, in- The basic need for control over the and the inability measure of listening deed, needed. level of volume, and the amplification of tions to convey a asserted, Because we rely on the ear to such a the low frequencies in relation to the performance, one consultant speaker units great extent, we must consider the ear as highs is certainly established experimen- "Now, in these multiple notice more depth of tone, a much a part of the entire system as the tally if you conduct several listening you will adequately de- amplifier or the speaker. It is the ear tests. Adequate control over "selective" quality which we cannot but which is, that is either sensitive or insensitive to amplification is ordinarily provided by scribe by our instruments, That depth is a certain tones, or levels of volume. There the "bass" and "treble" controls of the nevertheless present. effect caused probably by is no point in paying attention to sounds preamplifier or the first few stages of psychological from an area rather that only the dog or the canary can hear. amplification. the sound coming or that can be detected on an oscillo- than from a point source." the case, it is scope. The hi -fi equipment transforms Although not always Value of Listening Tests with higher the signals derived from a tuner or a usually true that the systems recording into acoustic waves which ex- The principal value of a series of list- price tags gave a higher level of per - (Continued on page 81) cite the listener's ear. Hence, the first ening tests lies in simultaneous compari-

AUDIO DECEMBER, 1957 25 Impedance and Feedback in Audio Circuits

HERMAN BURSTEIN and HENRY C. POLLAK

A simple presentation of the entire problem of feedback as applied to audio amplifiers. The authors explain Miller Effect and show how feedback can reduce distortion, improve frequency response, and change the effective impedance of amplifier circuits.

AUNDERSTANDING of the roles gain, A of the stage is equal played by circuit impedance to e /eyk = and it RLn +R,m)., feedback facilitates analysis of /(rp Under typical operating conditions, audio equipment design, which is often µ is a nearly constant quantity, so fairly sophisticated, and helps one to that gain varies essentially with the ratio fathom troubles due to component fail - = 40,000. CJt 6',.n /(rp +R,,,,). If a medium -mu tri - ure or improper wiring. It may 1w of ode were used, such as a 12AU7, further aid in solving problems inherent which INPUT lins an rp of only about 8000 ohms, then in the design or in the manner that a the effect of rp upon this ratio would be particular piece of equipment is con - negligible, and A would nected to other elements of approximately an audio equal µ or simply _ system. The audiofau has much to gain kaki), A D. For triodes of higher am, such as a 12AX7, from such knowledge. particularly if he ri, may range up to values is of an experimental nature and every as great as 100,000 ohms. Therefore rp cannot now and then inclined to make a change be ignored for triodes of this in his audio amplifier, control amplifier, sort. The higher the value rp, or tape recorder on of the smaller be- the basis of a Fig. 1. Typical two -stage voltage schematic appearing am comes the ratio RLD /(rp+Rip). If the in a periodical or plifier. ratio drops elsewhere. There below 0.7, gain declines sig- are pitfalls to be nificantly. avoided and possible improvements to Referring to (B) in Fig. 2, it is as- be made. voltage. Multiplying eyk by the tube's sumed that rp is 40,000 ohms and RLD This article is concerned with the amplification factor, µ, gives us the fic- is 153,000 ohms. Therefore R,,,,/(rp+ manner in which impedance and feed- titious signal source in the output cir- Rto) =0.79, representing a loss of about back affect gain, frequency response. and cuit of V,. The terns rp designates the 2 db from maximum possible gain. How- distortion. While the subject cannot be effective resistance, called plate resist- ever, if R,, were 68,000 ohms and Ry fully covered within the limits of one ance, of the tube. By Ohm's Law, given 100,000, R1 would become about 40,- article, the following discussion will try a voltage and given a corresponding 000 ohms, and the ratio would be only to highlight some of its most important current, resistance is implicitly defined; 0.5, a drop of 6 db, For triodes of aspects in relation to audio circuits. It r, is derived from the relationship be- higher plate resistance the loss in gain is hoped the discussion will make clear tween a small change in plate voltage due to insufficient load that one cannot achieve ntaximun, resistance would gain, and the associated change in tube cur- be still greater. maximuut frequency .espouse, and min- rent with grid voltage constant. The The reduction in available gain due imum distortion all at since, but must value of rp in Fig. 2 is typical. The to the output load assumes much greater make some compruIUiI'.. In other words, coupling capacitor, C, of Fig. 1 is omit- proportions in the ease of pentodes, the design considerations are often dif- ted in Fig. °_ because it is assumed for which typically have a plate resistance ferent for each performance charac- the moment to be large enough to have of 0.5 to 1 megolun. In fact, the gain teristic. tic: appreciable effect on the lowest fro - of a pentode may be expressed approx- queney of interest. Impedance and Gain Plate resistor R, is imately as its transeonduetaunce tintes shown connected to ground Dm because its the load resistance RLD, so that gain Figure 1 shows a typical two -stage tip end is at B4- and + the B filter ea- varies directly with load resistance; in audio amplifier, designed to handle a pacitor is a virtual short to ground for short, A gm RL D2 low -level signal at the grid of V,. To o.e. signals. Thus /t,, and It are effec- make clear the factors that affect gain, tively- in parallel. I Usually this relationship the equivalent circuit for is is given as l', pre- Ill Fig. 2, (B) is a simplification of :1- µR,, /(rp +R,,). This, however, assumes sented in 2. Fig. (A), the parallel plate and grid re- that R,, is large enough compared with RL L, this ligure, (A) shows a fictitious sistors being combined into a single load so that the parallel resistance of the two is signal generator, designated Repk, feed- resistance, which we shall essentially that of R,. Although this is call R,i, It often true, for purposes ing a resistive circuit. The term de- can of the present dis- e,, he seen that rp and R,D form a cussion it is not desirable to make this sim- notes the voltage between grid and voltage divider. The signal at the out- plifying assumption. cathode of V,, in 2 d - µIi,,,, this ease the input put, a , is therefore to eyk R,,,,/( rp + /(rp +R,,,), But in typical pentode rLL, R,,,,). If we refer back to the original circuits, is much larger. than IL.r so that :1 µff,p /rp. Since g,,,,'.0/rp, 280 Twin Lane E.. il'anlagh, \', F. signal at the grid V,. we - may say that rte R

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AUDIO DECEMBER, 1957 43 the three solid curves of Figs. 6 and 7 120 were calculated by the equations 110 G(y) = 10G(x), 100 G(y) = 2G(x), G(y) = 1/2G(x) The fit of the three sets of data is suffi- ciently good, we think, to justify the point of view taken in developing the formula. The calculated points for the 10- component tones agree with the observed ones when the proper value of bk is introduced into the formula. In this connection it is important to emphasize that in calculating the loudness level of a complex tone under the condition of 20 listening with one ear instead of two, a 20 factor of 1/2 must he placed in front of to the summation of Eq. (10). This will be explained in greater detail later. The 020 50 100 500 1000 5000 10000 20000 values of G for negative values of L FREQUENCY IN CYCLES PER SECOND were chosen after considering all the data on the threshold values of the com- Fig. 3. Loudness level contours. plex tones studied. These data will be given with the other loudness data on is used while the abscissae give the l (y,) = 2U(r,) = 2G(yo) =4 corresponding loudness levels for the where y, corresponds to x1 = yo, complex tones. It is interesting to note here that the threshold data show that same intensity level of the tone when G(y,) = 2G(xs) =2G(.í1,) =8 both ears are used for listening. If where y, corresponds to x2 = y 10 pure tones, which are below the thresh- +, old sounded separately, will com- binaural rs. monaural loudness data GOO = 2G (xk.) = 2G (yk-,) =2k when bine to give a tone which can be heard. actually fit into this scheme of calcula- where í1k corresponds to xk = í1k_,. tion these points should be represented When the components are all in the high In this way a set of values for G can be by pitch range and all equally loud, each obtained. A smooth curve connecting all component may he from 6 to S db below (;(?,) = 1/2G(ß') such calculated points will enable one to the threshold and the combination will Any one of these curves which was ac- find any value of G(x) for a given value still he audible. When they are all in the curately determined would he sufficient of .r. In a similar way sets of values can low pitch range they may he only 2 or to completely determine the function G. be obtained from the other two experi- 3 db below the threshold. The closeness For example, consider the curve for mental curves. Instead of using any one of packing of the components also in- two tones. It is evident that it is only of the curves alone the values of G were fluences the. threshold. For example, if necessary deal to with relative values chosen to best fit all three sets of data, the ten components are all within a 100 - of G so that we can choose one value taking into account the fact that the ob- eps hand each one may be down 10 db. It arbitrarily. The value of G(0) was served points for the 10 -tone data might will he shown that the formula proposed chosen equal to unity. Therefore, be low at the higher levels where b would above can he made to take care of these G(0) = 1, be less than unity. The values for the variations in the threshold. G(yo) =2G(0) =2 function which were finally adopted are There is still another method which where yo corresponds to x= 0, given in Table III. From these values might he used for determining this loudness function G(L), provided one's judg- ll!l FEELING ment as to the magnitude of an auditory 120 sensation can he relied upon. If a person 1iriNi/i%ié: were asked to judge when the loudness of a sound was reduced to one half it be that he would base 100 III MI ®NITA might expected MI his judgment on the experience of the _.,- decrease in loudness when going from the condition of listening with both ears 9 too -ouI1o- J to that of listening with one ear. Or, if W 70 JW \'1:!.,- the magnitude of the sensation is the number of nerve discharges reaching the e0 .¡i11\111-111 re0 brain per second, then when this has / decreased to one half, he might be able to say that the loudness has decreased Z 40 one half. III\\\MIll30 iii11/111/I In any case, if it is assumed that an observer can judge when the magnitude 20 IIII\11\i1111I/ of the auditory sensation, that is, the loudness, is reduced to one half, then II the value of the loudness function G can o 1311!!2.!NIíílIll be computed from such measurements. moor Several different research workers 20 00 500 000 5000 10000 have made such measurements. The meas- FREQUENCY IN CYCLES PER SECOND urements are somewhat in conflict at the Fig. 4. Loudness level contours. present time so that they did not in any

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AUDIO DECEMBER, 1957 45 for the 1024 -cps tone. The observed data 120 were taken front Table VII of the paper

1 I by Laird, Taylor and Wille.9 As shown

no t in Table V the calculation of the level for one fourth reduction in loudness 00 agrees better with the observed data corresponding to one half reduction in 90 loudness. Firestone and Geiger reported some 80 ': / m / preliminary values which were in closer 0 agreement with those obtained by Park- ±i 70 W Ham, > inson and but their completed paper has not yet been published.10 Be- 80 ,n cause of the laek of agreement of ob- N . served data of this sort we conclude z 50 j/ o that it could not be used for influencing D i the choice of the values of the loudness 40 function adopted and shown in Table /.jI/I, is to 1w hoped III. It that more data of 30.- Minia this type will be taken until there is a 4000 GR:iS 2000 A better agreement between observed re- z iffi/", - sults of different observers. It should be "°400-1874, emphasized here that changes of the , rz grA,,,NFAV,M - level above threshold corresponding to any fixed increase or decrease in loudness o A I ;eI©I will, according to the theory outlined in this _to paper, depend upon the frequency of -20 -t0 0 to 20 30 40 50 60 70 BO 90 $00 1t0 120 the tone when using pure tones, or upon INTENSITY LEVEL -DB its structure when using complex tones. ,to DETERMINATION OF THE FORMULA FOR 00 CALCULATING b,, Having now determined the function 90 I I G for all values of L or Lk we can /í proceed to find methods of calculating Bo bk. Its value is evidently dependent upon

cn the frequency and intensity of all the o 70 .,,, other components present as well as .AN. upon the component being considered. w 80 For practical computations, simplifying assumptions can be made. In most cases 50 the reduction of bk front unity is princi- UJ P/. due to the adjacent component on ó pally the side of the lower pitch. This is due iiiiiin to the fact that a tone masks another 0 30 tone of higher pitch very much more ./.I than one of lower pitch. For example, 20 in most eases a tone which is 100 cps higher than the masking tone would be t0 I,,. masked when it is reduced 15 db below the level of the masking tone, whereas o :/I,®/.. a tone 100 cps lower in frequency will be masked only when it is reduced from lo 40 60 db below level of the mask- -20 -10 0 II.,10 20 30 40 50 60 70 BO 90 100 110 +20 to the INTENSITY LEVEL-bB ing tone. It will therefore be assumed that the neighboring component on the /..,Fig. 5. (A and B)- Loudness levels of pure tones. side of lower pitch which causes the greatest masking will account for all the way influence the choice of the loudness 2b, 3a and 3b of their paper. The calcu- reduction in bk. Designating this com- function. Rather we used the loudness lation is very simple. From the number ponent with the subscript m, meaning function given in Table III to calculate of decibels above threshold S the loud- the masking component, then we have bk what such observations should give. A ness level L is determined from the expressed as a function of the following comparison of the calculated and ob- curves of Fig. 3. The fractional reduc- variables. served results is given below. In Table tion is just fractional reduction in the IV is shown a comparison of calculated loudness function for the correspond- bk =B(fk, fm, Sk, Sm). (15) and observed results of data taken by ing values of L. The agreement be- 9 Laird, Taylor and Wille. "The appar- Ham and Parkinson.' The observed tween observed and calculated results ent reduction in loudness," J. Acons. Soc. values were taken from Tables la, lb, 2a, is remarkably good. However, the Am. 3, 393 (1932) . to is now available. P. H. agreement with the data of Laird, Taylor This paper S. Parkinson, Geiger and F. A. Firestone, " The estima- 8 L. B. Ham and J. is very poor, as is shown by "Loudness and intensity relations," J. and Wille tion of fractional loudness," J. Acons. Acons. Soo. Am. 3, 511 (1932). Table V. The calculation was made only Soc. Am. 5, 25 (1933).

46 AUDIO DECEMBER, 1957 I11l(lllllillllllllll111

NEW 12" PRECISION TURNTABLE z,a9aa©OO Gyro-like Roto -Drive gives new Thorens TD -124 absolute speed uniformity. Heavier than 16 -inch turntables, yet it starts, stops in less than 2/3 turn! OUTSTANDING FEATURES v Four speeds, each with -I-3% speed 0 How to get the heaviest possible turntable for smooth, absolutely quiet operation adjustment. Built -in illuminated without sacrificing fast starts and stops. strobe disk for all speeds. Built-in level bubble and leveling screws. That's the problem Thorens engineers faced when they set out to build the 12 Precision 4 -pole motor, extra -corn. A best four -speed, -inch, hi -fi turntable money can buy. You'll be amazed at the pliant belt -drive and idler system simplicity of their solution. plus exclusive Thorens Roto -Drive O principle, provide complete vibration The new TD -124 really has two turntables in one: (1) a heavy 10 -lb. rim-con- isolation, absolutely constant speed. centrated , cast -iron flywheel (outweighs 16" aluminum turntables) (2) a light Provision for easily changing arms without leaving unsightly perma aluminum cover, or turntable proper. An exclusive, Thorens- originated clutch nent marks: -just replace low-cost couples or decouples the light aluminum table to the heavy flywheel for instant arm mounting board, available for starts and stops. What's more, the Thorens double turntable system gives you the 12" or 16" arms in various finishes. J Easy to mount, the TD -124 requires weight of a cast -iron table (3 times as heavy as aluminum) without danger of only 234" clearance below mount- - attracting any pickup magnet. And with this unique construction, your pickup gets ing board. Furnished with attached magnetic shielding from motor or transformer hum fields line cord, shielded cable and solder by the iron turntable. plate. Ask your hi-fi dealer to show you the Thorens TD -124. Better yet, arrange to hear one of those critical, slow piano records on the TD -124. If you don't know r3 who your dealer is, write Thorens Company, Dept. A127, New Hyde Park, N.Y. 7.9

HOREN5 SWISS MADE PRODUCTS

HI FI COMPONENTS LIGHTERS - SPRING-POWERED SHAVERS MUSIC BOXES

AUDIO DECEMBER, 1957 47 where f is the frequency and S is the 120 level above threshold. For the case when bk. I the level of the kth component is T db below the level of the masking component, where T is just sufficient for the p100 A component to be masked, then the value w of b would be equal to zero. Also, it is ó2 reasonable to assume that when the masking component is at a level somewhat less o BO than T db below the kth component, the z latter will have a value of bk which is unity. It is thus seen that the funda- Ó 11141 mental of a series of tones will always 0 N 530ti have a value of bk equal to unity. 1`J -TE TWO TONES For the case when the masking com- > /.II,- o-1000 AND 2000 ti ponent and the kth component have the W O -125 AND 1000 v saine loudness, the function representing uJi 40 ,r h / b,,. will be considerably simplified, particularly if it were also found to be inde- z . no pendent of fk and only dependent upon 20 the difference between fk and f,. From the theory of hearing one would expect that this would be approximately true for the following reasons: 0 The distance in millimeters between 0 20 40 60 80 100 120 140 the positions of maximum response on LOUDNESS LEVEL OF EACH COMPONENT-DB the basilar membrane for the two com- Fig. 6. Complex tones having components widely separated in frequency. ponents is more nearly proportional to differences in pitch than to differences 120 - in frequency. However, the peaks are sharpest in the high-frequency regions where the distances on the basilar membrane for a given Af are smallest. Also, 100 0 in the low frequency region where the distances for a given Af are largest, these om peaks are broadest. These two factors tend to make the interference between ,á B0 two components having' a fixed difference W in frequency approximately the same re- 2 o gardless of their position on the frequency scale. However, it would be ex- WJ 60 > traordinary if these two factors just w J balanced. To test this point three complex tones having ten components with x o-0. z q0 a-100125n. a common Af of 50 cps were tested for o x -40001. D loudness. The first had frequencies of Jo 50- 100 -150 500, the second 1400- 1450 1900, and the third 3400-3450 20 3900. The results of these tests are shown in Fig. 8. The abscissae give the loudness level of each component and the ordinates the measured loudness level 0 0 20 40 60 80 100 120 140 of the combined tone. Similar results / LOUDNESS LEVEL. BOTH EARS-DB were obtained with a complex tone hav- Fig. 7. Relation between loudness levels listening with one ear and with both ears. (Continued on page 83) TABLE I - VALUES OF G(4)

7 8 9 L 0 I 2 3 4 S 6 -10 0.015 0.025 0.04 0.06 0.09 0.14 0.22 0.32 0.45 0.70 0 1.00 1.40 1.90 2.51 3.40 4.43 5.70 7.08 9.00 11.2 10 13.9 17.2 21.4 26.6 32.6 39.3 47.5 57.5 69.5 82.5 20 97.5 113 131 151 173 197 222 252 287 324 30 360 405 455 505 555 615 675 740 810 890 40 975 1060 1155 1250 1360 1500 1640 1780 1920 2070 50 2200 2350 2510 2680 2880 3080 3310 3560 3820 4070 60 4350 4640 4950 5250 5560 5870 6240 6620 7020 7440 70 7950 8510 9130 9850 10600 11400 12400 13500 14600 15800 80 17100 18400 19800 21400 23100 25000 27200 29600 32200 35000 90 38000 41500 45000 49000 53000 57000 62000 67500 74000 81000 100 88000 97000 106000 116000 126000 138000 150000 164000 180000 197000 110 215000 235000 260000 288000 316000 346000 380000 418000 460000 506000 120 556000 609000 668000 732000 800000 875000 956000 1047000 1150000 1266000

48 AUDIO DECEMBER, 1957 THEALTEC 306A AM -FM TUNER

. "...the most sensitive tuner ever tested"* The ALTEC LANSING 306A features an exceptionally large six gang tuning condenser which is fully shielded and mounted directly to the chassis for perfect grounding, a dry rectifier for long stable life, complete isolation between transformers and power mains and a chassis layout which reduces coupling between circuits to a minimum that easily meets F.C.C. radiation requirements. The FM section features a Foster -Seeley (Armstrong) detector, a "cascode" low noise RF stage, a triode low - j' ' L e;^ noise mixer stage, AFC and two limiter stages. The AM section features three IF transformers with optimized coupling for flat pass band and maximum noise rejection. This use of specially designed and over- coupled IF transformers provides maximum band width with extremely sharp skirt attenuation for maximum fidelity. These features, careful chassis layout and intensive testing and alignment account for the superior performance of this tuner. Examine the 306A closely. Compare its performance critically. You will see why it is considered the world's finest tuner for sensitivity, selectivity, stability and long life. Like all ALTEC products its performance specifications are guaranteed. Price: (less cabinet), $198.00. Walnut, Blonde or Mahog- any Cabinet, $18.00. =According to one of nation's leading testing laboratories.

THE The 305A has been designed specifically for use in those areas where FM reception is not available or for use with the 306A for stereo broadcast reception. It provides the maximum possible quality from ALTEC AM broadcasting through the utilization of a special circuit which provides the greatest possible band width. Many AM tuners have both 305A broad and narrow band selection but the broad band position AM TUNER invariably has so little skirt attenuation that it is virtually unusable. The 305A uses ALTEC developed and produced IF transformers of an unusual design which permits them to be over -coupled to provide extremely sharp skirt attenuation. This sharp attenuation provides the greatest usable band width for maximum fidelity, and strong noise rejection for quiet operation and freedom from station interaction. Price: (less cabinet), $99.00. Walnut, Blonde or Mahogany Cabinet, $18.00.

Write for free catalogue ALTEC LANSING CORPORATION, Dept. Al2 ALTE[ 1515 So. Manchester Avenue, Anaheim, Calif. LANSING CORPORATION 161 Sixth Avenue, New York 13, N.Y, I3-7

AUDIO DECEMBER, 1957 49 Equipment Review Dyna Preamplifier and Dynakit III 60 -watt power amplifier - Fairchild 412 -1 turntable and 280 -A transcription arm -General Electric VR -II variable reluctance pickup -The Garrard Line

DYNACO, INC. Slightly over a year ago we reviewed the original Dynakit II power amplifier (Sept. 1956) with its unusual -for then -50 -watt output. Now there are many 30 -watt amplifiers on the market, and some of still higher power, and it is somewhat of a surprise to note how many of them employ the same circuit as that of the Dvnakits. Fig. 1. From a box The newest model, the Dynakit is 'III, of parts to a 60- rated at 60 watts and incorporates a few features that were not part of the earlier watt amplifier in model. While the circuit is essentially the about two hours, same, the output tubes are KT -88's, which the new Dynakit accounts largely for the increased output. Ill is a model any In addition, a filter choke has been added. kit builder will improving the signal -to -noise ratio, and a enjoy. 11.2-ohm resistor has been added front the cathodes of the output tubes to ground - an improvement towards more output lin- earity that has already been recommended as a suggested change for earlier owners of Dynakit II. The new unit is the same size as its predecessor -9 by 9 by 6% in. -and is of similar appearance, as shown in Fig. 1. Rated output is obtained from an input of 1.6 volts, and the model tested (which was assembled in slightly less than two hours) a turntable at the same time. Another very however. of the ease of construction, it is reached 68 watts at 2 per cent IM dis- desirable feature is the rectifier -filter cir- likely that most users would be very well tortion. Output impedances of 4, 8, and cuit which permits the use of a 6.3 -volt a :tislied with the Dyna models. M -18 16 ohms are available, and the unit pro- a.c. source to provide some 11.5 volts of vides power for Dynakit and Heathkit d.e. for heater supply. It should be noted preamplifiers directly, or for most others that when this arrangement is used, the FAIRCHILD if proper connections are made to the ground connection normally present in the In general it may be said that the sim- power socket. power amplifier should be removed, since plest form of any particular device might The Dyna Preamp is an interesting de- the ground on the heater circuit is hest well be the best, since there are likely to sign, conventional in some respects, un- obtained from the potentiometer in the be fewer parts and consequently less usual in others. The tone control action is preamp. The Dynakit III is normally wired chance of trouble. Thus the simplest form obtained from a feedback circuit with with the heater winding free from ground, of a phonograph turntable could well be somewhat less interaction than is usual and if it is to be used with any other the platter with a suitable bearing, a for the average preamp. One useful fea- preamplifier the center tap should be driving motor, and a belt drive between ture is the "Special" input which may be grounded. Similarly, if the Dyna preamp them. This permits the motor to be wired by the builder to be equalized for is used with any other power amplifier, the mounted as flexibly as possible, and re- microphone or tape head, or it may be ground on the heater circuit of the other moves any actual mechanical contact be- employed as an additional RIAA phono power amplifier should be lifted. Figure 2 tween motor and turntable, since the belt position, depending on the user's require- shows the external appearance of the Dyna would undoubtedly be made of some ma- ments. In the latter connection, it is pos- preamp, while Fig. 3 shows the internal terial which would not transmit vibrations. sible to leave two pickups plugged in at arrangement. The use of pre- assembled Such a device is the Fairchild 412 -1 all times, with front -panel switching -ac- etched- wiring panels reduces construction turntable -a single -speed model for those commodating, for example, a changer and to a relatively simple operation. In spite, whose principal interest in records centers

Fig. 2 (left). The Dyna preamplifier kit ends up as a neat and attractive unit with excellent performance. Note left slide switch which connects monitor circuit to tape recorder without need for changing plugs. Fig. 3 (right). Inside view of Dyna preamp. Tubes are completely enclosed and shielded when cover is in place.

50 AUDIO DECEMBER, 1957 it

UX -BO

LIX-120 UNAX SINGLE ELEMENT

DUAX' - -ELEMENT SYSTEMS

CX-12o Cx-22s

cx -15o CX.255 COAXIAL DUAX* 3- ELEMENT SYSTEMS HIGH FIDELITY LOUDSPEAKERS

You'll spend less for more performance ... get traditional Jensen quality!

Making the utmost of the hi -fi possibilities of two coordinated cones driven by one voice coil, Jensen's new DUAX speakers bring you a lot more performance at a lot less than you'd expect to pay. No one makes a better speaker at anywhere near the price.

Both acoustic elements operate together up to a "mechanical crossover" at 4000 cps; above this the small cone operates with special COAXIAL 2 -WAY SYSTEMS effectiveness. Frequency range, 40- 13,000 cps, with low end enclosure dependent, but working fine just about anywhere you put it. One pound new high efficiency DP- Alnico -5 magnet. Twelve inch DX -120, net S25.50; fifteen inch DX -150, only S35.50.

Free condensed Catalog 165 -B tells about the complete new Jensen line. Write for it now. TRIAXIAL' and T. M. R./. TRIAX KTX -2 "STEP -UP" KIT 3-WAY SYSTEMS Start with a DUAX, up -grade later to a true 2 -way system with compression horn THE tweeter for 2000 -15,000 cps. Easy to adc, WORLD'S costs only S32.50 net. MOST COMPLETE en en MANUFACTURING COMPANY HIGH 6601 South Laramie FIDELITY Ave., Chicago 38, Illinois LOUDSPEAKER In Canada: J. R. Longstoffe Co., Ltd., Toronto Division of The Muter Co. LINE In Mexico: Radios Y Television, S.A., Mexico D.F.

'T. M. R .

AUDIO DECEMBER, 1957 51 CAST AAAMIASAI TLI1.Ty.0

Fig. 4 (left). The Fairchild 412 -1 turntable mounted in a hardwood cabinet which accommodates also the 280 transcription arm. Entire unit is large, but a belt drive from motor to idler and another belt drive from idler to turntable holds rumble to a minimum. Fig. 5 (above). Cross - sectional view of the 412 -1 turntable showing relative position of the various elements.

around the LP. However, for those who from practically any voltage source -a.e. good pickup at a very low price. The over- need the other speeds, the Eleetronic Drive from 85 to 135 volts at from 40 to 400 all frequency range has been increased to unit nuiy be employed. Basically, there- cps; d.c., with any type of inverter, which provide better response above 10,000 cps; fore, the turntable unit consists of the does not need to be frequency- controlled; compliance bas been increased; and track- platter, a motor, and a belt- although, or batteries, with an ordinary vibrator - ing in a typical transcription -type arm is actually, to obtain suitable speed reduc- inverter. The Ell unit is normally used satisfactory at a stylus force of only 4 tion there is an intermediate idler, with with four fixed output frequencies, all of grams. Figure 6 shows the dual -stylus two belt drives. One belt drives the idler which have vernier adjustments, but the model 4G- series -the suffix numbers -050 from the motor, and the other drives the output frequencies could be tailored by indicating two sapphires, -052 indicating turntable from the idler. Figure 4 shows ally user having special requirements with a 1 -mil diamond and a 3 -mil sapphire, the complete unit, together with the tran- relatively little trouble. while -053 indicates two diamonds. scription arm. and Fig. 5 shows the me- The turntable unit requires a clearance With a load resistance of 6200 ohms the chanical arrangement in cross section. of 67/s in. below the mounting board, and cartridge has a roll -off which corresponds The driving motor -a hysteresis-synchron - the hardwood base shown in Fig. 4 is 21% with the RIAA curve, and the output at a ous model -is mounted in a flexible cradle by 141/_ by 7% in., actually not much stylus velocity 10 cm /sec has a nominal with highly compliant suspension which larger than the turntable unit itself. The value of 22 millivolts. Compliance is rated eliminates transmission of vibration (and top board is mounted with acoustic iso- at 1.7 x 10 -" em /dyne, which -while not audible noise) to the chassis. The idler lation to minimize the effects of external especially high- indicates that the pickup is mounted to the chassis with rubber vibration. should be sturdy and require a minimum cushions, and is equipped with Teflon The 280A transcription arm is an im- of "kid glove" treatment. Suitable track- sleeve bearings, the whole idler assembly proved model of the earlier Fairchild arm, ing force for the pickup -using as an in- being mounted in an eccentric which per- and has a minimum of bearing friction - dication the minimum intermodulation dis- mits adjustment of belt tension. The rec- both vertically and horizontally-low ver- tortion point-appears to be between 3.5 ognized speed constancy of the hysteresis - tical mass, and a detest which holds the and 4.5 grams, and the cartridge operates synchronous type of motor ensures extreme arm fixed in the rest position without any satisfactorily at a 6 -gram force in good - speed accuracy at the turntable proper- additional awns or holding devices. The quality record changers. the production models being held to an cartridge is carried on a removable slide Susceptibility to pickup of hum from absolute speed accuracy of closer than 0.3 to which electrical contact is made by a nearby fluorescent lamps or to static pops per cent. pair of springs which short out the leads resulting from build -up of static charges The turntable platter is a heavy alumi- when the cartridge slide is removed. Arm on the record surface has been reduced ap- num casting, dynamically balanced, and resonance has been held to a minimum, preciably by the use of an electrostatic its hardened steel shaft is carried in lapped with no effect whatever being noticed shield which is designed to be grounded well provided with lubrication grooves, above 12 cps. The arm is all attractive to the "low" terminal of the pickup when the thrust being taken on a hardened steel unit, and well complements the high qual- it is installed in the head. ball riding on a Nylon seat. Rumble was itv of th tunrtahl,. M -19 The body of the cartridge is not as wide so low as to be extremely difficult to meas- as in the previous models, which makes it ure, since even the u:modulated grooves GENERAL ELECTRIC possible to install the VR -II in some of on most test records show some "rumble" the narrower arms used in many of the when the reproducing equipment finally be- 'l'he new GE cartridge- VR -II -is likely "packaged" hi -fi sets. Thus better quality comes good enough. Suffice that rumble is to continue the long tradition its predeces- can be available to a wider group of po- entirely inaudible with any records we sor has maintained, that of being a very tential users than heretofore -a feature played at well above normal listening level. For those who need other speeds, the Electronic Drive unit may be added at any time. This unit simply provides other frequencies of supply voltage by means of au oscillator -60 cps being normal for the 331ís -rpm speed, and thus equivalent to Fig. 6. General 16% normal line supply frequency. For Electric's n e w rpm, the oscillator supplies 30 -cps drive VR -II cartridge, voltage; for 45 rpm the supply frequency in a is 81 cps; and for 78 rpm the frequency available is 141 eps. Since the absolute speed of the number of types hysteresis- synchronous motor is dependent and stylus ar- on the frequency of the supply voltage rangements. any speed desired can be obtained by changing the frequency of the oscillator. This makes an especially desirable unit for use in areas where 60 eps is not the normal line frequency or where the frequency is not carefully controlled. The Electronic Drive unit can also be used

52 AUDIO DECEMBER, 1957 what could be more exciting O d high fidelity enthusiast? new GLASER- STEERS Gs ,s-)e,4 s-.) the fully automatic record changer with turntable quality performance

At last - what every audiophile has been waiting for - the con- Every feature spells -Greater Convenience and Better Per- venience of a fully automatic record changer with the perform- formance - The ARM is shock suspended and damped, effecting ance quality of a transcription turntable. complete acoustical isolation from deck plate and motor and The new GS -77 provides a quality of performance unsurpassed practically eliminating resonance. An accessible vernier control by turntables up to double the price. Flutter and wow are virtu- adjusts stylus pressure to match any cartridge requirements. ally non -existent. Rumble has, for all practical purposes, been Once adjusted, the variation of stylus pressure between the first and tenth record eliminated. And as for automatic conveniences - it is, without on the table does not exceed 1 gram. doubt, the most advanced record changer of our time. Transcription arm convenience includes: finger lift for manual play, as well as indicator to facilitate location of stylus in groove. There is more originality in the GS-77 than in all other changers The MOTOR is 4 -pole induction, dynamically combined! See for balanced, hum yourself. shielded and shock mounted - all to assure accurate, constant 'SPEEDM/NDER":'...the amazing GS -77 feature that automati- speed, and smooth operation. cally selects correct turntable speed, and gives you record and The IDLER and other rotating parts are precisely stylus protection centered and no other changer can equal. mounted on low friction bearings. Idler automatically disen- gages in 'off' position. Prevents You simply set the indicator to 'SPEEDMINDER' and automation flat spots and wow. MUTING takes over... SWITCH and R/C filter network squelch all annoying sounds. The GS -77 is with the standard groove absolutely jam -proof - built for years of trouble - stylus in play position, the changer free performance. A single knob automatically plays at 78 rpm. controls all automatic and manual operations. The changer is pre -wired for easy installation, with the microgroove stylus in position, the changer auto- and is dimensioned to replace most changers. matically intermixes and plays 33 and 45 rpm records without less cartridge and base ONLY $5950 regard to speed, size, or sequence. - Styling of the new GS -77 is gracefully simple - enhanced by its TURNTABLE PAUSES during change cycles and doesn't re- ebony and brushed gold finish and oyster white turntable mat sume motion until next record has come into play position and For a thrilling experience - see it - hear it at your high fidelity stylus is in lead -in groove. Eliminates record surface wear caused dealer. Descriptive literature available on request. Dept. A -12. by grinding action of record dropping on moving disc -a common GLASER- STEERS CORP. 20 Main Belleville draw -back in other changers. And the change cycle lasts only Street, 9, N. J. 5 seconds - fastest in the field. In Canada: Glaser- Steers of Canada, Ltd., Trenton, Ontario. Export Div.: M. Simons & Son, Co., New York 7, N. Y. 6 Trademark 1 Patents Pending

AUDIO DECEMBER, 1957 53 MIN

Fig. 8. The Garrard "Professional" model Fig. 7. Garrard Model T "Mark Il" 4- 301 transcription turntable -a three - speed manual record player -neat and speed unit of exceptionally quiet per- Fig. 9. The RC88 record changer -four compact. formance. speeds, automatic or manual operation. which will be of special interest to the the common garden variety sinee these are The underside of the 98 is shown in Fig. audio service man who is called on to Hake the Garrard models most often encoun- 11, and it is identical with the 88 except improvements in sets of this type. It is tered-is shown in Fig. 9. This model uses for the vernier speed control housing quite likely, therefore, that the VR -II will the pusher platform type of record change shown at the left. carry on the tradition of being the "work for 1(1 "- and 12" records, and a center - Model RCl °l, shown in Fig. 10, uses horse" of the magnetic pickups. M -20 drop spindle for the 7" 45's. One interest- the simpler center -drop spindle for both ing and useful feature is the spring mount- types of records. This results in a smaller THE GARRARD LINE ing used for all of the changers as well hase plate that can usually be accommo- as for the Model T. To make installation, dated in the space available in existing 1t has long boon the custom of this de- the mountings are attached to the base phonographs when a change to a better partment to review equipment of the type plate and simply pressed into the holes on quality of turntable is desired or when that the average reader considers "stand- the user feels that he wants the 16% rpm ard" in that it rarely seems to change speed. Like all the other models, no belts appreciably from year to year. This de- are used between motor shaft and idlers, scription applies particularly well to the but a more conventional turret drive is Garrard line of record players and chang- employed to effect the speed changes. ers-as well as the 301 transcription turn- Figure 8 shows the top view of the table- because such minor improvements Model 301 transcription turntable, which as may be introduced into the various units has already established an enviable repu- are not sufficient to warrant a new model tation for itself. Using the saine basic designation. While the Model T "Mark drive principles. the transcription model is II" was reviewed in :hill. of this year. naturally constructed with every possible and the new TPS -10 arm was described in thought being given to the reduction of the October issue, the remainder of the rumble. The underside view of this model line has not been discussed since the in- shows the "battleship" type of construc- troduction of the RC88, R('98, and RCI_I tion, with the motor being supported in a models over a year ago. Fig. 10. Model RC121 is more compact cradle by means of rubber -damped springs, Figure 7 shows the Model T, which is because of the center -drop spindle, can and the vernier speed control isolated from a manual record player with four speeds. fit into many existing phonographs. the motor by springs to minimize any The pickup shell is the sane as those used transmission of motor vibration -and on the three changers, which simplifies the the motor board, levelling screws being there is very little from this dynamically problem of the user who may have a accessible from the top so that even when balanced motor -to the chassis. An inter- changer in his honte but who occasionally the motor board itself is not level the lock prevents changing speeds when the uses the smaller manual unit as a "port- changer can be made so readily. motor is running, and the ON-OFF switch able", for example. The motor starts when Model RC98 is essentially the sante as control is separate from the SPEED SELEC- the arm is moved fully to the right, and the 88 with the addition of a vernier speed TOR to eliminate the possibility of turning shuts off automatically at the end of the adjustment which covers the range of the unit on to a wrong speed -a disaster record. An arm rest is provided, and the about ±4 per cent, permitting those who in professional applications. entire unit is quite compact. wish to play records with a piano or other As the leader in the Garrard line, the The RC88-which might be described as instrument to match the pitch properly. 301 well deserves its excellent reputation.

Fig. 11 (below). Underside view of the deluxe RC98. The vernier speed control -which changes the electrical circuits of the motor itself -is in the perforated housing at the left. The RC88 is essentially identical except for this control. Fig. 12 (right). Underside of the 301 transcription turntable. Note the extremely rugged construction with thorough isolation of motor from chassis.

54 AUDIO DECEMBER, 1957 FOR THE PRESTIGE OF OWNING THE BEST . . .

BOZAK 6,&/(4fr.r

T H E R . T . B O Z A K S A L E S C O M P A N Y D A R I E N C O N N E C T I C U T i EXPORTS ELECTRONICS MANUFACTURERS EXPORT COMPANY PLAINVIEW NEW YORK AUDIO DECEMBER, 1957 55 EDWARD TATNALL CANBY

i constructive experiment, worth 1. WORDS, WORDS Three who t, a, cue person, speak one char- excellent and AMAZIN' acter's lines. who appear always together. trying many times again. Shakespeare: Hamlet -the Baylor Theatre You will ti ud that it all makes remarkably good sense, this facet icing of as character into Cervantes (trans. Starkie): Don Quixote. Production, 1957. Baylor Univ., Waco, aspens. You quickly become used to three Texas. Word Record W- 6002 -3 (3) suites for Hamlet, three for l 'olonius. and Excerpts read by Walter Starkie. you soon get to know them individually. as Mentor 12 -A 1 (With script, ill. booklet.) contrasting aspects of the persons involved. %Yowlers will never cease! Here k an ultra- That it does Hake sense. of course, is due This sin :fitly forbidding hooking title covers Hamlet to knock you for a loop. Blurb on the to some very expert tailoring of the actual out of the funniest and most unexpected °over says "The first deadly NEW Ili inlet in si s'ech patterns. dividing one text among three "literary" records I've hit yet -Don Quixote voices. The three net ors speak sometimes to- 355 years . three actors pia pi IU/ curb major wearing the Irish green. gether. sometimes singly often in overlapping was Spanish. His role " - -:n ,!. by golly, that is literally true. t'ervan tes. of cuti rse. phrases, with chorus -like repetitions. fading faunal:: satirical stories of the idealistic Don simultaneous here, There tee three hamlets out. fading in -and here is one of the oldest who chased windmills. assisted by his prosaic and three queens. three kings, three Polmtiuses, things about the whole production, particularly but faithful "squall" i squire). Sancho Panza- l)pielias, I.aerteses, Horatios. Even the play - interesting to an audio mail :- the Dun tali and gawky. Sancho short and fat within -the play has triple everything. The cast The broken-up lines, for three people. use on a donkey -were as studied jibe at the is enormous. Each appeaus as triple character extensive echo and pre -echo. al sl exactly as prosaic modern world of the i1 th century as a null. all three, and the trio act and speak we hear them in faulty 1.1' grooves and in eomp:ued to the flowering of gallantry and throughout as a team. When four or five tills print-through-and as we hear them knighthood of the past_ hideous new pistols, characters are onstage the babble of voices is every day deliberately produced. by tape feed- gunpowder. these were the modern horrors like Times Square in the rush hour. It takes back. for everything front cigarette eounuer- that had killed the spirit of chivalry -or so six people to play a love scene! vials to tais'sichord music. Whitt could be the Dnu thinks. Cervantes leaves you wonder- The play was staged in a theatre with more familiar. what more of the essence of ing. as the Dun's chivalry shatters the wind- swivel scats surrounded by stages on all sides ; note. than this echo -chorus! Here. it is used mill, :rasp unhorses the knight himself! the show goes on all around and the audience "live ", purely vocally. A line is pre- echoed, All that was Spanish: but Walter Starkie, pivots. \lusic conies from strange drums, front faintly, before it is said al I: or it is re- a longtime expert in Spanish culture, is from the inside of pianos, wood blocks. sections of pe:tted, echo -style, dying away into the back- Dublin University. Mix a bit of the Irish with iron pipe. Costumes and sets are timeless and ground as another voice picks up the fore- anything else and what do you gel? That's modern. The script -Shakespeare -is rear- ground. Sheer audio mixing technique, without what you have here. 11 is a beautifully done ranged and adapted. audio. translation anti a very exciting and utterly And yet. in spite of all this for because of I assure you that the effeel of this three- hilarious reading -straight out of Ireland. it), the production, even on records, is really dimensional speech rhythm is fascinating. The This man is a bond reader -actor. He has a eau r inei ug. new dramatic approach, the new intensity that high. wiry vote° and a positively fabulous Yes. there is a good deal of conventional it allows in the lines. is unforgettable. With mike personality. if unlike any you could have stage stuff left, perhaps more than the players this sort of speech counterpoint. who wants to imagined. Ile is violently enthusiastic, he gets ge single sentences spoken by a are aware. TOO mulch chanting and moaning. back to mere carried away by his own excitement and you as actors love to do in tragedies. too much single voice? Old fashioned, out of date. will be swept along ton. fateful thumping of drums. The speaking ac- Yes, I think I gn :tong with the Baylor lint best of all is the Irishness. In the parts cents are often forced, as Shakespeare usually people. Youthful or no, this really is it NEW concerning the Don himself it is Itot so much Hamlet. maybe the newest in 354i years, at in the speech as in the gusto. the tilt, the is today. I Some, however. are delightfully Texan. including one of the three Hamlets.) that. I recommend it. glitter of excitement and drama. I:ive an On casual listening you might class this as Irishman a stage. . The Sancho Panza episodes are something else, for there Mr. just another acting uproar, a lot of stage - Poetry Readings in the Cellar. Cellar Jazz st ruck fanatics nuking pretentious noise. Starkie simply converts the good Saticho into There is that aspect to it -as to much serious- Quintet; Kenneth Rexwroth, Lawrence a sheer IOil per cent Irish countyman, speech minded playmaking these (lays. Dreadfully Ferlinghetti. Fantasy 7002 awl all. and the same for his wife. Most of cue whab record side. thus. is an argument dedicated. \l.ayb, you saw the piece in Life uaag about Yet if you will sit down and follow the bet we'u Sa Hein aunt \Its. Satttci° as to the Sou Franscisco poets and the slightly 11 1141 script keep yourself straight as to whether ¡when success comes Sancho is printed (to renaissance of poetry and other arts whom is who) you will find this "lo,uy" made a Ilovern'rI \1 i's. S. and progeny shall how many of in that lively city. Here is the sound saw an exciting and moving show. as it has seldom you beruus' grrand aristocracy. She holds out for ill the pictures. and it'll make your hair curl. the been for us ordinary non -donna souls. The the simple virtues; he fights for grandilo- Kenneth Itexroth is a born rouser of fever- thing works. (tueuces. and the ensuing battle of words is pitch emotions and he knows it. Dogmatic, about as sp:naish as a Shamrock. Such a flow For. when you get down to it. titis is may sharp, fanatical, his rasping voice at first of eloqueuee 1 -:ulti you'II soon forget that it own ternis, simply Shakespeare done in our awake you smile a bit. at these old -ball poets: all comes foam one little Irish professor, as we du things. We like to divide and analyze but as the record continues and the violence expert in Spanish culture. people and things into facets. On the stage, grows ever more. you will stop smiling and l'. S. l'ou w'on't tint at better way to discover we divvy up characters into aspects. separate begin to churn. \\'hen the side ends, chances why old Cervantes is fatuous for his Don opera too. saute idea. Saint bent. And in are you will be furiously angry. f was. Say Quixote. Self -evident. in t Inse Irish terms. Theresa I and II in "Four Saints in Three no more -judge it for yourself, but expect a Acts" of Thomson. Dr. Jekyll and Mr. Hyde. very potent sort of shock treatment. The Living Talmud -The Wisdom of the The two sisters with the same name in Kurt The other poet, Ferlinghetti, is a more \Veil's "Seven Deadly Sins"; just two aspects pleasant personality and his intentions are to Fathers and its Classical Commentaries. sauce gal. even remember such of the You'll emertain as well as to satirize -his double - Judah Goldin. Mentor 12 -A 2 things in the movies, too. takes are acid but mostly pretty sharp too. W'e're crazy for symbolism. We want our I didn't mind him a bit, nor did the Cellar This could be meaningless for -Jewish actors to represent things, to be symbolical, audience. The Cellar is at night club, by the listeners, but it Is far from it. On the con- rather than to be whole people. So -three way. trary, thought a bit more is taken for granted Hamlets. each a facet of the whole man. The jazz improvisations are a good idea than most of us can understand (ternis un- and. in fan, the whole business of combining explained, for instance), the general exposi- 780 Greenwich St., New York 14, N. Y. this sort of music- making with poetry is an tion of the shape and significance of the great

56 AUDIO DECEMBER, 1957 o...o....-M ....., _gr. ,..... ,..-....,-- _ ,,,,,-,,,,1DIIZKES OF

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For the first time, I suspect, this and a very respectable and well thought out will bring to some of us u sense of the immense pair of interpretations. importance and living force pioneer of this curious It's odd that Bernstein plugs the old- tradition -where for thousands of years, fashioned, Romantic aspect of the Firebird scholars have pored over the meaning of every music, rather than the modern side of it -as T W E E T E R S phrase of the ancient fathers' maxims-and does old Pierre Monteux in his RCA reading. pored over each word and phrase of the later Perhaps it is that Monteux, who was around help to give you real interpretations, slowly adding more and more for the premiere, still feels the revolutionary to the mass. impact of Firebird, (as of 1910), whereas PRESENCE! The selected passages are from Judah Bernstein, of a later generation, hears it Goldin's own new translation. They are given primarily as an old- fashioned, youthful piece together with a with frequency range extending up very interesting look at the by a major modern composer. Interesting. Hebrew language. as of biblical times and as to 16,000 cps. As for ltonteo and Juliet. the ultra -poetic of a thousand years later in the times of the 1870 music just isn't for our day and our commentary-especially interesting in view of orchestras; with the best will, they simply the present -day rebirth of Hebrew as a still - cannot put into it the passionate excitement, growing language. The reverse side has the the marvellous sense for poignant detail that, PT-1 sante passages read in the original Hebrew, for instance, Willem Mengelberg got out of (CONE TYPE) and though I did not understand snore than a the score many years ago. To be fair to couple of words here and there (front singing Bernstein, his version sounds less forced, more various Hebrew musical works), I listened to natural, more genuine than any modern one Popular type the very end and found the language beautiful I've lately heard. It's good, and won't likely tweeter. Covers to hear. just as sound. be better played anywhere else. 3,000 to 16,000 Schubert: Rosamunde; Serenade, Op. 135; cps without peaks Dr. Watson, Meet Sherlock Holmes; The Psalm x23, Op. 132. Diana Eustrati, alto, or dips. Driven impedance, Final Problem. (A. Conan Doyle). Sir John 8 or 16 Berlin Motet Choir, Berlin Philharmonic, ohms ; power input, 20 watts. Gielgud, Sir Ralph Richardson, Orson Fritz Lehmann. Dacca DXB 144 (2) Welles, et al. London LL 1568. Hero is another complete version of the PT-1C Capital good entertainment . . and yet. various pieces that made up the rather exten- somehow not as capital as I had expected. If sive incidental music to the play, Rosamunde. (CONE TYPE WITH you are like ate. the very first words of these plus the earlier overture that was thrown in, SIMPLE NETWORK) dramatizations will conjure up dozens and the Magic Harp, and two lovely choral pieces dozens of Sherlock Holmes shows, extending for women's voices and piano. as serials back into the dim distant past as This Rosamunde Is big anti Brahnis -like and. far as you can remember -for who hasn't thus, both highly expressive and somewhat heard for seen) Holmes and Watson on the anachronistic. Schubert was not lirahms and radio. TV. stage, or filins? This will sound not a late -Romantic composer, though unlike a new episode in an endless series. Be deniably his music was on the way, in many sure to listen again next week. same tinte same respects, towards that heavier, thicker kind station . but, of course. a A simple dividing network that is it isn't serial: of Romantic expression. Thus in this version it's a record. the tempi tend to be heavy, matched to the rather the more optimum crossover Here we have an all -star cast, two nutin serious passages taken with tremendous por- frequency is built in the unit. Covers actors with Sirs on their handles, plus the tentousness; the sighs and paintings are done 1,000 to 16,000 cps; power input, 15 inevitable villain, Orson Welles. Good, and yet to it turn and there is much high- Romantic I found the whole thing rather ponderous. swelling and ; watts ; impedance, 8 or 16 ohms. dying away the orchestra sounds almost a bit sententious, the audible staging a enormous. trace on the amateur side. Could it be that Now this contrasts nicely with the West- our own eternal Holmes on the radio moved minster version of "Rosannmde" tX VN PT-2 faster. more lightly, with more excitement 18483i -which also includes the superb vocal and an ,osier sense of detective drama? I (HORN TWEETER) numbers-in that the Westminster version think so. under the American Dean Dixon is rather on version is PT -2 is the horn type This terribly British and oddly the formal, precise side, with a certain stiff- dated. The emphasis is not so tweeter designed for much on the ness to it. and no big -Romantic sweep at all. plot -which is ageless-as on the British Yet the use in two or three way Mixon reading, done by Viennese per- amenities. the well -bred British restraint and formers, is closer to the right feeling for this system. The moving coil ul sense for what is good taste and proper early -Romantic music, even if not as musically is wound with aluminum manners. Especially in a tight spot. Never set forth as this one. wire in order to improve the response. raise the voice, what ho, always display the Romantic or no, the chorus and solo parts Frequency range, 2,200 to 16,000 cps; perfect sang -froid ! Just listen to Holmes and In this new Decca version are lovely. The power input, 20 watts above 4,000 cps; \loriarty (villain) arguing ever so politely on Berlin Motet Choir is splendidly plastic and impedance, 8 or 16 ohms. the brink of a ghastly cataract, into which expressive, both in the "Rosamunde" numbers Holmes shortly will be deposited and in the two exquisite choruses for women's Not that this isn't in the original. It is, voices and piano. Diana Eustrati is the excel- and it is both very British and very Victorian. lent alto solo in the recording. t sur blood- and -thunder stuff today is pitched Note that most versions of the "Rosamunde PT-3 on a screaming emotional plane, in compari- Incidental Music" include only the orches- son. When our characters are in desperate tral sections, leaving out the vocal numbers, (RECTANGULAR st raits. they show it : they yell, or spit gravel which are decidedly not to be missed and HORN words. or shoot their way out. Not Holmes'- - perluyts the best nmsie in the collection. TWEETER) sot Dr. \\'atson ! Now this can be made dramatic today, as it Beethoven: Piano Sonata #17 ( "The always has been. I miss the drama in this Tempest "') Chopin: Three Etudes; Ma- recording. Perhaps it is because these actors take the Holmes -Watson characters so literally zurka Op. 17, #4; Scherzo Op. 39. Dor- and so much for granted) that their dramatic othy Eustis, pf. Alta 1001 force is lost on us. We don't take that sort of This disc is thing for granted any more. put forth first of all as a technical feat of piano recording. pressed Anti as for Ilohnles' fatuous violin. he on By adoption of o rectangular horn, the Mlcrofusion and recorded without dynamic , II':mupnliI one silly little piece. unctu- plays range limitation. As such please otsly, so many times over and over it will hi -fl that I fans and those interested dispersion characteristics are extremely road(' have wrung the idiot's neck. My Dear in recording prob- Holmes. not Holt -again? lems, for it is in fact remarkably free from good. Frequency range, 1,700 to 16,000 distortions and does appear to cover the whole I No, this ICI first rate ilolnsesiana. dynamic range without too much loss in the cps; power input, 20 watts above 2,800 soft parts. I would say that the potentially 2. CLASSIC superior faithfulness of Microfusion pressing is cps; impedance, 8 or 16 ohms. fairly well put into practice. Stravinsky: Firebird Suite. As to the miking -it is not especially ef- Tchaikowsky: Romeo and Juliet. N. Y. fective; for my ear the pano is too far away, Write for catalog to somewhat thin. the sound a bit amateurish, : Philharmonic, Bernstein. like many it recording made in the home. Columbia ML 5182. Probably it is in fact a faithful job -it's just we A 5 Otowacho 6-chome, Bunkyo-ku, Tokyo that are now accustomed to hepped -up Leonard Bernstein is now eo eondtrtor of piano sound and. in fact, require it for the ELECTRIC 111i' famous orchestra and as such he is more recorded medium. I ant not one to favor FUKUIN of Irss hound to perform the major works of literal realises when recorded trickery can get t standard repertory. though his strong point the musical power over better.

58 AUDIO DECEMBER, 1957 \hiss Eustis is an excellent pianist -- thanks be. Too many such technical experiments in- PILOT volve pour musical performance! No com- plaint. except for one odd instrumental mannerism : in the recitative-like passages in and only the ISeethoven, of a sort very common in his music I the Ninth Symphony. for instance 1. she pedals the notes together into n big blur. which is disturbing to anyone who associates recitative, as Beethoven surely did. with the declaiming of sung works by a solo voice. .\ minor item, if interesting. Schumann: Dichterliebe, Op. 48. Brahms: Six Songs. Dietrich Fischer -Dieskau, PILOT bar. Jòrg Demus, pf. Decca DL 9930 The German Lied is a world to itself, "i h its own peculiar laws of intepretation- - offers you peak performance peruliar, shall we say, as our own Jazz :Ind popular music. 'these are middle and late Romantic songs, and they are of the sort that can be interpreted with an enormously wide in high fidelity at low cost variation in the actual, physical sounds pro (hived -fur there is no set key, no fixed pitch they can be transposed at will). and no special voice designated. Yet the boundaries of this great freedom are surprisingly strict. when you come down to it Fischer -I lieskau is the prize licd singer of the I;ermmn younger generation and he shows it well enough. Yet his singing is curiously TUNE RS enlike that of older Gernnuns in the tradition. both male and female. Ile sings with the intense diction that is a part of this kind of Traditional Pilot engineering and quality assure optimum music--practically spitting at you- -and is so performance. All Pilot tuners feature Beacon tuning for often missed by Aunerica n. French or English All Pilot are also fully singers. Ile ..emotes," acts, as one definitely precise station selection. tuners must in thermal. song. I But not in American shielded to conform with FCC radiation specifications. or English folk song, to cite all olgiusite ex- uuple.I lint his whole delivery and approach. bas :t utore formal aspect to it. an almost classical fervor, that is utterly unlike, say. lotte lnlunaun. Another oddity is that. in ibis day of mike technique and the oven- toii..1 crooner FA FM -AM I "ischer Dieskaa is much given to loud and -550 ,:oft extremes of volume in his singing. No Has tuned RF stage end dual cascade limi- doubt this has grown the i ,'rn1:u1 engineers ter- discriminator FM circuit for maximum a few gray hairs. but they have managed to sensitivity; - perfect quieting even with r:gdure his peal, and his valleys without fringe signals; AFC with disabling switch; distress and so all is well- except. that you 111 KC filter for AM; flywheel tuning; built - will not find this ild background music: it in FM and AM antennas. Features preamp- requires 1.111,1:1111 :nut c:vful listening, audio control with five input channels; hum - But rhea ,o does all singing of the sort. free DC on tube heater:.; tape head and phono The German I,..l was never meant ill he inputs with separate equalization; bass and rro11nwl II/ low conversation. treble controls; separate cathode follower Excellent piano cooperation from the young outputs for tape recorder and power ampli- I ietuus, who hits the fisher IIieskau stride to fier- Housed in handsome enclosure finished perfection. in brushed brass and burgundy. Dimensions: 4% "h x 14!<, "w x 10',1 "d. $159.50 Complete Brahms: Sonatas x2, Op. 100; #3, Op. 108. Mischa Elman, vi., Jos. Seiger, pf. London LL 1630 FA -540 FM -AM Ilere is a highly worthwhile record for all lias tuned RF stage for high sensitivity - of us who relish :t vertain continuity with the perfect quieting even with fringe signals; past In tilts tine day of lighting -speed change AFC with disabling switch 10KC filter for )lischa Ehnen is a great violinist of another AM; cathode follower output; phono and day and another musical era. hardly after than auxiliary inputs; flywheel tuning; built-in of ISrahms himself: l- Uni:ut nude his debut it. FM and AM antennas. Housed in handsome I7u04. Ile brings to these works a flavor, : enclosure finished in brushed brass and teeln1ique, a brace of u.a1111erisus. that though burgundy. they may startle some of us though yntng'uns, Dimensions: 4% "h x 13'w x 831 "d. they are not those of a youthful player. still $109.50 Complete h:n'e an authent ieiIr that comes forth in the listening caul makes Ilr:ihms a bigger man th:ut he might otherwise seem to the tern age. I:cen the recording is a lilt .111 f11slüoned -- FM -530 FM Only the promin.ut I.1 Violin :11111 ih. ,lichtic -l. -I Has tuned RF stage for high sensitivity 11,1: pi:110 "a crow - pa liimenL iu perfect quieting even with fringe signals;

w ..11141 h I um-i 11:1.e been rer,.rdeil i AFC with disabling switch; cathode follower heyday : \C1 nr. n.sle.l to a real 6166.. 1p ..i output: phono and auxiliary inputs; flywheel bins :11111 lo 1.111., "IT remarkably hell for a tuning; built-in enterra. Housed in hand- veteran of uu.r., th:nt fifty pe:its ou the con- some enclosure finished in brushed brass and vert stage. ..1:1v a ,light horn u. - of breath" burgundy. in his bow aria. :u. orl:u Tonal iun,curncy Dimensions: 431'h x 13"w x 8'4"d. betray this ioü_ ,t p.rilnr. iu..., 1't the nui,i is strongly $89.50 Complete and .uII 1day...I. i:nt the styli-- it is full of Ih,. .1ul bcl.. d slide ,tither, hesitations, nusv ''li.tad by 111. niud1I llinist as old fashiou,,I but played t.116.11y u:.iurallx and out of habit lire. Goo. t, fur Ihese things Make your own performance test of these tuners at your Pilot dealer. e out of Itrnluu.s' usvu hoer and snit the For complete specifications, write to Dept. AN -111 tuusic. lint lhen i-' also a not '- oo.I lark of Tung line, a stay of pushing rn,rti not, at Ili. expense of the whole melody. whirl, doesn't Pricer slightly higher west of Rockies. help Itrahu,s nm.h, even it it was rather RADIO CORP., 37 -06 36th St., Long Island City 1, N. Y. Over 38 years leadership in electronics. typical of his day. In this Instance, today's matter. We hear of three types of pipe organ plus one of the biggest and broadest of Bach long- phrased, organ -like violin playing is better today ; the "Mighty Wurlitzer" theatre organ, Preludes and Fugues, the "St. Anne" in E for the Brahms melodies. Elam is all breath, the so- called Classic or Baroque organ, small, Flat. all quiver, all for the long -haired moment. with sharp, shrill tone colors after the great If you like this, there's another, all Bach As n matter of fact, it should be quickly organ builders of the 17th century, and finally. (Overtone 13). Overtone Records, 139 Shelton added that. in this music for two equal the huge, monstrous noise-maker organ of 19th .\ve.. New Haven 11, Conn. partners, the pianist, Joseph Sieger (or is it century France, ancestor of most of our local Seiger, as on the cover ?) does a perfectly organs large and small -those that haven't Pierre Cochereau in an Organ Recital at tremendous job. If it weren't for his strong, yet been rebuilt to the Baroque style. passionate piano, Elman would indeed sound Symphony Hall, Boston. (King of Instru- This is the French organ nt its best. Its tired and elderly. Sieger is one the of best worst. in a thousand muddy, ments, Vol XII.) Aeolian Skinner ltraIsms pianists I've heard blurred examples, and it is a shame is pretty bad and you can blame that he is placed even most organ slightly in the back- roaring and ranting upon the Trench school, The first of this notable series front a major ground in this recording, in organ was favor of the indirectly. But good French organ- that's company the description and ex- bigger name. Pianists who tackle Brahms another matter. planation of organ tone by the late G. Donald would do well to listen to his leadership here, Harrison, illustrated with organ excerpts; the in this increasingly difficult music. Marcel Dupr.. of the old school, plays this succeeding volumes were of more Interest to 1862 organ with real grace and musical sense, professional organists than to the general always tailoring his tempo to the echo so that Marcel Dupré Ploys Mozart and Bach. music listener. This one would be the same, confusion is avoided. using some lovely stops except for one very interesting facet -M. Cavaillé -Coll organ, Saint -Sulpice, Paris. of a sort we wouldn't have thought available Cochereau, a brilliant young French organist, Overtone 14 on this type of reverberant monster. Ile plays here improrixes an entire symphony on the some splendid music, too, a pair of very late spot, from three themes given him just before Ilere'.s a splendid example of a vanishing and movingly expressive Mozart pieces, In- the recording. breed of organ and of organ player, for that congrouly composed for a mechanical organ. Now this is an impressive accomplishment, though I suggest not as impressive as most of us might think. Improvising, for those who have practiced It, is not so very mysterious nor does it require superhuman powers. That is, unless you improvise as Bach or Beethoven did, tremendous works or highly organized structure. We ought to remember that Im- provising in the jazz or popular idiom is with us right and left. You can't play jazz at all without some ability to go it on your own, within a given stated framework. Ask any high school jazz player or popular beginner. Moreover, an organ is a wonderful tool with which to make impressive noises- You can roar and rant, shimmer and shake, bellow forth great pedal points and glittering jewel - traceries and it can be mostly bluff. The Organ's reverberation covers a lot of sins for the casual ear and if you get stuck, you can always hold onto what you have-the organ never runs out of breath ' The Cochereau symphony, in four move- ments, is thus a brilliant job and convincing, especially as to rhythm and color -he keeps the ball rolling very nicely. But it is diffuse and thin, it doesn't go far beyond the safe things that can be done effectively. Why should it? Why? Only because this particular improvisation is down for posterity, if posterity happens to have 60 -cps a.c. and a record player. And so, like recorded jazz, it's in a way to being permanent music. But where jazz improvisation is tied down to a solid framework of background harmony or melody and so can soar, this piece Is on the loose -and it Is loose, though in no case ineptly so. As I say, it's merely a bit diffuse, full of tone colors and rhythms signifying not a great deal. Pleasantly impressive listening and the great Symphony Hall organ never sounded better.

3. CADCETIZINC Hi -Fi? An audio system is like a chain. For optimum per- Heads-Facing surfaces of head gaps Why A Narrative Adventure formance, all the links must be equally strong... lapped to an optical flatness so precise Through High Fidelity. Barbara Cameron, they reflect a single light band l' /s micron) there can be no compromise with "weak- link" com- Steve Palmer. . . . Consultant CR 102 on flatness gage. This, plus initial surface ponents in the system. polish of 6.8 micro -inches, insures sustain- This was a gimmick disc passed out at the ed frequency It was on this premise that the Ampex Al 22-SP Port- response with negligible shows this year and might not warrant change in characteristics over many thou- a mention, except that in ways It isn't half able Stereophonic System was designed. Each link in sands of hours of operation - many times bad, considering. the chain -from recording and playback heads to longer than with ordinary heads. Considering that the whole presentation speaker -was forged to the same exacting stand- fairly reeks wills opportunism, as of the Amplifier- Speakers - Ampex- design- Shows, and considering the disc Is ards and precision tolerances which guide that itself the manu- ed, Ampex -built as on integral part of sys- atrociously pressed-my copy Is both off- center facture of world- famous Ampex professional record- tem ... yet may be used separately with and badly warped. It wows unmercifully. Good ing and playback equipment. other units of your system (has front -panel tracking test for your pickup, anyhow. input switching for Tape, Tuner, TV, or \'e hear an informal discussion among three Phono). Amplifier v sensitivity 0.25 ±for maxi- people, the explaining engineer and his two mum power output; 20- 20,000 cps 1/, db pupil- friends, a man and is girl, guests for the AMPEX AUDIO. INC. output with well under i% harmonic dis- evening in his hi -fi living room. Considering 1036 KIFER ROAD. tortion. Speaker features unusually high how stilted and dogmatic such recorded ex- SUNNYVALE, CALIFORNIA total gap energy, converts a maximum of planations often are, these three speak with Please send free color brochure to: output power into sound energy, with rare informality. They talk like human beings, smooth, peak -free response. most of the time- though sometimes the script gets too cute to be carried off. NAME Write to. Complete Specifications - There are frequent musical examples, well doy for free new full -color brochure con- intended but not very well chosen for effect. ADDRESS taining complete specification sheet and The record wow messes them up in my copy. full line description of of unmounted units, Even so, their intended points do get over. A CITY consoles, modular table -tops and portables. tweeter tweets, a woofer woofs, bad needles so AUDIO DECEMBER, 1957 distort and good ones don't, ancient phono- either work. "Peter" has come a long way mostly irrelevant and in the way. graphs screech and new hi -fi sounds blare. from its earlier recorded versions, beginning Anybody ought to know, too, that It is You won't find deep or thorough explana- with the quavery. once- upon- a -thue tones of highly unwise to match up musical imitations tions here and matters of controversy or Richard Iiale with the Boston Symphony in of natural sounds with the sounds themselves. opinion are carefully avoided. But basic ideas the Thirties, through Basil Rathbun, Brandon It either kills the music -or makes the sounds are got over, the difference between component Ile Wilde, and Arthur Godfrey. Everybody, it themselves seem unreal. That's what happens and one -piece hi -fi is made quite clear (no pref- seems, gets to "Peter" sootier or later. This here, mostly. What a hideous hose -like squeal erence expressed, of course) and in the end the one is pretty blasé. "Look out," says Garry in a real elephant makes -and how odious to listener will have soaked up a beginning, at matter-of-fact tones as the wolf grabs for the put this brutal noise before the stately and least, of the hi -fi point of view. little bird, where other readers have always imaginative elephant music in the Saint - As I say, not bad under the circumstances shouted "LOOK OUT! !." It's all that way - Sains! It is lucky that a few of these sounds and you can safely give this to your Aunt just a bit on the tired side. are reasonably unobtrusive or the record would Minne for Xmas if she's not too intellectual. M. Saint- Sains' little Carnival is very im- be a real bust. The birds and the donkeys (Note: I can't figure out who the third aginatively played by the Viennese orchestra actually blend with the musical Imitations character might be. Credits on the jacket under Scherchen and by the two pianists. well enough not to hurt. (Must have taken a seem to give only two names, as above.) Josef and Greve Richter. But the final assembly whale of a lot of work to get the effect.) of the other elements makes a pretty sad The Saint -Sal us musical satire -Berlioz, hodge -podge of the affair. Mendelssolut, Offenbach themes grotesquely Sounds of Steam Railroading. This time. Garry is assisted. first, by actual and wonderfully distorted -'s of course en- O. Winston Link Railway Prods. animal sounds recorded at the zoo nod, second, tirely put aside in this zoo -ish preoccupation. by a set of inane verses. openly influenced by sure even be (58 E. 34th St. New York 16, N.Y. l'm kids would more interested If the famous lines of tgden Nash (which proba- a record were done pointing out these genuine I don't have the classic in this field, Cook's bly weren't available) and not worth a line aspects of the piece and by- passing the real, famous Rail Dynamics, to compare with this of then[. If you ever thought Nash was corny, live animals. They belong in the zoo, please, one, but I must commend the promoters of just try these For size. Not only corny but not the concert hall Æ this specialty for a good job, in their special lingo. That is -if you don't mind listening to trains and trains and more trains, if it thrills you rather than inducing yawns, then this is you disc. Hi -fi quality -yes. Let's take that for granted, with hydrofeed latheing of high quality original tupes. Moreover, the author takes photographs as well, usually simultaneously with the recordings, and they're good ones. Special feature, aside from good sound, is long -term continuity. Each episode is continued for as long as there is anything to hear; trains that roar past small -town cross- ings are preceded by minutes of local audible scenery, people talking and laughing, children and dogs, crickets. Sets the mood beautifully. This is a technique first exploited on discs by Cook and to great advantage -it is as good here. The R.R. is the last steam outfit in operation in this country, the Norfolk and Western. If you've got steam- engluitis, better rush right down there and get your tape recorder to work. Or buy this. N.B. Next issue, Mr. Link, let's have a real booklet of those superb pictures of yours. Worth extra cash.

The American Scene. A Concert of Ameri- can Band Music. Band of Her Majesty's Welsh Guards. Vox VX 25.280 What's this -a bit o' competition? Not quite, since the Welsh outfit plays our music while the Highland Scots play their own. Aside from the slight oddity of a Welsh baud playing an all- American program, this one comes off very nicely, though the program isn't my dish of Postum. It tends towards some fairly fancy stuff, ranging from semi - historical evocations (Kentucky 1800) to a definite touch of the Rhumba and the Polka, of all things. (Of all things for her Majesty's Guards to play. . . .) Band lovers will find it interesting to sense the definite but not so easily pinned down difference in playing style between these Recorder- Stereophonic Reproducer Here is o stereo system you'll be as proud to show -Two- speed, precisionbuilt tape trans- furriners and our own bands at home, in our as you will to operate. The Ampex A121 -SC Modular port, capable of ploying over 4 hours from music. A certain more fruity mellow quality, home music system was designed to satisf) not only perhaps; a sweetness and softness in contrast a single 7" reel of tope; sustained frequen cy response 16,000 the needs of the audio perfectionist, but the to our perky precision and snap ... well, let's 30- cps (7t /a ips), with also leave it to the 1'.S. bandsmen to figure that dynamic range over 55 db; Flutter and increasing desire for a system thot is as pleasing to wow under 0.25% rms of 7'a ips; Precision one out. the eyes as it is to the ears. timing accuracy affords perfection of pitch held to tolerances of less than m/s of a half The A121 -SC is an integrated system, and though any Prokofieff: Peter and the Wolf. tone at highest frequencies. of the individual units con be incorporated smoothly Saint -Sains: Carnival of the Animals, Amplifier- Speakers - Electronically into your own system, the combination of the three and acoustically matched for optimum re. Garry Moore, narrator; Philharmonic provides a level of performance not passible to Symph. of London, Rodzinski; production of stereo and monaural sound. Vienna These units deliver more undistorted sound achieve by any other means. State Opera Orch., Scherchen. Assorted per watt than the great majority of 12" animal sounds. Westminster XWN 18525 and 15" speakers available today. Envi. ronmental inverse feedback from speaker AMPEX This double concoction may amuse you for voice coil circuit to cothode of first ampli- AUDIO. INC. 1036 ROAD. awhile and the musical part is well fier stage affords improved damping, lower FIFER played SUNNYVALE, CALIFORNIA in both works, but as an ensemble job, via distortion. Tilt -out pushbutton control pan. Please free brochure tape editing, it tends towards the incongruous el for selecting input (Tape, TV, Tuner, or send color to: and tasteless, what with animal recordings, Phono); bass, treble and volume controls. verses and Garry Moore. Mr, Moore's contribution is a goodly dose Complete Specifications Information of his dry, slightly bored personality, very on the units shown above, plus consoles, modern, quite the expected and, as far as my portables, and unmounted units, available ear is concerned, not very sympathetic to in free new full -color brochure. CITY

AUDIO DECEMBER, 1957 61 for LOWEST hum...noise... microphonics éTc. in a high -p dual UD' triode ... Edward ratnall Canby

Three -Way Stereo -The Center Carrier I I

EvER OPTIMts'rlc, I originally had planned poitiolt with one of the tracks in both to get to the gist of the argument in- speakers. On "monaural," the sound volved in this series before the end of seems to narrow, and to move in and the last installment; but space didn't allow forward ; it concentrates in a smaller us to progress from Two-way to Three and space, straight between the speakers; it I left you -all high and dry (I hope), just scents to conte closer, to be deader and crazy to know how I was going to explain more confined. Switch over to stereo play- the phenomenon of three apparent tracks ing, and your sound suddenly widens, from two real ones, as per much recent broadens, and jumps awav, further back. stereo reproduction. The whole perspective is bigger. Having in the November issue gone into A good stereo sound doesn't jump too '1\ the ways of two -track stereo- farsighted far -the middle isn't broken, though it is the and nearsighted -and into the Number One stretched out, so to speak. A poor stereo Stereo Plague, doubling of the image, I splits straight down the center and the hereby continue with the tricks of the ear sound leaps aside into the two speakers, Am that can make you think you are hearing leaving a hole. perex three tracks out of two speakers. Switch back to "monaural," and it leaps forward again into the center. ECC 8 3 A PLUG -IN The Monaural Middle Now -and perhaps you already See my reasoning not REPLACEMENT FOR THE -why use this monaural 12AX7 I mentioned that there mere several ways centering effect along with the stereo to use the three -channel is pe of recording. sidewise spreading? Why not use "mon- Here is what seems to Mc to be the idea aural" and "stereo" simultaneously? MICROPHONICS: behind Mercury 's excellent and, indeed, Why not put two stereo tracks on the out- unique two -channel commercial stereo side and a third track in the center, mon- Negligible in amplifiers requiring an tapes, that do not quite sound like any- aural -style? All you have to do is to feed input voltage of at least 50 mv for an body- else's I've heard so far. Specifically, a single ( "monaural ") track equally to output of 5 watts. No special they sound like three- channel tapes, with precautions against microphonics both speakers and you'll hear it repro- niuch close -up "fi" yet astonishingly little duced exactly in the middle. necessary even though the tube Is where you would most expect doubling, it What single mounted in the near vicinity of a loud- in ordinary- two -channel recording. track? Well. of course, the speaker with 5% acoustical efficiency. middle track in a three -track stereo master. Am I suggesting that with a three - If you fed it alone to your two speakers. channel original, you can make a two- HUM AND NOISE LEVEL: dividing it in half, you would hear the channel tape sound literally like a three - sound directly between them. The same Better than -60 db relative to 50 mv channel one I am. As I figure it out, you thing will happen if you feed it along with when the grid circuit Impedance Is no actually hear that third channel, along the other two channels, mixing it into greater than 0.5 megohms (at 60 cps), with the other two. What's more, it is each of the side channels. A sort of carrier the center tap of the heater Is specifically heard in the middle, not at the system. sides. The side grounded and the cathode resistor is speakers act as joint car- Now you may doubt this at first. How riers for the middle channel. bypassed by a capacitor of can you mix two recordings into one chan- at least 100 mfd. Look at it this way-. Suppose you were to nel? But just think a moment. The best play a single (monaural) channel through feature of sound vibration is that it can two speaker systems, spaced apart on either carry any number of "separate" messages, side of you. What would be the effect? separate wave forms, and the ear can sort OTHER Amperex TUBES FOR Common enough. You can get it by them out and hear them simultaneously. HIGH FIDELITY AUDIO APPLICATIONS: playing any stereo tape with the machine There's every reason to anticipate, then, EL84/6805 9.pin power pentode; 17 W PP in the SINGLE or MONAURAL position, that your ears can hear a left channel, 6CÁ7 /EL34 High -power pentode; 100 W PP where one track is fed to both speakers. a right channel and a third channel re- EF8616267 Low noire high. s pentode You hear the sound precisely in the middle, corded in both, without any interference ECC81 /12AT7 lownoise medium -p dual triode centered exactly between the two speakers. at all. No different than hearing a multi - ECC82 /12AU7 low -noise low -µ dual triode (That is, if your speakers are phased mike pickup in standard reproduction. ECC85 /6Á08 High -A dual triode for FM tuners correctly. If the phasing is reversed, you And we can lay out the theoretical GZ34 /5ÁR4 Cathode -type rectifier; 250 ma. hear severe doubling, the sound comes "Mercury" carrier technique, as I figure EZ80 /6V4 9 -pin rectifier; cathode; 90 ma. from the two speakers individually, and it to operate. Three stereo tracks, A, B, C. EZ81 /6CA4 9 -pin rectifier; cathode; 150 ma. there is a sharp division in the middle. Divide the middle track, B, feeding it Assume, however, correct phasing.) equally to the outside tracks as though it At Alt Leading Electronic One track through two speakers (rightly were a "monaural" signal going to two Ports Distributors pleased) and you do not hear doubling. loudspeakers. Release the result of this All the sound is in the middle. In fact, in a two -track stereo recording. V it has a curious way of pushing forward, When you play it at home- Amperex LIMILLD almost out in front of the two speakers. Track A is heard through the left ELECTRONIC CORP. This is one of the odd effects you may speaker to the left of your listening 230 Duffy Ave., Hicksville, Long Island, N.Y. have noticed in switching a good two -track position. stereo tape from stereo to the monaural Track C is heard through the right

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AUDIO DECEMBER, 1957 63 speaker, to the right of your listening position. Track B is heard "monaurally" through both speakers and Therefore centers itself exactly between the speakers-where it belongs. That means that you really are hearing three separate, distinct stereo tracks, in their proper relation, via two channels. This, if I am right, is what Mercury is now doing in its Living Presence stereo tapes, from three -channel originals. There are other three -track users and I don't imply that they aren't doing similar things. I single out Mercury here because, it seems to nie. Mercury is now exploiting this particular "carrier" technique to its full implication, taking advantage of the third track quite literally, as though it actually were available in the home. Funny thing is -it is. Thus you will note that the Mercury tapes are made surprisingly close to the big orchestra, with a sharper, drier sound than in the "farsighted" type of two - channel tape. Instruments all the way across the orchestra seem to be close -up, in the hi -fi manner, and yet there is not the expected doubling at the sides. The reason must be that the middle-area close -up sounds come from that third track, in the middle, and are now beard in the middle via the "monaural" use of both speakers. If the third track is heard selectively by you just where you want it in space, does it matter how it gets there? I guarantee you, it is there! The proof of this pudding is in the hearing.

The Blimp -like Virtuoso It remains to point out another and quite different use for the center channel in three- channel master recording. Again, this one overlaps the other, but we can afford to look at it as a separate principle. INSIST ON THE ALTEC M -20 One of the biggest problems in stereo is the big -name solo performer with orchestra. Why? You ask. Just put hint on the 41 MICROPHONE I stage and let him play ; if your tape is good, he'll be just where he ought to be in SYSTE M a real concert, on the stage in front of the orchestra, somewhere near the center. 1 True, there are plenty of soloists who do, indeed, appear quite naturally in stereo in a simple and effective stage -relationship with the orchestra as a whole. One of the finest I've heard is the pianist in Rolf Liebermaun's Concerto for Jazz Band and IN CRITICAL HIGH FIDELITY recording and broadcast installations Symphony Orchestra, on RCA Victor ECS where highest quality is a "must," there is no substitute for the Altec Lansing :1. He plays over to the left side of the M -20 microphone system. Only the M -20 "Lipstik" microphone combines stage, in the orchestra, and you won't ever highest fidelity with the compact size of a lady's lipstick. The proved quality find a more natural and realistic piano. of this system is also indicated by its wide acceptance for laboratory But he's not a big name artist. acoustical measurements, and for medical and scientific uses which demand It's all very well to put a piano, or a market. solo violin or a trumpet solo, right on the the highest quality microphone on the stage with an orchestra, and it works to perfection. But what'll you do if you are 10 to 15,000 cps frequency response RCA and you have Arthur Rubinstein on 3be" long; 0.6" diameter your hands with his famous piano, or microphone, base, cable and connector Jascha Heifetz with his indomitable fiddle? weigh only 5 ounces You can't just put them down with the printed circuit between tube socket and microphone cord to minimize wiring and mere orchestral players. They must be BIG. facilitate tube replacement Why? Well, simply because we've been omnidirectional; ideal for television making them sound big and out of pro- broadcast, interviews portion for all of thirty years now (since M.20 system includes mircophone holder, electrical amplification made it possible) pocket clip, and power supply and it's no time for a sudden change. Our ears are so thoroughly accustomed A SOUND REPUTATION SECOND TO NONE to hearing every big -name solo player vastly enlarged, huge against his accom- panying orchestra, that it is unthinkable (or almost unthinkable) to relegate him one more back to a "normal" concert hall stage volume. Solo mike is a term that ALTE[ Dept. ÁJ12 is ultra- familiar to all recording celebrities. 1515 S. Manchester Blvd., Anaheim, Calif. LANCING CORPORATION (People who haven't ever been to concerts 161 Sixth Ave., New Ycrk 13, N.Y. are often horrified to find how puny a solo

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I ENCLOSE $ in full payment violin sounds when it plays naturally against a live orchestra without amplification.) And so, for an outfit like RCA Victor or, indeed, for any outfit with big soloists to record, there is a real problem -how to A GREAT TAPE RE DER blow up a soloist to the conventional huge size in a stereo recording. Yep, give him a solo mike and feed it into both stereo channels. That's how it can be done in two -channel recording and that is how it has been done. Feed a bit more on one side than the other and you'll put him slightly to one side or the other if you are lucky. - If you aren't lucky, and /or if the home listener 's set -up is punk, you '11 get doubling, and doubling on a big scale, too! I don 't know how many concerti I've already heard in which there are two soloists most of the time, one of "him" on each side. With two -track stereo recording, you must figure out the tricky balance at the recording session and get it right, then - or never. But how about that third channels Why not put your soloist, from his single close -up solo mike, right on the third channel, in the center? Then, when you come to editing and dickering, you can alter him as you wish -and choose your balance from an infinite variety of possible mixings. That is what RCA does with solo players these days, among other things. An excellent idea. In the final mixing, for two -channel commercial tape, the third channel can be added to one or both of the main stereo channels in any proportion you may wish. You can fuss as long as you want, to get the best possible blend. Now of course this middle solo channel the new imported inevitably will have a good deal of the general sound on it. How much depends on the engineers. An ultra -close solo mike doesn't really get much of any background CONTINENTAL' sound. The background level is far below NORELCO® that of the soloist, at close range, and so, in effect, it is not heard. On the other hand, if you back away a bit with your mike you'll get proportionately less solo volume the and more of the general sound. Also, the world's soloist will be less close, nearer to the general over -all sound. Move still further most and you no longer have a solo mike -the advanced middle mike joins the outside pair for an equal three -way coverage. all-in-one Thus, you see, the "RCA" technique portable (my own speculation, of course) can merge into the "Mercury" technique (again, so named by myself for convenience). There TAPE RECORDER is every degree of in- between compromise engineered by Philips of the Netherlands, you may wish ; the middle channel can contribute all solo, all -background, or any- world pioneers in electronic design thing between. precision -crafted by Dutch master technicians In terms of listening, you may place styled by the Continent's top designers your third -track soloist anywhere from an three speeds (7'/z, 334, and I7/a ips) ... twin tracks ... pushbutton -controlled inch away to a distance equal to that of special narrow -gap (0.0002 in.) magnetic head for extended frequency response the rest of the music. And you may control built -in wide -range Norelco speaker middle-track volume, too, all the way from lightweight ... easily portable ... rugged zero to extra -loud. Take the two together, can also be played through external hi -fi system straight three -track and two- tracks -with- solo, and you have a remarkably flexible For the name arrangement. It 'a not surprising that three - and address track stereo recording is going ahead fast. of Your nearest I'll have to observe, to end, that my Norelco dealer, own musical taste is against the loud, write to close -up solo in stereo -but I'll probably NORTH AMERICAN PHILIPS change. I'll get used to it, as we CO., INC. all have High Fidelity Product, long since become accustomed to big, Diri,ion blown -up solos in standard recording. 230 DUFFY AVENUE HICKSVIILE, L. I., N. Y. As of now, I find stereo a bit too realistic for these mammoth soloists of monaural tradition! For my ears, now, they seem like immense floating monsters, musical giants, that hover out somewhere in front of the obviously more distant orches-

AUDIO DECEMBER, 1957 65 tra, great musical blimps suspended in space between me and the stage. They are tangible-they can almost be touched. I prefer to imagine Mr. Heifetz and his big fiddle anchored on solid ground, where he belongs. I think the trouble is that in standard - type listening we tend to imagine ourselves down on stage, in the midst of the music, the soloist right beside us, at his solo mike. But in stereo there is too much of a real sense of space to allow this. And so we find ourselves hack in the hall -and the big, close -to soloist simply follows us right out into the air, where as I say, he hovers before us like a great blimp. Be that as it may, we'll have to concede the enormous usefulness of three -track recording from the engineering and editing viewpoint, and if it brings us three separate channels for the price of two, we ought to be able to take a few blimps and stereo pink elephants along the way.

FOAM One of the interesting developments in new materials these days is in hardened MODEL FOUR plastic or rubbery (latex) foam, which can THE be had in various almost weightless types with ex- A complete -range loudspeaker system of distinctly superior performance of rigid or flexible material, tremely useful qualities of springiness, air same time, The superiority of the KLH Model Four stems from an ex- penetrability and, at the rigidity. With such attractive features and haustive effort to bring as close to perfection as possible especially with its weightlessness, foam in- every factor affecting loudspeaker performance. evitably has found its way into loudspeaker design, where it obviously offered a fine field for exploitation. It was some years ago that Paul A. The KLH Model Four is a two -way loudspeaker system housed in a 131/2H x 25W x 12"O DeMars attached a large square of rigid cabinet. The low -frequency section is the same acoustic suspension mechanism used in foam to the front of a speaker and thereby the KLH Models Two and Three. Its very low distortion and smooth extended low - produced a new type of air piston that frequency response result in a quality of reproduction which is unique among loud- pushed a lot of area, yet weighed almost speaker systems. nothing. That was one line of thinking, given weightless rigid -type foam. The high -frequency section uses a small diameter direct radiator designed to operate Another approach makes use of more as a piston throughout most of its range. Its wide dispersion and exceptionally smooth springy light foam as a means of surround- extended frequency response immediately distinguish it as one of the very few available ing and supporting the cone of a speaker. high -frequency reproducers which fill every part of the room with sound free from With foam, it could be guessed, the cone any harshness. could move more freely in its piston -like direction, yet be held in the proper support Unequaled smoothness throughout the mid range is achieved by use of specially position. If things worked out rightly, you developed loudspeaker cones and by exceedingly careful attention to the design of a would have a very compliant system with re- cross -over network which integrates the low- and high -frequency speakers into a duced likelihood of the irritating break -ups complete -range system of such smoothness that the presence of two different speakers in the cone that are a peaty trouble in cone is undetectable. movement. The foam should have plenty of its own compliance, in responding grace- A new standard of quality control in the manufacture of loudspeakers fully yet firmly to cone excursion, and at was introduced into the industry by KLH with the production of its the same time it ought to damp out those Models One, Two, and Three. The same scrupulous care is applied running break -up vibrations that tend to be to the production of the Model Four, thus assuring the uniformly reflected back by the usual curled- trough high quality of every Model Four that leaves the KLH factory. cone edge. All in all, this surely looked like a fine idea and something to try-all that was needed was a vast amount of specific research by loudspeaker experts, into the Although the development of the Model Four involved extensive engineering size, shape, and most important, the texture measurements, a truly fine loudspeaker system cannot be adequately described and formulation of material. in terms of numbers, graphs, or other technical data. An appreciation of the The results of this sort of research are of the Model Four can really be developed only by now becoming evident. I now note two lines magnificent performance this principle, one will notice that its of speakers involving careful listening. When you do listen to the Model Four, you British and one our own, and I assume that, superiority as an instrument for reproducing music becomes especially evident patents allowing, there will he other appli- when it is compared, at the same Volume level, with any other loudspeaker system. cations of the general principle. At selected dealers. $209.00 to $231.00. Wharfedale Slightly higher in West and Far South. I haven 't heard the British version, hut I note that on current Wharfedale speakers of the several sizes there has been a wee, tiny change in the complex designation, model for model. Thus the speaker that RESEARCH AND DEVELOPMENT CORPORATION used to be the Super 12/CS /AL is now 7 called the Super 12 FS /AL. An F for a C, and the difference is a big one -for the old code meant "Cloth surround, aluminum voice coil" and the new indicates MASSACHUSETTS 30 CROSS STREET CAMBRIDGE "foam suspension . . ' Wharfedale has

AUDIO DECEMBER, 1957 66 converted from cloth to foam, and thereby hangs a small tale. Cloth surrounds, it seems, are an excellent system for producing a compliant, New ALTEC 1568A and 156944 low - resonance loudspeaker but they are not at all easy to manufacture. In fact, they are strictly a craft article, made individu- Power Amplifiers ally, piece by piece. G. A. Briggs, Wharfedale's big speaker man, told me some years ago that his famous cloth surrounds were a big headache because they were all eut by hand and the cutting was so expert that he lead only a couple of old men left who could do it right. The entire Wharfedale's line, I gathered, was dependent on the work hours of these elderly master craftsmen! Well, it looks as though the craftsmen had finally reached the end of the line. CS is now FS, the superb hand -made cloth surround is now replaced by the equally RELIABILITY superb but presumably manufacturable foam surround. Probably just came along STABILITY in the nick of time. Clearly, the reason we have never had cloth -surround speakers in any large way in the United States is SIMPLE OPERATION simply that they are by nature unadaptable to quick and efficient mass production.

Racon The new compact ALTEC LANSING 1568A and 1569A power amplifiers provide dependable economical operation for paging, music distri- In this country, Racon went to work some time ago on the possibilities of foam bution and sound reinforcement systems requiring low distortior., wide materials for a new type of woofer that frequency range and complete operational stability with any type of load. would have not heavy but relatively light The frequency response is within 5 db mid range value ï moving parts-for better transients, better of from cycle response to the damping capacities of the per second to 100 KC. new amplifiers. The first finished resulta of Outstanding features designed for fast, inexpensive installation, ease of the Racon development were written up technically in AUDIO a while back (May, operation and service include a hinged front panel on which are mounted 1956) and now there is a complete line of the power switch, fuse, pilot light and a continuously variable gait con- "Hi -C" woofer and full -range speakers trol; circuitry which is completely accessible for servicing when the front from Racon built on the Racon refinement of the foam idea. I've had one of the big panel is open; input and output terminals provided in the form of barrier - speakers in my apartment in New York type terminal blocks mounted on the rear of the chassis; and pre -wired competing unsuccessfully with a streetful 3- conductor power cord terminating in a 3 -pin of huge Diesel trucks, that out -produce it in connector. heavy bass almost any morning. Consider- Unlike most professional amplifiers, these new ALTEC uni:s are ing the disparity in size, the Racon did designed to withstand "hot switching" and other punishment which might positively nobly. The Diesels resonate at all sorts of heavy frequencies and my windows be given them in the hands of untrained operators. and Venetian blinds shake themselves to Adding to their adaptability, the 1568A and 1569A also feature a pieces with them. Racon resonates at a neat 70 volt distribution system to permit 24 cps in the 15 -inch models, yet the mov- connection to a large numter of ing structure is light and quick- acting speakers, each to operate at its own power level as required. (deliberately so, in contrast to many heavy, A unique device to protect horn loaded drivers in systems without massive woofers) and the transients come dividing networks is provided by through correspondingly clean and sharp - means of strapping which can introduce edged. selected steps of low frequency attenuation. Racon didn't stop with a mere foam Compare the unusual features of the 1568A and I569A at your edge to the cone. There aro also rigid foam dealer's. structural supports on the back of the cone You'll insist on nothing less for your installation. itself which impede break -up vibrations Specifications yet add almost no weight at all. Foam is marvellous stuff 1 And, it appears, the foam 1568A: Gain: 65 db; Power Output: 40 watts at less than 2% thd 41) to surround also acts rather curiously as a ± 20,000 cps; Frequency Response: 1 db, 5- 30,000 cps; db, 1-10C,000 viscous damping agent -not the foam it- ±4 self so much as the air which manages to cps; Input Impedance: 70,000 ohm or 30/50,125/150, 250/300, 500 '600 work its way through it, from pore to pore. ohms with 4665 Plug-in Transformer; Load Impedance: 8, 16 Viscous air, held 4, ohm + back and made "thick" volt by the stowing -down effect of the semi- 70 ungrounded. permeable foam material. 1569A: Gain: 68 db; Power Output: 80 watts at less than 2% thd 60 to Bacon's Hi -C speakers come in Twelves 20,000 cps, 80 watts at less than and Fifteens in all the usual combinations. 5% thd 40 to 20,000 cps; Frequency In Response: ±1 db, 5- the larger size there are two " three - 30,000; ±5 db, 1- 100,000 cps; Input Impedance: way " systems with dual cone plus a sepa- 70,000 ohm or 30/50, 125/150, 250/300, 500/600 ohms with rate tweeter, one dual 4665 Plug - -cone full -range model in Transformer; minus tweeter and a straight woofer job. Load Impedance: 4, 8, 16 ohm -i- 70 volt ungrounded. The twelve include a similar range, one of each type. The tweeter in this line, by the way, is ALTEC LANSING CORPORATION, Dept. A112 a cross between a compression -horn type 1515 S. Manchester Avenue, Anaheim, Calif. and a direct radiator, with a stiff paper ALTEE diaphragm in front of a compression cham- 161 Sixth Avenue, New York 13, N.Y. lwSMO COIVOI0,00 ber. Interesting idea. It sounded good to me, though my listening, in New York City, 12-rok was too much impeded by extraneous low -fl

AUDIO DECEMBER, 1957 67 interference from the city itself for me to come up with any very positive conclusions. The tweeter clearly didn't seem to have the "horny" edge that I ordinarily find ob- jectionable in many horn -type tweeters.

ENDS AND ODDS Recently I ran a trick program in my New York broadcast series in which I discussed the new electronic "tapesichord" music, then proceeded to make up a tape piece of my own, patching and copying all sorts of odds and ends that were lying around on loose bits of tape, using simple feed -back of the Ampex output into an input channel to get tape echo, whistling, screeching, coughing -I even patched in a bit of Canby talking backwards and double speed. It was fun and I called the Opus the Canby Home Tape Concerto for Odds The and Ends. Quite a dizzy piece. Well, I got reactions, both aurally and via the mail. I quote you a handful. Most cartridge of the hearers got the point -that I was being funny -and also enjoyed the serious point I was making behind it all, that however zany this stuff is, it does have poten- of tialities and it will, in all likelihood, develop into a useful and important "serious" musical technique. It has already, in many ways, of course. But boy, can taped tomorrow music be corny, especially when that old feed -back echo gets working. "Your program on tape recorded effects was hilarious. My husband and I certainly is enjoyed it. Mrs. Ralph Stots." That sort of answer made me feel that maybe my fun was other people's fun too. HERE! But another lady had a different reaction. She was so violently moved by my Tape Concerto that she wrote not one, but two postcards, mailed in the same mail. To ride in America's first jet airliner, you'll have to wait until 1959 - 1. "Can anything be worse that Me sounds we have been subjected to in but the cartridge of tomorrow can be yours today! The sensational new horrid the last half hour -1 to 1:30 o'clock ?" ESL C-Ou electrodynamic cartridge, as advanced as tomorrow's jet .3. "HORROR. Please don't do it again!!!''again! and musical as a rare Stradivarius, is now at your audio dealer's. She shall be nameless, and I trust she got over her agitation in time to get some Hear it, and you'll be astonished at the C -6o's dramatic superiority of Sunday lunch in. Sometimes I wonder reproduction quality. You'll be astonished, too, at its ruggedness in any whether I make sense. I do, evidently, to one sturdy old lady, who has written me record changer or arm. With a voltage output five times the minimum dozens of times and each letter more is German specified for the world -famed ESL Concert Series cartridge, the wonderful than the last-she born and has never quite got herself ESL C -bu will easily drive all modern preamplifiers. straight on the English language and, more especially, its punctuation. Her name is Like all fine ESL cartridges, the C -60 can greatly increase the life of your Gussie, and here is Gussie's reaction: "Even with the competition of two ex- records and styli. Write for free information on the cartridge that's years celent, varieties, from 10:30 to 1, a, head, ahead: the ESL C -Où. Better yet, make it yours today. Only $39.50. of yours, you sometimes win out on atrao- tion. "Blasting away the irresistible, and clearing up the music fog. hard for me, later, to keep, INIMAN PERE E DATA, "It was separated the facts, which of, you, said, ® Frequency response flat within 1 db 18 cps to 20,000 cps what, even you, all three, used different (Elektra 35 test record) composers to illustrate. ' Response extends beyond 30,000 cps Time, Period, Gramar, Personalities'. Minimum output 5 my at 5 cm sec In other words, Music Alive. Not only, a Minimum compliance 6.8 x 10' cm 'dyne heavenly entitety, an unexplainable charm. X,r45 Dynamic mass 1 mg This was a Creation of your own, out of IM distortion almost immeasurably small those music blends, an unforgetable ex- Vertical stylus force 2-6 gms perience, brought down to Earth." Output impedance 40 ohms at all audio frequencies Now a letter like that makes you feel No transformer nor transistor amplifier ordinarily required good! I love to think of myself as blasting Performance by load resistance unaffected away, irresistible, clearing up the music - fog. Also, the audio -fog. And as for an unforgettable experience brought down to FOR L I S T E N I N G AT ITS B E S T Earth, that's the way any composer wants to feel about his brainchild -even a tapesichord composer. Music blends and tape Electro -Sonic Laboratories, hic. blende. She really has a way with our this Guseie, and I'll be glad to Long Island N.Y. language, Dept. A 35-54 Thirty -sixth Street City 6, bring more of my creations down to Earth any day for her, if she'll just keep os writing. JE s AUDIO DECEMBER, 1957 6$ NEW LITERATURE

Belden Manufacturing Company, Chi- ene4e,ficailk cago 80, Ill., in a new electronic wire and cable catalog, announces the development of a new lightweight hi -ft pickup -arm cable. It consists of 32 -guage stranded i' copper conductors, vinyl insulated, with two conductors cabled. Belden trade number is 8430 and the cable is color -coded New listening pleasure awaits you \ with black and red. M -11 when you hear music over the 1 JansZen Electrostatic. Transient E. K. Scott, Inc., 111 Powdermill Road, response reaches a perfection i Maynard, Mass., has just released a new hitherto unknown, record scratch I hi -fl catalog which pictures and describes is reduced because it excites no the complete line of Scott components. In- audible resonancesandclartyand f cluded are three amplifiers, five tuners, a realism are maintained at all i turntable, and two power amplifiers. Along listening levels. with technical information there are \ / photographs showing Scott hi -fi equip- I ment installed in the home. Requests for Model 130 e a free copy should specify Catalog P. e K-12 --- Lafayette Radio, 165 -08 Liberty Ave., Jamaica 33, N. Y., is now mailing its 180 - page general catalog No. 305 for 1958. In JansZen addition to a complete listing of the newest high- ftdelity items of major manu- C)YNAM IC facturers, a full line of Lafayette's own amplifiers, tuners, speakers, enclosures, turntables, pickup arms, and custom hi -fl systems, in a wide range of prices, is ---- presented. Also, a large assortment of electronic parts, public -address compo- o/ nents and systems, ham equipment, tools, books, microscopes, binoculars, cameras, // and drafting equipment is offered. Cater- % ing primarily to the economy -minded I the new The JansZen Dynamic sets new hobbyist and industrial buyer, standards in cone woofers. 1968 Lafayette catalog will be mailed free upon request. M-13 Unique design concepts, combined with new materials has sel Canto Magnetic Recorded Tape, 2919 resulted inawoofer system which S. La Cienega Blvd., Culver City, Calif., can be used singly or in pairswith will mail tree a catalog listing of stereo- the JansZen Electrostatic. phonic recorded tapes. One of the most Interesting collections of stereo tape to cross this desk, the Bel Canto collection is widely diversified, including such items as "Memories of France" by the Paris Theatre Orchestra, music from the origi- l nal score of "Around the World in Eighty Model 250 measures only 18r/í" high (exclusive of legs) by 2414" wide by Days," and "Polovetsian Dances" by the The Z -200 System 14" deep Hamburg Philharmonia Orchestra. M -14

Waveforms, Inc., 333 Sixth Ave., New York 14, N. Y., has available a descriptive sheet containing complete technical data on the company's new Type 401A general purpose audio oscillator. Among the in- A complete range loudspeaker strument's features are a range of 10 cps system using the incomparable \ to 100 kc, 0.25 per cent distortion for all conditions, high output, and a flexible JansZen Electrostatic mid and high attenuator system. A newly- developed range speaker (Model 13011) with oscillator circuit permits remarkably low the new JansZen Dynamic. Here is distortion and freedom from switching a loudspeaker of nearly perfect and tuning transients. A copy of the de- naturalness incorporating the lat- scriptive sheet will be mailed upon re- est advances in the art of music / quest. M -15 reproduction. Its design simplicity / makes it suitableforusewitheither Audaz Division, Rek- O -]Int, Inc., 38-19 traditional or contemporary décor. 108th St., Corona 6S, N. Y. has recently published a revised edition of "Electronic _s i I Phono Facts," a 21 -page booklet which _____ -i answers hundreds of questions about high - fidelity sound reproduction. Written by Maximilian Weil, whose patents cover Model Z -200 measures only 32" high many of the audio industry's basic de- (including 4" legs by 2414" wide velopments, the brochure covers such by 14" deep varied subjects as stylus alignment, turntables, tone arms, and care of records. Requests for copies must be accompanied by twenty -five cents to cover cost of NOW more than ever. e e mailing. M -16

United Catalog Publishers, Inc., 60 Madi- son Ave., Hempstead, N. Y., announces Hear the Music, not the Speaker publication of the new 1958 edition of the Designed by Arthur A. Janssen Radio -Electronic Master catalog. Contain- ing 1584 pages, it is the largest catalog Write for literature and the name of your nearest dealer ever published for the electronic industry. More than 150,000 items of 350 manufacturers are included. The massive Master Products of NESHAMINY ELECTRONIC CORP., Neshaminy, Pa. catalog may be obtained from electronic Export Division: 25 Warren Street, N.Y.C. 7 Cable Simonlrice, N.Y. parts distributors. M -17

AUDIO DECEMBER, 1957 69 direction of a smaller stylus. He looks forward to the time when it might become an industry standard. Its widespread use would permit further advances at 16% rpm, but its final size and shape seems to depend upon the development of a stereo pickup. Again the question of Compatability arises, and it is likely to be an important factor in all experimental work along these lines. Some monaural cartridges already employ the % -mil size used by London in its stereo demonstration, though Fairchild is working on an elliptical stylus of the same dimensions. But both these, and other manufacturers, are aware the ideal may be found to lie somewhere between the two sizes. Prestige entered the picture late last Spring when Bob Weinstock, twenty -nine- year -old head of the jazz company, was discussing with Van Gelder its reissue program. He speculated that it might be ad- CHARLES A. ROBERTSON visable to explore the possibility of putting some of them on 16% rpm. At first, Van Gelder thought news of his work for Vox Miles Davis and the Modern Jazz Giants this fall, and experience gained since then had leaked out. He found this was not so, not an honest answer until Prestige 16-3 lias led to further improvements." but could give In his combination office and tape -editing he had permission from Vox. As Vox is not One measure of the historical importance room at Vox, where he deals with the com- in the jazz field, it was finally decided to of a jazzman is the value collectors place plications besetting a recording director, schedule first releases by both companies on alternate takes of his sessions. When Botsford played sections of both the origi- for October. separate masters were made for distribu- nal 33% rpm and the first test pressing. "I have been a collector since the age of tion to several pressing plants, some of There is no appreciable difference in sound thirteen," said Weinstock, while outlining them were assiduously tracked down and between them and, unexpectedly, the volume some of his plans, '`and my immediate compared. Except in the case of a Charlie level is the same. He stated that on most reaction to the extended playing time was Parker, where the end of a career brings it subsequent tests the volume level is higher that it would permit other collectors to out of the vaults, the use of tape makes than on the original. When asked about keep performances of their favorites in such material somewhat of a rarity. The what trials the tests might have been put the most compact space possible. And I position Miles Davis holds among modern through, he said, "No one has tried to hope it will succeed to the point where trumpeters makes a detailed study of his play one until it is worn out, but our first newer collectors will be helped in putting creative impulse desirable. And it is now pressings have been around for nearly a together a representative selection cheaply. made economically attractive by the use of year and have withstood severe treatment. Our first releases are designed with this a speed previously limited chiefly to talking Both Dr. Van Gelder and I feel that re- in mind. One, in Concorde, groups two books, permitting a total playing time of duced friction at the slower speed will en- LP's by members of the Modern Jazz 85 minutes and a program formerly con- sure them longer life. Many audio fans Quartet which still sell well at the other tained on three 10 -inch LPs, plus three are overly conscious of the weight on the speed. "Trombone by Three" with J. J. alternate takes. These are the fresh items stylus and forget that wear on the grooves Johnson, Kai Winding, and Benny Green among the reissues selected by Prestige to is caused by friction. There is also less presents them in their earliest recordings make up the four records which introduce chance of surface noise, though it shouldn 't as well as later examples of their work. jazz to 16% rpm. be noticeable now on a good pressing at Another, by the Billy Taylor Trio, is meant At the same time, Vox is making an the other speed. We have played them on for a stretch of relaxed listening as it initial release of four 12 -inch Extended various grades of equipment and the most comes as close to mood music as anything Long Plays of remastered classical items, popular record changers. Once the motors we have in the catalogue. carrying up to two hours of music on a warmed up, there was no difficulty." "As for the Miles Davis sides, I would single disc, and a "Cook's Tour" of seven " As to the future," he continued, "1 like to make it clear that the alternate countries in the popular category. Both wouldn 't want to predict anything beyond takes are not the warmup run -throughs. companies are scheduling future releases, our January releases, but there is a lot of Some labels have salvaged such material some containing previously unissued ma- room for speculation. The distributor re- from Parker sessions, but I make it a rule terial. sponse is gratifying and the dealers seem to erase all tapes the musicians would not While speculation on the development of to be happy with something to offer cus- want released. They were taped as final a stereophonic disc occupied the audio lime- tomers who ask why the fourth speed is on takes and then the musicians decided to light in months past, the two companies their turntables. Several record companies have another try at them. I had forgotten were quietly preparing to offer the public wrote for test pressings as soon as they about them until they were found in the the first music compatible to home systems heard about our venture and we intend to files with the rest of the tapes from the at the speed found on many of the newer encourage them. There is nothing about dates. They were untouched as I don't turntables. It began with a conversation in their production not available to all. Our believe in the practice of intersplicing two June, 1956, between Dr. Rudy Van Gelder, pressings are by Plastylite, while Prestige tapes to obtain the best moments on each. who does quite a bit of mastering for Vox, uses the Abbey Record Manufacturing Co. Nor do I approve of switching the order and that company's Ward Botsford, who It is not often a small company pioneers a of choruses and the other tricks of the tape tells the story: "We agreed that advances brand new product of such importance, editor. The only time I do anything along all along the line in respect to both home and industry support will help it succeed. these lines is when somebody blows an equipment and manufacturing facilities "I think the 33% rpm speed will be the ending. Then it is redone at once in the made a quality product possible at the more popular for some time to come, de- studio and spliced on later. It is not always slower speed. It was decided to go ahead pending upon the progress of the stereo- easy to switch from free improvisation to and try to cut a master to he produced by phonic dise. Eventually, many fine monaural a written ending. When I hear a track our plating and pressing companies as part performances may be preserved only on the which fades out without one, I can 't help of a regular run. Compatability was some- slower speed. Right now," Botsford calcu- wondering what happened to it. what of a watchword all the way through, lated, "I am more concerned as to the "However, Miles has approved the re- as we didn 't want an expensive oddity number of compatible turntables. When we lease of these takes and I think collectors which would not survive in competition ran the first tests, both the plating and will want them. The session with Milt with other speeds. pressing firms had older machines." Jackson and Monk took place the day be- "Not only do our test programs include Dr. Van Gelder told a similar tale of its fore Christmas and quite a few people piano concertos, among the most exacting development and also pointed out: "Now have written in asking us to reissue it. Four material to reproduce, but one side plays we have a record label which can be read extended LP's are scheduled for December sixty -five minutes. Dr. Van Gelder deserves while it is revolving on the turntable." He to feature some of the newer men such as full credit for the engineering and a test said the mastering was done on his Scully Phil Woods, Pepper Adams, Dave Amram, pressing was ready on November 25, 1956. automatic lathe and, though the grooves Idrees Sulieman, and John Jenkins. All and a It warranted planning our first releases for are cut to accommodate the 1 -mil stylus, this material is previously unissued -disc album called "East 73t The Parkway, Mamaroneck, N. Y. expressed keen interest in the trend in the proposed two AUDIO DECEMBER, 1957 70 Coast School" will now appear on a single record." INTRODUCING When asked about other plans for the slower speed, Weinstock said, " It opens lots of possibilities, but everything depends on public reaction. Moondog wants to do a reading of some of his longer works and it may well fit this speed. One reason I came into the business in 1949 was to do some of the things other companies were passing over. Some of the best moments of that period and the swing -era are lost because jam sessions were neglected. Now that they have practically disappeared from the scene, I try to recreate that atmosphere in the studio about once a month. I don't expect all of them to catch fire, but try to select musicians who will inspire each other. Often there is no other way for men of different units to get together and they really appreciate it. Everyone seems to like these dates but the critics, yet they become enthusiastic when a writer or arranger simplifies a jam session idea and works it into a score. I think even the workshop or laboratory composer will agree that jazz would soon become sterile without them. They are what I like to do most and I want to do as many as I can with men of different schools and styles." Weinstock prepares and edits tape on an Ampex stereo recorder in his office, but does most of his listening in the basement of his New Jersey home, where the most elaborate of his three rigs is kept. It consists of an Altec Voice -of- the -Theatre speaker system, Bell Amplifier, Rek -O -Kut turntable, and GE arm and cartridge. "I worry more about good sound outside the studio," he said. " When I am supervising a date, I don 't want anything to interfere with my concentration on the music and musicians. That 's why I like recording at Van Gelder 's. I know he is going to do that part of the job and it is a weight off my shoulders. My only other staff member now is Esmond Edwards, who comes along to take photographs, as I have found what the speaker that opens you do yourself is likely to be the most satisfying." The Miles Davis album is the product of a new world of sound! two recording sessions. The first was held For years, engineers have strived to achieve really BIG SPEAKER PERFORMANCE on June 29, 1954 and features Sonny Rol- lins, tenor sax ; Horace Silver, piano; Percy IN SMALL SPACE. Today, we can say it has actually been done! Because the Heath, bass; Kenny Clarke, drums. Two Audette Sr. -the newest of hi- fidelity speakers - employs all the features of systems takes of But Not For Me complete a program of Doxy, Airegin, and Oleo. many times its size! It is a two-way speaker system, with true Helmholz construction. Three members of the MJQ were present It has an extremely wide frequency range (45- 17,000 cps), and an amazing balance of at the second on December 24, 1954. They sound. Yet you were Percy Heath, Kenny Clarke, and Milt natural it gives all this in a cabinet measuring only 22" wide x 101" Jackson on vibes, in company with Theloni- deep x 27" high, including matching legs! See it today, hear it today ... you'll recog- Monk ous on piano. Alternate versions of nize it as the perfect answer problem The Man I Love and Bags' Groove are to the the hi- fidelity industry has long sought paired with Bemsha Swing and Swing to solve - BIG SPEAKER PERFORMANCE IN SMALL SPACE! Spring. As superior performances of increasing historical moment in what is Can be used singly for monaural or in pairs for Stereo Systems. likely to be their final recorded form, they should be welcomed by all collectors. For IN M MOC:wv $69.50 IN WALNUT OR BLONDE $74.50 their benefit, a short talking stretch by Miles was not deleted from the tape, as a remembrance of the time before his voice deepened. For Small Space without Sacrificing Quality That this development should emerge on the Tenth Anniversary of the long playing record is perhaps significant, for it makes inclusive use of the many advances of a decade of progress in audio. Direct comparison with an early LP is a comforting experience. With the war of the speeds behind it, the industry is aware of the need for compatability in a stereo disc and Superb two-way speaker performance able ) or place on table, bookshelf, any- cartridge. I wouldn 't want to hazard a in a cabinet that measures 11 x 23% where! Richly grained Brown or guess as to whether there ever will be a x 10. Use as a consolette (legs avail- Blonde Tan Leatherette covered case. stylus to play stereo or monaural at 334 $49.30 -(i brass legs $5.95) rpm and monaural at 16% rpm, but the prospect is enticing. I have listened to four different pressings exclusive U.S. distributors of jazz and classical music at 16% rpm 1KINGDOM y 11 PRODUCTS, Ltd. 514 Irudway, New York 12, N.T. WORTH 6 -0600

AUDIO DECEMBER, 1957 71 and many nice things can be said about them. To say they are the equal in sound to a large majority of records on dealer's //F/ti U/'12r/nrilLl# shelves might he accurate, but it would not mean too much. So far, I find a turntable without wow or rumble at 331 rpm, detectable to the ear, is not likely to de- Ot.fir.l- gol.rn%ra velop either at the slower speed. Ït is too worthwhile a step to be judged by any written recommendation, or disparaged on anybody 's sayao. Your own opinion should he formulated on the equipment in your home. No audio fan or record collector can afford to miss such an important first.

Brother John Sellers In London London LL1705 Restrictions hare made it difficult for American musicians to tour England and Im- possible for them to record with their British cousins. What can happen in the way of really inspired playing when such a fusion of forces conies about is strikingly exemplified In a dozen blues. ballads and spirituals sung by Brother John Sellers, during a London visit quality designed by GRADO this August. hacked by a sterling (undevaiu. ated) sextet of that city's jazzmen. Perhaps the most versatile of the blues artists, Sellers ranges from the sacred to the almost profane We announce with pride the development of a custom crafted and from traditional to modern blues. He is phonograph cartridge of revolutionary design ...THE GRADO accompanied only by Stan GreiR s piano on Motherless Child and House of the Rising CONSTANT IMPEDANCE MOVING COIL TRANSDUCER. Sun, and by Pia Dizley on I Want a True This unit for the first time reproduces the peerless quality of the Lover. Clarinetist Wally Fawkes and trumpeter is precision made by master watchmakers Al Fairweather amply demonstrate their ca- master tape. The Grado pabilities on all the others, with Frank to the highest electronic standards. Clarke, bass. and Tony Kinsey, drums. Greig as is admirable on Backwater Blues. Used by leading audio manufacturers and research technicians Eight of the compositions are by Sellers a laboratory standard. and he somehow managed to smuggle a tam- bourin, Into the studio to give propulsion to his dynastic Chicago Hop. England has sent Audiophile Net Price $45.00 us no better jazz. to my ears, since before the 4614 SEVENTH AVENUE BROOKLYN 20, NEW YORK War. If one lane blues singer can get such GRADO LABORATORIES results, the powers- that -be might do well to EXPORT DIV. 25 WARREN ST. NEW YORK 7, N. Y. consider what a further lifting of restrictions could accomplish. Fine sound. as is usual with this label.

Elder Charles D. Beck: Urban Holiness Service Folkways FR8901 The midnight service of The Church of God TAPE RECORDERS in Christ at Buffalo, N. Y., recorded by Wil- liam TI. Talimadge on December 30 and 31, 1956, appears here in edited form. Though AND his success as a faith healer takes him all over the country. Elder ('harles Beck Is on TAPE RECORDING home ground and leads Brothers and Sisters through gospel songs in the shouting style loved by the Holiness denominations. Said to By hare taught himself to play all musical instruments- he switches from trumpet to vibra- phone and hongo drums in Don't You See and Old Satan Away, Lord. ' Harold D. Weiler Drive / Because lie carries a large troupe on tour, '^', r Author of Elder Beck appears mostly in urban centers to it might be used in 'High Fidelity Simplified" present religious music as W EILEa Africa. One of its members. (;oldia Haynes from East St. Louis. shows a magnificent . voice on Job. and the Heavenly Cospel Singers The first complete book for the home recordist. Tells why, how, do / Knorr the Lord; He Laid His Hand On Me. Also heard are Walk in the Light, Search and what in easily understood language-not too technical, yet Me Lord, and I'm a Soldier. The hypnotic room micro- rhythms of the concluding Satisfied lasted an technically accurate. Covers sound, acoustics, hour in actual performance. The engineering phones, microphone techniques, editing and splicing, sound is of radio broadcast quality, and the record b. valuable in revealing some Afro -American effects and how to make them, maintenance, and adding sound origins of jazz. to slides and home movies. Jimmy Rushing: If This Ain't The Blues Vanguard VRS8513 RADIO MAGAZINES, INC., Book Division Not only is Jimmy Rushing one of the P. 0. Box f29, Mineola, N. Y. greatest of blues singers. but it is now pretty evident that there will never be another quite Please send me copies of Weiler's TAPE RECORDERS AND TAPE RE- like him. This Is a record to be treasured it is not CORDING. I enclose check° money order D. Paper cover, $2.95. and described in superlatives, for likely the circumstances which produced this fifty- four -year -young projector of the bare Naue sentiments and steady pulse of the blues will be repeated ever. Ile Is a most significant Address figure in a transition period which saw the transformation of the country blues into the modern blues. His style combines rare inven- Clio Zone Sato tiveness with the earthy strength of the

72 AUDIO DECEMBER, 1957 former, while avoiding the complexities of the latter, or the banalities of rock and roll. All jazzmen must retrace. sooner or later, his 1 course which begins at the life- giving roots ALLIED'S OWN knight® HI -FI COMPONENTS and draws unceasingly from them. Of the eight numbers, five are basic blues, 6- MONEY -SAVING HI -FI COMPARABLE TO THE FINEST while Dinah Pennies from Heaven are and LI swing classics made his by adoption. Oh Love Olí * Advanced Design, Performance and Styling is typical of the Kansas City style and the Outstanding For Superior Musical Quality absorption of blues into other forms. Rushing's * own tune, Sometimes I Think I Do, along with * You Get the Very Finest For Less his delivery of My Friend Mr. Blues, I Can't * Each Unit Guaranteed For One Full Year Understand, and Take Me With You, Baby, explain from whence his reputation arises. The splendid octet enlisted in his support could only have been chosen by John Ham- mond, who reaches up his sleeve to produce a EASY TERMS fine guitarist in Roy Gaines. His every chorus AVAILABLE is worthy of study, as is the work of Emmett Berry, trumpet; Vic Dickenson, trombone; Buddy Tate, tenor sax; Clarence Johnson. piano; Aaron Bell, bass; Jo Jones, drums. Adding an electronic organ, played by Marlowe Morris, to this complement, would be to court disaster at the hands of less accomplished engineers. Besides, there is enough of the vox HUMANA stop in the Rushing voice to make it hardly necessary. But it might be interesting Model $9950 to hear him with the organ alone. KN -110 77 only $9 95 down Wilbur De Paris: Jimmy Witherspoon Sings New Orleans Blues Atlantic 1266 KN -110 FM Features: NEW knight Deluxe -AM Tuner A singer with several hits in the rhythm Equal to the finest, yet far lower in cost. Features and blues field is promoted to the company of 2''/, Ay FM Sensitivity remarkable sensitivity -2 microvolts for 20 db of the Wilbur De Parts band on ten numbers, Dual Limiters quieting on FM, 5 microvolts for 1.5 volt output on none of which New AM. Supplied with FM folded dipole antenna. Deluxe can be called Orleans blues. RF on FM and AM Jimmy Witherspoon sings well in a strong. Stage features: Separate RF stages on FM and AM for extra Tuning Meter for FM and AM sensitivity; FM discriminator with dual limiters; cath- polished voice on traditional tunes and two ode follower with 2 outputs; AFC on FM, tuning meter modern blues of his own composition, aided AFC "Lock -in" FM Tuning and flywheel mechanism for effortless tuning; 10 kc by the clarinet obbligatos of Omer Simeon. Flywheel Tuning Mechanism whistle filter on AM; rotatable AM Ioolstick antenna; Unfortunately, the echo- chambered recording U.1,. Approved. Handsome teat her -tone case. 4 x 13 I¢ x Tape Output Jack I0". Shpg. wt.. 17 lbs. technique, usually reserved by this label for 59950 its rock -and -roll clientele, is employed. As an Illuminated Slide -Rule Dial Model KN -110. Net. F.O.I1. Chicago, only effort to broaden the popularity of De Paris, it might be laudable, but it prevents the band from ever sounding as though it is together with the singer and will hardly please its NEW Deluxe 30 -Watt Hi -Fi Amplifier usual audience. knight Model KN -530 Rumble and Scratch Filters Buck Clayton: Buckin' The Blues "A-B" Speaker Switch Vanguard VRS8514 $9450 Variable Loudness Control Only down DC on Filaments of Preamp When Buck Clayton first put his rumpet on $9.45 Tubes record more than twenty years ago. his highly More output, more features, more style for your money. vocal way of playing, based in the tradition of Response, ± 0.5 db, 20- 4(1,000 elm. Harmonic distor- the great Joe Smith, was a fully formed image tion at rated output, 0.5'; at mid -frequencies -never exceeds 1.5' ; f 30-20,000 cps. Additional features: a inputs for allsignal sources; of consummate good taste and intense per- full eq uaiiza tiun for all records; separate Bass and Treble controls; variable damp- sonal statement. It has not changed in sub- ing. Leather -t"ned ease, only 4 x 15th x II". Shpg. wt.. 311 Ile. f9450 stance since then, though it has broadened Model KN -530. Net, F.O.R. Chicago, only with the absorption of as carefully- sifted ideas. More recently, due to the increasing demand on his services to direct recorded jam SELECT FROM A COMPLETE LINE OF MONET- SAVING knight 111 -FI COMPONENTS sessions, it has taken on more of the driving force required of a leader. Though this album is devoted to the blues, they are present in such variety that the Clayton horn shines in 09 4QpOO several tempos and assorted moods. Featured with the Benny Goodman Orches- Irelu.e I ht AM 30 wau aewre 59450 IS Watt -Bantam" 56450 "bantam" (M -SM $7450 Hi r rpnrr 19950 Hi .I r Anrulluer i tra and Sextet when the recording was made Ni-I Ampliher Hide Tuner in March, 1957, Clayton brought along another member, the brilliant new guitarist Kenny Burrell. and pianist (lank Jones. Earle Warren on alto sax, trombonist Vic Dickenson and e e" pOO,Q_ drummer Jo Jones are all companions from C his days with Count Basle. Aaron Bell was ',fl Wnit $4Y95 IMAM Slereo. 57950 ..,,im li" L Wall 51195t Tuner 513950 called in to replace the ailing Walter Page on )' Havr runer Monaural Ili I Amnlher Ni I i Am,rnlinr 14 Mess rase rrearnpllr,r bass. Aunpldier I'reamplilier

All his originals, Buck Hackles and Clay - Soo our l956 Catalog for full details tenia are mellow -textured items taken at a 4 medium pace and the tempo increases on Cool Too and The Queen's Express. Even that ALLIED RADIO modernist Hank Jones seems to enjoy himself wbtLCae 1ií: 0.43Á. on Bailin' the Jack and Squeeze Jle. as Clayton a ft our drops in an Armstrong touch. is 37th Ile supreme 404 -PAGE ALLIED RADIO, Dept. 17 -M7 on Good Morning Blues. and his Blues Blasé 100 N. Western Ave., Chicago 80, III. year is a finely conceived showcase for trumpet 1958 alone, said to be his first recording of a com- Ship the following KNIGHT Hi -Fi Components: plete solo number. Wonderful balance is kept ALLIED throughout the recording to continue the high CATALOG f enclosed standard set on this series. Your Buying Send FREE Ittn A1.I.I1:1) 4u4 -Page (':,ttlog Webster Young: For Lady Guide to the Prestige LP7106 world's largest selection of Hi -Fi com- Name ponents, complete This is such 'music systems, a good idea that the wonder recorders, Public Is why it was never done before. It most cer- Address Equipment Address tainly will be repeated among the sheaf of -as well as Everything in Electronics. releases to accompany the completion of the Send for your FREE copy today. Cdy Ton, Sint. autobiographical film on Billie Holiday. A J AUDIO DECEMBER, 1957 73 choice sextet of instrumentalists express their admiration for the singer on five numbers she has made pretty much her own. and pay re- flective tribute in The Lady, a dedicatory piece by cornetist Webster Young. A disciple of Miles Davis and new arrival on the scene, he CJapJÌwIjeOkil:/ exhibits at twenty -five a good command of his instrument in a tantalizing likeness of the Holiday vocal style. r.. Arrangements by Mal Waldron, her present pianist, deliver the message of God Bless the Child and the soul -tearing story of Strange THE PERFECT Fruit. Paul Quinichette, tenor sax, relenting

t ITAPE in his determination not to resemble Lester INDEXING SYSTEM Young too closely. matches the style which \ 1 accompanied her so often. before having his own say. The musicians also know and love Simple Good Morning Heartache and Don't Explain, and give long-awaited instrumental expression k /l ,gyulllrru, .SVOOJ yv, to them in this excellent recording. Earl May, Accurate li. bass. and Ed Thigpen, drums, are from the , Billy Taylor Trio. There is a tendency nowa- d` days to emphasize the sad and somber theme Economical capeg" of the Holiday career. Guitarist Joe Puma , helps recall her lighter and swinging side on Hamlin' Lou. If it prompts someone to en- gage Buck Clayton for a similar treatment of her earlier tunes, this album, already doubly /II welcome for Webster Young. will more than pay its dues.

The Stylings Of Silver Blue Note 1562 iodic your recorded tape The non who Is doing the most to extend accurately -and as easily as the of the jazz piano is you apply a postage stamp. boundaries Horace Index as many as five reels with Silver. He could safely rest on his laurels for 6 tabs each for only $1.00. the balance of his career, for lie has reached Companion product to Tape Indic, the point where he is being showered with 'Perma-File" to identify credits for accomplishments not entirely his. your tabs and catalog But such !decency is not in the Silver your titles only $1.00. makeup, and his restless imagination is con stantly exploring new horizons. As the leader of his own quintet. he is able to write originals for it which make it an extension of his own creative channels. It has. in consequence, a cohesion of thought and a wholeness of expression all too rare in such units. 520 Fifth Ave., New York 36, N. Y. It is with this spirit of muscular sureness that it moves through this album, which finds Silver at his most earthy in five originals. On The Rack Beat, he is rhythmically adventur- ous, and Aletamorphosis involves a beguine. No Sookin'. Sosh'ille and Home Cookin' are accurately descriptive titles. The melody is played in octaves on the ballad Mg One and Zeal, Only Lore, and the piano blends well with the horns in the recording. Hank Mobley, ABOUT tenor sax, is always at his best with Silver. REVISED EDITION AVAILABLE and Art Farmer, trumpet. is in good form. Teddy Kotick, bass. and the excellent young December 1, 1957 drummer. Louis Hayes, complete the rhythm section.

Max Roach: Jazz In 3á Time EmArcy MG36108 ELECTRONIC Kenny Dorham: Jazz Contrasts Riverside RLP12 -239

Of the modern groups which exercise a MUSICAL prerogative to deal freely with established ballads, or create fresh material in their image, the musicians gathered about Max Roach have always been most successful in INSTRUMENTS mating absolute jazz values to popular forms. 1Vhether this is due to the skill and taste of the drummer, the way Sonny Rollins. tenor By Richard H. Dorf sax. can take tune apart, or the ability of 'AUDIO Library - Vol. I trumpeter Kenny Dorham to play intelligently at slow or rapid tempo is not of moment here, as all three are present on both discs. Up -to -date information about Perhaps due to the acclaim which greeted Rollins' l'aine Hot, with its Noel Coward SCHOBER $7.50 quotes. Mercury's Bob Schad asked Roach to put his ingenuity to the test of this tempo CONN Postpaid and discover what could be done to finish out MINSHALL an LI'. Roach added his tightly -woven Rluea THOMAS Waltz and n lilting Little Folks. The others are the evergreens I'll Take Romance. Lover, KINSMAN and The .Host Itenutijul Girl in the World, ORGAN TUNING all of which began their careers as waltzes. In showcasing the Dorham trumpet. River- Customary discounts to dealers and distributors side aims at the contrast of a quiet mood and a more intense expression of the same feeling. If you missed the first edition, you're sure to want this new and revised second Harpist Betty Glamman is added on Rut Oryce edition. And even if you have the first edition you are sure to want the latest Beautiful and the Mai arrangements of Larne and My Old Flame. Dorham sets the the newest instruments. Order direct, Dept. E2, Radio Magazines, information bout pace on Falling in Love with Love, PH Re- Inc., Mineola, N. Y. member April, and his original La Villa, aided by pianist Hank Jones and Oscar Petti-

74 AUDIO DECEMBER, 1957 ford. bass. Roth recordings are good and your choice Iles between the ballad or waltz.

A Night At The Five Spot Signal S1204 To record a jam session in memory of Charlie Parker before a live audience might seem a happy thought, but its success entails careful planning and no little luck. The room selected is one of New York's newest clubs devoted to Jazz. the Five Spot Cafe on the outskirts of Greenwich Village. It encourages a respectful audience and boasted a new Steinway when Rudy Van !:elder moved his recording equipment in one Monday night last August. Don Schlitten, Jules Colomby and Harold Goldberg of Signal picked Cecil Payne. baritone sax. to head a sextet of Phil Woods. alto sax. chosen for his devotion to the Parker

idiom : Frank Socolow, tenor sax ; Duke

Jordan. plano ; Wendell Marshall, bass; Art Taylor. drums. The compositions by Parker had been recorded by him in different periods of his career. Steeplechase is his well -known conception nt / Got Rhythm. and Scrapple from the Apple presents his thoughts on Honeysuckle Rose. Parker's Mood and Buzzy are also heard at length. When the session began with a warmup set at nine o'clock. the time for planning was over. What went on the tape could be a pale imitation, a carbon copy or a fitting tribute. Thanks to the sharply contrasting reeds and the ready rhythm section, the result is a record packed with emotion and New! And the Best Yet! Inspired playing. The sound is excellent for an on- the -spot production and the crowd not too distracting. When the equipment was hauled away at 2 a.m., the era of Parker had been recreated. THE FABULOUS

The Bud Shank Quartet Pacific Jazz PJ1230 A flutist of unfaltering lyricism and beauty, Bud Shank carries the same qualities to his playing of the alto sax in a pleasantly varied program. ranging from a dewy Softly, as in a Morning Sunrise to the fervently swinging FISHER Jive at Fire and Night in Tunisia. A balladic treatment is given Polka Dots and Moonbeams. and All of You is begun as a ballad by the flute. before rising to medium tempo. [laude Williamson, featured on piano and celeste, conducts a few experiments in the blues during his three -part suite Tertia, and his rapid 90-T Theme. Ile feels the blues most thoroughly in the uptempo moments, but borrows on Ravel for a pensive introduction to Lamp /s Low. Don Prell on bass and drummer Chuck Flores FM -AM TUNER do well In solo and rhythmic passages. It is gratuate work by members of the West Coast school in a fine recording. ELEVEN momentous features now available for the first Kenny Drew: This Is New time -plus TWENTY other terrific features. The 90 -T Riverside RLP12 -236 reflects engineering excellence without equal. It incorpo- An aptly titled album brings Kenny Drew rates the celebrated FISHER GOLD CASCODE RF ampli- into the studio in a quartet, featuring trum- fier and widest -band circuitry, to provide astonishing one- peter Donald Byrd on four numbers. which is expanded to a quintet by the addition of microvolt FM sensitivity. The new FISHER MICROBEAM Hank Mobley, tenor sax, on three others. One TUNING INDICATOR i5 more accurate on weak signals most promising pianists, Drew of the younger than conventional meters or tuning eyes. At fingertip- has been overshadowed during much of his career by Horace Silver. whose footsteps he touch, the exclusive, three-position FISHER PUSH- has followed with growing individuality. BUTTON FM MUTING /AM BANDWIDTH SELECTOR elim- though he was born a month earlier in 1928. Both have the sane sound background and inates FM inter-station noise, and assures maximum AM technical skill, but now seem bent on diver- reception with minimum interference. The Audio Control gent paths. Silver is becoming more preoc- a new PRESENCE CONTROL and three - cupied with complex rhythm and Latin beats, Center includes while Drew turns here to the show tune in position, sharp-cut -off NOISE and RUMBLE FILTERS. You're My Thrill, It's You or \'o One, Why Incomparable in performance and appearance. THE De / Lore You, and the title tune. Also In this direction is his melodic original Carol. an FISHER Model 90 -T will meet the critical requirements emotionally moving indication of his maturing of even the most particular professional. talent. Byrd contributes Little T, while Wilbur $23950 Ware. bass. and G. T. Hogan, drums, are Mahogany or Blonde Cabinet, $19.95 rhythmically agile in uptenspo numbers such as Rollins' Paul's Pal. WRITE TODAY FOR COMPLETE SPECIFICATIONS Randy Weston: Jazz a la Bohemia r FISHER RADIO CORPORATION Riverside RLP12 -232 FISHER RADIO CORP. 21 -29 44th Drive L. I. City 1, N. Y. To realize the advantages and disadvan- 21 -29 DRIVE Please send specifications of THE FISHER 90.T tages of a live performance in a club, it is 44th only necessary to compare the piano of Randy LONG ISLAND CITY 1, N. Y. Name Weston in this on- the -spot session at the Cafe Bohemia. last October. with some of his studio AddreN work. It contains some of the most inspired ,11la1I1111I11111111111111111111111111111111111111111t1i. -J

AUDIO DECEMBER, 1957 75 choruses be has yet recorded. In the balance. there are a few make- weight choruses which would not be carried over into the studio. The engineering by Ray Fowler favors the NEW... by sound. CRAY it a pleasant piano, and the room gives When Cecil Paynes joins the trio on baritone sax, the balance is not as good. You Go to My Head and It's All Right With Me are by the trio alone, with Ahmed Abdul-Malik, base, and Al Dreares, drums. Weston includes his Chessman's Delight, Hold 'Em Joe, and a ro- bust reading of Sid Catlett's Just a ¡tiff.

Duke Ellington: Such Sweet Thunder Columbia CL1033 That Shakespeare should serve as the basis DUAL viscous - damping of a jazz suite by Duke Ellington is appropriate as both possess the same ageless quality and a parallel might be drawn between their respective positions in jazz and litera- DUAL Viscous- Damping and complete static balance around the ture. A prelude by the band on the title theme introduces eleven vignettes to feature its solo- vertical pivot GUARANTEES maximum tracking stability -pro- ists on some of the best writing the com- duces fuller, rounder, more natural sound reproduction. poser has done in years. When conveyed by his strongest instrumentalists such as Harry Carney, Johnny Hodges, Quentin Jackson. and FEATURES FOR THE HI -Fl PERFECTIONIST Clark Terry, they are most successful. Most weak are a violin -clarinet duet and a bass though Cat Anderson, cast as a dis- Seated viscous- damping on BOTH Cartridge slide plugs in interlude. Hamlet, plays surprisingly tasteful vertical and horizontal pivots traught Stylus force adjustable -eliminates trumpet. Ellington has scope, wit and logic, '' Up to 12 inch records cartridge weights regardless of any new insight into Shakes- peare. and can turn to Proust for inspiration. '« Can be used with ALL popular Only $34.00 -for any budget where I'm concerned, if similar results are cartridges assured. Get yours today at your local weight High Fidelity dealer, or write for Ni Counter-balance perma- Leith Stevens: The James Dean Story complete details on ALL features. nently adjusted at factory Capitol W881, World Pacific P2005 Despite Hollywood's willingness to pay well for movie scores, the very nature of the me- THE GRAY MANUFACTURING COMPANY dium usually defeats the best efforts of composers to maintain a high creative level. Be- 18 ARBOR ST., HARTFORD, CONN. cause original passages must be followed by barren patches or bombastic interludes, a film track is often robbed of sustained interest. A solution to the problem may well be Circle 76A in these two albums of a score by Leith Stevens. who was known to musicians as a workmanlike arranger and underrated composer in New York broadcasting studios nearly two decades ago. Since then he has gained no little reputation as a writer for movies, and the film score on Capitol displays an orches- trator's knack for making the patches less bare and the Interludes more restrained. On World Pacific, the new naine for Rich- ard Bock's Pacific Jazz in its expansion to other fields, Stevens worked with arrangers Johnny Mandel and Bill Holman to strip the score of nonessentials and frame its nine themes to fit a fourteen -piece orchestra of contemporary jazzmen. There is an abundance of space for urbane solos by Bud Shank and Chet Baker, whose trumpet has never seemed more beautifully poised, and an eloquent performance shows the most inventive and moving portions of Stevens' work at length. Mike High Fidelity speakers Pacheco plays bongos and Claude Williamson need not and should not be is pianist. Included In both well -recorded albums is the Jay Livingston and Ray Evans complicated. They must, how- ballad Let Me Be Loved. ever, be designed as complete systems Johnny Richards: Wide Range including the enclosure rather than be a Capitol T885 collection of individual units and cross -over Les Brown: Composer's Holiday networks, with the increased possibility of error Capitol T886 BASIC and the lack of necessary equipment for tests In the program launched this fall by Cap- itol to return big bands to favor. two albums SPECIFICATION in the home when finally assembled. hold more than ordinary interest for original obtain a motor -car by buying the composition. Johnny Richards, who most re- 12" and IS" models Few people would cently worked with Stan Kenton. has assem- engine, chassis, body etc. and assembling it at bled much the same type of band from se- Frequency response lected sidemen in a move to the East Coast. home. They would rightly regard this as a job for 30- 20.000 c.p. 3dB. His writing favors the big sound, with tym- expert engineers -and so with loudspeakers, where pani and large sections. and is leavened by Polar Distribution for the playing of Gene Quill, alto sax. on Tappan naturalness not novelty is the desired result. Zee, and trombonist Jimmy Cleveland on Cim- 60° inc. angle -9dB. arron. at 10.000 c.p.s. A lively holdover frosts the swing era, the DUAL Les Brown band is noted for its danceable Intermodtdation tempos, and the leader called on Hollywood Products CONCENTRIC composers Andre Previn, George Dunning, less than 2% Frank Comstock, Marty l'alch and Dominick SPEAKERS Frontiere for fresh material. Most tuneful are Tropics at Five and Alfred LTD. 38 PEARL STREET. NEW YORK. 4, N.Y., U.S.A. Elmer Bernstein's TANNOY (AMERICA) -perfumed Park Avenue Es- LTD. 36 WELLINGTON STREET EAST. TORONTO 1. ONTARIO. CANADA Newman's highly TANNOY (CANADA) capade. Most suited to the band are the Clrela 2A AUDIO DECEMBER, 1957 76 Brown trombonist Jim Hill's Bone Voyage and Apple Valley, and trumpeter Wes Hen - sel's Especially for Two is a joyous flag- waver. Capitol knows how to engineer big bands and they are back, at least on records.

Curtis Fuller: The Opener Blue Note 1567 Excerpts from PRESS COMMENT on the The latest graduate from the school of young midwest jazzmen centered In Detroit to arrive on the larger scene is Curtis Fuller, at twenty -three a full -toned modern trombonist, who is given a chance to show his wares on both a slow and fast blues of his own. Also the ballad Here's to My Lady, boon, and a swinging Lovely Way to Spend an Eve- ning. He acknowledges his debt to his mentor J. J. Johnson in Oscalypso. Naturally force- ful, though still raw in conception, his style is not beaten into the glassy cascade of notes favored by some technicians. Already well - grounded on his instrument, with greater shading and a tight grip on what is his own. be can go far. Hank Mobley, tenor sax, with pianist Bobby Timmons, bassist Paul Cham- bers and drummer Art Raylor, makes his introduelion pleasant.

Jimmy Smith: Plays Pretty Just For You High i (f.rstr.d ht the Now) Blue Note 1563 Jillel iy In relation to other discs at the Hammond .. With the (tweeter) control set to suit my taste (best described as rowM- oriented), organ by Jimmy Smith, this can only be oscillator tests indicated that bass was smooth and very clean to below 40 cycles, was audibly called a mood album. But in relation to the enfeebled but still there at 35, and dropped out somewhere around 30 cycles. No doubling work of other jazz organists, It is in a class was audible at any frequency. with the all- too -few organ solos recorded by From 1,000 to 4,000 cycles there was a slight, broad dip in the response (averaging perhaps Fats Waller, whose Jitterbug Waltz occupies 2 db down), a gradual rise to original level at 8,000 cycles, and some minor discontinuities a place of honor beside East of the Sun and from there out to 12,000 cycles. Then there was a slow droop to 14,000 cycles, with rapid The Nearness of You. With his new guitarist Eddie McFadden and drummer Donald Bailey, cutoff above that. he runs through Autumn in New York, Pent- Because of its slightly depressed 'presence' range, the AR-2 has what is to me a refreshingly house Serenade, Old Devil Moon, I Can't Get sweet, smooth, and highly listenable sound. Music is reproduced transparently, and with very Started, and The Very Thought of You. Like good detail. Its high end is unobtrusive, but its ability to reproduce the guttiness of string Waller, he places his own stamp on every- tone and the tearing transients of a trumpet indicate that it is, indeed, contributing highs when thing he does. In this case, it is a relaxed needed. This, I feel, is as it should be. melodic one in fine sound. Its low end is remarkably clean and, like the AR -I, prompts disbelief that such deep bass could emanate from such a small box. Leon Berry: Giant Wurlitzer Pipe Organ, .. Like the AR.1, the AR -2 should be purely on its sonic merits ... not on the theo- Vol. 2 Audio Fidelity AFLP1829 judged retical basis of its 'restrictive' cabinet size. When so judged, it can stand comparison with In the first volume of this series, Leon many speakers of considerably greater dimension and price.- 1.G.H." Berry engaged in a pyrotechnical display of some of the more dramatic aspects of the theater organ located in Chicago's Hub Rink. As though to prove it has another side, he now subdues It with the melodic and moody playing of quiet tunes. Of a dozen numbers, only a rousing College Medley and Tango of the Drums disturb the comparative calm. But there is no lack of material to demonstrate instrumental effects on Syncopated Clock, I Hear You Knocking, and Three O'Clock in the Morning. And they remain in balance at low volume in this close, well -defined recording. Included are such favorites as Squeeze Me, Louise, Night Wind, No Other Love, and Boulevard of Broken Dreams.

The Story Of Moondog Prestige LP7099 The third installment of the Moondog story finds him busy with further experiments in rhythm on instruments of his own design. Some are carried out against a background of the roar of Broadway in his impressions of Birdland and the Palladium. Drummer Sam Ulano helps describe the jazz emporium in a 1/4 time dog trot. Moving a block North to detail Afro-Cuban rhythms, he is aided by Suzuko on the Yukh, a log suspended from AUDIO a tripod and hit with two rubber mallets held -T-'-, In the right hand. Ray Malone joins him for .. I find the AR-2 remarkably like the AR1 in over -all sound coloration. Its cone tweeter a softshoe dance in 5/4 and 7/4 time. Is not the same, but there isn't much difference in sound. (It costs less, but that doesn't Other of his inventions are the Oo and prove much.) On direct comparison, given a signal with plenty of bass component in the very Tuji, and he set plays his last of square drums bottom, you can tell the difference between the two in bass response. Most of the time, in made before shifting to the triangular- shaped ordinary listening, I am not aware of it at all. Trimba. A piano improvisation, organ solo and his howling wolf thence are also en- ... I find AR.2, as with AR -1, remarkably clean and unobtrusive in its sound, easy on the graved for posterity. Moondog likes to record ears for long- period listening, easy also to ignore in favor of the music itself. Either speaker when and where the mood strikes, so the has a way of simply fading into the surroundings (the We helps) leaving the music unattached quality of the fourteen tracks is variable. and disembodied in the room. Excellent illusion!..." Most apropos is the cover design by Reid Miles, with its artful use of calligraphy by Prices for Acoustic Research speaker Systems, complete with cabinets, (AR -1 and AR -2) are Andy Worhol's mother. That she also signs all his drawings makes her signature better $99.00 to $194.00. Size is "bookshelf." Literature is available from your local sound equipment known to Madison Avenue than Broadway, dealer, or on request from but it is a match for the "secret music" of Moondog. ACOUSTIC RESEARCH, INC . 24 Thorndike St., Cambridge 41, Mass.

AUDIO DECEMBER, 1957 77 NEW PRODUCTS

British AM PM SW Tuner. Now avail- lustrated, employs a single AccuSonic able in the l'... for the first time, the woofer with matching tweeter to obtain British -made Chapman Model S -52 "Globe - a smooth frequency response from 45 to master" high -fidelity tuner provides good 16,000 cps. Cabinets are made from % -in. sensitivity and selectivity with drift -free furniture plywood throughout with hand - tuning on standard FM and AM broadcast rubbed finishes. Descriptive sheets will bands, as well as short -wave bands of 90- be mailed on request. Write: United 250, 35-100, and 12.5 -37 meters. All AM Speaker Systems, 34 New St., Newark 2, Lands use a tuned -r.f. amplifier, a triode/ N. J. X-5 hexode frequency changer and a high -gain 470 -kc i.f. amplifier. Sensitivity is better Plastic Taps Container. A new perma- than 8 microvolts for a 20 -db signal -to- nent plastic package for its line of Sono - noise ratio. The FM scetion of the Chap- ramie recording tapes has recently been man employs two I f. stages. The second introduced by Ferrodynamics Corporation. serves as a high -level limiter and Lodi, N. J. The Sonoramic is a stage has provisions for multiplex reception so container that it will be able to handle any future type of stereo broadcasting. For a complete descriptive bulletin on the new Model 330 stereo tuner write: H. H. Scott, Inc., Department P, Ill Powdermill Road, Maynard, Mass. X-3 High- Output Miniature Pentode. Devel- oped primarily for use as a class B power amplifier in hi -fi equipment with over 20- watt power rating, the new Amperex Type 6BQ5A delivers 24 watts with only 4.0

shatter -proof high-impact polystyrene is followed by a high- quality wideband box with a hinged front that snaps open ratio detector. Sensitivity is better than the flick of a finger, pushing the reel 4 microvolts for 20 db quieting at 22.5 kc at deviation. Remarkably small considering forward for easy access. The box closes its many functions, the tuner measures tightly to protect tape against dust and 12" w x 9'4" d x 7ÿi" h. The Globemaster dirt. Pressure -sensitive index labels are is manufactured by C. T. Chapman Re- provided with each container to permit producers. Ltd., High Wycombe, Bucks., the user to identify recorded tapes. M - England, and is distributed in the U.S. by Ercona Corp., 551 Fifth Ave., New York Small P. A. Amplifier. A 20 -watt tran- 17, N. Y. X-1 sistorized plug -in amplifier for p.a. systems, which replaces comparable unite more than eight times its size, is now be- Stromberg- Carlson PM -AM Tuner. Re- cently added to Stromberg- Carlson's "Cus- tom Four Hundred" line of high -fidelity components, the Model 403B tuner has a frequency response of 30 to 15,000 cps with less than 1.0 per cent total harmonic distortion. Sensitivity is 3.0 microvolts per cent distortion. It is one of the new Amperex series of "preferred" types for high -quality audio applications. Detailed data and applications engineering information are available from Special Pur- pose Tube Division, Amperex Electronic Corp., 230 Duffy Ave., Hicksville, N. Y. M-4 United Speaker Systems, Two new models recently added to the United line, Types X -200 and X -100, in the moderate - and low- priced categories, respectively. are both of low -boy design and are suitable for either wall or corner placement. The X-200 employs two matched 8% -in.

for 20 db quieting on FM, and 5.0 micro- ing produced by Universal Transistor volts for 0.1 volt audio output on AM. Products Corp., 143 E. 49th St., New York Temperature -compensated oscillator cir- 17, N. Y. Measuring but 5" x 5" x 2 ", the cuits prevent drift. Fully enclosed in a amplifier is equipped with built -in equal - handsome hand -rubbed mahogany cabinet, ization, has a signal -to -noise ratio greater the 403B has an edge -lighted slide -rule than 30 db, and covers a frequency range tuning scale, and is equipped with two of 50 to 20,000 cps. It incorporates peak utility outlets for plugging In auxiliary clipping and gain control, and meets mili- equipment. Front controls are an FM -AM tary on vironment a1 specifications. M -7 selector, and tuning knob. A volume control is located on the rear of the chassis. Glaser- Steers 4 -Speed Record Changer. The 403B meets all FCC and EIA specifi- Many features of interest to high fidelity cations for spurious radiation, and is U.L. enthusiasts are incorporated in the new approved. Stromberg- Carlson Corporation, "GS Seventy- Seven" record changer re- Rochester 3, N. Y. X-2 cently introduced by the Glaser -Steers Corporation. Belleville, N. J. Unique is the Scott Stereo Tuner. Advanced engineer- fact that the turntable stops during the ing design has raised FM sensitivity to change cycle, resuming motion only after 2.0 microvolts for 20 db quieting in the the next record is in playing position. newly -announced improved version of the thus eliminating the grinding action H. H. Scott Model 330 stereophonic tuner. which results when a stationary disc is In addition to improved performance, new dropped upon one which is revolving. A features include new chassis design for four -pole hum -shielded motor with dy- easier panel installation and illuminated namically- balanced rotor and highly cush- signal strength meter. AM and FM sec- AccuSonic bass drivers coupled to an ex- ioned mounts reduces rumble to a level tions are completely separate. Stereo Is ponential horn with a mouth area of 4 which compares favorably with that of a achieved by connecting one amplifier to sq. ft. High frequencies are reproduced manual turntable. The pickup arm is an the AM side, a second to the FM side, by two 3 -in. cone tweeters. Frequency re- aluminum die casting, acoustically iso- each with its own speaker. The tuner also sponse is 37 to 18,000 cps. The X-100, 11- lated, with an easily accessible vernier

78 AUDIO DECEMBER, 1957 are you sure you have the best?

SIDE VIEW

Consider the one forward step by which sound reproduc- Technical details and specifications. Model crossovers attenuate at the rate of 12db per tion could be vastly improved: 372 Stereo system. octave outside of their transmission hand. A servo- mechanism to feed data from speakers to ampli- Servo System The unit employs 6 direct All servo amplifiers are coupled to their coupled transformerless transistor ampli- respective speakers without the use of out- fiers to correct distortion even before it begins. fiers feeding 6 specially designed loud- put transformers. speakers. Information Even from each speaker the finest conventional sound systems distort ... the is fed back to its own servo amplifier. This An input signal of 1 volt is required for distortion coming from room acoustics, cabinet resonances, data continuously and automatically cor- the full power output of 72 watts. rects and especially the loudspeakers. All this could be dramati- for the effects of room acoustics . Rssponss Each Integrand cally reduced -actually, could have been reduced years ago cabinet resonances and the distortion Servo- Speaker System is supplied with an -by this one change! arising from amplifiers and the non -line- individual calibration of its own pressure arities of the magnetic structures and sus- response from 35 to 16.000 cycles and is The servo principle has been used for years in automation, pension devices inherent to any guaranteed to he ± 3db over this range. where servo -mechanisms check output to keep it correct. loudspeaker. The result is an acoustic out- Obviously, audio engineers have recognized it too: some put uniquely free of distortion. Distortion G I Specifications The Model is guaranteed to he less than I c/t, over the 372 Stereo Servo-Speaker System is housed have even incorporated a few of the servo -speaker prin- entire audio range when operating at 1 in a handsome contemporary cabinet ciples in their own sound systems. Yet the speakers and acoustic watt (Radiating into a solid angle 44"w x 30 "h x 20 "d. Cabinets available in amplifiers available to you have continued to be offered of ,r /4 steradians; approximately 20 elec- a selection of finely finished Walnut. Teak in their conventional form, year after year. Until Integrand. trical watts). or Limba.

Just off the drawing board, the Integrand is the first com- Loud All speakers in the sys- Model 372 may be instantly changed from plete amplifier - speaker system employing servo tech- tem are specially designed to produce pis- stereo to monaural operation by switching niques. Distortion? The Integrand system permits less dis- ton operation over their operating ranges. the two servo channels into parallel. Each Each voice coil is wound with system is guaranteed for 2000 operating tortion in the overall sound than a good amplifier alone rectangular wire and bonded with high temperature hours (approximately 5 years t. The system will produce under laboratory test conditions! Sound repro- Epoxy to assure extreme rigidity and contains a built -in timing device to protect duction long from the Integrand Servo- System is very, very life. The two 15" woofers are each equipped this guarantee. near the ultimate ... and very, very superior to any con- with a magnetic motor assembly weighing ventional system. Both stereo and monaural systems are in excess of 1252. lbs. High and mid -range Model 372 Walnut $595.00. Monaural and available. ring radiators are constructed coaxial and other lntegrand Servo- Speaker Systems coplanar to each other and thus provide from 5375. All prices and specifications There are many other remarkable differences in the an unprecedented smoothness in the subject to change without notice. Integrand which contribute to superior sound reproduction. response at crossover. The mid -range ring Integrand does far more than slash previous distortion radiator is foam rubber edge damped. The levels. Among other new features: Original speaker design. high frequency ring radiator features a Transformerless, direct coupled amplifiers, one to power new type of acoustic horn termination that each of the three matched speakers. Fully transistored am- completely eliminates the standing wave dip which plifiers and crossovers. Full stereo sound. And an uncon- exists on most high frequency radiators at about ditional guarantee for 2,000 hours of operation (about 12.000 cycles. five years). Transistorsd Amplifiers and Cross- overs Each of the 6 To get the whole story, you'll want to write for complete fully transistored amplifiers contains its own crossover net- specifications, test data a and folder reprinting what the work. Crossovers are at 350 cycles for the experts are saying about this new system. And you'll want woofers. 350 and 2500 cycles for the mid- to listen to the Integrand, so we'll Block diagram for basic buerrand three send you the name of the range ring radiators and 2500 cycles for way system. Model 372 Stereo Servo -sys- audio dealer near you. Write to: the high frequency ring radiators. All tem contains two (one for each channel) BRAND PRODUCTS, INC. Dept. Al2: Westbury, New York Marketing organization for Integrand Corporation

SERVOINTEGRAN SPEAKER AMPLIFIER SYSTEM

AUDIO DECEMBER, 1957 79 adjustment for stylus force. Specifications state that the arm has no resonance within the audio range, and that variation PROOF OF of force between EXTREME HIGHS ,e\ stylus the first and tenth J 1 a§rw I 1 I MID -RANGE HF -61A MASTER-'r CONTROL PREAMPLIFIER KIT $24.95 e WIRED $37.95 h (powered by any EICO power amplifier) HF61 KIT $29.95 (with Power Supply) WIRED $44.95 "...the HF -6I's performance rivals that of the most expensive preamps. There are inputs for several types of phono cartridges; record on the turntable Is less than one five phono- equdlization curves; a tape out- gram. Other features Include single, con- put which follows the filters but precedes centric operating control, muting switch, the tone -control stages; inputs for tape and jamproof operation -the arm move- recorder, tuner, TV, and an auxiliary; AC ment may be restricted during change sockets for four other pieces of equipment; cycle without damage, or the arm may the Compentrol be relocated during automatic play with- type of loudness control out tripping the change mechanism. -8 with a separate level control; the excellent X tone -control action of the Baxendall circuit; Transistorized Amplifier. Although de- a hum adjustment; and low- impedance signed primarily for use in home music main output. All in all, here is an example reproducing systems, the Vico Model 77 of a high level of engineering skill, which amplifier Is equally suitable for installation on trains, buses and aircraft. At has managed to achieve fine performance normal listening levels it consumes less with simple means and low cost." power and generates less heat than an Joseph Marshall AUDIOCRAFT, April, 1957 electric clock. Maximum rated power output is 20 watts. Frequency response Is HF60 60 -WATT Ultra- Linear POWER within ± 0.5 db from 20 to 30,000 cps. Dis- tortion is less than 0.5 per cent. Hum is AMPLIFIER with stated to be more than 100 db below rated ACRO TO -330 output. Component life is expected to be Output Xfmr BASS RANGE KIT $72.95 __... .-. - rs,tsta WIRED - ee $99.95 4.4. to DISTORTI ni iT/ , +....r 7proudly presents ... Min ==3 .ODUa/aNtl.m1111alft=Me ..eenittittttit.r ...a.n 1Oa 1ltiti111 t111111 1:=11 L/1111e11 a major break -through in uwlumnw infinite since the maximum applied voltage is only 15 volts. The amplifier is de- speaker system development o 111uu..11au r.uui signed for operation from a 117 -volt 60- InÌ mmumluullummiII cycle source or from a 12 -volt battery. Úi It may be operated directly from vehicle a new combined 03 0.507 t 2Rlet 3 S 7 10 20 30 50 70 100 batteries without requiring vibrators or horn and direct - POWER OUTPUT WATTS other power conversion devices. The front radiator system hav- IM dis orfen vs. power ou put as measured panel is provided with bass, treble, input by AUDIOCRAFT. selection, and loudness controls. Complete ing uncolored tran- "As far down and as far up as we are equip- technical specifications may be obtained sient response, ped to measure, the frequency- response by writing to the manufacturer, Video In- superb damping. specifications were met strument Company, Inc., 2340 Sawtelle easily. Square -wave Blvd., Los Angeles 64, and non -directional response was nearly perfect with any kind Calif. X -9 sound distribution. of load: resistive, inductive, or capacitive. In -Line Stereo Tape Head. An inter - includes built -in LC The only way we could make the amplifier channel magnetic shield which affords a high degree (48 dividing network show noticeable high -frequency ringing was db) of crosstalk rejection balance control. to operate it with NO load at - is a feature of the new Model TLD -S re- and all. Low cording head, frequency stability was excellent also . . recently announced by The Nortronics Company, 1015 S. Sixth St., Frequency Response: Listening tests confirmed the fine instru- essentially flat 45- ment test results without question. Our 20,000 cps; useful re- HF -60 produced firm. well- defined bass sponse 30-40,000 cps. and clear, sweet treble on the finest speaker Rated impedance: systems available. It clipped momentary 16 ohms. overloads very well and recovered quickly, Efficiency: and this gave listeners the impression of can be driven saris -. tremendous reserve power. In our opinion, factorily from good it is one of the best -performing amplifiers amplifiers having a extant; it is obviously an excellent buy." power output as low AUDIOCRAFT Kit Report, July, 1957. as 10 watts. Also Rated Power Handling: 30 watts Integrated program Available: material. HFSO 50 -WATT Ultra- Linear Power Amplifier with extremely high quality Chicago Standard Output Dimensions: 36" high, 151/2" wide, 111/2" deep. Weight Transformer. Identical in every other respect to 45 lbs. HF60 and some specifications up to 50 watts. Finishes: hand -rubbed mahogany, walnut, or blonde. KIT $57.95 WIRED $87.95 Price: $139.95 net. Blonde, $144.95. HF52 Integrated 50 -WATT Ultra- Linear Amplifier If you appreciate the difference between arti and Preamplifier- Control Section on one chassis. finial "hi-fi" and truly natural sound. listen All preamp features of HF61 less scratch and to the EICO New Standard Speaker System at Minneapolis 4, Minn. Developed for high- rumble filters. Power amplifier section essentially fidelity recording and reproduction in both your local distributor. For complete data, write identical to HF50. monaural and stereo applications, the for free Bulletin AX -12. KIT $69.95 WIRED $109.95 head can easily be compensated to provide Prices 5% higher on West Coast flat response between 30 and 10,000 cps. IN STOCK at your neighborhood distributor It Is ideally suited for use in new equip- 33-00 Northern Blvd. Write for free Catalog A -12 ment design, modernization, replacement, and for conversion of existing tape han- E/CO Long Island City 1, N. Y. dling equipment. Economically priced, the Prices 5% higher on West Coast LONGDISLAND CITY 1, N. Y. Norco head is now available to manufacturers in quantity. X -10

80 AUDIO DECEMBER, 1957 a high quality system at HOW TO PLAN two more BEST BUYS... /COL (front page 25) low cost... fromi7E from I7E/CO' NEW! farmanee. How much quality is gained by an additional outlay of money is im- 20 -WATT FM TUNER portant for the planner to have in mind Ultra- Linear HFT90 before becoming obsessed with any one particular system, or with the struggle Williamson -Type KIT, less cover $39.95* to achieve the ultimate. INTEGRATED WIRED. less cover $65.95 * After reviewing several synthetic sys- HIGH FIDELITY Cover $ 3.95 tems, one begins to realize that high - AMPLIFIER HF20 .excise tax incl. quality audio reproduction can he complete with Preomp-Control Section Newly -designed. extremely sensitive. low -noise "front end", supplied in a cast housing com- achieved. In fact, some of the more ad- KIT $49.95 WIRED $79,95 pletely pre- wired. pre -aligned. ready to use. vanced systems will give a performance Employs temperature-compensated compo- During its first year, the H120 has received nents and advanced circuitry to completely that is virtually indistinguishable from consistently high praise from users -has eliminate need for AFC. Drift less than 2 become established as the outstanding value parts in the original. The second significant point in 10,000 from cold start. Radiation amplifiers of this power class. Employs an sapressed far below FCC standards. out Also fea- is that the cost of a high -quality system put transformer capable of tures new DM -70 traveling tuning eye. Sensi- handling far in tivity. unapproached among FM tuner kits, is likely to be a little more than had excess of its rated 20 watts, a full Ultra- Linear Williamson of 1.5 uy for 20 db quieting. Input :300 ohms, originally been estimated. The choice of power amplifier, and the finest pre- IF bandwidth 260 kc, detector peak separation amplifier- control facilities. Rated Output: 20 w of 600 kc. Freq. reap. 20- 20.000 cps ±1 db. components that will lie ahead will be (54 w pk.) IM Distortion (60 & 7,00(1 cps @ 4:1) : Audio output 1 V for 10 uv input with 75 kc 1.3% @ 20 w. Harmonic Distortion: below 1% deviation. Hum 60 db below I V. Cathode fol- rather delicate because the mistakes can from 20. 20,000 cps within 1 db of 20 w. Freq. lower and multiplex outputs. Flywheel slide- he costly. rule tuning, ACC, stabilized low limiting thresh- Resp.: ±0,5 db 15. 30,000 cps as any level from old for excellent performance from weaker sig- Although the actual measures of per- I mw to 20 w; no peaking or raggedness outside nals. broad -band ratio detector for audio range. Square Wave Resp.: 20.20,000 cps improved formance of hi -fi capture ratio and easier tuning, full -wave a system are subjec- essentially undistorted. Sens,: 4 my on mag rectifier and heavy filtering, very low distor- tive, the person who has gained a lim- phono & .4 v on tuner, etc., for 20 w output. tion. Uses 1- ECC85 /6AQ8, 3 -6AU6, 1 -6ÁL5, Hum 8 Noise: 60 db below 20 w on mag phono, 1 -6C4, 1 -DM70, 1 -6X4. Flexible "low silhou- ited amount of listening skill should be 75 db below 20 w on 5 ette" design adaptable to any panel thickness tuner. etc. feedback for console installation: optional cabinet. in a position to make comparative tests equalizations for LPs & 78s. 4 hi -level switched HWD: :irh," x 12" x 8'¡ ". Operates from 110- and to place his subjective reactions on inputs (tuner, tv, tape, crystal), unused inputs 125 VAC. 60 cps line. grounded to eliminate cross -ta:k; 2 low.level "Typical unit, measured with Marconi TF a quantitative basis. If such crude meas- inputs for proper loading with all cartridges. 955A/2 FM -AM signal generator. ures can be made, then one can rate dif- Low distortion variable crossover feedback tone ferent systems. With these controls: ±15 db @ 50 cps & X15 db at 10 kc, ratings to- with mid- fregs. & volume unaffected. Hum bal. gether with the cost control. DC superimposed 12 -WATT data, one can then on tube filaments to Williamson construct the "cost- effectiveness" curve eliminate cathode -heater leakage as hum source. -Typo Centralab printed circuit "Compentrol." HIGH FIDELITY Loud- which can be an invaluable aid to system ness control & separate level set control on front INTEGRATED AMPLIFIER HF12 planning. In the beginning we panel. Extremely fine output transformer: inter- with Preamplifier, Equalizer and Control Sec recommend that leaved windings, tight coupling, careful balanc KIT $34.95 Wired $57.95 the rater confine his attention ing, grain -oriented steel. Speaker Connections: Compact, beautifully packaged and styled. to the general impression of "listening 4, 8 & 16 ohms. HtVD: 81,42" x 15' x III ". 24 lbs. Provides complete "front -end" facilities and pleasure" Matching Coser E1, 54.511. true high fidelity performance. Direct tape or "presence" and take up head and magnetic phono inputs with NARTII more detailed refinements at a later time. (tape) and RIAA (phono) feedback equalizations. 6 -tube circuit, dual triode for variable Initial tests of this kind are sufficient NEW! 30 -WATT turnover bass and treble feedback -type tone to convice some "interested listeners" controls. Output Power: 12 w cont., 25 w pk. High Fidelity IM Dist. (60 Sc 6000 cps @ 4:1) : 1.3% @ 12 that the systems of moderate quality are w; 0,56% @ 6 w; 0.3%,. @ 4 w. Freq. Resp.: POWER I w: +0.5 db 12 cps -75 kc: 12 w: -0.5 db 25 adequate for the purpose, but others will 1 1 cps - 20 kc. Harmonic Dial: 20 epa: 2% @ lay aside all thoughts of intermediate AMPLIFIER HF30 4.6 w; %% @ 2.5 w; 30 eps: 2% @ 11 w; tF_% @ 6 w; 40 cps: 1%. @ 12 w: 'F_'$. @ 9 w: 2000 steps and plan for the highest standards KIT $39.95 WIRED $62.95 cps: 1/2%. @ 12 w; 10 ke: 1% @ 10 w: '42% @ 4 w. Transient Reap: excellent square wave of performance that are possible. Four EL84 output tubes in push -pull parallel; reproduction (4 usec rise- time); negligible high power sensitivity eliminates need for extra ringing. rapid settling on 10 kc square wave. driver stages, permitting Williamson-type circuit Inverse Feedback: 20 db Stability Margin: 12 with large inverse feedback and high stability db. Damping Factor: above 7, 20 cps 15 ke. - margin. (i lb. Sensitivity (input for 12 WI: Mag. Phono. output transformer, extensively - interleaved windings 9 mv; Tape Head - 6 mv: Tuner. Aux - 0.5 & grain -oriented steel lam- v. Hum & Noise Level (below 12 W) : Mag. inations. Surgefrex, high reliability power sup- Phono - 60 db: Tape Head - 55 db: Tuner. ply using two F:78I full -wave rectifiers. Power Aux - 75 db. Speaker Connections: 4, 8. 16 8 take-off socket for FICO HF6IA Preamplifier, ohms. Tone Control Range: @ 10 kc, X13 db; Rated Output: 30 w (47 w pk.) IM Distortion: @ 50 cps, X16 db. Tubes: 2- F.CC85 /I2AX7, (60 & 7,0(10 cps @ 4:1) @ :30 w; 0.83 @ 1- ECC82 /12AU7, 2 -EL84, lá'7.81. Mounts in 2' 20 w; 0.35% @ 10 or out of cabinet. Size: HWD: :t "," x 12" x w. Harmonic Distortion: 80í ". 13 lbs. 6 below I% frons 20- 20,000 cps within I db of includes effect 30 w. Freq. Resp.: ±0.1 db 15- 30,000 cps & of compensation. X1.5 db 15. 100,0011 cps, at any level from I mw TWO -WAY to 30 w; no peaking or raggedness outside audio range. Square Wave Resp.: 20- 20,0(10 cps essen- SPEAKER SYSTEM tially undistorted. Inverse Feedback: 20 db. HFSI $39.95 Stability Margin: 15 db. Damping Factor: above complete with Il). 20 cps to 20 kc. Sens.: 1.24 V for 30 w, Hum: 80 db. below 30 w. Speaker Connections: FACTORY -BUILT 7 4, 8, and IO ohms. HWD: 5" x 12" x 7 ". 17 lbs. CABINET Matching Cover E -3, ík3,95. Jensen heavy -duty R" woofer & matching Jensen compression- driver exponential horn tweeter, Smooth clean bass & crisp, extended 33-00 NORTHERN BLVD. neutral highs. Overall response: --6 db 70- Go 50 100 LONG ISLAND CITY 1, N. Y 12,000 cps. Power -handling capacity: 25 w. ISO Impedance: 8 ohms. Bookshelf size: 23" x 11" Please send FREE catalog and name of neighbor 5 - -O Sf OF SPEAKER AND ENCLOSURE x 9'. 25 Iba. Wiring Time: 15 min. hood distributor or high fidelity specialist.

IN STOCK at your neighborhood distributor. Name Writs for free catalog A-12 Fig. 2. Curve of cost vs. performance as Address 33 -00 NORTHERN BLVD. constructed from the dato in Table I, LONG ISLAND CITY 1, N. Y. covering the test of the least costly City Zone Stet* Prices 5% higher on West Coos' systems. Prices 5% higher on West Coast A -12

AUDIO DECEMBER, 1957 l31 curves. These latter ratings set a lower TABLE I standard of `low- cost" perform- 1 limit or COMPARISON OF SPEAKERS AND AMPLIFIERS - TEST No. ance. The region of high -fidelity begins ENCLOSURE AND SPEAKER TOTAL PERFORMANCE RATINGS M. F. H. F.Ovadl with an over -all rating of about 6. The DYNAKIT Type Cost Spkr No. Cat COST L.F. 8 7 -all rating was derived from three A Ie.m 1 41.60 59.60 6 8 over A 18.03 2 45.03 63.00 6 8 8 7.5 separate components, one to evaluate Preamplifier 72.50 S 8 8 7 A 18.00 3 54.50 low- frequency response and freedom A 18.00 4 76.50 94.50 6 8 8 7.2 An Outstanding Companion A 18.00 5 57.60 75.50 6 8 8 7.2 from distortion, one for medium fre- Kit to the World Famous A 18.00 6 54.00 77.00 6 8 8 7 quencies, and the third for the highs. A 18.00 7 60.00 58.03 5 8 7 6.5 The two curves show the extremes Dynakit Amplifiers A 18.00 8 70.50 38.50 5 8 7 6.5 A 18.00 9 27.m 45.00 5 8 7 6.5 available for home listening. The com- A 18.03 10 25.03 43.03 5 8 7 6.5 binations between these extremes are A 18.00 II 79.50 97.50 6 8 8 7 many, and the measures that can be A 18.00 17 116.00 132.00 7 9 9 8 K 50.00 13 74.50 124.50 8 9 8 8.8 taken to reduce the costs of the systems not in Williamson -type amplifier 15190.00), record changer (568.00), and of highest quality are exhausted magnetic pickup not changed dying test these two initial tests. For instance, one Speakers tested included single-cone extended-ronge models, and see could two - and thee. -soy integral models. would like to whether a system

Enclosure types: A is bass rafle in kit form, unfinished plywood be assembled having a performance be- K is Kahan -type, in kit form. tween 9 and 10, but at a substantially listed in the tables. Typical Test Results lower cost than those This handsome new control unit gives By using the "do -it- yourself" kits for the crystal clear, noise -free reproduction The results of two tests are tabulated from modern program source. Its more complex systems, if they are avail- any in unique all feedback design by David in Tables I and II, and are plotted able, such costs can be reduced ; but one Hafier sets a new standard of pre- graphical for in Figs. 2 and 3. These may be forced to forego the styling and amplifier performance. The design of curves show a distribution of points up fine finish of the speaker enclosure and the Dynakit preamplifier is a synthesis and down the scale of performance or which produce the auxiliary cabinets. Cost reduction by of outstanding features costs of smoother, more natural sound. Corn - effectiveness, plotted against the a factor of two is a reasonable expecta- pare these features with any other units the respective speakers and enclosures. tion. regardless of price. The performance generally rises with At this point, one may have enough cost. The total system costs could be de- information to stir his enthusiasm, but * Unequalled performance not enough to be sure of his precise needs Actually less than .1% distortion under TABLE 11 all normal operating conditions. Response be laid out. There AND TEST No. 2 so that the system can ± .5 db 6 cps to over 60 kc. Distortion COMPARISON OF SPEAKERS ENCLOSURES - and response unaffected by settings of vol- is still another step the beginner may ume control. Superlative square wave per- ENCLOSURE AND SPEAKER TOTAL PERFORMANCE RATINGS take before making any major decisions. formance, and complete damping on any Type (Finished Unit) COST L.F. M. F. H. F. Overall pulse or transient test. This step is not essential for one who (o) with amplifier and prea, at 519003. Speokns include two- and thin-way types has made up his mind but is recom- * Easiest assembly who wish to develop All critical pars supplied factory- mounted SACK- LOADED HORN 244.50 7 9 9 8.5 mended for those on XXXP printed circuit board. Eyeleted better judgment. This step is to con- construction prevents damage to printed BACK -LOADED HORN 276.00 7 9 9 8.5 wiring. This type of construction cuts struct an "interim system" which will wiring time by 50% and eliminates erron CORNER HORN 330.00 10 9 9 9.3 of assembly. Open simplified layout offers permit the experimenter to observe over complete accessibility to all parts. CORNER HORN 720.00 10 10 10 10 a period of time the factors of impor- 100.00 9 9 8.3 * Lowest noise INFINITE BAFFLE (Duel Spkn) 8 tance to him which affect the perform- Integral dc heater supply plus low noise INFINITE BAFFLE tine -way) 126.00 5 8 9 7 ance of the system. With a judicious components and circuitry bring noise to choice of components, one could apply less than 3 microvolt equivalent noise in- (6) with amplifier and wean, at 5203.00. put on RIM phono position. This is any items purchased for the secondary better than 70 db below level of 10 milli- INFINITE BAFFLE (5 Spkn) 256.00 7 9 10 volt magnetic cartridge. system to the more advanced one. This INFINITE BAFFLE (9 Spkn) 450.00 9 IO IO 9.5 experimental approach has the advan- * Finest parts Sao ahenga aid magnetic used throughout. of allowing one to study his re- I% components in equalization circuits to 1568.00) pickup tage insure accurate compensation of recording characteristics. Long life electrolytic capa- by adding the amplifier and grade compo- rived citors and other premium 10 nents for long trouble -free service. changer costs in each case. The most expensive system was $978, while the least * High Flexibility Six inputs with option of extra phono, costly was $296, but the lower figure tape head, or mike input. Four ac outlets. could have been reduced by using less a Controls include tape AB monitor switch, loudness with disabling switch, full range expensive amplifiers without affecting z feedback tone controls. Takes power from á Dynakit, Heathkit, or any amplifier with acoustical performance. octal power socket. The distribution of points shown is u 6 only one some other z * Outstanding appearance peculiar to rater. If bone white or charcoal brown rater was to evaluate the same systems, Choice of O decorator colon to blend with any decor. be would probably place the points in 4 Finished in indestructible vinyl coating with solid bran escutcheon. different positions, but he would most likely get curves of about the same shape * Best Buy Available from your Hi -Fi dealer at only after averaging the points. In conferring 2 $34.95 net (slightly higher in the West) with other listeners, however, the most and yet the quality of performance and parts is unexcelled at any price. expensive system was consistently rated as the top in quality. This unit was arbi- o Descriptive brochure available on request 400 600 300 trarily scored as 10, thereby establishing o 200 Pat. Pending AND . J'E 3 - COST OF SPEAKER EN.LJ a standard at the top of the scale. At DYNACO INC. the lower level, the table model radio con- 617 N. 41st St., Philadelphia, Pa. and a radio phonograph were scored at Fig. 3. Curve of cost vs. performance but these structed from the data in Table II, cover- Export Division: 25 Warren St.. New York 7, N. Y. about 3 and 3.5 respectively, scores are not shown in the data or ing the test of the most costly systems.

AUDIO DECEMBER, 1957 82 quirements more closely and to develop time to turn attention toward the second a better understanding of actual rather step in the planning cycle, that of select- than fancied needs; it may also serve ing the individual components in such a to stimulate more interest in still better way that the over -all cost is minimized performance. Another experimental ap- without sacrificing the performance DYNAKIT proach is to take advantage of the free standard. In principle, at least, the be- home trials offered by local shops. As ginner could extend the technique of much may like Amplifier Kits as you a piece of equip- listening tests so as to arrange the comment in the store, sometimes it may not ponents to suit his need. We know of no A proven circuit finest "wear well" at home. of sound better way to choose a speaker, but se- quality in a new deluxe 60 watt A little rummaging around in the attic lecting a particular amplifier depends to model and in my own case produced components standard 50 watt model some extent on how much the that were adequate for the interim ap- experi- menter proach. For the dance party require- borrows from the "sound engi- ment, there developed a need for power neer" and the "music critic." Many would output-undistorted-that was well be- be satisfied with a simple substitution yond the ability of the secondary system. test using the chosen speaker and enclo- The audience was found to absorb sub- sure, and make use of a home trial. Se- stantial amounts of acoustic power, and lecting an amplifier in itself can be a in addition, create an ambient noise level detailed study the scope of this discus- which had to be overcome by the speaker sion ; in fact, much has already been output. The lack of low- frequency tones written on this subject. in the secondary system became appar- Thus, if one can arrive realistically at ent because the lows often carry the some conclusions regarding his require - rhythm needed for dancing. For listen- ments in relation to what he can afford, ing to concert music, the volume level the task of selecting the units for the had to be reduced to keep peace in the system is reduced to manageable pro- family, so the loss of lows was again portions; and one's limited energies and accentuated. The lack of extreme highs funds are not misdirected into unpro- MARK III 60 Watts 7995* net caused no comparaable deep concern, so ductive channels. These two approaches 4, 8, 16 ohm outputs the extended high -frequency coverage are advocated as aids to planning: The will be included in the final system if it comparative evaluation of system per- The new Mark III includes all the can be gained for a modest cost. formance by actual listening tests, and sensational attributes of the popu- If you have been able to establish a the improvement of personal judgment lar Mark II plus these outstanding standard of performance that the hi -fi through experience with an experimental deluxe features system must eventually meet, then it is or interim hi -fi system. Æ *60 watts at less than 1% distortion. Instan- taneous peak power of 140 watts. 1M less than .05 at average listening levels. * Choke filtering and low noise circuitry re- LOUDNESS, ITS duce hum and noise to 96 db below 60 DEFINITION watts. (from page 48) * New rugged KT -88 tubes and other heavy duty parts used conservatively. ing ten components of equal loudness To determine the value of b for this and a common frequency difference of range in terms of Af and Lk, a series of MARK II so Watts 6975 100 The results Fig. 9. measurements was made upon n et cps. are shown in loudness 8, 16 ohm outputs It will be seen that although the points complex tones having ten components corresponding to the different frequency with a common difference in frequency The Mark II is the best buy in high ranges lie approximately upon the same Af and all having a common loudness power high fidelity kits curve through the middle range, there level Lk. The values of Af were 340, 230, are consistent departures at both the 112, and 56 cps. The fundamental for * Ease of assembly due to uniquely simple circuitry and printed circuit construction high and low intensities. If we choose each tone was close to 1000 cps. The ten - with factory -mounted parts. the frequency of the components largely component tones having frequencies * Highest stability using patented stabilizing in the middle range then this factor b which are multiples of 530 was included networks with minimum number of phase will be dependent only upon Af and Lk. in this series. The results of loudness shifting stages. Suitable for all loudspeaker systems including electrostatic. TABLE V * Dyna Biaset (patent pending) for simplified adjustment and complete COMPARISON OF CALCULATED AND OBSERVED FRACTIONAL LOUDNESS (LAIRD, TAYLOR freedom from effects of unbalanced components. No AND bal- WILLE) ancing adjustments required to meet published specifications. for Level 1 Loudness Reduction * Dynaco Super -Fidelity output transformer Original Loudness Cal. Level for t with patented para- coupled windings. Level Loudness Reduction This is the finest available transformer of its Cal. Obs. type for the most critical audio uses. 100 92 76.0 84 =Slightly higher in West 90 82 68.0 73 80 71 60.0 60 Available from leading Hi -Fi dealer: everywhere 70 58 49.5 48 Descriptive brochure available on request. 60 50 40.5 41 50 42 31.0 34 40 33 21.0 27 DYNACO INC. 30 25 14.9 20 20 16 6.5 13 617 N. 41st Street, Philadelpnia, Pa. 10 7 5.0 4 Export Division: 25 Warren St.. New Yet 7, N. Y.

AUDIO DECEMBER, 1957 83 TABLE IV COMPARISON OF CALCULATED AND OBSERVED FRACTIONAL LOUDNESS (HAM AND PARKINSON) t -m KITS 350 Cycles Fractional Reduction in Loudness for the best Advanced designs S L G In high fidelity reproduction Cal. % Obs. % Build and save do- it- yourself 74.0 85 25,000 100 100.0 70.4 82 19,800 79 83.0 See them at your local 67.7 79 15,800 63 67.0 radio parts distributor 64.0 75 11,400 46 49.0 59.0 70 7,950 32 35.0 54.0 65 5,870 24 26.0 15.0 /heu/ 60 WATT 44.0 53 2,680 11 34.0 41 1,100 4 8.0 HIGH FIDELITY 100.0 AMPLIFIEFIER 59.5 71 8,510 100 57.7 69 7,440 87 92.0 PREAMP HIT 55.0 66 6,240 73 77.0 49.0 59 4,070 48 57.0 An integrated high power omolrfer pa;.age for the 44.0 53 2,680 31 38.0 audio perfectionist - complete with versatile pre. 47 1,780 21 25.0 in high at a 39.0 amplifier one compact styled unit - 12 13.0 budget price. Undistorted power output is guaranteed 34.0 41 1,060 to be 60 watts from 20 to 20,000 cps. Intermodu- 24.0 29 324 4 6.0 lotion i I% at 60 watts and below 0.25% at ordinary s listening levels. Model 19K 579.95 1000 Cycles Cabinet 7.50 86.0 86 27,200 100 100.0 /tell/ 25 WATT 82.4 82 19,800 73 68.0 79.7 80 17,100 63 53.0 HIGH FIDELITY 76.0 76 12,400 46 41.0 AMPLIFIER - 71.0 71 8,510 31 26.0 20.0 PREAMP KIT 66.0 66 6,420 24 56.0 56 3,310 12 13.0 Top quality integrated omplifer preamphfer system 46.0 46 1,640 6 8.0 on o tingle chassis at exceptionally low price. Per formance equals or exceeds any available amplifier 56.0 56 3,310 100 100.0 up to toted power of 25 wa ^.. 54 2,880 87 93.4 Model 21K ..... 559.95 54.2 Cabinet 7.50 51.5 52 2,510 76 74.5 48.8 49 2,070 62 55.0 46.0 46 1,640 49 40.9 41.0 41 1,060 32 24.5 WILLIAMSON 36.0 36 675 20 10.8 TYPE 20 -WATT 2500 Cycles AMPLIFIER 74.0 69 7,440 100 100.0 Frequency response flat and 0 70.4 64 5,560 75 86.4 smooth thre entire audible range 67.7 62 4,950 67 68.1 Less than .0025 distortion of normal 3,820 51 49.5 levels Ecollent transient characteristics. 64.0 58 listening 59.0 53 2,680 36 32.8 Model TM -15A, complete with tubes - sockets terminal strips, and connectors mounted $49.95 54.0 48 1,920 26 23.3 44.0 39 890 12 13.0 34.0 30 360 5 6.7 PREAMPLIFIER 44.0 39 890 100 100.0 with Cathode 42.2 37 740 83 94.6 Follower Output 39.5 36 675 76 82.2 36.8 33 505 57 61.1 34.0 30 360 41 46.0 4 input channels Separate boss and treble 26 222 25 27.8 controls 3.posilion equalizer AC outlet for 29.0 auxiliary equipment Powered by main a mplifer. 24.0 21 113 13 14.9 Modal TM-17P, complete 519.95

TV Chassis Kil For Picture Tubes Up to 21" 17001 NI -FI The most up-to -date TV FM TUNER kit, with the latest improvements. Coils ore preadjusted and tuned at the factory. Sockets, SUPERHET t terminal strips and con- Tuning range 87.109 Self- contained power supply nectors riveted on chassis Super -selective, 12- channel Grounded-grid RF Mc 200Kc IF bandwidth turret tuner New 600 ma, rugged, low -drain tubes AC -DC RADIO with cutoff Micro stage AFC frontcontrol Operates Iv elestrostatic -focus pin tubes Circuit ratio detector 4 u vernier tuning No -drift 9 microvolts at 20 p-p Three -stage Standard der sensitivity of sensitivity for 20 db quieting stagger -tuned IF AGC Synchro -guide horizontal hold Broadcast Band - 550.1720 KC Super-sensi- .8 volt RMScothode- follower emphasis network with AFC Size 17' s 17" s 9". tive circuit with builtin loop antenna AVC Output 3.2 volt RMS highinspedance output 5 tubes. Switch -controlled Same as above but with IF 300 ohm input impedance Model 5516W ... Model 365K, complete with tubes and hand- for auxiliary equipment. AC receptacle section fully wired and aligned. Uses Standard some bakelite cabinet (less wire and solder) FM complete with punched chassis, tubes, Model -18, tuner (sensitivity 7 Irv) _. 599.50 519.95 and hardware (less wire and solder) $29.50 Write for latest catalog of complete Tech -Master line tm a product of TECH -MASTER CORPORATION KITS 75 Front Street, Brooklyn 1, N. Y.

AUDIO DECEMBER, 1957 84 120

110

o-FUNDAMENTAL =1001. 100 - " =10001. ° '00, a - " = 30001. / 90 m / O N Z 80 4, . lJ z O 70 O U 0 ' 4 60 Ó / For over thirty years Bakers have J IV / 50 been making quality speakers for W / J / the discriminating British audio- V) phile. These speakers are so out - W 40 v ó a standingly superior that they have D / o / , long been known as "the best of J 30 / the British speakers." 20 Mister,

so . you're 0 / lucky .. 0 // for the new 2020 -10 0 10 20 30 40 50 60 70 80 90 '00 LCUONE55 LEVEL OF EACH COMPONENT-DB Bakers Ultra 12, / Fig. 8. Loudness levels of complex tones having ten equally loud components 50 full- frequency cps apart. range, 12" speaker is now available in America for the first time. 12o A loudspeaker cannot be any better than what is put Into It. The (takers Ultra 12 Is the best, not because of claims, but because no design, parts. materials, and care in construction make it so. So look at the "specs." Fre- quency range 20 to 23,000 cycles. Flux O - FUNDAMENTAL = 501, / density . . 18,000 gauss; 190,000 maxwells. 100 + =14001, High compliant, plastic foam. cone suspen- a - n = 3400.v sion. Non -resonant, cast, open, aluminum frame. Light, sens' ' 'e aluminum voice coil 90 and former. Fully tropicalized. Hand assem- oO bled. Extra powerful Alcomax Ill encased in red cellulose. Dust, rust, and damp proofed. N apex, cone. Power z 80 Exponential, bakelized 20 watts plus. Voice coil impedance ... 15 W z ohms. A full spread of 20 to 25.000 cycles O without distortional crossover networks. In- í° 70 i genious design and the use of new materials, O processes, and techniques now nuke cross- 1 unnecessary. Acoustic, impedance and o overs 60 f efficiency mismatch; "disembodied highs ;" of Ó and other undesirable characteristics J / crossovers, are thus eliminated. W > 50 W This combination of features, which cannot J be found in any other speaker. nukes the VI N Bakers Ultra 12. unquestionably. the finest 40 0 i reproducer today. And the price . . . a mere 0 883.00 . . . the best. D for o J 30 If you want a speaker that is far superior to / anything now available, insist on a dealer . s/ / demonstration. You will be amazed at its 20 smoothness, definition, cleanness, naturalness / . . . a certain "something" that you have never heard before. Lucky owners say, 10 "Mister, this is it." The "specs" tell you why. a O / Write for literature . . . / / and become sound happy. 10 BRADFORD AUDIO CORP. Sole distributors for the United States 2020 -10 O 10 20 30 40 50 60 70 80 90 100 LOUOtaFSS LEVEL OF EACH COMPONENT-DB 27 East 38th Street Fig. 9. Loudness levels of complex tones having ten equally loud components 100 New York City 16, N. Y. OX 7 -0523 cps apart. AUDIO DECEMBER, 1957 85 o available now ... 10 the much talked about 1St Tape Reeordir 90 , with the mo 80 magnetic clutch drive V1 Or 2 W z 70 o nI- M 60 /

50 W > JW 40 rA N Ar W 2 D 30 O -1 . o FREQUENCY DIFFERENCE- 340 " = 230 i 20- i v :112 the most talked about j - 50 development in the industry 10 features Magnetic clutch braking and tope eí tension control - foul proof and / virtually fool proof. Handles tope 0 ° 0 10 20 30 40 50 60 70 80 90 under oll conditions and at all LOUDNESS LEVEL OF SINGLE COMPONENT -DB speeds without the possibility of spilling or breakage. Synchronous lope drive at 3a/e Fig. 10. Loudness levels of complex tones having ten equally loud components with and 71/z ips or 71/2 and 15 ips. a fundamental frequency of 1000 cps. Mounting space for six heads in all presently used head configurations. balances are shown by the points in the series of 10 components having a Designed for rack mounting with Fig. 10. common loudness level Lk, the value of integral amplifier. Dual inputs and controls for By taking all the data as a whole, the L is related to Lk by mixing line and high impedance curves were considered to give the beat inputs. fit. The values of b were calculated from G(L). (1+ 9bk)G(Lk) these curves follows: THE ISI IS AVAILABLE NOW as or by solving for bk FOR EARLY DELIVERY ON A DI- According to the assumptions made RECT FACTORY TO USER BASIS. above, the component of lowest pitch in bk = (1/9) [G(L) /G(Lk) -1]. (16) A truly professional piece of re- the series of components always has a cording gear, the ISI is ideally suited value of N. equal to unity. Therefore for (To be continued) for the serious audiophile, military and industrial data recording and the commercial recordist - priced from $345. The price of the machine is determined by the head compliment IMPEDANCE AND FEEDBACK and accessory fittings. For comprehensive information on (from page 34) this outstanding recorder write to: back. In the case of current feedback pedance of a voltage -amplifier stage, Mid- Continent Engineering, Inc. and plate -to- cathode voltage feedback, whereas current feedback increases it. 1712 Marshall N.E. Minneapolis, Minnesota the cathode swings in the same direction This is of vital importance with respect as the grid, although not quite to the to frequency response and can also be of same extent, so that the potential be- moment in the matter of gain. The lower tween the two is less than between grid the source impedance, the greater the IF YOU ARE MOVING and ground. For example, assume the assurance of flat response within the incoming signal between grid and ground audio range, as discussed in the section Please notify our Circulation Departmnt is 5 volts. Current or plate -to- cathode on impedance and gain. at least 5 weeks in advance. The Post Office feedback may be such that the cathode Why does negative voltage feedback does not forward magazines sent to wrong with respect to ground varies decrease the output impedance/ Refer- unless pay additional post- potential destinations you and assuming a age, and we can NOT duplicate copies sent 4 volts. Thus the grid- cathode signal ring to (C) of Fig. 14 to you once. To save yourself, us, and the voltage is only 1 volt and can be handled heavy capacitive load on Va, it was pre- Post Office a headache, won't you please by the tube with much lower distortion viously explained that self -regulating cooperate? When notifying us, please give 5 volts. action maintains flat frequency response. new address. than your old address and your Similarly, a suitably small resistor in with the capacitive load (see (B) Circulation Department Impedance series Feedback and maintain frequency RADIO MAGAZINES, INC. in Fig. 5) would the response to the same degree. Therefore P. 0. Box 629, Mineola, N. Y. A fundamental difference between two types of negative feedback is that the effective output impedance is that of voltage feedback reduces the output im- the hypothetical small resistor.

1957 86 AUDIO DECEMBER, Negative current feedback, instead of effect upon the preceding stage, and the keeping output voltage constant, instead input capacitance of the following stage tends to keep output current at a con- has practically no effect upon frequency stant value because changes in load response. current are opposed by the resultant The high input impedance of the change in potential between grid and cathode follower may be explained in a cathode. Therefore slight changes in cur- manner analogous to Miller Effect. As- rent flow through the output circuit are sume there is a positive -going signal at accompanied by relatively large voltage the grid. Feedback resistor Rf also goes changes across the load on the tube; that positive due to increased current flow is, with the load changing due to varying through it and the tube. Consequently capacitive reactance at different frequen- the voltage across grid resistor RD is less cies, the output voltage varies since volt- than if the resistor went directly to age equals current (nearly constant) ground. A decrease in potential across a times load impedance (varying). This resistor of course decreases current flow situation is equivalent to that at a gener- through it, in this case the current of the ator with a high output impedance inas- signal source. But a decrease in current much as a large resistor in series with is precisely the same effect that would the capacitive load would result in simi- result from an increase in the value of lar voltage changes across the load as the grid resistor. In sum, as far as the the capacitive reactance varies. signal source is concerned, the effective From the foregoing it may be seen value of RD is increased because of the that although unbypassed cathode re- small potential across it and resultant sistors are very useful as a means of re- decrease in signal current. ducing distortion by cancellation and /or The input impedance of a cathode by increasing the signal handling capac- follower such as Fig. 17 is very nearly ity of a tube, at the same time they can Z RD /(1 -K), where Z is impedance be a source of difficulty in maintaining and K is the gain from the input to the treble response because of the resulting tap on cathode resistor Rk (junction of increase in output impedance. If the the 1000- and 47,000 -ohm resistors). following stage is a triode and has large When the grid resistor is connected to input capacitance due to Miller Effect, the cathode end of Rk or when the cath- serious loss of high frequencies can take ode bias resistor (1000 ohms) is well - place. bypassed by a capacitor, the value of K EXTENDED There is one special and very impor- is equal to A, the gain of the cathode tant case in which negative current feed- follower. A =(4/(1 + (4+ rp /Rk), where back effects a great decrease in output Rk is the total cathode resistance and rp RANGE impedance, at the same time sacrificing is the plate resistance. In cases such as voltage gain altogether. This is the case Fig. 17, where rp is substantially smaller LOUDSPEAKERS of the cathode follower, which illustrates than Rk, we have an approximate for- some of the important relationships be- mula, A (A+ 1). Typically, A is and tween feedback, impedance, and fre- about 0.95. Assuming this gain for Fig. quency response. Figure 17 is a typical 17, we have K = 0.95 x 47,000/48,000 MULTIPLE cathode- follower circuit. It has very high 0.93. Therefore Z 1 meg/(1 -0.93) input impedance and very low output 14.3 megs. Had the 1000 -ohm cathode SPEAKER impedance. Thus it has scant loading bias resistor been bypassed, K would SYSTEMS

EFFECTIVE CAPACITANCE OF AT CI HIGH FREQUENCIES IS V I LESS THAN 4p1 BECAUSE OF OUT FEEDBACK ON INNER SHIELD -150 ppf-; --CI 150 C7 9 ppf :i:- TAPE e PLAY - BAC

_EA- SHIELDED For complete information on Goodmans' CABLE loudspeakers, speaker enclosure kits and

I the famous Goodmans' Acoustical Re-

TAPE RECORDER PLAYBACK sistance Units, write to Dept. AG12, EQUALIZATION NETWORK; Rockbar Corporation, Mamaroneck, N.Y. ABOUT 36 db FEEDBACK AT HIGH FREQUENCIES (above 3000 cps)

Fig. 16. Minimization of input capacitance at high frequencies by means of negative feedback. American Sales Representatives fer Goodmans Ltd.

AUDIO DECEMBER, 1957 87 for the first time!

DO -IT- YOURSELF Rk - 45,000 TEST RECORDS Fix and Test Your Hi -Fi System So easy, so simple to fix your Hi -Fi system with any one of these records. Instructions and tests are in plain layman's language. No 89" technical knowledge required. Fig. 17. Typical cathode -follower circuit. QUIET, PLEASE! Checks rumble. been equal to A, namely 0.95, and Z WHAT! NO HUM! :treasures hum. would have been 20 tnegohms. HOW'S YOUR STYLUS? Stylus wear test. TRACKING SPECIAL! Measures funda- have been equal to A, namely 0.95, and mental arm resona nee. anolyzes damping problems. Z would have been 20 megohms. The low output impedance of the cath- VERTICAL /LATERAL RESPONSE! Measures ratio of vertical to lateral response. ode follower may be explained as fol- in value as PERFECT CHRISTMAS GIFT - for wOw! a FLUTTER, TOO! Checks wote lows. If the load is so small Christmas, give your Hi -Fi friends and flutter. to decrease the voltage at the cathode by one or all six of these records. AVAILABLE AT YOUR HIGH FIDELITY DEALER reducing the ground -to- cathode inrped- once, this also decreases current feedback. Accordingly, there is less opposi- tion to the input signal, thereby produc- Components Corporation ing more current flow through the tube Q DENVILLE, NEW JERSEY and a higher voltage at the cathode. We have, then, the situation of small voltage changes at the output accompanied by relatively large current changes, which by Ohm's Law indicates a small effective AT LAST! a.c. resistance. Looking at the situation another way, a small resistance in series The book you have waited with the load would permit the same for so long - constant voltage output as does the cathode follower. EDGAR M. VILLCHUR'S Cathode follower output impedance is expressed by the formula Z = Rkrp/ [r p + Rk( 1 + IL)]. But for the type of tube HANDBOOK OF ordinarily used, Rk is substantially greater than r9 (about 8000 ohms for a SOUND REPRODUCTION 12AU7), so that the approximate formula becomes Z = Rkr,/ [Rk( 1 + N) ], For over two years, this material ran in con- or Z = rp /(1 + ii). Since is large com- secutive issues of AUDIO and was followed pared with 1, we may further simplify, avidly by every reader. Now available in writing Z R /r9, or Z = 1 /gm. The g,,, book form, with corrections and minor revisions, this material will be recog- of a con- nized as the basis of a thorough course in sound reproduction. Covers the 12AÚ7 under typical operating subject from the elements of sound to individual chapters on each of the ditions is about 2200 microinhos. There- important components of a sound reproducing system. Ready for immediate fore Z x 1,000,0110/2200 = 450 ohms. It delivery, $6.50 postpaid. is apparent that a cathode follower can Customary discounts to d.alen and distributers accept a very great capacitive load without significantly affecting high -frequency response (although signal handling ca- RADIO MAGAZINES. INC., Book Division be radically affected). . P. 0. Box 629, Mlrr..la, N. Y. pacity may

Please send me copies of Villchur's HANDBOOK OF SOUND

REPRODUCTION. I enclose chock money order for $6.50 each. AUDIOCLINIC (from page 4) Nam. This same procedure should be followed Address for each speaker removed. Resistors used should be of appropriate wattage rating. City Za.. State This substitution need not be accomplished by bodily removing the speaker and then

88 AUDIO DECEMBER, 1957 EONARD RADIO. INC. NCMI..wM.M..

presents a complete stereophonic system created by madison fielding

THE MADISON FIELDING SERIES 320

40 WATT STEREOPHONIC AMPLIFIER

Fig. 1 replacing the resistor. One means for do- changes with just one multideek rotary ing it is to place on each speaker a single - switch. Such a switch would have to con- pole double -throw switch. In one position tain many positions, since provision would a resistor is switched in, while in the other, have to be made for connecting these the speaker is switched in. (See Fig. 1.) speakers to the amplifiers in various com- Means could be devised for making these binations. PRICE $6995 2 complete amplifiers an one brilliantly engineered chassis, together with 2 fully integrated preampli'iers. Provi- STEREO RECORDER sion for phonograph or tape -head playback, both fully equalized. (from page 23) Individual controls for each section as Concertone is running during these for practice in aural comprehension. well as a master volume control for He adjusting stereo program levels. Dual pauses, the tape made on channel 1 will can use it as dictation by stopping the magic eye takes the mystery out of level- setting. In addition to its stereo contain these pauses just like the com- player at the end of each sentence, writ- application, this versatile duo -amplifier mercial language records, and can now ing down either the French version or the will serve in monaural use as a corn - plete electronic crossove system to be used for channel -to- channel sound -on- English equivalent, and in the end com- feed separate woofer and tweeter corn - sound practice. paring his results with the original ma- b in ation s. terial. He make his own dictation tapes Making our own Recordings of the English versions for practice in THE MADISON FIELDING I have devoted some time to records, providing the French versions. Playing SERIES 330 not only because they have been so use- the tape back on the Concertone the can ful to us, but also because they are likely use the sound -on -sound technique to FM -AM MULTIPLEX TUNER to be the most available source of well - practice pronunciation and evaluate his spoken French for readers who want to progress. experiment with their own private lan- The versatility of the Concertone 23 guage laboratory. is most evident at this point. Earlier We have found, on the other hand, it was suggested that owners of mon- that some of our most fruitful activity aural tape recorders should purchase with the tape recorder has consisted of phonograph records with pauses rather making our own recordings with the help than tapes containing the same material, of French -speaking people. We can get since the disk and a microphone signal 95 onto the tape precisely what we con- could be recorded simultaneously on one PRICE s129 sider we most need and get it in the form recorder, while the use of a tape original 2 complete ultra- sensitive tuners on we want it one compact chassis. The AM and FM would require a second tape player. tuners of this unit can be used indi- Take Larry's school work, for exam- With live recording at home the original vidually, in single channel operation OR at the turn of a switch, both sig- ple. Het is given periodically a group of must be a tape. This presents no prob- nals are available simultaneously for the latest stereophonic broadcast tech- French sentences and phrases along with lems for the stereo recorder. But if the niques. their English equivalents. Whenever he owner of a monaural recorder wants the gets such material, a young French Special Multiplex output permits later tremendously valuable sound -on -sound adaptation of the most advanced form friend, Allen Couturaud, records it for practice, he will have to borrow another of stereophonic reception. Exclusive Dual "stereoscopic" tuning indicator him. Larry handles the recorder him- tape player. enables proper center -of channel tun- self, timing Allen with a movement of I myself have a similar use of recording of both signals simultaneously. the hand so that he leaves a pause after ings made at home with native French Moil & phone orders filled each sentence. When the recording is speakers. I find that a large portion of 25% deposit, balance C.O.D. completed Larry can use the tape in a the stock phrases and sentences on number of ways. Playing it on his own phonograph records and in textbooks are 'LaNAR RADIO. INC. tape player he can run it continuously of little use to me. I have not, unfor- York 7 N Y COnb.d, 7031

AUDIO DECEMBER, 1957 89 startling silence for the perfectionist tunately, had any contact with French Except during the summer months, customs officers, porters. station masters spoken French programs are generally and hotel keepers in many years and it is given every Saturday afternoon over eeiggett;f4eeet, quite possible that I won't for some years the city station WNYC. Even the TURNTABLE more. I also don't, in the normal course dreary stretch of programs in which of my life, have occasion to say very only the French "classics" are broadcast much about pens, pencils, blackboards, will provide much that is useful, and aunts, and people's preferences as to the broadcasts of modern plays and spring, summer, autumn, and winter. poetry provide exciting and valuable We don't even have any brothers and practice material. Since everything is re- sisters around. Also, most of the conver- corded in France, no concession is made sation I read in to the problems of Americans learning The hush of an empty church, even though French literature is the synchronous motor is running - this is spoken by Frenchmen who apparently French. Some of it is spoken so fast the Connoisseur, crafted in traditional don't travel, go to school, or care very that even our French friends have some English quality. Precision machining assures pure sound reproduction. Non -magnetic, 12" much about seasons. And what they have difficulty with it. This very fact makes lathe -turned table; precision ground spindle; to say about concierges probably the broadcasts particularly useful for ±2% should phosphor bronze turntable bearing; not be repeated by American tourists. practice in aural comprehension. variation provided for all 3 speeds; hysteresis motor. $110.00 From French literature I gather that the When we could only listen to these TURNTABLE: Rumble -better than 50 talk in French homes is pretty much programs we could catch some of the db down; Wow -less than 0.15% of like the talk we hear in American homes. dialogue, but a great deal more was lost rated speed; Dimensions: 131/2x15% ". So from this literature and from conver- for good. Now we record as we listen PICKUP: Frequency Response - 20- sations with French -speaking people. I (or have someone record for us) and we 20,000 cps ±2 db at 331/2 rpm; Effec- tive Mass -4 mg; Impedance -400 have collected a large number of expres- can re -run the tapes as often as we wish. ohms at 1000 cps. sions which are really common in every- It is something of a game to see how "Dynabalanced" tone arm with Mark II day conversation and am attempting to much more of the dialogue we can un- super- lightweight pickup introduce these into our own conversa- derstand each w /diamond stylus with replay. If we have 549.50 tions at home, utilizing them not for too much difficulty and we think the ma- 412141 w /sapphire stylus random practice but in situations calling terial is important enough, we obtain 534.50 for their use. Write today for literature. the text of the play or poetry and study ERCONA CORPORATION Again the tape recorder is our most the text and tape together. In the case (Electronic Division) useful tool. Our French friends record of Moliere's "Le Misanthrope" this pro - B51 Fifth Ave.. Dept. 24, New York 17. N. Y. the expressions, the recording is made cedure was so successful that when the Co. Ltd. !n Canada: Astral Electric on channel 1 along with my beloved 44 Danforth Road, Toronto IS play was presented in New York City by Circle 90A pauses. Then all members of the family the Renaud -Barrault company, we had can practice this material. After a good no difficulty at all in following the deal of practice we find ourselves adopt- spoken lines. SAVE '/2 PAY PART -BY -PART HAVE FUN - - ing the phrases in our own conversation. When we finally get tired of a par- Assembling the SCHOBER This consistent use of the tape re- ticular broadcast we have taped, we erase ELECTRONIC corder for commonly used expressions the tape and re -use it. has also helped us immensely to under- If a modern play which we have taped ORGAN in KIT form stand French people to whom we speak. contains a great deal of conversational We find our expressions constantly pop- French which we think will be useful ping up in their conversation and don't practice material, we utilize the editing even feel the urge to translate them. Un- technique previously referred to for re- ñ10 -SP,ECIÁL- fortunately, our French friends some- recording the play on channel 1 of a new SKILLS ; __ _ times become too impressed with our tape with pauses inserted after each NEEqED,;:.- progress and forget to give us any kind complete expression. This tape is then of a break, rattling away at high speed used for practice with the sound -on- and mumbling. I'll know when I'm really sound technique, recording the short Now you can afford a real, full concert organ, just doing well in French -when I can un- speech units followed by our own repe- like those made by the foremost organ manufac- derstand French mumblers as well as I turers. Because over 1/2 the cost is saved when you tition on channel 2. assemble it yourself. And it's REALLY EASY: only understand the English- speaking variety. There must be many other sources of 24 separate units, all with printed circuits, and detailed -to- the -smallest -step instructions. In addr- Incidentally, we have found a real use good language material with which we lion, you purchase each of the 24 kits when you are for something I generally regard as an are not yet familiar. We'll keep search- ready for it - and can afford it. You'll get a real kick out of putting the Schober unmitigated bore-the "bugging" of con- ing for them. But with just the material Electronic Organ' together - and then sitting down versations. We have recorded some of and pulling the stops for Strings, Trumpets, Clar- we have found, our private language inets, Diapasons, Flutes, etc. Electronic Percussion our conversations with our French laboratory looks like a great success optional; available. chimes friends. The replaying of these conver- to us. Compact CONSOLE sations has been a lot of fun and ex- One of the many exclusive features of this excep. tremely useful at the same time. tional organ is the handsome console, in a wide English Speech Training variety of finishes. It is equally at home in a tradi. tional or modern setting, and takes little more space Recording Radio Broadcasts One of the most immediate and dra- than a spinet piano. The extent of radio broadcasting of matic achievements of the tape recorder foreign language programs in the United in our home was in the field of English Complete descriptive booklet and price list are States naturally varies with the size of speech. At about the time we got the available on request. And, if you wish to hear the glorious pipe organ tone of the Schober Electronic the city, the importance of foreign lan- instrument, Larry had entered a school Organ, a IO" long- playing demonstration recording is He had chosen available for $2. This is refundable when you order. guage groups in the area, and the gen- recitation competition. Write today and see what a fine instrument you can eral cultural importance of the language one of Thurber's "Fables for Our get at such a great saving. being studied. Times." This is a type of thing not often The SCHOBER ORGAN CORP. In New York City, for instance, you encountered in junior high school reci- York 24, N. Y. 224* -K Broadway, New can hear Italian and Spanish programs tations, and requires unusually effective 'Designed by Richard H. Dorf delivery to put over. A large part of Circle 90B throughout a large part of each day.

90 AUDIO DECEMBER, 1957 Larry's success in getting among the top hear it in the concert hall," had left me finalists for his school can he credited more than a little skeptical and bored at to the tape recorder. with the whole stereo business. For much of this application, as for However, you simply cannot go on music and foreign language learning, the forever ignoring the musical possibilities last... Concertone 23 is used as a single -track of a stereo recorder that's sitting right recorder. Within this limitation it does there staring you in the face. Besides, clean two jobs well: it permits Larry to record now that I have (quite unintentionally) himself and listen critically to the play- provided music-loving AUDIO readers back, and it trains him to be at ease with an irresistible justification for the record with a microphone. This last is not un- purchase of a stereo recorder -the fact important. We know of numerous cases that it is so desperately needed for the where students who did well when prac- good of the children -I think I ought grooves, r. ticing without a mike got quite a case to say something about my conversion to of jitters when the final presentation stereo for music. ! had to be made in front of a mike. In a way it was those of my friends no static The uses of two -track sound -on -sound with the most costly monaural systems are not so obvious for English speech who drove me into taking an interest in training. In training for a specific reci- stereo music reproduction. As a result tation or speech, we think it would he of their prodding I set up a system unwise to provide the learner with a which, however, dismayed them no end. model which he can imitate. He must To the Wharfedale twelve -inch speaker work hard at developing his own style already installed in a large floor -to -ceil- of delivery. ing bookcase baffle that separates our However, for general speech practice rather large living room from a foyer, the developing of skill in consciously I added another twelve -inch Wharfedale. imitating the style of delivery of an- One speaker is fed by a Marantz 40 -watt other person is a worthwhile achieve- amplifier, the other by a modified 10- ment. With a sufficient variety of models watt ADC amplifier which is installed in to follow there is little chance that the the same case that holds the recorder CANA f, t60 learner is going to get into a stylistic preamps. Of course, said the purists, rut. My wife, who has had some stage even if stereo were superior, other things RECORD training, often provides the model. We being equal, how could two direct radia- also use phonograph records, or record tors in an open bafe, fed by two dif- CLEANING KIT ferent kinds of amplifiers, compare with good speech from the air. For practice The only record cleaning kit with these models, the two -track s -o -s their massive n -way speaker systems? engineered to clean record feature of the stereo recorder is invalu- Halt! One fellow whose speaker alone first able. It is difficult to mimic a delivery cost almost as much as our entire set -up grooves! Contains the style if you first have to listen to an and who uses a pair of cascaded elec- functionally- designed groove - entire speech. But if you can break it tronic cross-overs and three top -notch cleaning applicator and a down into individual sentences, with a power amps following his pre -amp, ad- recognized anti -static detergent. pause after each sentence to provide for mitted ruefully that he would change for A few drops of Lektrostat and a repetition, it is a simple matter indeed. our stereo set -up as is. But I know what few strokes of the special he'll really end up with he can get Here the Coneertone and the Viking are -if groove-cleaning applicator it all in his apartment-the tape re- used together to get the "paused" version eliminates static ... thoroughly on channel 1 of a new tape, and the two - corder plus another set -up just like the not only the surface but track s -o -s technique records the sen- one he has! cleans tences of which the model followed by But to get back down into this world the grooves. Sold through the repetition of the learner on channel and our own set-up. What comes out of dealers in New York area - or it sounds line no seat I ever found in a 2, given the learner an opportunity to s200 replay the two together and evaluate concert hall. In many cases the spatial send for complete kit relationships are obviously even more just how good his imitation actually is. check or M.O. - no C O.D.'s distorted than with single -channel repro- I have a feeling that we have only ,n scratched the surface in finding special duction. Yet one need not understand I 1 uses for the stereo recorder in English the nature of the stereo effect or even be speech practice, but it has already convinced that it is more true to the live proved its great worth. original to feel the very great difference between stereo and monaural reproduc- Stereo Music tion. The rest of my comments are nothing Although I am very much interested more than tentative ideas that have anti -stat lc groove -cleaning olasTie in both live and reproduced music, stereo struck me during some months of listen- oetergcnt apphcator pouCC music reproduction was certainly not ing to stereo. uppermost in my mind when I decided The special quality of stereo is ap- must be satisfied or MONEY BACKT to buy the stereo recorder. On the con- parently not just a matter of the spread trary, the pointless and noisy demon- of sound. This has been seriously sug- Chemical strations of moving horses and fifty - gested by some visitors. But we have corp. foot -long pianos at the most recent audio both the monaural LP record and the dexter consumer products division show, together with what appeared to stereo tape of the RCA recording of the me to be pretty extravagant nonsense in Berlioz Symphonie Fantastique, and we 845 Edgewater Rd.. New York 59 advertisements and magazine articles and visitors have often compared the world's foremost chemical anti -static about reproducing sound "exactly as you playing of the monaural reproduction, research organization. o.

AUDIO DECEMBER, 1957 91 with the two speakers connected in we are ashamed parallel, with the stereo reproduction. CLASSIFIED Almost everyone has agreed that for this gates: 10e per ward per Insertion fr aa.waasrelal particular number the two speakers were advertisements; 25' per word tar aawwwial sow- Peelings. gates are net. and ne thwarts .111 M better than one in monaural playback, .Hewed. Copy out be awwaaal« ay r....tte00. h monaural tell, and asst reap the Raw rat Pew b the Met H but that the effect of the re- the month preceding the date H laie. production with the two speakers in parallel was not nearly as sonically ex- THE .11' DIO EXCHANGE has the larges citing and satisfying as the stereo repro- selection of new and fully guaranteed used duction from equipment. Catalog of used equipment on tape. rreeqquest. Audio Exchange, Dept. .E 159-19 Another tentative conclusion relates to Hillside Ave., Jamaica, 32, N. Y. AXtel 7 -7577 ; 367 Mamaroneck Ave., White Plaine, N. Y. Made in England the "bearable" loudness at which music 1VI1 8-3380 ; 836 Flatbush Ave., Brooklyn, can be played. No one in our family likes ItUckminster 2-5300. loudness for its own sake, and we make HIGH FIDELITY SPEAKERS REPAIRED to mention the price! Amprite Speaker Service every effort to play at comfortable lev- 70 1'esey St., New lork 7, N. Y. BA 7 -2580 els, particularly avoiding the "larger- New 0 Coaxial 700 Series Mark Ill LOOKING FOR CLEAN RESPONSE TO 20 than- life" sound, But when I am listen- CYCLES? Listen to the radically new Bacon suspension speaker. Bacon are ashamed to in "H1-C" 15" foam Some manufacturers mention the ing dead earnest to the reproduction Electric Company Inc.. 1261 Broadway, New price because it is so high we hesitate be- ... 1, N. 1. cause it is so low f We know that most Audio- of a large orchestra there is one ideal York philes feel they have to make a big investment requirement I would like to have a re- to get a quality speaker. They spend hours FOR SALE : AMPEX 300, 350 -2, 600, 601, reading claims that look impressive on paper producing system meet as closely as pos- 601 -2 and A- Series, available from stock at Roslyn, Pa. TUrner 7 -4277. but fall down severely when translated mto sible: that when it off Grove Enterprises, actual performance. All we ask is that you close gives with sounds your eyes and listen to the majesty of sound that are as loud to my ears as those I CUSTOM HIGH FIDELITY systems de- that floats out of the R & A coaxial phenome- signed and installed. Equipment expertly non. Compare it with others ... or your pres- would receive at some seat in the concert serviced and repaired. Free pickup and de- ent speaker. Your eyes will pop when your hall, I should be able to listen livery in New York City area. Eastern Audio dealer whispers the price to you -less than the to these Co., 6139 Tyndall Ave., Bronx, N. Y. KI 9-8134 cost of 2 good seats at the Met reproduced sounds as comfortably as I 8 ", 1 and 12" Models -all with can listen to Write us before you buy any hi -e you'll be Alcomax Ill Aniso -tropic Magnet sys- the concert hall sound. A glad you did. Immediate replies. Key Elec- tems of 12,000 Gauss Flux Densities. good test with which to judge how well tronics, 120 Liberty St., New York 6, N. Y. Buy it . . try it . we back claims with EV 4 -6071. a money bark guarantee. At all hi-fi dealers. a system measures up to this standard is ERCONA CORPORATION to note the reaction of ordinary folks Long Playing records 20 to 50% discounts: ; factory fresh ; unplayed ; all (Electronics Dm.) (not hi -fi brand new 551 Fifth Ave., Dept. 25, New York, N. Y. fanatics) to high intensity labels. Send 20t for catalog to Record DIs- In Canada: Astral Electric Co., Ltd. levels, before you have beaten them into count Club, 1108 Winbern, Houston 4, Texas. 44 Danforth Road, Toronto 13 submission with verbal and musical at- RECORD CUTTING SERVICE and Circle 92A tacks on their sense and Tape to Disc. Write for literature sensibility. Prices. Electronic Associates Dept. C. Box 91, (I'm not too bad a subject for this test Merion, Pa. ELIMINATES myself. Some of my friends wake up FOR SALE : Weathers pickup system; new RANDOM MORE EFFICIENT from the blissful coma their "bigger bang oscillator, 16" arm, sapphire stylus, $40. Ozzello, 3559 S. Lenox St., Milwaukee NOISE TIME James SAVER for the buck" has put them into only to 7. Avis. find that I've gone off). Now I have AVitlt factory cooperation I can furnish 4- noticed time and again that people who inch 30- minute tape for corresponding. In- tend to complain about anything louder cludes strong lightweight box, only $1.00. Can Faster, more be used repeatedly for only 40 postage. Gee. than background music will accept Bischof, 1503 E. trickery Blvd., Fort Worth, effective tape quite high loudness levels in stereo without Texas. degaussing -for batting an eyelash. I haven't the least FOR SALE : UTC 3A Equalizer, $55 ; Mag- professional, necorder 93X5 Tape Playback Amplifier and idea why this should he so, but for seri- $30 military or Power Supply, ; Arthur Marko, 429 But ous listening where the music should be 70th St., New York 21, N. Y. REgent 4-3573. home use loud the greater "bearableness" of loud AMPEX Model 600 tape recorder, with stereo sound is an extremely valuable special playback control on front panel. New heeds, dual track. Guaranteed 30 to 15,000 characteristic. cps, $400. H. White, 2123 Kenmore Ave., Not everything is rosy with stereo, Bethlehem, Pa.

though. Everyone who has purchased TA l'E 11 'Y- Leading manufacturers' re stereo tapes knows what the big rub is. cording tape; full frequency range, top qual- MODEL N.7 ity guaranteed. Acetate : 1200 ft. 1%-mil Cost. You can buy a lot of LP's for the $1.39, four or more $1.69 ; 1800 ft. 1 -mil $1.57. four or more $1.69 ; Polyenter : 1200 THE LIBRASCOPE MAGNETIC $18.75 that the Symphonie Fantastique ft. l'_ -mil $2.02, four or more $1.88; 1800 ; 2400 ft. costs, A lot of people ask me about this ft. 1 -mil $2.60, four or more $2.35 % -mil $3.01, four or more $3.32. Add 25t nolscrascr aspect of stereo, but I'm no better as a per shipment. Other tapes available. Hi- Sonic, Because it thoroughly "cleans" the tape of prophet than they are, and for the pres- Box 86 -T. New fork 63, N. Y. random signals as well as prior recordings, these Librascope Noi.seraser units are pre- ent I can only give them the kind of FISHER AM -FM 50 -R tuner, realigned for ferred by professional broadcasting record- optimum sensitivity. Excellent throughout, ing technicians, exacting military users advice I give to my students in color $95. Also. 53-ft. heavy -duty sectional antenna and Hi -Fi enthusiasts. Several models are photography who complain about the tower only $120, cost $270. L. Carini, Weth- available. high cost of color materials: "Better ersfield. Connecticut. Tape up to 1" and reels to 14" dia.; operates on standard 110V AC; erases new as little but better." Keep your large LP well as used tape. Made by one of the foremost manufacturers of computers and library, but for some occasions when controls. Bulletin M500 -1 you want something really superior, EMPLOYMENT available upon request. build up a small, select stereo library. ENGINEER WANTED : By progressive , manufacturer of intercoms and related equip- There are, of course, ways in which ments, located in New York City. Top salary to man experienced, in the latest tuner and very resourceful people can build up audio circuitry. Write to AUDIO Box 1201. IBKASCOPE stereo tape libraries at a somewhat more Leading Tape recorder manufacturer needs INCORPORATED modest cost. If the reader is that re- aggressive representatives for the following sourceful he won't have to embarrass areas : Ohio, Texas, Oklahoma, Colorado, a - SANTA ANITA AVE.. BURBANK. CALIF. Northern California, Wisconsin. Must be Circle 92B me by asking how. handling Hi -Fi lines. Box 1202.

92 AUDIO DECEMBER, 1957 PROFESSIONAL ,/`jusb% DIRECTORY /'ne eee CAPSULE COMMENT ON THE 1957 NEW YORK HIGH FIDELITY SHOW: Listen knowingly Huzzahs galore to Edwin Cornfield, executive secretary of the institute of High Fidelity Manufacturers, who directed the ee.r!l,ru./y Súrcc /944 show to :t success which saw approxi- for more musical mately 35,000 visitors cross its threshold, and to Elliot Davis, his newly -chosen :assistant. By far the most interesting and HOLLYWOOD ELECTRONICS popular exhibit of high fidelity equipment enjoyment t date, the show verified the fact that 0 STRIBUTORS Il OF H1-F1 COMPONENTS onnponent high fidelity is the nation's la this book one of the best -known and most . . e t u . , v . . , fastest growing hubby. Knuckle raps are due a few exhibitors who displayed their highly regarded American composers shows equipment too loud-otherwise, everything was hunky -dory. you how to increase your enjoyment of music PEOPLE AND THINGS: Henry Klaus, through creative listening. Now you can 7460 Mri,o,r a.r- Los Angeles 46.CelilWEb.terTa208 Malcom Lowe and Anthony Hoffman, officials of KLH Research and Develop- listen to more music -hear ment Corporation, gave the it with greater understand- Circle 93A first public showing of the new KLH speaker systems ing and enjoyment -when with resounding approval ... ditto Joseph Grado of Grado Laboratories who dis- you know and can identify CANADA played the new Grado pickup which has the elements, forms, and High Fidelity Equipment been on the market for only a few months, along with a new tone arm which will be qualities with which the Complete Lines Complete Service marketed within the near future composer has worked. Hear Ampex Audio turned out virtually en Hi -Fi Records - Components niasse, with Art Foy and Him Farrow the great masterpieces of and Accessories from California headquarters taking turns music as the composers with Dick O'Brien and his New York staff In manning the lavish exhibit of tape wanted you to hear them! &LEC:TRO i)O10E recorders. Hal Lawrence, Ampex account executive for the Boland Associates ad- SOUND SYSTEMS vertising agency, was also in attendance. gal OlA1OAS ST. WBlT. TORONTO, CANADA. Bill Shredsr, Washington's pioneer cus- New Revised Edition Just Out tom builder and industrial sound contrac- tor, reported a recent sound reinforce- Circle 93B ment installation which called for 3000 Altec Lansing Model 755's ... Peter Mes- What to Listen for singer, of \Vashington's L.E.E., Incorpo- rated, elated at acceptance of the com- the finest in Hi-Fi pany's new line of Catenold speakers . . in Music //H Sidney Prey, head of Audio Fidelity Rec- ords, was the show's largest individual By AARON featuring [ecloydlCt exhibitor, occupying three large rooms on COPLAND two floors . . Karl Kramer, representing HIGH FIDELITY COMPONENTS Chicago's Jensen Manufacturing Company. 307 pages, 51/2 x 8, $3.95 displayed a new outdoor full -range speaker with full weather -proofing, along with the Jensen line of speaker systems for custom SOUND installation. THE author first discusses the creative r4[/ C O R P O R 4 T i O N Larry Ratios attended the show in his J. process and the elements of musical anat- dual capacity as proprieter of New York's omy- rhythm, melody, simple harmonic struc- 820 W. Olympic Blvd. L.A. 15, Calif. RI 70271 Ht -Fi HQ, custom builders, and top camera man for CBS Television News. Shot a ture. He then gives a full and clear explana- scene of healthy length for the Douglas Circle 93C tion of the principal musical forms- simple Edwards news program . AMI, Inc. of Chicago, represented by amiable Bill Pits - dance forms, the fugue, the variation, the Gerald, exhibited a grouping of walnut sonata, the symphony, the symphonic poem, HIGH cabinetry which set a mighty high high the opera. - FIDELITY HOUSE for both design and finish. . The New Most complete stock of Audio York Tintes Review of the show, which Chapters on contemporary was not entirely flattering, singled out music and film components in the West British Industries Corporation for express- music have been added to the new edition. ing good taste in its choice of Phone: RYan 1 -8171 demonstra- Also new is a list of recorded music to illus- tion music and the loudness (or softness) 536 S. Fair Oaks, Pasadena 1, Calif. with which it was played. Personal credit trate each topic covered. should be accorded Leonard Carduner, Circle 93D Eugene Cardnner, Arthur Gasman and Frank Hoffman. Praise for What io Lisen jor in Music Missing and missed at the show was (First Edition) Emory Cook of Cook Laboratories, Inc., FMAZ without whose presence nothing seemed `The best book I know to explain things Just right. He is on the receiving end of deep sympathy from the entire sound in- to the layman." -Oscar Letant antenna systems dustry for the recent fire in which he was "Sound, practical, and sanely modern." Nyb Is BrWbud Tsai M star. usages* te Seek seriously burned and his Connecticut plant 72 wet 300 abe lank M Olep FU. destroyed. . Prue A. Kutner, writer on -The New Yorker high fidelity and manufacturer of Musur- APPARATUS DEVELOPMENT CO. "By far the best Dept. C WefherelleW 9, CewesMcst gia Records, announcing completion of his thing of its kind yet to new book devoted to so- called consumer appear. " -Modern Music research" organizations. Expresses with Circle 93E lucidity his impression (and ours) of "One of the most helpful, sensible and irresponsible persons and /or groups who engaging discourses on the set themselves up as authorities in fields subject ever where they are not published." -Victor Record Review PROFESSIONAL RECORDING SERVICE qualified to have responsible opinions. . Another hi -fl writer, Irving Greene, author of several Tapes made, copied, masters cut, processed, SEE 10 pressings books, making his first appearance as head IT DAYS FREE made-short runs our specialty - of the ad agency bearing name, aH AMPEX 300'a Telefunkea d Altec, his sharing time in exhibits of three principal cli- r i1 HYDROFEED Lathes, monolusion presses ents, Pickering, Tetrad, and McIntosh. RADIO MAGAZINES, INC. Components Corporation, 106 Main St, Adolph Gross, Hilton Thalberg and P.O. BOX 629, MINEOLA, N. Y. Denville, N. J. Phone: ROckaway 9 -0290 Gersh Thalberg, importers and distributors of NI iracord record changers and Send me Copland's What to Listen for in Nth ,Ltw in pickups, giving initial showing Music for 10 days' examination on approval. Circle 93F to a number of audio accessories which In 10 days I will send 23.95, plus few cents will be announced In the near future . for delivery costa, or return book postpaid. Anthony Dosahek, head of Pro -Plane Sound (We pay delivery cost if you remit with cou- BE HAPPY AGAIN! Systems, inc., presided over one of the pon; same return privilege.) Write us your hi -fi needs now show's interesting. displays -a 6- ft. -sq. (PRINT) you'll be glad you did. speaker system designed for placement in Name ...... the center of a room -weighs 760 lbs. and Immediate replies. Cenplste stink Address ...... sells for twenty -five hundred dollars . Dept. AE Another attraction was the new Weath- City Zone State KEY ELECTRONICS CO. ers turntable, introduced by Paul Weath- Company 120 LIBERTY ST., N. Y. ers, president of Weathers Industries, Inc. 6, N. Y. In place of a powerful motor and heavy Position ... LSS Phone:: EYerereen 4.6071 table, it uses a small 12 -pole clock -type Fer piss sad germ staid U. S. motor and relatively light table to achieve Lwrite McGrew -flit Intl, N.Y.C. Circle 93G results which are truly remarkable. J

AUDIO DECEMBER, 1957 93 SUBJECT INDEX 1957

fidelity; Bruce H. Verde- ACOUSTICS Which tube shall I use ?; George Fletcher Toward ultimate Cooper, Nov. 30. man. Apr. 17. Auditorium acoustics and control facilities tor reproduction in auditory perspective; E. H. Bedell, Sept. 24. DISTORTION MANUFACTURING does it. Feb. 30. Sad case of a half -watt resistor; Walther How the factory AMPLIFIERS Richter. Dec. 36. Understanding internmdulation distortion; MEASUREMENTS Care and treatment of feedback audio Mannie Horowitz. Aug. 22. amplifiers; W. B. Bernard. Jan. 30. Hum specification measurements; Mannie Electrical adjustment in fitting a new out- Horowitz. June 26. put transformer; Norman H. Crowhurat. ENCLOSURES Translator VU meter; Paul Penfield Jr. Apr. 19. Apr. 22. High- quality treble amplifier; Charles W. Aperiodic loudspeaker enclosure; Dr. E. Harrison Jr. Ang. 15. De Boer. July 13. High -quality tape recorder amplifier; Her- I get hot music from a cool cabinet; David MERCHANDISING man Burstein and Henry C. Pollak. I K. Slifer. Mar. 24. Hi -Fi salesman- friend or foe ?; Marco Jan. 15; II Feb. 32. Integral speaker systems, pro and con; Karpodines. May 26. How an output transformer causes dis- Herman Burstein. Oct. 40. tortion; Norman H. Crowhurst. I Feb. "Standard" speaker system; C. G. Mc- 20; II Mar. 21. Proud. Jan. 26. MUSICAL INSTRUMENTS Impedance and feedback in audio circuits; Toward ultimate high fidelity; Bruce H. C. Pollak. Vardeman. Apr. 17. Violin and its hi -fi analogies; Anthony Herman Burstein and Henry I 17; II Oct. 42. Dec. 26. Doachek. Sept. Low -noise transistor microphone amplifier; James J. Davidson. Oct. 28. EQUALIZERS NETWORKS Output transformer specifications; Norman H. Crowhurst. Recording characteristic simulator; S. K. Equalizer design; Norman Ghandi. Apr. 24. H. Crowhurst. June 20. I Aug. 17; II Sept. 34. Sad case of a half -watt resistor; Walther Professional equalizer -preamp suitable for Richter. Dec. 36. home use; Kenneth W. lieteh. Feb. 18. PATENTS Single- channel transistorized remote amplifier; John K. Birch. May 36. Cascode amplifier for phono preamps; Stereophonic magnetic recording amplifier; EQUIPMENT REVIEWS Joseph Marshall. Apr. 26. Arthur W. Wayne. Oct. 21; Nov. 38. Essentials of combination patents; Albert Stereo -monaural companion amplifier for AR -2 Loudspeaker; Sept. 54. Woodruff Gray. Mar. 30. the " Preamp with Presence"; Louis Audak KT Arm; Mar. 35. Forbidden fruit of patent pooling; Albert Bourget. Nov. 19. B -J series 90 Arm ; Nov. 64. Woodruff Gray. Nov. 42. Transistor playback amplifier; Fred Wy- Bogen ST10 stereo conversion amplifier; Phonograph pickup arnt-a problem; H. man. Sept. 20. July 26. A. Schwan. Apr. 28. Two -channel mixer for Auricon film cam- Cappa condenser microphone; Mar. 35. Professional equalizer- preamp for home era: Donald K. Haahr. Nov. 36. Connoisseur turntable; Feb. 40. use; Kenneth W. Betsch. Feb. 18. Two -channel transistor remote amplifier- Dyna preamp and Dynakit III; Dec. 50. Transistor preamp for low -output pickups; mixer; Donald K. Hanhr. Sept. 46. ESL "Dust Bug "; Oct. 52. Anton Schmitt. July 20. Which tube shall I use ?; George Fletcher Fairchild 412 -1 turntable, 280A transcrip- Cooper. Nov. 30. tion arm; Dec. 50. Garrard line of phono equipment, Dec. 54. PREAMPLIFIERS Garrard Model T "Mark II'; July 26. Cascode amplifier for phono preamps; ATTENUATORS Garrard TPA -10 Arm; Oct. 48. Joseph Marshall. Apr. 26. General Electric VR -II Pickup; Dec. 52. Transistor preamp for low- output pickups; High - impedance mixing for professional Grado Pickup; Sept. 54. Anton Schmitt. July 20. audio equipment; George L. Augspurger. Kingdom Audette Sr.; Sept. 56. Feb. 13. Metzner Starlight turntable and arm; Oct. Matching impedance, variable attenuation 52. PRINTED CIRCUITS box; Harold Reed. May 46. Miratwin, Miracord, and Miraphon line; of wiring In high fidelity; Sept. 52. Role printed Phillips tape recorder; Nov. 80. Norman H. Crowhurst. May 17. BELL TELEPHONE LABORATORY Series Pickering Fluxvalve cartridge; Feb. 38. Acoustic illusion telephonically achieved; Pilot AA -920 and AA -903B amplifiers; Oct. PSYCHOACOUSTICS Harvey Fletcher. July 22. 50. Above all, the ear; Jennie A. Nunley. May control facili- Shure Bros' I)ynetic pickup; May 48. Auditorium acoustics and Apr. 36. 15. ties for reproduction in auditory per - Sonotone HFA -150 amplifier; Acoustical and electrical considerations in 24. Steel Slides Feb. 40. spective; E. H. Bedell. Sept. Oct. 48. symphony orchestra reproduction; Wal- Auditory perspective; W. B. Snow, Aug. 20. Stephens Fie -80 loudspeaker; ter T. Selsted. Jan. 22. definition, measurement, and Tape -Indx and Perms -File; Oct. 101. Loudness, its 60 amplifier; Acoustic illusion telephonically achieved; calculation; Harvey Fletcher and W. A. Tech -master Model 19K -watt Harvey Fletcher, July 22. July 25. Munson. I, Nov. 53; II, Dec. 40. systems; Nov. Adequate audio power in the home; James Loudspeakers and microphones for audi- Wharfedale 3 -way speaker Moir. Mar. 16. tory perspective; A. L. Thuras. Oct. 34. 62. Auditory perspective; W. B. Snow. Aug. 20. Reproduction of orchestral music in audi- Nophonic reverberation unit. Nov. 64. Electrostatics, watts, realism and concert tory perspective; June 16. halls; Gilbert A. Briggs. Feb. 26. Fidelity perilous; George L. Augspurger. FEEDBACK Oct. 30. BOOK REVIEW Care and treatment of feedback audio am- Hi -Fi in the home -musical sound or blast; Acoustics for the Architect; Harold Bur- plifiers; W. B. Bernard. Jan. 20. Leonard Warren. Mar. 15. and Lewis Goodfriend. Oct. 77. Impedance and feedback in audio circuits; Loudness, its definition, measurement and ris -Meyer Herman Burstein and Henry C. Pollak. calculation; Harvey Fletcher and W. A. Dec. 20. Munson. I Nov. 53; II Dec. 40. Loudspeakers and microphones for audi- BROADCASTING tory perspective; A. L. Thuras. Oct. 84. Low -noise transistor microphone amplifier; HUM New concept on psychological aspects of James J. Davidson. Oct. 28. stereo sound; H. F. Hume. Mar. 26. Single- channel transistorized remote am- Hum specification measurements; Mannie Reproduction of orchestral music in audi- plifier; John K. Birch. May 36. Horowitz. June 26. tory perspective; June 16. Two -channel mixer for Auricon film cam- More about hum; Harold Reed. Jan. 25. "Third distension" in sound; Sept. 22. era; Donald K. Ilaahr. Nov. 36. Two- channel transistor remote amplifier - RECORDING, Disc mixer; Donald K. Haahr. Sept. 46. LAW Essentials of combination patents; Albert Recording characteristic simulator; S. K. Woodruff Gray. Mar. 30. Ghandi. Apr. 24. CONTROLS Forbidden fruit of patent pooling; Albert Take your recording room with you. Feb. 24. "Free- riding" control relays; Ronald L. Woodruff Gray. Nov. 42. Ives. Mar. 20. LOUDSPEAKERS RECORDING, Tape loudspeaker enclosure; Dr. E. Dubbings duplicator; Herman Burstein. CROSSOVER NETWORKS Aperiodic Nov. 23. De Boer. July 13. recorder amplifier; Her- RC crossover compromise; Norman H. Integral speaker systems, pro and con; High- quality tape I Crowhurst. July 17. Burstein. Oct. 40. man Burstein and Henry C. Pollak. Herman Jan. 15; II Feb. 32. Loudspeaker damping; Edgar Villchur. magnetic recording ampli- Oct. 24. Stereophonic DESIGN compromise; Norman H. fier; Arthur W. Wayne. I Oct. 21; II RC crossover Nov. 38. in audio circuits; Crowhurst. July 17. Impedance and feedback system; C. G. Mc- Stereo recorder-a revelation and an edu- Herman Burstein and Henry C. Pollak. "Standard" speaker cation; Joseph E. Freda. Dec. 19. Dec. 26. Proud. Jan. 26. AUDIO DECEMBER, 1957 94 RESISTORS How to plan your Iii -Fi System; C. R.TBANSISTORS Sad case of a halt -watt resistor; Walther Tiernan. Dec. 24. Richter. Dec. 36. Integral speaker systems, pro and con; Low -noise transistor microphone ampli- Herman Burstein. Oct. 40. fier; James J. Davidson. Oct. 28. System simplicity in audio; R. G. Chap - lick. Single -channel transistorized remote am- STEREOPHONIC Jan. 38. plifier; "Third dimension" in sound; Sept. 22. John K. Birch. May 36. Acoustic illusion telephonically achieved; Transformers in transistorized equipment; Harvey Fletcher. July 22. Norman H. Crowhurst. Nov. Auditory 48. perspective; W. B. Snow. Aug. TEST EQUIPMENT Transistor playback amplifier; Fred Wy- 20. man. Sept. 20. Loudspeakers and microphones for audi- Matching impedance, variable attenuation tory perspective; A. L. Thuras. Oct. 34. box; Harold Reed. May 46. Transistor preamp for low -output pickups; New concept on psychological aspects of Anton Schmitt. July 20. stereo sound; H. F. Hume. Mar. 28. Transistor tone -control circuits; F. D. Reproduction of orchestral music in audi- TONE CONTROLS Waldhauer. Sept. 27. tory perspective; June 18. Transistor tone- control circuits; F. Transistor VC meter; Paul Penfield Jr. Stereo -monaural companion amplifier for D. Apr. 22. the "Preamp with Presence"; Louis Waldhauer. Sept. 27. Bourget. Nov. 19. Two -channel mixer for Auricon film camera; Donald K. Haahr. 36. Stereo recorder -a revelation and an edu- TRANSFORMERS Nov. cation; Joseph E. Freda. Dee. 19. Two -channel transistor remote amplifier - mixer; Donald K. Haahr. Sept. 46. Electrical adjustment in fitting a new out- SYSTEMS put transformer; Norman H. Crowhurst. Apr. 10. Acoustical TUBES and electrical considerations in How an output transformer causes dis- symphony orchestra reproduction; Wal- tortion; Norman H. Crowhurst. I Feb. Which tube shall I use ?; George Fletcher ter T. Selated. Jan. 22. 20; II Mar. 21. Electrostatics, watts, realism, and concert Cooper. Nov. 30. balls; Gilbert A. Briggs. Feb. 26. Output transformer specifications; Norman H. Crowhurst. June 20. Ford Memorial Auditorium exemplifies TUNERS sound redesign; Bert Ennis. May 28. Transformer impedance transformation; High- impedance mixing for professional Harold Reed. June 24. Add a tuning indicator to ratio - detector audio equipment; George L.Augepurger. Transformers in transistorized Feb. 15. equipment; FM receiver; Carl R. Wischmeyer. Apr. Norman H. Crowhurst. Nov. 48. 32. AUTHOR INDEX 1957

Augapurger, George L. Doschek, Anthony High -impedance mixing for professional Pollak, Henry C. and Herman Burstein The violin and its hi-ti analogies; I Sept. A high -quality tape recorder audio equipment; Feb. 15. 17: II Oct. 42. amplifier; Fidelity perilous; Oct. 30. I Jan. 15: II Feb. 32. Ennis, Bert Impedance and feedback in audio circuits; Bedell, E. H. Ford Memorial Auditorium exemplifies Dec. 26. Auditorium acoustics and control facilities sound redesign; May 28. for reproduction in auditory perspective; Reed, Harold Sept. 24. Fletcher, Harvey A matching impedance, variable attenuation An acoustic illusion telephonically achieved; box; May 46. Bernard. W. B. July 22. More about hum; Jan. 25. The care and treatment of feedback audio Loudness, its definition, measurement and Transformer impedance transformation; amplifiers; Jan. 20. calculation : I Nov. 53: II Dec. 40: Jun. 24. Freda, Joseph E. Betsh, Kenneth W. Richter, Walther The stereo recorder -a revelation and an The sad case of a half -watt resistor; Dec. Professional equalizer -preamp suitable for education; Dec. 19. home use; Feb. 18. 38. Ghandi, S. K. Birch, John K. Recording characteristic simulator; Apr. Schmitt, Anton A single- channel transistorized remote 24. Transistor preamp for low- output pickups; amplifier; May July 20. 3e. Gray, Albert Woodruff Bourget, Louis Essentials of combination patents; Mar. 30. Schwan, H. A. Stereo -monaural companion amplifier for The forbidden fruit of patent pooling; The phonograph pickup arm -a problem; the "Preamp with Presence"; Nov. 19. Nov. 42. Apr. 28. Haahr, Donald K. Briggs, Gilbert A. Belated, Walter T. Two-channel transistor remote amplifier - Acoustical and electrical Electrostatics, watts, realism and concert mixer; Sept. 48. considerations in halls; Feb. 28. symphony orchestra reproduction; Jan. Two -channel mixer for Auricon film camera; 22. Burstein, Herman Nov. 38. Integral speaker Harrison, Slifer, David K. systems, pro and con; Charles W. I get Oct. 40. High -quality treble amplifier; Aug. 15. hot music from a cool cabinet; Mar. The Rubbings 24. duplicator; Nov. 23. Horowitz, Mannie Snow, W. B. Burstein, Herman and Henry C. Pollak Hum specification measurements; Jun. 28. A high -quality tape recorder amplifier; l'nderstanding intermodulation distortion; Auditory perspective; Aug. 20. I Jan. 15: II Feb. 26. Aug. 22. Thuras, A. L. Impedance and feedback in auditory cir- Hume. H. F. Loudspeakers and microphones cuits; Dec. 26. for audi- New concept on psychological aspects tory perspective; Oct. 34. stereo of Cooper, George Fletcher sound; Mar. 57. Tiernan, C. R. Which tube shall I use ?; Nov. 30. Ives, Ronald L. How to plan your hi -fi system; Dec. 24. "Free- riding" control relays; Mar. 20. Crowhurst, Norman H. Vardeman, Bruce H. How an output transformer Karpodines, Marco 'toward ultimate fidelity; Apr. 17. causes dis- Ili -ti salesman- tortion; I Feb. 20: II Mar. 21. friend or foe? ; May 26. illchur, Edgar Electrical adjustment in fitting a new out- McProud, C. G. Loudspeaker damping; Oct. 24. put transformer; Apr. 19. The "Standard" speaker The role of printed wiring in high fidelity; system; Jan. 20. Waldhauer, F. D. May 17. Marshall, Joseph Transistor tone- control circuits ; Sept. 27. Output transformer specifications; June 20. The cascode amplifier for phono preamps; The RC crossover Apr. 57. Warren. Leonard compromise; July 17. Hi -fi in Equalizer design; I Aug. 17.: II the home -musical sound or blast; Transformers Sept. 34. Moir, James Mar. 15. in transistorized equipment; Adequate Nov. 48. audio power in the home; Mar. It Wayne, Arthus W. Stereophonic Davidson, Munson, W. A. and Harvey Fletcher magnetic recording amplifier; James J. Loudness, its definition, measurement and I Oct. 21; II Nov. 38. Low -noise transistor microphone amplifier; calculation; I Nov. Oct. 28. 53: II Dec. 40. Wischmeyer, Carl R. Nnnley, Jennie A. Add a tuning indicator to ratio -detector De Boer, Dr. E. Above all, the ear; May 15. FM receiver; Apr. 32. The aperindic loudspeaker enclosure; July Penfield, 13. Paul Jr. Wyman. Fred A transistor VIT meter; Apr. 22. A transistor playback amplifier; Sept. 20. AUDIO DECEMBER, 1957 95 the the sound of Magnificent ADVERTISING erry rap INDEX TALENTED Acoustic Research, Inc. 75 Allied Radio Corporation 73 hands Altec Lansing Corporation .. 41, 49, 64, 67 Model 3A /N Amperex Electronic Corporation 62 in an era of mass production and auto- I portable) some Ampex Audio, Inc. 29, 60, 61 mation there are still products with built in which are individually assembled by speaker. Apparatus Development Corporation . 93 band -slowly with painstaking care and 3% -71/2 ips Audio Fidelity, Inc. 57, 63 attention to details. Vitavox loudspeak- Audiogersh Corporation 6, 7, ers are tine examples of this skilled $379.50 workmanship in the art of sound reproduction. They are created for the high Bell Telephone Laboratories 18 fidelity enthusiast who listens with his Bogen, David Co., Inc. Coy. II ears and his heart -rather than trying Bozak, R. T., Sales Company 55 to digest a table of specifications. The Range - Bradford G Company 85 I)Ú120 Duplex Coaxial Full Loud speaker is truly one of the most remark- Brand Products, Inc. 79 able achievements in audio craftsman- facing p. 1, 3 in the twentieth century ! The world's finest British Industries Corporation ship Classified 92 hi -fi tape recorder Components Corporation 88 Connoisseur 90 VITAVOX The ultimate in high-fidelity tape Duplex recorders for home and professional use. Datrel Company 74 Dual -speed, dual -track FERROGRAPH Dexter Chemicals 91 Coaxial recorders are also available in custom Dynaco, Inc. 82, 83 FULL RANGE decks LOUDSPEAKERS models (tape available, Elgin National Watch Company 14 $195.) and with 7% from Electro -Sonic Laboratories, Inc. 68 15 field and ips speeds. Independent Electro -Voice Sound Systems 93 performance tests rate Frequency Made in El CO 80, 81 England Response at ± 2 db between 50 and by Vitaror Ltd., Ercona Corporation 90, 92, 96 London 10,000 cycles with wow and flutter less than 0.2(,; at 7% ips. Ferrograph 96 at leading hi -fi dealers Quality standards have restricted our Ferrodynamics Corporation 31 may delay Fisher Radio Corporation 77 ERCONA CORPORATION production and unforsecn demand (Electronic Division) delivery, write TODAY for literature. Fukuin Electric (Pioneer) 58 551 Fifth Ave., Dept. 26, New York 17, N. Y. ERCONA CORPORATION General Electric 45 in Canada: Astral Electric Co., Ltd. (Electronic Division) Glaser- Steers Corporation 53 44 Danforth Road, Toronto 13 551 Fifth Ave., Dept. 23, New York 17, N. Y. Grado Laboratories 72 In Canada: Astral Electric Co. Ltd. Gray Manufacturing Company 76 i 44 Danforth Road, Toronto 13 Circle 96C Circle 96A Heath Company 8 -11 High Fidelity House 93 Hollywood Electronics 93 MAGNETIC TAPE ERASER Hycor Division of International Resistance Corporation 12 Induction Motors Corp. 15 JansZen Speakers (Neshaminy Electronic Corp.) 69 Jensen Manufacturing Company 51 Key Electronics 93 Kingdom Products, Ltd. 71 Kierulff Sound Corporation 93 Erases recorded signals and noise from magnetic tape without rewinding. Spindle mounting of reel permits rapid coverage KLH Research & Development Corporation 66 without missed spots. Noise level reduced below level of Lansing, James B. Sound, Inc. 33 standard erase heads. Restores tape to like new condition or better. Reel size range 5', 7 ", 101/2 ". May also be used for Librascope Incorporated 92 demagnetizing record-playback -erase heads. Leonard Radio, Inc. 89 $2750 Model HD-1 1 Price McIntosh Laboratory, Inc. Cov. III TELEPHONE PICK -UP COIL Mid -Continent Engineering, Inc. 86 Microtran Company, Inc. 96 For transe rib ing telephone cones r sat ons nith recorder making messages audible amplifier or on North Am. Philips Co., Inc. 13, 65 May also be used as probe for locating sources of hum. More constant signal level than base Orradio Industries, Inc. 2 mounted units. Suction-cup mounting on any telephone receiver. Supplied with 68 Pickering & Company 17 e shielded cable, terminated with standard Professional Directory 93 5 phone plug for recorder or amplifer. Pilot Radio Corp. 59 GIBSON GIRL TAPE SPLICERS Model HP -61 I. SemiPro SPA S 3.50 Robins Industries Corp. 96 2. Junior TS.4JR 6.50 MATCHING TRANSFORMER Rockbar Corporation 35, 87 3. Standard TS.4STD 8.50 4. De lase TS -4DLX II 50 A precision transformer developed to enable the audiophile to 92 RGA 5. Industrial (S sizes to I ") (net) SS.00 modify, enlarge, redesign, or rearrange his speaker systems. Rigo Enterprises 4 ROBINS PHONO AND TAPE ACCESSORIES Permits use of additional speakers of different impedance 6. Splicing tape ST-500 S .39 ratings with present amplifier, or crossover net- 90 Schober Organ Corporation 7. Jockey Cloth for Tapes JCT -2 1.00 without impedance mismatch. Delivers works, Sherwood Electronic Laboratory, Inc. I B. Tape Threader TT -I .98 equal, or 3 db. adjustable power, to all speakers. Sonotone Corporation 37 9. AUD.O -FILE AF -50 (net) 23.99 Power 50 watts, 100 watts peak. Frequency 0. Changer Covers CC -I, 2 2.00 Inc. Coy. IV response 15 to 30,000 cycles. Matching range, Stephens Trusonic, I. Turntable Covers CC -3 2.50 2. EID. 12 (pkg) 1.20 any combination of 1 to 3 speakers of 16, 8, 4 76 DisClosures Tannoy 3. Jockey Cloth for Records JC -I 1.00 Model HM -80 Price $2175 Tech -Master Corporation 84 4. KleeNeeDLE. NB -I 1.50 Thorens 47 5. Phone Cushion. IO". 12" PC 10. 12 1.50 4. Atomic Jewel SE -90 5.00 A66116416 Croon rrerironlr end Audio University Loudspeakers, Inc. 5 At Dealers Everywhere

Viking of Minneapolis 39 ROBINS INDUSTRIESTRIES CORP. COMPANY rAr S ItF CI, STRIES61tW role micRoTRflll Inc. Vitavox 96 Valley Stream, L. I., N. Y. Weathers Industries, Inc. 43 P Circle 966 Circle 96D

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colnnn3 1 1 1 1 1 1 1 A W N N N N N- W N -O .O At the end of each item of New Litera- preciate hearing about them. To get O P ture, New Products, or Equipment Re- more information about the products 1 Vt A W of W N_ V N views you will notice a letter and a num- that are advertised in each issue ber -the letter indicates the month and AUDIO -use the same card. Circle the W W C.) W N the number indicates which item it is. number of the page on which the ad- V UI V O. ln A W- All you have to do to get full information vertisement appears. When there are N about the product or to get the literature two or more ads on a page, each one Ut ut ln A A A A A W z Ut W-`O V Ut W- on0 described is to circle the oppropriote hos under it a notation such os Circle number, odd your name and address and 23a, Circle 48b, or Circle 76c and the P the rest, some numbers appear on the card. Num- P P P P O O ln U Jr moil it to us. We'll do and you IT ln A(J N V P may be sure that we'll be prompt because bers C -2, C -3, and C -4 refer to the we ore just as anxious for your inquiries covers-C -2 is the inside front cover, the inside back cover, and C -4 is the V V V V ...IV OA O. P to get to their destination os you are - C -3 UT A(..] .O CO V OP N- m and besides, we don't have room enough outside back cover. SB is "The Sounding

CO around the office to accumulate a lot of Board." CO Ñ wV Á .O V 0" cords. Circle one item, if you wish, or P CO CO W oll of them-we'll carry on from there. The only way to derive any benefit This whole system breaks down if there from this service is to use the card for all o o .O .O ,a `O `O m w N IV _ O O ,a m Ó o- o o- is a charge for the New Literature de- the information you want. We think you scribed, so if you can suggest any im- will find this new system more convenient 40 -0 o,o.o 0 provements in this service, we would ap- and that you will use it more and more. CT ó m C.) n FLEXIBILITY GUARANTEED

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McIntosh 1011 1r Intus AO C -8 Professional net) Audio Compensator and Pre -Amplifier C-8(Less Cob 588.50 Re-cold Reproduction to satisfy the novice or the most critical listeners is achieved by the more than 500 compensation positions on these unique bass and treble switches. Room acoustics and electrical characteristics are completely controlled only in the flexible C -8. Ramete 9eete,t >doceta e000-eadattvi A five position control de- Five fixed positions of bal- signed to eliminate the annoy- anced volume reduction with ing mechanical rumble inher- equalization for the hearing ent in turntables and record losses experienced at low vol- changers. A narrow band sup- umes. Greatest flexibility for pression that rejects noise not greatest enjoyment. music.

Here is the only compensator designed to critically balance electrical playback of records plus the flexibiliy to correct for all listening room acoustics. McIntosh, creators of the

world's finest amplifiers and pre amplifiers guarantees 1 Flexi- bility, 2 Specifications, and 3 Craftsmanship. Hear McIntosh today at your favorite dealer.

Send for complete information or visit your nearest Franchised McIntosh Dealer. lillotoshL B R T . A O A O R Y I N C 4 Chambers St., Binghamton, N. Y. Export Division: 25 Warren St., New York 7, N.Y. In Canada manufactured under license by McCurdy Radio Industries, Ltd. Cable: 22 Front Street W., Toronto, Canada SIMONTRICE N. Y. AE-11-57 A loudspeaker generates sound by moving air. If the speaker cone suspension is tight, the excursion buckles and bends the cone during operation. Stephens Trusonic has engineered the speaker cone in "free suspension," mounting it

flexibly with a newly developed plastic-impregnated compliance. This allows the speaker cone

to move as a true piston.

The cone has a free excursion. eliminating distortion,

giving a maximum bass response and the best transient 12 inch 120 FR 8 inch 80 FR response. The clarity and definition of Stephens Trusonic's new "free-cone suspension" speakers herald

a new engineering achievement in high fidelity equipment.

These new r a 1t" Speakers a refreahi new kind of sound. No suo om shrills or lse lows. These sp kers must be heard to be belde ed. Ask for a fistration at your udio dealer's. Irovide

Listen...you'll always hear more from: ST= :'ENS z-RT-T cav IC Ziv 8538 .VARNER DRIVE. CULVER CITY. CALIFORNIA