NOVEMBER 1966 with High

NOVEMBER 1966 6Oc

... the authoritative magazine about high fidelity Opera at Lincoln Center

Opera at home with high - fidelity stereo and video

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Check No. 50 on Reader Service Card.

www.americanradiohistory.comAmericanRadioHistory.Com November, 1966 Vol. 50, No. 11 Number 39 in a series of discussions by Electro -Voice engineers Successor to RAD10. Est. 1917 AUDIO SANFORD L. CAHN Marketing Director GEORGE PORTER C. G. McPRouD Art Director Editor and Publisher THOMAS WALSH DANIEL J. TOMCIK Asst. Art Director Chief Engineer, LARRY ZIDE Contributing Editors Organ Division Managing Editor LEE IRGANG JOSEPH GIOVANELLI Circulation Manager HAROLD D. WEILER HAROLD LAWRENCE R. KENNETH BAXTER Today, electronically -aided musical in- Video Editor CHESTER SANTON Production Manager struments dominate much of popular wind instru- BURSTEIN music. Indeed, conventional EDWARD TATNALL CANBY HERMAN HENRY A. SCHOBER ments may go almost unheard in a Music Editor BERTRAM STANLEIGH Business Manager group that features electronic guitars and organs. That balance may be upset, however, AUDIO Articles with the introduction by H. & A. Selmer, Inc., Elkhart, Indiana of their new Vari - Trackability 19 James H. Kogen tone electronic saxophone. To their professional saxophone, a small ceramic High -Quality Phono Preamp microphone has been added. A control with FET's 26 William A. Rheinfelder box is mounted to the body of the sax Simulated "Live vs. Recorded" Test and is connected to a combined preamp/ for Loudspeakers 33 Edgar Villchur power amplifier/speaker unit. An Amplifier for the Armchair In addition to 75 watts of straight ampli- Listener 38 R. E. Baird fication (continuous sine wave rating) a variety of special Part 10 52 Norman H. Crowhurst the Varitone boasts Audio Measurements Course, effects. Tone control tabs permit a boost Annual August Issue-Addenda 60 or cut of both high and low frequencies. A synthesized echo and a 4 Hz. tremolo can also be introduced by the performer, the ampli- AUDIO Reviews as well as volume control of fied sound. The AUDIO Music and Record Most fascinating effect, however, is the Review Section sub -octave or Octamatic feature. This 44 multivibrator circuit produces a tone one Record Review 44 Edward Tatnall Canby octave below the fundamental of any Light Listening 46 Chester Santon note played. Special circuits inhibit it Jazz and All That 48 Bertram Stanleigh from responding to other sounds, such as key noises and the like. Volume of the Octamatic output is independent of the fundamental, so that the player can AUDIO Profiles freely combine the basic sax sound with that of the amplified sub -octave. Model S-8800 Sherwood Stereo Receiver 40 The microphone is not located in the Stanton Stereo Cartridge 41 Model 581 EL bell of the Selmer Varitone as you might BSR Automatic Turntable 42 McDonald 500 expect, since this location is seriously af- fected by ambient acoustics. In addition, not all saxophone sound is radiated from the bell. Optimum location of the micro- AUDIO in General phone proved to be in the neck of the instrument, quite near the mouthpiece. Audioclinic 2 Joseph Giovanelli High sound pressures and high humidity Letters 6 dictated a specialized ceramic micro- Audio ETC 10 Edward Tatnall Canby phone in this application. Its location does not interfere with normal playing Editor's Review 16 or the acoustics of the instrument. Tape Guide 64 Herman Burstein It might be noted that sound level varia- New Products 70 tions inside the saxophone are remark- Audio Bookshelf 76 ably wide, due to standing waves gen- Industry Notes 77 erated while playing. Sound pressure Advertising Index 82 varies with pitch at most points in the air column, making precise microphone placement essential to the success of the AUDIO (title registered U. S. Pat. Off.) is published monthly by North Varitone. American Publishing Co., I. J. Borowsky, President; C. G. McProud The tone cabinet, solid state electronics, and Arthur Sitner, Vice Presidents. Executive and Editorial Offices, 134 North 13th St., Philadelphia, Pa. 19107. Subscription rates-U. S., and control system were developed by Possessions, Canada, and Mexico, $5.00 for one year; $9.00 for two Electro -Voice in conjunction with Sel- years; all other countries, $6.00 per year. Printed in U.S.A. at Blanchard mer. It is expected that this unusual ap- Press, Inc., Garden City, N. Y. All rights reserved. Entire contents copy- INSTITUTE OF righted 1966 by North American Publishing Co. Second Class postage proach to musical instrument design will HIGH FIDELITY paid at Philadelphia, Pa., and additional mailing offices. have a major impact on popular music INC. REGIONAL SALES OFFICES: Sanford L. Cahn, Art Sitner, Robert in the immediate future. Cooper 663 Fifth Ave., New York, N. Y. 10022: (212) 753-8824. Richard Reed, 205 W. Wacker Drive, Chicago, Ill. 60606: (312) 332-3910. Ohio 44125 (216) 621-4992. Leonard Gold, 1900 Euclid Ave., Cleveland, technical data on any E -V product, write: Jay Martin, 9350 Wilshire Blvd., Beverly Hills, Calif. (213) 273-1495. For ELECTRO -VOICE, INC., Dept. 1163A AUDIO, Editorial and Publishing Offices, 134 N. 13th St., Phila., Pa. 19107 602 Cecil St., Buchanan, Michigan 49107 Postmaster: Send Form 3579 to the above address. Circle 53 on Reader Service Card

www.americanradiohistory.comAmericanRadioHistory.Com AUDIO CLINIC Next Month Joseph Giovanelli Coming

Organizing a "patch Panel" Articles Q. It is my desire to organize a only used for the experimental Annual Tape Recorder Issue con- "patch panel" circuit for my stereo nection of external speakers (tempor- 'The Early Flutter Spoils the system, which includes: arily). In any event, all speakers have 1. Marantz stereo control Recording' in which Lewis A. Center independent on and off switches. 2. Marantz dual power amplifier In Harlow gives us some hints on addition, I wish to connect the 3. Fisher 200 FM tuner output signal from the TV set (1 pro- how to maintain a recorder and 4. Fisher 1000 MX adapter pose to tap the output signal from what kind reels of to use for 5. Sony 7775 type recorder the terminals of the TV speaker, minimum flutter. 6. Revere Pro tape deck through an SPTS switch, thence to the 7. Eico HFT92 AM -FM tuner center 'The Hows and Whys of Tape channel of the main speaker 9. Rek-O-Kut L-34 turntable system, allowing Editing' by noted editing author- me, I believe, to 10. Empire turntable and tonearm choose whatever speaker I wish, with ity Joel Tall. 11. Bogen P-61 turntable both speakers being activated by the 'Get to Know the Decibel- 12. Shure cartridge TV amplifier.) Naturally, the main 13. Lafayette K-165 remote con- (Hi-Fi) speaker Better' in which George H. R. would be off on such trol stereo adapter occasions. O'Donnell simplifies the unnec- 14. The system also includes a TV Lastly, I have a transistorized mixer cessary calculations involving set. which I also propose to connect into the ubiquitous dB. It is my impression that in using the the same patch panel as the other appropriate plugs (pin/phone), sock- components. I cannot see any objec- ets (pin/phone), plus shielded cable, tion or conflict here. I can simply duplicate the outputs and I would appreciate your analysis of Profiles inputs on the rear apron of the the suggested arrangement, and any Marantz equipment by connecting the suggestions, changes, or recommenda- Altec A7-500, A7 -500W-1 Speak- aforementioned shielded cable and tions. er Systems plugs into the various inputs and out- Alfred N. Williams, St. Albans, N.Y. puts and bringing them out to the Sony Integrated Amplifier-TA A. What you propose is basically a face plate of the patch panel. In addi- good idea, especially when a large 1120 and Servomatic Turn- tion, if I repeat this process with the amount of equipment is involved as table with arm and cartridge. remaining components, again using is true in your installation. Your ap- the appropriate plugs and sockets, and proach is exactly what I took in my again bringing the connecting cables recording facilities. out to the patch panel, I should be Keep in mind that there are various able to make whatever connections design considerations to observe. and disconections that I wish, without Once the Marantz system has been having to move either the components grounded to the rack by way of the or the entire console cabinet in which speaker connections, you must watch the components are installed. I believe your shielding. Connect all shields to About the Cover it is also feasible to connect speaker the plugs on the rear of the amplifier cable (No. 18) to the two sets of and preamplifier. Do not terminate speaker connection terminals on the the shields to the conectors on the The ultimate goal is to diminish Marantz amplifier and bring them out patch board, however. the difference between live and re- to the patch panel; here I would con- The connectors for use on the corded performance not by reduc- nect the speakers to separate terminals patch board should be standard ing the quality of live but by ever or to the appropriate number of pins phone jacks and plugs rather than raising the capabilities of repro- or phone jacks. pin plugs. (Pin plugs work satisfac- duction. Would there be a noticeable loss of torily when they are not going to be output capacity with Our model's gown is an original such an arrange- disturbed very much, as in the case of ment? I recognize that any additional permanently by Minissale, furs are by Becker installed music systems.) speakers that I connect here will re- In your case, the whole object is to & Burns, and photography is by duce the output capacity of the am- have a system in which flexibility is Mano Mehanian-all of Philadel- plifier to the main speaker system, the keynote. This means that the phia. but these speaker terminals would be patches will be constantly connected,

2 AUDIO NOVEMBER, 1966

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60 Mk II 4 -speed Automatic Turntable, NEW manual cueing and pause con- $74.50. Developed from the "best trol permits placing tone arm on buy" AT60, its superior engineer- record in any position by use of ing features have been refined to cueing lever NEW automatic assure excellent reproduction with anti -skating control Lightweight the latest ultra -sensitive car- cutaway shell with new cueing tridges. pointer and finger lift NEW turntable mat with large trim ring over Tubular, dynamically balanced heavy, cast, balanced oversized counterweight -adjusted tone arm turntable Two interchangeable NEW resiliently mounted counter- spindles: short for manual play, balanced weight NEW built -In center drop for intermix automatic stylus pressure adjustment as- operation when desired Super- sembly with precision knurled sensitive trip with Dupont Delrin® optical instrument type dial for Double shielded Laboratory smooth, highly accurate settings Series® motor.

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www.americanradiohistory.comAmericanRadioHistory.Com disconnected, and re -connected in various ways. Further, I do not suggest that you use the miniature plugs and jacks found on transistor radios and other portable equipment. I believe you will have strain relief problems involving the cables associated with such plugs. Further, I am not sure that the jacks will stand up under such heavy use. Here is another point whereby you considerably increase your flexibility. The phonograph cables should appear on the patch panel rather than be plugged directly into the Marantz preamplifiers. It is not good practice to connect the cartridges directly to the patch panel (this will result in a loss of highs because of excessive cable length and will also introduce hum into the system.) I suggest that you obtain some kind of amplifier -equalizer for each phonograph system. The output of these amplifier -equalizers should appear on the patch panel. The equalizers should have the required number of equalization settings and sufficient gain to enable their outputs to be patched into high-level inputs on your tape recorders or your preamplifier. This arrangement makes for even more flexibility than you might think. Suppose that the cartridge is plugged into a minibox with a switch on it which can connect the two "hot" leads of the cartridge together. This will allow the cartridge to be used for monophonic records. Merely by opening the switch, stereo can be heard once more. The output of the switching arrangement can be fed to another set of terminals on the minibox. These, in turn, can be fed to the input of your equalizers. If your tape deck does not have preamplifier outputs, it would be a good idea to use similar amplifier - equalizers to The depth probing Ad -men will feed from the tape heads. shudder at the use of such a title These equalizer outputs can be fed but we can think of no better into the patch network. description for a good loudspeaker. As for the speaker arrangements, Character in the music; character each speaker should be brought to in the instruments; character in the its artist-yes, but no character in the own jack on the board. The amplifier loudspeaker, please! output connections should also be brought to the board. This permits connection of any external amplifier to the speakers, and to connect any external speaker to the amplifier. Here, again, it is possible to obtain greater flexibility by using what are called "normal" jacks. These "nor - mals" are really nothing more than closed-circuit phone jacks. Let's examine the speaker connections. Each speaker is connected to the closed- circuit jack just as though it were an open -circuit jack. The amplifier for the closest approach the original sound. output to (Continued Write direct to: Ref Audio, on page 72) ACOUSTICAL MANUFACTURING CO. LTD. HUNTINGDON, ENGLAND Check No. 55 on Reader Service Card.

4 AUDIO NOVEMBER, 1966

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www.americanradiohistory.comAmericanRadioHistory.Com LETTERS Up- grade Tape Track Fringing occur at 1 wavelength, with progressive Snt: smaller dips at 2 wavelengths, 3 wave- In occasional EQUIPMENT PROFILES- lengths, and so on. Some professional for example, the one on the Knight KG - recorders now provide variable low - 415 in the January issue-the comment frequency equalization to minimize the has been made that frequency -response effect of head bumps. measurements made with Ampex stand- The standard tapes you referenced will your ard tapes 31321-01 and 31331-01 that ensure accurate high-frequency equaliza- "the bump at 100 Hz on the 7/-ips tion adjustments on narrow-track equip- curve we have seen so often on many ment. However, the lower frequencies different recorders that we have come recorded on these tapes will result in to believe that the standard tape has correct reproduce indications only for the boost, rather than all of the re- full -track recorders. A correction factor, corders." determined for the particular recorder The two standard tapes referenced are under test, would be necessary to make recorded full track, and this seeming such readings valid for narrow -track sound increase in response at lower frequencies heads. If low -frequency equalization on is perfectly normal when the tapes are such recorders is adjustable, it should played back on half-track, two -track, or be accomplished by adjusting for flat four -track equipment. Two factors in- over-all (record -reproduce) response. fluence this apparent rising response- For your information, Ampex Stand- the playback head "fringing" effect, and ard Tape No. 31321-04 is specially re- playback -head "bumps." Both are func- corded on 7-ips, /-track equipment. tions of the wavelength of the signal This tape should be used when testing recorded on the tape, and are therefore such recorders. Whatever your receiver or amplifier is dependent on tape speed. HAROLD W. LINDSAY, Manager, Fringing is the result of the magnetic Audio Engineering Department. doing, EMI loudspeakers capable of have flux on each side of the head (as well Ampex Corporation, a unique way of making it sound better. as directly under the head gap) con- 401 Broadway, tributing to the current induced in the Redwood City, Calif. 94063 Perhaps it's the ease with which EMI head coil. This additional current, of loudspeakers project sound. So smooth course, appears as an increase in signal and natural, it seems to float on the air output. Fringing becomes quite pronounced at long wavelengths, and grows Mate for "El Cheapo" in all its concert hall glory. Filling the progressively more noticeable as the SIR: room. wavelength increases. (Had the equip- I recently obtained several back issues ment under test provided better low - of AUDIO here in Japan. A friend and Or perhaps, it's the deep bass, the in- frequency response, the reproduced out- I have started construction of "El comparable realistic midrange and the put from the full -track standard tape Cheapo 2-30" which was featured in the would have continued to rise to the 50 - November, 1964, issue. We are using highs. full, silky Hz region.) The degree of fringing de- Japanese parts and American transistors. Or it could be the subtle detailing of pends upon the playback -head shielding, Both of us intend to expand our re- and a factor cannot be speci- spective systems to include a tape deck, their transient perfect response that correction fied which will apply to all heads. At turntable, and FM multiplex tuner. We catches you unawares. 7/ ips, different recorders may exhibit are attempting now to find a compatible the "El We do So, for better sound from your receiver a fringing effect ranging from less than pre -amp for Cheapo." 1 dB to approximately 5 dB when full - not desire the multitude of equalizing or amplifier, come on up to EMI loud- track tapes are reproduced on narrow- controls prevalent in some preamps but speakers. track heads, even though the recording want a circuit equal to the power ampli- is "flat." fier's quality and drive requirements. There's an EMI loudspeaker Head bumps are a function of play- The circuit should be transistorized. Has to meet any requirement and back -head geometry, resulting when the a suitable circuit appeared in a past issue pole pieces on the head (as well as the of AUDIO? If so, I would appreciate budget. From $49.95* to gap) begin to pick up the magnetic flux knowing the issue in which it appeared. $395.00* and transmit it to the head coil. As J. M. RUDHOLM, frequency decreases, bumps and dips in USNSGA, Box 12, *Slightly higher in South and West the output may become noticeable. The FPO San Francisco, Calif. 96668 largest bump will occur when a / wave- (Our recommendation would be the se- EMI/SCOPE length of the signal on the tape equals ries of five articles by Aschinger which Scope Electronics Corporation the distance across the two pole pieces; started in November, 1963, and ended in 470 Park Avenue South there will be progressively smaller March, 1964. We have had few submis- New York, New York 10016 bumps at 1/ wavlengths, 2/ wave- sions of good preamp circuits since then. Also available in Canada. lengths, and so on. The largest dip will Ed.) Check No. 75 on Reader Service Card. 6 AUDIO NOVEMBER, 1966

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specs: 100 watts of Take a close look while you have a Frankly, it's just a matter of time remarkable at .5% thd (only .25% thd at chance. That's what all -silicon - before all components use 100% power transistor circuitry looks like. No silicon -transistor circuitry. We 70 watts); frequency response of a sensitive audio transformers to cause distor- were first because we already knew ±1 db, 15-30,000 Hz; and with a four -gang tion. No heat -producing vacuum how. (We've been building solid- FM stereo tuner the tubes. No heat -sensitive ger- state audio amplifiers for profes- tuning condenser that provides to manium transistors. sional, commercial, and military best possible ratio of sensitivity nearly ten years.) selectivity to reduce cross -modula- 711A was the first stereo users for Our tion through 80 db image rejection, in the world to use silicon This unique Altec experience has receiver 100 db IF rejection. transistors exclusively. That way, other advantages. It nót only made our story: enjoy years of listening, not the 711A possible, but possible at But that's only part of you can your Altee tinkering. Silicon transistors are the the practical price of $378. (You To get all of it, visit at it, ask him most ruggedly reliable solid-state don't wind up paying the cost of dealer. While you're catalog. devices known to date. (If you need educating our engineers.) You do for the new 1967 Altec to be convinced, just remember that get the kind of over-all quality, reli- the military specifies them because ability and performance that only they can take up to 100% more heat tangible, state-of-the-art experi- than germanium.) ence can bring. You also get some

Forget the guts. ALTE[ This is how the 711A will look to you, year after year.

A Division of 65'M Ling Altec, Inc., Anaheim, California Check No. 57 on Reader Service Card. AUDIO NOVEMBER, 1966 7

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You may be one of the thousands of discriminating stereo in one or two rooms separately or simulta- music lovers who have wanted the incredible realism neously; front -panel headphone jack; tape monitor; of Harman-Kardon solid-state stereo in a price range contour and continuously variable balance controls where such quality simply couldn't be offered before. ... and of course the wideband realism that distin- These new Nocturne receivers are your answer. guishes Harman-Kardon instruments from all others. You expect styling innovations from Harman-Kardon. All for $239.50 The beauty, the great sound, the You expect the newest advances in solid-state circuitry complete controls-all are designed into the Nocturne from Harman-Kardon. You expect controls and other Two Hundred (FM and FM stereo) for the low suggested quality features on Harman-Kardon units that appear retail of $239.50*. The Nocturne Two Ten adds AM only on more expensive competitive models. But now radio at just $269.50*. Treat yourself to the thrill of even Harman-Kardon seems to have outdone itself in Harman-Kardon's new look of elegance ... new sound sheer high-fidelity value. of realism, at your Harman-Kardon dealer's. Or write You know you're experiencing something entirely for illustrated brochure. Harman-Kardon, Inc., 401 new when first you see a new Harman-Kardon Nocturne. Walnut St., Philadelphia, Pa. 19105. The tuning scale, meter, and stereo indicator disappear behind gleaming ebony when Nocturne is off. Turn it *Slightly higher in the West. Walnut enclosure optional. on and the panel comes to life in rich amber that complements the golden accents of knobs and trim. SPECIFICATIONS Power Output: 50 watts IHF Frequency response ± 1 db: MOSFET front end Typical of Harman-Kardon's em- 8 to 25,000 Hz at 1 watt (normal listening level); 10 to phasis on outstanding quality is the use of the most .23,000 Hz at full rated power Harmonic distortion: Less advanced and effective MOSFET (metal -oxide silicon than 1% Hum and noise suppression: 90 db Damping field-effect transistor) in the FM front end. The MOSFET factor: 25:1 from 20 to 20,000 Hz Square -wave rise time: provides significantly better front-end performance 4 µsec Usable FM sensitivity: 2.7 µv IHF Image rejection: Better than 45 db Spurious -response rejection: Better than than any other transistor or FET. It makes possible 70 db FM I.F. rejection: Better than 75 db Multiplex advances in Nocturne circuitry which produce lower separation: 30 db AM sensitivity: 50 µv/ meter AM selec- cross -modulation and crosstalk, improved rejection of tivity: 10 kHz bandwidth at 6 db points AM I.F. rejection: unwanted signals, and superior sensitivity due to lower 55 db (AM specifications refer to Model Two Ten only) inherent noise. Also, it isolates the antenna circuit to Dimensions: 141%6" wide, 41/2" high, 131/4" deep Shipping weight: 20 pounds. assure an improved match with the antenna under all conditions. Superior Harman-Kardon quality features are here: harman kardon Inherently cool operation for installation anywhere A subsidiary of The Jerrold Corporation without fans; no heat deterioration with age; two - system speaker switches permitting enjoymert of LEADER IN SOLID-STATE STEREO COMPONENTS

Check No. 58 on Reader Service Card. 9 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com I have one thorny question to solve concerning Seraphim. Isn't that word a plural? At this writing, nobody around here seems to know and my dictionary ain't. Maybe by next month I'll find out whether it ought to be Seraph for mono and Seraphim for stereo? (Our AUDIO ETC. dictionary says yup, Seraph is but one high -order angel; Seraphim is many. ED.) Edward Tatnall Canby Angel must be holding in reserve that other Angelic term and its plural-Cher- ub and Cherubim. Remember those an- cient lines, "Cherubim and Seraphim, ta -da, ta -da, ta -da," etcetc ...? All very Baroque, this Angel stuff! By the time you read this . . . well, you can add the rest. Umpteen more new labels, priced at either $2.49 or $2.50 for mono and stereo (boy, that penny seems important), and based very largely, as with Nonesuch and the other THAT LP REVOLUTION ... earlier $2.50 labels, on European imports. With roughly twenty discs per initial release for each of these, we will have such a plethora of LP records, I. Angelim and Seraphim price.) come Xmas, that bulldozers won't be As I confidently predicted in July (see Philips, as noted in July, has enormous able to shove through the piles. upper right corner of p. 45, July issue), resources to throw into the $2.50 musi- No-I still hazard a guess that the the new low -price LP revolution has cal hopper. Their first release, too, lists first -line celebrity records will not come broken out this fall all over the place, no less than 20 items, out of Europe. down to $2.50, nor anything like it. and particularly among the big com- The big specialty of this label, which You just can't pay for the Boston Sym- panies. It's very frustrating for me, at I'll put aside for the moment, is CoM- phony, for Callas and de los Angeles the moment; because with our new and PATIBILITY-one, single record for both and Resnik and the other opera names, long -leisurely deadline for monthly copy, mono and stereo. At last-somebody big for Heifetz and Horowitz, Stokowski and many of the new record lines have been has come out with the inevitable . . . Bernstein and von Karajan (and even announced as I write-yet the discs but more of this later, below. such high-priced ghosts as Toscanini, themselves are still to be seen and heard RCA Victor? Well, no news to re- Bruno Walter et al.) and still have in solid plastic. By the time you get to port at this early juncture and I bet I money left over for publicity and for the reading this, you can rush right out and can guess why. RCA already has so stockholders. buy them. All I can do is talk. many labels it doesn't know where to go Instead, as I figure it, there is now (Yah, yah, I know-my colleague re- next. As an earlier pioneer in the "plain underway a very healthy competition - viewers elsewhere probably've got there Jane" low-cost reissue field, RCA has style development among the upper - with the mostest firstest, or something. had two labels straddling the new price bracket offerings, namely, a more -for - Well-OK! No new label worthy of its area-Camden and Victrola. What has your -money movement. Fine! Not only plastic will fold its tents for at least a happened now is easily guessed. I dis- fine quality-a crucial requirement-but couple of months; so I'll get to 'em.) covered in September that the erstwhile superb extras such as high -style decor In July, I figured the big companies Camden label was nowhere to be seen and, more important, voluminously would soon begin to move into the new in Schwann's price listings. Only RCA handsome program and art material, of field come this fall, and so it has hap- Victrola. And guess what the new price the sort that is mostly impossible to in- pened. That's what I'll talk about first. on the old Victrola label is? Well, you clude in the low -price issues. Quite awhile back, Epic, sister -label to didn't guess quite right. RCA has gone At a list price of $4.79 mono and Columbia (or should I say niece?), an- halfway. Yep, $2.50 for mono, all $5.79 stereo-or often the higher price nounced its new low-priced line, called right. But $3 for stereo. How long will for both types of disc, as in many im- Crossroads Records. Just guess what the that last? Shall see. And see below, II. ports-these quality extras are the most list price is. You guessed right. $2.49 Then, still another entry, we have a significant aspect of the price picture for stereo/mono. (Seems everybody has to quite sensational line from Angel (out those of us who buy in both price undercut the original Nonesuch price by of E.M.I. in England, with all the multi- ranges. A big sixty -four -page book, with that big one cent.). No Crossroads discs farious E.M.I. world -over connections), texts, background material galore, hand- are on hand at this writing. Floods ex- called, by the most seraphic of logic, some pictures, is enough to sell some pected momentarily. The label listed 20 Seraphim. albums without any records at all. Splen- releases in the first batch, all of them The Seraphim label, very neatly pack- did thing, I say. out of the Czech Supraphon catalogue. aged in pre-shrunk cellophane, white with Go look at the multiple -disc RCA, Columbia isn't talking-yet. Let Epic black type and an overlay of blue, is as Columbia, Angel albums, and many take the rap. prolific as the others-a huge batch of others at the same price, and you'll see Then we have the European giant, these discs came in just in time to swamp what I mean. Worth it. Philips, whose local outlet, aside from its me at the last possible minute. Seraphim, own name -products, is Mercury. Big new it seems, is going to run to high -quality II. $5.79 vs. $2.50 doings over there. Philips announces its reissues of the fabulous earlier E.M.I. 1. Are the $2.50 discs worth it, in World Series label (no baseballs in- repertory, back into 78 -rpm days but also terms of technical quality? 2. What about cluded), to sell at the unbelieveable low up into stereo and to the present in some the high -price imports versus the low - price of . etcetc. (Philips puts the releases. I've tried one very recent (con- price imports on these new labels? Is it penny back on again. It's $2.50, flat, for tinental) recording on the label-just really meaningful, this $2.50 vs. $5.79 any record in the line, as of the list lovely, and as good as an Angel. differential, as among rival imports? 3.

10 AUDIO NOVEMBER. 1966

www.americanradiohistory.comAmericanRadioHistory.Com Marantz makes an incredible move forward...

model 15 solid-state 120 -watt stereo power amplifier With one devastating move, Marantz has check -mated all existing power amplifiers. The strategy far of the was straightforward-build an amplifier to a set of specifications bordering on the edge are possible, then add a series of unique features to complete the coup. The 15's specifications the limit designed to test the mettle of your other components, while allowing them to perform to from 20 to of their abilities. Power output -60 watts per channel, with safe, full -power operation ampli- 20,000 Hz. Harmonic distortion - less than .1 at full power, infinitely better than any other ±1 from 10 to 60,000 Hz. fier. Hum and noise - better than 90 db below 60 watts. Response - db of equal As playing partner to these performance characteristics, Marantz has created features caliber. A safety circuit rendering short circuits completely harmless, even at full power. Instanta- High input neous, distortion -free overload recovery. Separate power supply for each channel. having the finest impedance, permitting the use of even tube pre -amps without distortion. If power amplifier ever built is important to you, no need to ponder your next move. See and Ar there's R C O IP E. INC. A SUBSIDIARY OF S U P E S hear the 15 at your Marantz dealer's immediately. ZZ

ST., WOODSIDE, NEW YORK 11377, DEPARTMENT C-17. FOR FURTHER INFORMATION, WRITE MARANTZ, INC., 37.04 57TH Check No. 59 on Reader Service Card. 11 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Who would you put in the box?

And what about stereo -mono compatibility, along with synthetic stereo? These are remaining big questions. 1. There is much misunderstanding, I think, in respect to the technical quality possible at the new low price. Actually, there is every reason why it can be precisely as good as at the high -price level -and it often is. For, indeed, the records are mostly made in the same plants, on the same equipment, indiscriminately. Without the slightest doubt, given a first - quality tape, the $2.50 record can be and "Dizzy" often is technically identical with the high-priced spread, if you see what I mean. Cast Iron Cutting Styli I say this because I think many record buyers have the mistaken idea that low-priced records are somehow pressed on separate equipment, probably obsolete, on inferior plastic that includes, perhaps, 10 per cent powdered sand as a filler along with a bit of cornmeal and a dash of grated Fiberglas. Also, that the masters are cut on old celluloid with cast iron cutting styli of variable radii, unpolished. 'Taint true! There is not the slightest doubt that a large number of $2.50 discs (often available at lower prices, discounted) are technical duds. I should know. My own second record of the Canby Sing- ers has suffered from certain troubles of the sort, not including Fiberglas and sand. (But it has been re -cut, to correct the unintended trouble, along with others of the sort.) There is also not any doubt at all that many $2.50 discs are just plain superb in quality. First -line. I think we must realize that the differences Uncle Louie singing are largely, in the over-all, a matter of "Danny Boy"? quality control, which can be more rigid in the more expensive lines, and/or in small volume runs. The $2.50 market has expanded so fast that the processing plants, already operating on small margins, simply haven't been able to do a good job. A whole passel of related human factors unite here, to make it probable that the big -volume low-priced disc, pressed and cut identically with the high-priced lines, will tend to come out variably as inferior products. Against this, the reputable manufacturers fight tooth and nail, as best they can. It all depends on who is doing the needling, the checking, the supervising Build a world of your own on Scotch Magnetic Tape of a million details. And how big, how fast, how pressured the rush -job turns Whatever your listening preference ..."Scotch" Brand "Dynarange" out to be. In this tossing maelstrom of Tape helps you create a new world of sound. Delivers true, clear, super -production, in this maze of split- faithful reproduction across the entire sound range. Makes ting executive headaches, things can go all music wrong, horribly wrong, in so many sec- come clearer ... cuts background noise ... gives you fidelity you didn't onds. Quality is up for grabs. First -line know your recorder had. quality is a miracle of achievement- Best of all, "Dynarange" is so sensitive it gives you the same full but, keep in mind, it is always possible and, in fidelity at a slow 33% speed that you ordinarily expect only at 71/2 ips. spite of all, even quite probable. Lets you record twice the music All of which reminds me of an old per foot! The result? You use less tape and honorable practice in the audio com- .. save 25% or more in costs! Lifetime silicone lubrication protects ponent field (and many others), by against head wear. Ask your which two product lines emerge from an dealer for a demonstration. magnetic Products Division 3mm identical design, differing only in the degree of tolerance in quality control. Check No. 60 on Reader Service Card. Check No. 61 on Reader Service Card.-* 12 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com For people who really listen, we offer the first receiver with $400 specifications that sells for $279 ADC 606 90 watt, solid-state, FM Stereo Receiver

SPECIFICATIONS FEATURES Amplifier Section Tuner Section First, true bookshelf depth: Musical instrument input Power: Usable FM Sensitivity IHF: 17" wide, 5" high, 9" deep Automatic frequency control 90 watts (IHF) @ 4 ohms 1.6 uy Side panels eliminate need for (switchable) for FM 70 watts (IHF) @ 8 ohms Harmonic Distortion separate cabinet Independent control for 2 Total Harmonic Distortion: (100% modulation): .5% Large, readable, FM dial sets of speakers @ rated output, .5% FM Stereo Separation: Complete tape playback and Each channe- separately fused, 3 db below rated output, .2% 35 db at 400 Hz monitoring facilities plus main power fuse IM Distortion: 32 db at. 1,000 Hz Headphone jack Automatic FM stereo switching @ rated output, .5% 20 db at 8,000 Hz 2 -year warranty 3 db below rated output, .3% Signal -to -Noise Ratio Frequency Response: (100% modulation) : 70 db 10-60.000 Hz ±1 db Spurious Response Rejection: Hum and Noise: 80 db With volume control Capture Ratio: minimum, -78 db 3 db Magnetic phono input, -65 db Musical instrument input, -60 db Auxiliary input, -75 db Input Sensitivities: Magnetic phono, 3 mv Musical instrument. 50 my Tape, 100 my Auxiliary,. 100 mv

Audio Dynamics Corp. Pickett District Rd. New Milford, Conn. CID Z

www.americanradiohistory.comAmericanRadioHistory.Com Though it is not by choice, of course, much of the fluctuating quality found on the new $2.50 discs, good and bad, is due to this factor, quality control. Or slipping controls, out of control in the mad scramble to meet deadlines. Other factors are of truly less import, and, believe you me, that includes the quality of if you the original recorded material. For as haven't seen these we know, many of the low-priced reissues are significantly improved over the original releases of some years back, or from many years ago. Quality control is all oucr the broadcast tìeld... what really counts. (And so I'm hoping the next copy I get of my own record won't have bub- bles in the plastic, the way the last one did.) Thump, thump, thump. A typical quality -control error.

Imports vs. Imports 2. As to high-priced vs. low-priced imports, I refer you again to the July issue, which said it all in so many words. There is, again, virtually no technical differentiation between the $5.79 import and the $2.49 domestic-release import. Only the same old outward differences- availability, quality control, associated art and booklet material, exclusivity. And so, as expected, there are now more inadvertent overlappings such as the Heliodor vs. Archive release mentioned in July (p. 45). I've just caught Angel out on a similar limb, for instance. Last season, Capitol Imports sent out a detailed listing of all the many European releases available, high-priced, along with its periodic bulletin, something about a Grape Vine ("News of Great Import . . ."). Listed there was it's lust because you German Odeon ST 91262, which featured nine unusual Handel songs in Ger- man, sung by Edith Mathis. I was much interested in this particular disc for haven't been musical reasons, and as a buyer I would looting! gladly have paid the $5.79 (am I right?) price for its exclusive virtues. But look now, quick, at the new Sera- phim label. Did you ever! Seraphim Rek-O-Kut has been a household word in the broadcast and re- stereo 60015 is none other than Edith Mathis singing nine Handel cording business for a quarter century. You find them in broadcast songs-the very same recording! Only now she sells operations wherever you go. That's because a Rek-O-Kut is built at $2.50 list. Absolutely Angelic, too. to perform ... and maintain peak performance for years and years. I suspect you'll find plenty more of The Model B -12H and B12GH are in use in hundreds of radio these curious identical twins, at two prices, if you do an occasional bit of stations. We send them a few parts once in a while, but you don't snooping around. That is, twins until the encounter problems with either of these models. Check these direct -import people get around to re- specifications. You'll discover you get measurably more from moving the higher -priced item from a Rek-O-Kut. their lists. Takes time. The direct imports that remain at specifications. SPEEDS: 33A rpm, 45rpm, 78 rpm NOISE LEVEL:- 59 db $5.79, of course, are still-for the mo- below average recording level (B-12GH: - 57 db) WOW AND FLUTTER: ment-decidedly worth considering as 0.085% RMS. (B-12GH: 0.09% RMS) MOTOR: B -12H: custom-built exclusive items for the connoisseur and computer type heavy-duty hysteresis synchronous motor. B-12GH: high worth their higher price. But you never efficiency hysteresis synchronous motor, life -time lubrication 45 RPM know when they'll suddenly jump. Many HUB: removable PILOT LIGHT: neon light acts as "on/off" indicator won't, ever. FINISH: grey and two-tone aluminum DECK DIMENSIONS: 14" 15'1/,6" x So you see, again, technical quality is Minimum Dimensions: (for cabinet installation) B -12H: 1734" wide x 16" not the determining Demand, deep x 3" above deck x 6'/4" below deck. B-12GH: same as B -12H, but 4%4" factor. below deck. distribution, and sales, plus the old spec- ulative urge, determine which discs go out at which prices. (Continued on page 81) rot -o -tut by koss electronics inc. 2227 N. 31st Street Milwaukee. Wisconsin 53203 KOSS-IMPETUS 2 Via Berna Lugano, Switzerland

Check No. 62 on Reader Service Card. 14 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Q 1966 FISHER RADIO CORPORATION No ad man can do it justice. If you follow the ads in the hi-fi publications, you know that every tuner from $99 up is the absolute ultimate in sensitivity, selectivity, separation and frequency response. That's what ad men get paid for. But suppose somebody really does make the finest FM stereo tuner. What is there left for his ad man to tell you? Only this: Forget about the ads. Make the rounds of the stores and listen to as many tuners as you can. Compare. Espe- cially on a live multiplex music broadcast where distortion is easily detected. Count the number of stations you can tune in clearly. And while you're tuning, watch the signal - strength meter. Between stations, it should drop all the way to zero. That's an indication of selectivity. Even if you do nothing else, you'll have no trouble evaluating Fisher against other makes. But if you feel technologically insecure, take an engineer friend with you. Or an electronics technician. Ask him what he thinks of the new all -solid-state TFM-1000, Fisher's most expensive FM stereo tuner at $499.50. Above all, ask your expert friend what he knows about Fisher and what the name means to him in comparison with others in the field. Then you can read the stereo ads just for laughs. (For more information, plus a free copy of The Fisher Handbook, write to Fisher Radio Corporation, 11-22 45th Road, Long Island City, N.Y. 11101.)

ILLUSTRATED: THE FISHER TFM-1000 BROADCAST MONITOR SOLID STATE TUNER. FIVE IF STAGES. NEWLY DESIGNED FRONT END UTILIZING FET'S. EXCLUSIVE COUNTER-DETEC- TOR CIRCUIT. SYMMETRICAL, HARD LIMITERS. USABLE SENSITIVITY (IHF), 1.8 MICRO- VOLTS. SELECTIVITY (IHF), 70 DB. CAPTURE RATIO (IHF), 0.6 DB. $499.50. CABINET, $24.95. A er PLEASE WRITE TO FISHERThes RADIO INTERNATIONAL. I.C.. LONG ISLAND CI,. N.Y. 11101. FISHER RADIO CORPDRA1r 11,1I.0..11 GRa11 ROAD, uONG ISLAND CIir,N. v.111.11. OVERS_AS AND CANADIAN RESIDENT-

Check No. 63 on Reader Service Card. AUDIO NOVEMBER, 1966 15

www.americanradiohistory.comAmericanRadioHistory.Com EDITOR'S REVIEW

WELL, THAT WAS THE WEEK THAT WAS, as they crossover equipment, both to be available in early say on TV. The week in question was, of spring. One was a complete amplifier with three chan- course, the week of the High Fidelity Music nels, and the other was only the network device. We Show in New York. But those of us hi-fi buffs who are not mentioning names intentionally because the infest hi-fi shows are never unhappy about a show, no products are not yet available, and it would only build matter where or when. Of little interest to us are the up hopes in some readers' minds that they could order attendance, the hours, the site, or the attitude of the one tomorrow. We are still often beset with requests for attendees. a complete construction article on a three -channel elec- On the other hand, of course, are those whose busi- tronic crossover. (And if this isn't an invitation for a ness and livelihood depends on the kind of people contributor who has such a story all ready, we didn't who come to hear and see, as well as on how many of write the previous sentences with sufficient clarity.) them there are. And in the long run, that includes us, A new changer is on the way, along with a number naturally-us at AUDIO, that is. of additions to the already accepted changer lines. More We hear many comments about all facets of every elaborate integrated amplifiers and receivers are here, hi-fi show-the location, the weather, the attendance, and we must leave the details to the manufacturers' ad- and so on. We also hear the over-all tenor of the ex- vertisements and literature. hibitors' opinions. It also appears that the stereo tape cartridge for the Basically, however, we at AUDIO are more interested automobile is going to be carried from the car to the in the apparent trend of the industry as far as the prod- living room in the coming season-one reel-to-reel tape uct lines are concerned. Of this year's bash, we cer- recorder has an extra slot for the cartridge, and one tainly cannot say that there is a trend toward more compact system is similarly equipped, although the transistorization, since that was true for the last two former was not exhibited in the N. Y. Show. There years. A trend-possibly a hopeful one-that we did were, however, a number of adapters for in -the -home notice this year was toward the use of larger and larger use for cartridge playing. speaker systems. Not that there is any diminution of The competition between the two tape cartridge sys- interest in the small or medium "bookshelf" enclosures, tems seems to continue unabated. Whereas a fairly but, particularly on the part of the old-timers in hi-fi, large number of manufacturers have chosen one type, there is a re -vitalization of interest in large systems. the sheer weight of the auto industry which seems to At least, that is what several of the larger -system manu- have plumped for the other type may develop into an facturers told us. extremely powerful factor. The best solution seems to Not that there has ever been any question about the be to duplicate all your tapes on both systems. value of the small speaker systems-especially to those who are not quite so dedicated to hi-fi that they will AUDIO'S FIFTEEN -YEAR ADVERTISING CLUB go to any ends to get the quality and decor they feel The second meeting of our 15 -year Advertisers Club best suits them. On the other hand, it is most likely was held during the show and was the occasion of the that the small speaker system has been responsible for induction of eleven new members. Readers will recall many of the more recent converts to hi-fi. One has to that there were seventeen at the initial meeting in Los start somewhere-like from roller skates to bicycle to Angeles in March. The eleven new companies are hot rod. But it does appear to be a trend, in any case. Ampex, Audio Devices, Belden, Klipsch, JBL, Magne - We were pleased to note another product which has cord, 3M, Reeves Soundcraft, Rek-O-Kut, and Uni- been absent from the audio market place for a few versity Loudspeakers. We were pleased to welcome years is on the verge of coming back. Two manufac- them to one of the more exclusive clubs in existence turers showed prototypes of three -channel electronic -28 members.

16 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com The total performance cartridge.

New Pickering V-15/3 Micro -Magnetic' cartridge featuring Dustamatic" stylus and Dynamic Coupling.

Now, Pickering offers you total performance from all your records with the newly designed V-15/3 cartridge. The exclusive Pickering V-15 Micro -Magnetic cartridge assures you of the finest in natural sound, while the famous patented V- Guard Floating Stylus provides the ultimate in record protection. And now, there's a new dimension in the V-15 line. The extremely functional Dustamatic brush assembly for cleaning records as you play them, and an entirely new moving system with Dynamic Coupling of stylus to record groove for positive tracking. There's a Pickering for every installation, from conventional record changers to the most advanced turntable / tone arm systems. That's total performance. Clean records for clean sound. Por free literature on the Pickering V-15/3, plus information on how to choose the correct "application engineered" cartridge for your system, write to Pickering & Co., Plainview, L. I., New York. For those who can hear the difference. Pickering

Check No. 64 on Reader Service Card.

17 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Compare these new Sherwood S-8800 features and specs! ALL- SILICON reliability. Noise -threshold -gated automatic FM Stereo/mono switching, FM stereo light, zero -center tuning meter, FM interchannel hush adjustment, Front -panel mono/stereo switch and stereo headphone jack, Rocker -action switches for tape monitor, noise filter, main and remote speakers disconnect. Music power 140 watts (4 ohms) G 0.6% harm distortion. IM distortion 0.1% el 10 watts or less. Power bandwidth 12-35,000 cps. Phono sens. 1.8 mv. Hum and noise (phono) -70 db. FM sens. (IHF) 1.6µv for 30 db quieting. FM signal-to-noise: 70 db. Capture ratio: 2.2 db. Drift ..01%. 42 Silicon transistors plus 14 Silicon diodes and rectifiers. Size: 1634 x 4;; x14 in. deep.

NOWT look at the,ØZ' Sherwood specs!

V-Vacuum Tube Power (IHF) Model S -ALL- 2 channels FM SILICON 4 ohms Sensitivity Dollars T -Germanium Price Per Transistor Watts Microvolts Watt Sherwood S-8800 S 140 1.6 $ 359.50 $ 2.57 Altec 711A S 100 2.2 378.00 3.78 Bogen RT8000 T 70 2.3 319.95 4.57 Dyna FM -3, PAS -3 & S-70 V 90 4.0 404.85 4.49 Fisher 700T T 120 1.8 499.50 4.16 Fisher 440T T 70 2.0 329.50 4.70 Harman-Kardon SR -900B T 100 1.85 449.00 4.49 McIntosh 1500 V&T 85 2.5 499.00 5.87 Marantz 8B, 7T, & 10B V &T 75* 2.0 1340.00 17.87 Scott 348 V&T 120 1.9 479.95 4.00 Scott 342 T 65 2.5 299.95 4.61 References"T" or"V&T"(above( may include some silicon transistors. Figures above are manufacturers' published specifications except (( which are published test findings.

IN ALLSILIDON TUNERS AND AMPLIFIERS

9-ViAR WARRANTY S -8000140 -watt FM ALL -SILICON Receiver $359.50 for custom mounting $388.50 in walnut leatherette case $387.50 in hand -rubbed walnut cabinet

Sherwood Electronics Laboratories, Inc., 4300 North California Avenue, Chicago, Illinois 60618. Write Dept. A-11 Check No. 65 on Reader Service Card. 18 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com TRACKability

Part I

JAMES H. KOGEN*

much better in The poorest phono cartridge in use today in a hi-fi system is undoubtedly now we'll prob- all respects than the best one of, say, fifteen yeare ago, and fifteen years from here is the first ably be saying the same thing. In the meantime, the cartridge described presents the problem, shows of a "new generation of cartridges by one maker. The author a leader in its field. how it should be solved, and concludes with a product which may well be

of "Trackability" IN SOLVING TECHNICAL PROBLEMS, yet we still must solve the same basic Definition we often go full circle. When we problem encountered by Edison, name- The necessity of keeping the stylus first design a product, we solve as ly, keeping the needle in intimate con- in contact with the record at all times many of the problems as possible. tact with the groove. is basic. We call the ability of a stylus After we are finished, even though the A few years ago, Shure's engineers to do this "trackability." product works, we are practically decided to take another hard look at A phonograph stylus with good never satisfied with the solution. So we the existing top-quality phonograph trackability will follow the modulation start all over and try to provide bet- cartridges. The objective was to deter- in the record groove no matter how ter solutions. This isn't simply a mat- mine what might be done to make a wild the undulation. A phonograph ter of fun for the engineers. It is the better cartridge. As usual, the latest stylus with poor trackability will lose basic element that makes for technical products seemed to be the utmost of contact with the record. When this progress. what could be manufactured. Never- happens, the stylus can no longer per- Phonograph cartridges have been theless, there were a few areas where form its basic function. The sound made, in one form or another, for performance could be improved. may become muddy. Irritating, scratch- over sixty years. A primary require- In order to correct the existing im- ing noises may be produced. In the ment in building the first phonograph perfections it was agreed that a worst case, the stylus may jump com- cartridge was that of making the thorough, fundamental analysis was pletely out of the groove. Good track - needle stay in contact with the modu- needed. Rather than try simply to ability is essential to top performance lation in the groove of the record make improvements on the latest prod- from a phonograph cartridge. (which at that time was a cylinder). ucts, a decision was made to go right The question the engineer must an- Since then we have worked on solving back to the beginning. Many of the swer is, "How Good?" Engineers must many esoteric problems, such as the questions that were asked must have always seek a compromise between elimination of tracing distortion and been the same ones that Edison asked; the perfect, ideal solution and the tracking distortion. The product of but the solution had to be infinitely practical one. Fortunately, the solu- today is advanced far beyond that of better. In the following sections we tion usually does not have to be per- Thomas Edison's original stylus. And will discuss some of these fundamental fect. In any case, we must always de- *Chief Engineer, Shure Brothers, Inc. considerations. termine what constitutes satisfactory

AUDIO NOVEMBER, 1966 19

www.americanradiohistory.comAmericanRadioHistory.Com 4 ) r III» MIS/ MO 44M+Ilerlrf lIllill I.14M NA -44MN » 421164111116/144$18111114 4. MeM MIS* A

SLOPE OF DOTTED LINE IS

PROPORTIONAL TO VELOCITY / \ B

DISTANCE ALONG GROVE 1411e1.0111 i .. 00.11183b" 10" .,.y (B) Fig. 1. (A), left, is a photograph of a record groove fróm directly above the record surface. This groove exhibits extremely high velocity modulation. (B), right, shows modulation amplitude vs. distance along the record groove.

graph cartridge, we must now talk performance of the stylus. A cartridge cerned directly with trackability, not about satisfactory trackability in terms which has poor amplitude trackability with compliance. of 1966 records. will mistrack on large amplitude, low As a comparison, consider some frequency sounds, such What Problems do the as those of the things that concern an auto- which come from a bass drum, bass mobile owner, such as acceleration Records Impose? fiddle, or an organ. This is a common and mileage. These are performance In Fig. 1, (A) shows a photograph failing in many phonograph cartridges. factors. The average automobile owner of the modulation in a typical record is not concerned with the piston stroke Trackability as it Relates groove, and (B) shows a plot of the to or compression ratio, even though modulation in terms of amplitude Amplitude these parameters may be related to versus distance along the groove. As How can the user determine whether performance. He is primarily con- the needle follows such modulation, a phonograph cartridge has good cerned with the functional charac- there are three conditions which must amplitude trackability? The method teristics or the way the product per- be met: which has been in vogue for many forms. 1. The needle must be able to follow years is to refer to the compliance In the case of the phonograph cart- the maximum amplitude variations of specification. It is assumed that if the ridge, the user is interested in the the modulation. This means that the stylus has high compliance, the track - performance at low frequencies rather needle in its compliant mounting must ability at low frequencies (amplitude than the compliance. The manufac- be able to move up and down far trackability) is good. For example, a turers should concern themselves, enough to reach the maximum and top -performance cartridge rated at 1 therefore, with providing good ampli- minimum extremities of the modula- gram tracking force might have a tude (or synonymously, low -fre- tion, such as points A and B in (B) compliance of 25 X 108 quency) trackability. of Fig. 1. cm/dyne, whereas a 1 2. The phonograph stylus must be able poor cartridge at -gram To decide what constitutes good to move at the maximum velocity im- tracking force might have a compli- low -frequency trackability, we can posed by the modulation. This veloc- ance of 5 X 108 cm/dyne. look at the standards to which phono- ity is related to the slope of modula- The use of the term "compliance" graph records are made. These stand- tion as shown at points (C) and (D). is really an inferential way of specify- ards specify the maximum groove 3. 3. The phonograph stylus must be ing amplitude trackability. The user amplitude which should be cut on a able to follow the acceleration con- must infer that high compliance ditions is record. This maximum amplitude is imposed by the modulation. synonymous with good amplitude Acceleration conditions would about .005 centimeters (.002 inch). be max- trackability. Is it necessary imum at a point such as (E) or (F), to use such Hence, if the record is made accord- and would indicate a maximum rate an inferential specification? We think ing to the standards, the phonograph of change of velocity. it is not necessary. The user is con- cartridge must be able to move this The stylus must be able to satisfy cerned with how the stylus performs, distance without losing contact in order all three of these conditions in order not with measurements of internal to follow any possible modulation to have satisfactory trackability. It is parameters. In other words, he is con- which would be cut on the record. very important that we emphasize the word "all" in this statement. Hereto- fore, emphasis has been placed on the "The word 'subtle' has proved to be a relative one in amplitude aspect, some lesser empha- the history of high-fidelity reproduction. There have sis on the velocity aspect, and very been times when many in the hi-fi community were cer- little emphasis, or even concern, over tain that we had reached the ultimate. Each time the the acceleration aspect. subtle difference changed to an obvious difference The ability of a phonograph when stylus better to perform its amplitude-tracking func- equipment came along." tion is related to the low frequency

20 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com This then is the specification on the required an acceleration of 1500 g's amplitude trackability for an ideal at 14 kHz. This compares to a typical, phonograph stylus. good-quality phonograph cartridge capability of 300 to 400 g's at that _a Velocity Trackability frequency. The acceleration require- these records were then ó Velocity trackability relates to the ments of for the ideal capability of the stylus to track in the chosen as an objective 800 to 2500 Hz. In cartridge. FREQUENCY IN HERTZ range of roughly (A) this range we have many fundamental tones of the human voice and the The Sound of Poor Trackability majority of musical instruments. No Poor trackability can often he quite standards exist regarding maximum obvious and can more often be quite velocity of modulation as for ampli- subtle. In one obvious case, the needle o tude modulation. The requirement on may actually skip from one groove to ó velocity trackability which must be another. In another obvious case, a met by the phonograph stylus is there- distinct rattle can be heard, usually fore the maximum velocity imposed with a loud, high -frequency note. In FREQUENCY IN HERTZ (B) by the records of the day. the more subtle case, we may have Measurements on a great many rec- poor reproduction of a sound which Fig. 2. (A) is a representation of proper ords indicate that a maximum velocity is accompanied by many other sounds. trackability with a tracking force of 2 on good quality stereo records runs This might be the case, for example, grams. (B), shows improper trackabil- a tracking about 25 cm/sec. We have found of a poorly reproduced cymbal clash ity of the same cartridge with 3/4 gram. velocities as high as 40 cm/sec on which occurs along with the output of force of some seven-inch rock-and-roll records, the full orchestra. In this case, unless but these are usually discounted in we are very good listeners, the mask- rather poor cartridge. In practice, such determining the performance require- ing effect of the remainder of the or- a situation occurs in a relatively small ments of a high -quality phonograph chestra will cover up the poor repro- percentage of records, so that the ex- cartridge. When one considers that duction of the cymbal clash. pert still prefers to use the very good typical, good-quality records are cut The word "subtle" has proved to be cartridge. Ideally, he would like an play at a normal velocity of about 3 to 5 a very relative one in the history of even better cartridge that would cm/sec it is clear that 25 cm/sec is a high-fidelity reproduction. There have the most difficult modulation. very high velocity, and would produce been times when many in the hi-fi a rather loud sound in the average liv- community were certain that we had Effects of Frequency -Response ing room. This maximum velocity thus reached the ultimate. Each time the Measurements defines the specification for velocity subtle difference changed to an obvi- Thus far we have tried to stress the trackability of a practical, ideal cart- when better equipment ous difference of trackability with regard ridge. We believe this to be the importance came along. amplitude, velocity, and the "subtle" differences in to following case for requirements imposed by Acceleration Trackability acceleration trackability. Today, this acceleration the record. We have related these re- Acceleration trackability refers pri- subtle difference may only be noted by to the need to provide true marily to the high -frequency capability who describes it as quirements the expert listener original sound. We of the phonograph stylus. Here we "muddy" or "raspy." When we have reproduction of the will now discuss the effects of track - have the problem of tracking high - achieved the desired acceleration track- on the measurement of fre- frequency notes and overtones. Sound ability, this sound suddenly becomes ability response. from such instruments as cymbals, clear and even the inexpert listener quency bells, and castanets can impose severe can tell the difference between the The frequency -response measure- requirements for acceleration track - new and the old. ment has long been considered the for measuring the ability. Another interesting aspect of this primary technique of a phonograph stylus. This Acceleration requirements can be is some records a quality situation that on whether the stylus determined in a number of ways. In rather poor cartridge may sound better measurement tells of reproducing frequencies the final analysis, however, we really than a good one; although neither will is capable within the audio spectrum of 20 to ought to look at the records which are as good as the ideal. The reason sound It tells whether there being manufactured. After assessing the fact that a 20,000 Hz. also for this is apparently or reduction of the requirements of the most difficult cartridge reproduces nothing of will he accentuation poor within this spectrum as de- records we might then determine what the high acceleration modulation. The frequencies noted by peaks and valleys in the the phonograph stylus must do. good cartridge reproduces this modula- response curve. In order to get a good cross section, but imperfectly. To illustrate, we -response -to -play records," might compare the two cartridges in It is basic in frequency tion of "difficult track the record critics through- trying to play the modulation pro- measurements that the stylus Shure contacted To make a These critics duced by a castanet. The very poor modulation in the groove. out the United States. measure- for their recommendations cartridge will reproduce practically proper frequency response were asked cartridge the on records which they have found nothing. Hearing nothing, the listener ment of a phonograph he driven to a point to A long list of sug- would not be upset unless he knew stylus must not difficult play. with the record. was the records that the castanet was supposed to be where it loses contact gestions obtained, trackability must be were purchased, and evaluated by present. A good cartridge would par- In other words, the complete frequency - Shure's engineers. Some of these rec- tially reproduce the castanet sound, perfect during ords were found to have acceleration but might not do so perfectly. The response measurement. requirements beyond the capabilities listener would be irritated because he It has been our observation that of any known phonograph cartridge. would hear a distorted sound. In such many frequency-response test records For example, one good -quality record a case, one might well choose the are cut at a modulation level beyond

AUDIO NOVEMBER, 1966 21'

www.americanradiohistory.comAmericanRadioHistory.Com the tracking capability of most phono- tion of poor trackability wherein the graph cartridges at their minimum POLE PIECE crosstalk resonance is 2 to 3 kHz high- BEARING specified tracking force; particularly er in frequency than the resonance /MAGNET in the high -frequency region. This indicated by the main -channel re- means that the response measurement, sponse. This curve indicates that the POLE PIECE usually above 10 kHz, is most prob- main -channel response measurement ably erroneous. When proper tracking was taken under conditions where the takes place, the response curve is stylus was not tracking properly. normally quite smooth, although there Figures 2 and 3 indicate that unless may be peaks and dips. When good proper tracking exists during the meas- SHANK trackability is not obtained during the urement an erroneous frequency -re- frequency response measurement, the sponse curve will be obtained. The MOVING MAGNET curve will appear quite ragged, and trackability problem in frequency -re- PHONO STYLUS may even show double peaks where sponse measurements almost always TIP only one would be expected. In Fig. occurs in the high -frequency region Fig. 4. Representation 2, (A) shows the kind of frequency - above 10 kHz. This problem arises of the generating response curve one would expect when element of a modern moving-magnet primarily because of the inability of cartridge. the needle is tracking properly, and the stylus to satisfy the acceleration (B) shows the kind of curve which trackability requirements imposed by is often obtained under conditions the test record. where the needle is not tracking properly. In a measurement of a stereo cart- The Design of the ridge we usually show both the de- Stylus and Transducer sired -channel response and the cross- So now we have the challenge of which appeared even remotely feas- talk response. The desired -channel re- trackability. The stylus must be able ible, it was concluded that we simply sponse would be obtained, for ex- to satisfy the amplitude, velocity, and could not find a better transducer than ample, in the right channel by play- acceleration requirements. Concur- the one which we had been using, ing a groove with right -channel modu- rently, the phonograph cartridge must namely the moving magnet. This translation. The crosstalk response would have a suitable frequency response. It ducing device, as shown in Fig. 4, be obtained in the right channel by must be reliable and insensitive to the has the following advantages: playing a groove with left -channel effects of temperature. It must not col- 1. It adds no stiffness to the system. modulation. We have found that the lapse after being played for extended The magnet is simply attached to the resonant peak of the crosstalk response periods of time. It must have reason- end of the stylus and in moving produces an electrical signal in the is usually a good able clearance between coil. indication of the the record and 2. The moving magnet transducer re- actual response of the stylus, and the under surface of the cartridge, so quires no external source of bias volt- should coincide reasonably well in fre- that the cartridge will not bounce age. quency with the main -channel reson- against warped records. It must be in- 3. It does not require large permanent ance. (A) in Fig. 3 shows a measure- sensitive to hum. It must be capable magnets which may be attracted to ment made under proper tracking con- of minimizing tracing distortion and steel turntables. ditions where the two peaks coincide vertical -tracking -error distortion (it 4. The stylus is removable for easy re- placement. in frequency, and (B) shows a condi- should have a 15 deg. vertical tracking angle). And finally, and certainly far 5. Output level is sufficient for any hi-fi amplifier as evidenced by the millions it from least, must be manufacturable of such cartridges now in use. at a reasonable cost. 6. The transducer is rugged, since no RESONANT With these requirements in mind, moving wires are employed. I FREQUENCY RESPONSE Shure engineers began the design of 7. Hum pickup can be eliminated with- a new phonograph cartridge. They did out difficulty. not ask the question, "How 8. The transducer is not temperature á can we improve our present product?" The sensitive. ó CROSSTALK question which was asked was, "If we 9. The mass added by the magnet con- wanted to design the ideal, practical stitutes only about 10 per cent of the total effective mass of stylus and trans- cartridge, how would we do it?" FREQUENCY IN HERTZ ducer at the stylus tip. As will be (A) The first part of the study involved shown later this amount of added an evaluation of the restrictions im- mass in within the limit allowable for posed FALSE by the acceleration-trackability meeting trackability and frequency - RESONANT requirement. This requirement limits response requirements. FREQUENCY -W inertia and compliance of the stylus Consideration was also given to RESPONSE and transducer. more esoteric methods of transduction, To start, a study was made of trans- such as light -beam pick offs from the

1n110- RESONANT ducing mechanisms. This study cov- stylus, capacitive pick offs, and acous- FREQUENCY tical pick offs. CROSSTALIc ered a variety of aspects such as the All of these added con- simplicity of the transducer, cost, re- siderable complication to the system liability, and the restrictions that the and offered little or nothing in the FREQUENCY IN HERTZ transducer might place on the over-all way of advantages. (B) design. The latter requirement means As a result of this study, our con- Fig. 3. (A) Response (upper) and cross- that one would not be able to use a clusion was that the moving-magnet talk (lower) curves of a cartridge track- transducer with excessive mass, or one transducer would offer the most po- ing properly at 2 grams tracking force. with excessive stiffness. tential for meeting the requirements of (B) Curves of same cartridge tracking After an exhaustive study of the the ideal cartridge. improperly at 3/4 grams. pros and cons of every transducer Continued Next Month

22 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Some plain talk from Kodak about tape: Uninterrupted listening pleasure... and the answer to a searching question

with the built-in wrong box), and a dynamically bal- Recording a pop tune or even the you are still ahead output anced reel that reduces the stress and whole top ten isn't much of a problem quality of KODAK Tapes-high strain on a thin tape, and you can see with standard sound tapes. But people tape Type 34A, with its output and why KODAK 12P Tape is becoming so always want more-like getting a noise advantages, or low -print tape popular. whole Wagnerian opus on a single reel. Type 31A. Actually, the problem of long playing Some like it thin. The other avenue r time involves two variables: how fast °flak is to go to a thinner tape ... one that you run the tape, and how much tape packs more length on the reel. This length you get on a reel. The latter too is an appealing idea-one that ex- KODAK variable is a function of reel size and plains the proliferation of double and tape thickness. The following chart triple play tapes. So what's the catch? SQUNU will give you an idea of running times Well, for one thing, very thin tapes re- with different lengths of tape: quire careful habits on the part of the RECßRDi home recordist. Your recording/ play- 400 TAPE Er: 380 back heads should be in good shape, 3606 hrs. 340 as thin tape is more liable to physical types 320 distortion and breakage. Make sure KODAK Tapes-professional á> 300 the long-playing variety-are 280 that your recording equipment is in and 260 camera, top shape so that it produces smooth available at most electronic, l 240 stores. If you've had É 220 starts and stops. You can help with a and department 2X away trouble finding them at your favorite clea 3 hrs. smooth start by turning the reels

160 help. Simply from one another (gently, please) so as store, Kodak would like to tell us where you'd like to buy KODAK 120 2 M. to take up any slack in the tape which cc 100 can do . may have occurred during threading. Tape, and we'll see what we 80 IZP. about having these stores stock it. In 60 1 hr. Also, forget the fast -rewind knob - 40 rewind the meantime, we'll rush you the 20 store tapes "as played." Fast dealers where 2600 3000 3400 3800 names of nearby Kodak 0 200 600 1000 1400 1800 2200 can set up a lot of tension and often Feet of Tape Tape; cause erratic winding. All this can re- you'll be sure to find KODAK a very informative booklet"Some Some like it slow. Taking it slow is sult in "stretched" or "fluted" tapes. also, Plain Talk from Kodak about Sound the obvious way to get longer playing In a nutshell, treat thin tapes with lov- Recording Tape." Just fill out the cou- time. Halve the speed and you double ing care. When you record, be careful pon below. the time it takes for the tape to run. not to overload on input (if you have a be- This works very well up to a point. As VU meter, keep the needle slightly Mail coupon today level you would nor- a matter of fact, it is the historical low the record Eastman Kodak Company Last trend-from 15 ips to 71 ips to 33/4 mally use for regular tape). but Department 940 N.Y. 14650 ips and so on. But as you cut the not least, make sure you get your tape Rochester,

I to the re- from a reliable maker-like Kodak. It Gentlemen: would like to be able speed, and thereby compress Recording Tape at care in winding, get KODAK Sound cording, you make the microscopic takes a lot of extra the following stores: perfection in the tape more and more slitting and over-all handling to come 1) important. Furthermore, at slow up with a superior triple -play tape like Camera store Because speeds the increased dependence up- Kodak's famed Type 12P. 2) Department store on short wavelength information and of its highly efficient oxide, Type 12P a signal-to-noise ratio bet- 3) the concurrently reduced flux -carrying gives you Electronic supply store tape makes head and ter by close to 6 db compared to the capacity of the Please send names of nearby out- equipment design more difficult. But other leading triple -play tape. Add lets and my free copy of "Some Plain even though improved quality slow - to this the advantage of back printing Talk from Kodak about Sound Record- ing Tape." play tape recordings are strongly de- (so you always know what type of tape pendent upon improved equipment, you're using - even when it's in the Name Address

EASTMAN KODAK COMPANY, Rochester, N.Y. City & State Zip

ti J

Check No. 66 on Reader Service Card. AUDIO NOVEMBER, 1966 23

www.americanradiohistory.comAmericanRadioHistory.Com www.americanradiohistory.comAmericanRadioHistory.Com the most important advance in phono cartridges since the advent of stereo

{_ J l > H R ( S V E L w=i ...a new genre of cartridge, analog -computer -designed, and measured against a new and meaningful indicator of total performance: "TRACKABILITY"

bear- recording called "An Audio Obstacle V-15 TYPE II heralds bearing; the viscous damping of the The radically new recorded Course" to indicate cartridge trackability. in high performance car- ing; the tracking force; the a new epoch The num- It is without precedent, and will be made the measurement of their velocity of the record, etc., etc. tridges and in combinations of available to Shure dealers and to the in- We call it the era of high ber of permutations and performance. staggering, be- as a whole. You may have your Because of it, all your rec- these elements, normally dustry Trackability. trial - by writing directly to better and, in fact, you came manageable. Time-consuming own copy for $3.95 ords will sound eliminated. Years check. (Note: some recordings tracked at light and -error prototypes were Shure and enclosing your will hear into months. more forces for the first time without distortion. of work were compressed The test record cannot be played After examining innumerable possibilities, than ten times with an ordinary tracking evolved. Working new design parameters cartridge, regardless of how light the PROBLEM: in new configurations, THE with new materials force, because the high fre- minimum track- theory was made fact. tracking While audiophiles prefer characteristics will be erased by to minimize record wear and analog -computer -designed, quency ing forces Thus, the first action of the stylus.) preserve fidelity, record makers prefer to superior trackability cartridge was born: the groove-deforming cut recordings at maximum levels with the Shure SUPER -TRACK V-15 TYPE II. (2) A reprint of the definitive technical maximum cutting velocities to maximize It maintains contact between the stylus paper describing the Shure Analog and signal-to-noise ratios. Unfortunately, some and record groove at tracking forces from trackability in cartridges, which appeared "loud" records are cut at velocities so Y4 to 1% grams, throughout and beyond in the April 1966 Journal of the Audio great that nominally superior styli have the audible spectrum (20-25,000 Hz), at Engineering Society, is available (free) to been unable to track some passages: the highest velocities encountered in qual- the serious audiophile. notably the high and midrange transients. ity recordings. It embodies a bi -radial ellip- (3) A representative list of many ex- Hence, high level recordings of orchestral tical stylus (.0002 inch x .0007 inch) and cellent recordings with difficult -to -track bells, harpsichords, pianos, etc., cause the 15° tracking. available is yours for wildly passages currently stylus to part company with the ingenious "flip -action" These records sound crisp, ceases to It also features an the asking. undulating groove (it actually built-in stylus guard. clear and distortion -free with the Shure this produces an audible track). At best, Type 11. gross distortion It is clean as the proverbial hound's tooth V-15 click; at worst, sustained V-15 TYPE H Is noise results. The "obvious" and musical as the storied nightingale. The Shure Super-Track and outright at dealers at $67.50. solution of increasing tracking force is THERE ARE MANY WAYS TO PROVE available your impractical because this calls for a stiffer ITS SUPERIORITY TO YOURSELF: Shure Brothers, Inc., 222 Hartrey Avenue, stylus to support the greater weight, and (1) Shure has produced a unique test Evanston, Illinois 60204 a stiffer stylus will not track these transients or heavy low -frequency modulation, to say nothing of the heavier force accel- TRACKABILITY AS A NEW SPECIFICATION: erating record and stylus wear to an in- tolerable degree. 40 scores of these de- V -I5 TYPE II (1 GRANO Shure has collected 30 manding high level recordings and pains- them. / takingly and thoroughly analyzed (after 20 / VI(3/4TGIIAM) It was found that in some cases L___,_ only a few playings) the high velocity were (1 GRAM) high or midrange groove undulations , ' ., "shaved" off or gouged out by the stylus 4V. CRAMJ "^.,. ` thus eliminating the high fidelity. -.ti --. records, which were off-handedly .--.. Other (84 GRAM) \ \\ dismissed as unplayable or poor pressings were found to be neither. They were ' simply too high in recorded velocity and, ; -\ , by existing styli. \ therefore, untrackable %, (14z GRAMS.)..-'....".... A as a result of these . \ Most significantly, \ analyses, Shure engineers established the 1 maximum recorded velocities of various , `y.` frequencies on quality records and set would ') ,..., about designing a cartridge that track the entire audible spectrum of these maximum velocities at tracking forces of 2, 00 4,000 6000 8.000 10. less than 11/2 grams. 100 200 400 600 800 1,000 FREQUENCY H'

ENTER THE COMPUTER: This chart depicts the new perform- ceed these theoretical limits. The The solution to the problem of true track - ance specification of trackability. Un- smoother the curve of the individual ability proved so complex that Shure en- like the oversimplified and generally cartridge being studied and the greater gineers designed an analog-computer that m;sunderstood design parameter spec- its distance above the grey area, the closely duplicated the mechanical varia- ifications of compliance and mass, better the trackability. The trackability of total per- bles and characteristics of a phono car- trackability is a measure of the Shure V-15 TYPE II is shown device they were formance. The chart shows frequency tridge. With this unique by the top (solid black) lines. Rep- able to observe precisely what happened across the bottom, and modulation The resentative curves (actual) for other when you varied the many factors which velocities in CM/SEC up the side. $32.95, end of represents the maximum cartridges ($80.00, $75.00, affect trackability: inertia of tip grey area dotted, dashed the magnet end of the theoretical limits for cutting recorded $29.95) are shown as the stylus or lines for comparison stylus; the compliance between the record velocities; however, in actual practice and dot -dash and the needle tip, or the compliance of many records are produced which ex- purposes. the stylus shank, or the compliance of the T.M.

Check No. 67 on Reader Service Card. www.americanradiohistory.comAmericanRadioHistory.Com of fact, a FET single -stage amplifier was driven into heavy output overload (heavily clipped sine wave) with about 30 per cent distortion. When measured at the gate, the distortion still read 0.01 per cent (the distortion of the generator itself). This means that distortion in FET's is limited to High Fidelity Phono output overload which is essentially determined by supply voltage. Below the start of output clipping, output Preamp distortion in FET's runs at extremely with FET's low levels, far less than with both vacuum tubes or transistors. The reduced noise WILLIAM A. RHEINFELDER level and higher output capability result in an increased dynamic range for the FET amplifier. Other characteristics, such INTRODUCTION TO FET's as gain in excess of pentode amplifiers and performance at low FET's or Field Effect Transistors current are a newcomer to the family of amplifying levels are obvious advantages. Among devices which includes vacuum tubes and normal transistors, which are often these is excellent temperature called bipolar transistors in contrast to FET's. In bipolar transistors amplifica- stability. tion is achieved FET circuits were demonstrated which by use of both types of carriers, electrons and holes, while a FET relies on carriers of one polarity only, such as electrons, and is also called perform without deterioration when a unipolar transistor. submerged in liquid nitrogen FET's function very much the same way as vacuum tubes and amplification is (=200°C) and at ambient tempera- achieved by control of an electric field. This field is set up in a semiconductor tures as high as +180°C. by applying voltage to the ends of a channel, such as a bar of N -channel germanium (rich in electrons or negative charges). The electrodes are termed Circuit Designs with FET's source (cathode) and drain (plate) and are biased exactly like a vacuum tube The obvious question then is what for a N -channel device, with positive voltage to drain. In order to control the circuit -design procedures must be fol- field set up in the semiconductor, a third, insulated electrode is added, the lowed to obtain this excellent per- gate (grid), which is biased negatively with respect to source (cathode). In a formance. Briefly, the essentials are field-effect device no gate (grid) current flows, but rather a control voltage is correct d.c. biasing, realistically speci- used to control gain just as in a vacuum tube. Because of this similarity, it fied FET's, and high-impedance am- is generally much easier to follow the existing tube circuitry for design. Knowl- plifier design as with vacuum edge of standard transistorized circuits is of little use with FET's. However, tubes. design A with FET's is much simpler than with normal transistors, due to their FET behaves in any respect as high input impedance and ready capability. New work, shown in this article an ideal pentode not having a screen indicates the superiority of FET's over both vacuum tubes or normal transist- grid (with the possible exception of ors, particularly in audio applications. feedback capacitance). FET's, being For a better understanding, the chief characteristics of transistors, tubes, and "field" devices, want to operate at FET's are summarized in Table I. high voltage for best performance. Drain current is of little importance as long as the drain voltage itself FET Performance is Characteristics FET's provide more signal than even correct. Extensive tests indicated that NEW CIRCUIT DESIGN PROCEDURES tubes for the same distortion. the optimum drain voltage in voltage - for FET's were recently devel- The linearity of FET voltage ampli- amplifier applications falls at 45 per oped1.2, which result in far fiers itself is phenomenal. Take the cent of the supply voltage, regardless superior circuit performance than is typical case of a transistor stage run- of the specific FET or drain current. possible with the best transistor or ning about 5 per cent distortion in the Also, for the best all-around perform- vacuum tube circuits. It appears now, output. If the distortion is measured ance in audio circuits, a load resis- that FET's will replace both vacuum directly at the base, it will read about tance of 100k ohms is best (lowest dis- tubes and bipolar transistors in all 4.8 per cent. This is typical for nor- tortion, wide frequency response). linear (amplifier) applications within mal transistors because the distortion Another good choice is 220 K ohms the next two to five years. Presently is generated in the very nonlinear for- where increased gain is achieved with available FET's3 surpass all previously ward -biased base -emitter diode, while increased distortion and somewhat known active devices with regard to the amplification process itself is reduced frequency response. All of noise, overload, linearity (distortion), usually reasonably linear. The high this is quite familiar from vacuum - gain, current economy, input imped- distortion of normal transistors is in- tube design. The objective is then to ance, and so on. For example, while herent and cannot be removed but bias the FET so that the required transistors have a lower noise level only minimized. than tubes (4 to 6 dB at audio frequen- A vacuum tube by comparison may 1"Biasing Consideration for FET's," En- cies, about 3 db in uhf-TV -tuners), read 10 per cent distortion in the gineering Report 2. FET's in turn are better than the best output, with about 0.5 per cent read (Available from Dickson Electronics transistors. An improvement of 2 to directly at the grid. The distortion Corp., 310 S. Wells Fargo Road, Scotts- 4 dB over the best bipolars was noted generated in the grid circuit is mainly dale, Arizona.) with presently available FET's in due to the normal grid current of Literature audio circuits. Tubes as a rule have vacuum tubes of 1 about microamp. 2"Design Criteria for an output capability from 12 to 20 A FET measured FET Voltage Am- under the same plifiers", Engineering Report 3. ibid. dB higher than bipolar transistors in conditions shows no measurable dis- audio voltage -amplifier circuits. Again tortion in the gate at all. As a matter 3Q -series by Dickson Electronics 26 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Soundsibility!

Soundsibility - superb sound with sensible features - it's a tradition with Viking tc pe recorders. In keeping with this tradition Viking introduces the new Modal 423 - designed to bring you excellence in performance, true stereo fidelity and the utmost in practical operating convenience. Other A three-speed unit with solid state stereo electronics, Model 423 also hos three motors for highest reliability. features include hyperbolic heads, illuminated recording meters and directional cortrol levers. A remote pause control* easy So fits every Model 423 and lets you interrupt and resume recording or playback conveniently from your chair. sensible even the model number is meaningful -4 tracks, 2 heads, 3 speeds. Uniquely, with all these features, it's less than $250.00. *Remote pause control and walnut base optional accessories.

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10. i , 1

88 Stereo Compact 880 Stereo Portable 807 "lape Turntable" Connects to music system for play- The "final touch" for stereo music Same features as. Model 88 plus de- back only of all standard monaural systems. Features tape monitor with tachable speakers, power amplifier tapes. Features two popular three heads, sound -on -sound record- with stereo headphone output in or stereo Use it also to duplicate topes ing, exceptional fidelity even at slow portable case. Carry along for "on speeds. with another tape recorder. Walnut speed for less than $340.00. the spot" recording or connect to musk system for less than $440.00. base included for less than $125.00.

kin gOF MINNEAPOLIS y DIrtSION OF THE TELEX CORPORATION 9600 Aldrich Ave. S. MinneepoNs, Minnesota, 55420 .11

Check No. 110 on Reader Service Card. AUDIO NOVEMBER, 1966 27

www.americanradiohistory.comAmericanRadioHistory.Com drain voltage is achieved (determined by the above conditions). TABLE 1 It was clear after running numerous tests that conventional FET specifi- COMPARISON OF TUBES, TRANSISTORS, AND FETS cations fall far short of what is essen- (Approximate normal values) tial amplifier information. For exam- Vacuum Tube Transistors (NPN) FET (N -Channel) ple, tests performed on one type of Plate Collector Drain FET (one 2N number from one Electrodes Cathode Emitter Source manufacturer), showed the optimum Grid Base Gate gate voltage to range from 0 to 10 Plate Supply 100 to 250 V. 10 to 35 V. 100 to 250 V. volts. What makes matters worse is Grid Bias -0.5 to -10 V. +0.2 to 0.6 V. -0.5 to -10 V. that the exact gate voltage must be Grid Current 1 µA 100 µA 1 nA accurate to a tolerance of 20 per cent Plate Load 22 to 220 k ohms 1 to 22 k ohms 22 k to 220 k ohms in practical circuits. Consequently, Filaments yes no no every FET needed a tedious manual Power Gain high low very high adjustment and production circuits Noise Level medium low very low Distortion low on that basis are, of course, imprac- high very low Input Resistance 50 M ohms 1000 ohms tical. The following 5000 M ohms parameters of Temperature Range -50 to + 200°C -50 to +80°C -200 to +80°C FET's were found absolutely meaning- less: pinch -off voltage, shorted drain current, shorted transconductance, and were dumped into one basket and At least one manufacturer4 has rec- so on. Going through a typical FET labeled by the same type number ognized this problem and has come data sheet, not a single parameter was based on a parameter such as cathode out with a new series of FET's fully found that was useful for amplifier current or filament voltage, or the specified for amplifier performance. design. It was a situation similar to like. Intelligent circuit design is then Using these devices, truly excellent a case where fifty different tube types an impossibility. performance is possible. In addition to correctly specified 120V/2rA devices, a few points on circuit design should be observed. Biasing of FET's is t 20 about as critical as for a pentode4 20 CHANGE TO .02 FOR DASHED CURVE IN FIG. 5. if a high supply voltage is used (120 .015 V). At bipolar transistor voltages o (15 V.) bias becomes much more critical (2 per cent tolerance) DNN-1.8-A and DNL-1.8-A this causes difficulties in .05 practical circuits. Therefore, high voltage oper- TO TONE CONTROL UNIT ation is essential. Since the drain voltage in small signal amplifiers is close to but never more than 60 volts, a CARTRIDGE minimum FET breakdown of 60 -volts TO MAGNETIC LOAD ó is required for small -signal CARTRIDGE applications (100 volts and up for large - signal applications). Only for lowest noise operation is a reduced supply voltage justified (30 volts), particularly since distortion is not as critical 3100 pF 75K in input stages. Gate bias itself is best achieved by 11 a self -bias resistor in series with the 1200 pF source -terminal. Due to the lower cur- FEED BACK NETWORK FOR DASHED CURVE IN FIG. 5. rent drain of FET's as compared to Fig. 1. Phono equalizer -amplifier with FET's. tubes, this self -bias resistor is usually considerably larger than with vacuum tubes and generally should be by- passed. If feedback is to be applied to the source terminal, this is best 60 accomplished by a separate feedback ...... resistor in order to keep the local feedback down. 5000.e... Phono -Equalizer Section Fig. 2. with FET's 40 Response of equalizer -ampli- For the hifi-hobbyist, the superior ¢I fier of Fig. 1. performance of FET's suggests their 30 immediate application to all kinds of hi-fi circuits. For the purists (like the 20 author himself and many professional audio people), transistors were never a substitute for tubes. They simply

t0 20000 100 000 10000 had too much distortion and were FREQUENCY IN HERTZ 4Dickson Electronics Corp.

28 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Great new ideas have one thing in common.

The new Empire Royal Grenadier, in principle, is really over 2000 years old. The Romans discovered that a cylindrical shape was best for projecting sound in their outdoor arena. They used an urn. This knowledge was not brought to bear on modern sound reproduction until 1963 when Empire developed the Grenadier. The cylindrical design was applied to get the woofer as close to the floor as possible and thereby prevent standing waves from developing in the listening area. Sound from the woofer is diverged through a circular aperture in the front loaded horn. This creates a full 360 degrees of sound dispersion. The powerful 18 lb. magnet structure woofer, midrange direct radiator and compression tweeter are coupled by mathematically exact electrical and acoustic crossover networks. The wide-angle acoustic lens produces 50 oercent broader sound propagation than conventional speakers and projects phenomenal stereo separation. You can listen anywhere in the room without distortion, dead spots or changes in pitch. The sound you hear then is not only accurate sound, but startlingly beautiful; and it can charge you with its presence. But none of this just "happened." It came about only by an awareness of, and tenacious experimentation with, long-standing scientific principles. The result is most certainly a "first." Write for 1967 color brochure "Stereo Decorating & Basic Record Guide." Empire Royal Grenadier. One of the Great Firsts. Empire Scientific Corp., 845 Stewart Ave., Garden City, N.Y.

Check No. 68 on Reader Service Card. www.americanradiohistory.comAmericanRadioHistory.Com too unstable. Perfectionists who are used to equalization tolerances of -}0.1 dB never could "warm up" to TABLE II transistors. Also, the peaks of certain COMPARISON OF PHONO PREAMPLIFIERS musical instruments are up to 30 dB Tube Transistor FET above the average, and the required Device, 1st stage ECC83 2N1192 DNN-1.8-A Device, 2nd stage high output capability is simply not ECC83 2N1193 DNL-1.8-A Gain, 1000 Hz possible with bipolar transistors. The 40 40 40 dB Min. Output Noise, wideband 66 -72 dB* situation is quite different with - -74 FET's. Min. Input Noise, at 1000 Hz. 106 -112 -114 dB* The first portion a - of phono -pre- Max. Output Level, per cent THD . +26 +13 +31 dB* amplifier consists of a phono equal- Distortion at 30 V. output in heavy overload 0.06 per cent izer. The circuit for this equalizer is Overload -to -noise ratio 92 85 104 dB shown in Fig. 1 and its frequency Supply Voltage 180 15 120 V. response in Fig. 2. The popular two - Current Drain 1 5 2 mA. stage feedback circuit is used with series voltage feedback from the out- Note: All measurements with identical equalization and gain. put into the first "source." This type *With respect to 1V. of feedback decreases the output impedance and increases the input im- mental output below about 80 Hz. the following tone control. pedance particularly at the high fre- For correct bass boost, for example, The performance of this phono - quencies where this is most beneficial. frequencies from 70 to 150 Hz only equalizer is excellent and reliable. Any incorrectness in equalization should be boosted. Boost below 70 Different FET's of the same type will (which is sometimes called a dis- Hz results in change of tonal charac- operate equally without circuit read- advantage of the circuit) is easily ter, and above 150 Hz in so-called justment. The equivalent input noise compensated by added components in "boomy" bass. Consequently, equal- at 1000 Hz is -114 dB5, the wide- the feedback network. The following ization extending indefinitely at low band output noise is -74 dB5 (gain changes as compared to a vacuum frequencies is a serious shortcoming is 40.0 dB at 1000 Hz). This noise tube circuit are noticed: of many preamplifiers because noises level is 8 dB lower than in the best a) Self -bias in the first stage by a by- other than music are emphasized. professional tube circuit using d.c. passed 7500 -ohm resistor. This resistor Ideally, a rather sharp roll -off should filaments and with all traces of hum re- may have to be changed for different be provided. Two possibilities are moved. It is 2 dB better than the type FET's. given in Figs. 1 and 2 to suit the in- best transistor circuits. The overload b) Large decoupling resistor for the first dividual's needs. Both input and out- level for 1 per cent distortion is +31 stage (560 K). This resistor drops put coupling capacitors are utilized dB5, 5 dB better than a tube circuit the first -stage drain supply to about for low -frequency rolloff. Therefore, (even operating 30 volts for least noise. at twice the supply these capacitors may a c) Drain resistor for second stage is 27 need slight voltage) and 18 dB better than a nor- K. This resistor was accurately ad- readjustment with different resistors mal transistor circuit. Distortion at 30 justed for least distortion with feed- for the cartridge load or the input of (Continued on page 74) back connected. Due to the parallel 1000 loading of the feedback network it- +120V self, a rather low value of drain re- TONE CONTROL sistence results. C3-300 d) The gate resistor of the first stage is .05 made equal to the load resistor for the cartridge rather than using a 1/2 -Meg. 70 DNL-1.S-A gate resistor and a separate cartridge TAP 5 0 load. A smaller gate resistance results in reduced noise due to possible leakage currents. While the amplifier will work with large gate resistors, it is a + 25 good idea (also in tube circuits) to keep the d.c. gate resistor as low as C2-100 possible. Since the cartridge load is LOUDNESS -VOLUME - needed at the high frequencies only, Fig. 3. FET audio control circuit, simplified. a.c. coupling is permissible. As a matter of fact, d.c. coupling may also be used, although here some rejection of unwanted lows was desired. The exact cartridge load depends on the compli- 111111 11111 _.. 1 ance of the stylus and the cartridge in- TREBLE MAX +15 ' I ductance and is best determined with MAX a test record. The correct value re- +10 .1" sults in the flattest response above 10 'f1 Fig. 4. Tone -con- kHz. (Before this test, the minimum trol response stylus force should have been deter- Pa O IIIIII[I!!!.i1l curves from the ined, usually at 100 Hz and peak am- I Baxandall circuit 10 plitude by observing tracings distortion ,11'11I'11111111. of Fig. 3. on the oscilloscope.) -15 BASS MIN TREBLE MIN In addition, the following comments are offered regarding low -frequency 25 equalization: Most musical instru- 20 I 20 me ments (with the exception of the 200 ,2000 FREQUENCY IN HERTZ organ) produce no significant funda - Check No. 69 on Reader Service Card. - 30 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Sony has developed the world's finest audio transistors... here's the proof

have made fa.rly good transistor The integrated amplifier, the TA -1120 features a Many manufacturers for amplifiers. Until now nobody has made a great one: sensible arrangement of the frcnt-panel controls And everybody knows :he reaso-r. distortion. Unfor- the greatest versatility and ease of operation tunately, most transistor amplifiers d stc rt in a very We believe, that these are the fi -st great trans_stor what o:her man- way. Not so much at top power, but rather pcver amplifiers. How can Soiiy d4 special transistors. more at normal listenirg levels where it hurts most. ufacturers couldn't? Sony is a picneer in tunnel diode. Transis- -1120. amplifier and TA-3120 With first after first. Such as the The Sony TA integrated video tape re- amplifier are the first high-powered transistor tcr television. .1-1(1 the all transistor power transistors To uni:s to really overcome the problem of distortion. At corder. The point is that Sony knows new, advanced types all power levels, at all frequencies distortion is kept the 'n'th degree. And designed stages cf these bellow that of the finest tube amplifiers. The TA -1120 ea-oeciatly for the driver and output are used throughout. and TA -3120 both pro..i:e 120 watts IHF at 8 ohms, arrplifiers.Àndsilicon transistors TA -1120 integrated both channels operating Distortion, at rated output, is They are the most stable. The oit-finish walnut enclo- 0.1%. And at normal listening laves it is even less, amplifier, 5399 50. A handsome is The power arrpli'_irr, TA -3120, $249.50. at '/2 watt. 11 addition, they have achieved an sure optional. 0.05% dealer and make him erotraordinarily high damping factor, better than 70 at Visit your Sony high fidelity the money. Maki him. com- 1000 cps to assure clean, low-frecueicy power re- prove that Sozy is worth amplifers. We think you'll sponse. Frequency response is practically flat from 10 pare it with the finest tube with a Sony. For a free brochurelleewrces st to 100,000 Hz (+0 db/-- db). Fcr safey% sake, an SCR end up Rèesred (silicon controlledrecti_ier' protects the power transis- O Corp. of America, 47-37 Van Dram St., tors against accidental shorts and oche- overloads. Long Island C ty, N.Y. 110 Dept. H

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your if turntable speed is off you won't hear the recorded music at its original musical pitch. How much is "off"? NAB broadcast equipment Standards, to which all AR turntables must conform to pass factory inspection, allow no more than 0.3% inaccuracy- a maximum drift of one line every three seconds on the strobe card shown above. Pitch is kept accurate to within one -twentieth of a half tone. Some record players have uncorrectable speed errors as high as 1.5%-strobe card drift of 5 lines every three seconds-creating a pitch error of a quarter of a half tone. It is as though the conductor directed his orchestra to tune its instruments higher or lower.

The 2 -speed AR turntable meets NAB broadcast Standards in rumble, flutter, wow, and speed accuracy.* The price is $78 including oiled walnut base, transparent dust cover, and center piece for 45 -rpm records. In comparing prices be sure to count the cost of these accessories when, as is usually the case, you have to buy them separately.

Literature on AR turntables and speakers will be sent on request. *Confirmed by many independent test reports. Four magazines chose the AR turntable for their top stereo systems from a field of competing units costing up to twice as much. We will be glad to send you their lists of selected components; you may also have, on specific request, a reprint of an article on how to check turntable characteristics at home.

ACOUSTIC RESEARCH, INC., 24 THORNDIKE ST., CAMBRIDGE, MASS. 02141

Check No. 70 on Reader Service Card. 32 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Simulated "Live vs Recorded" Test for Loudspeakers

You think you know how to compare speakers? After you read this you won't be so positive. The author, a respected speaker manufacturer, to be sure, points up the problems and pitfalls likely to be encountered in hit-or-miss speaker comparisons. This study in psychoacoustics was derived from a lecture given by the author to a N. Y. Section meeting of the AES, and is complete except for the aural demonstrations.

EDGAR VILLCHUR*

THIS DISCUSSION be described very exactly; it is mostly tion that the purpose of sound -repro- THE SUBJECT OF not is a method of evaluating loud- subjective; it depends on your taste ducing equipment is to reproduce, - speakers with a listening test and hearing; and the use of a direct to create, and that the best sound which whose central characteristic is that it comparison with the original sound in reproducing equipment is that has controls. When one introduces a the so-called "live vs. recorded" con- produces the most accurate reproduc- ac- new procedure it is not only neces- cert is a misleading procedure. Specifi- tion, and that high fidelity and sary to demonstrate the validity of the cally an article in one of the well- curacy mean the same thing. procedure, but to show that it solves known periodicals, entitled "The Pros- Now suppose you play a brief in- through a a problem-that is, that it serves pects for Psychoacoustics" (although terval of reproduced music some useful purpose. So I will begin it was actually about listeners' tastes) specific loudspeaker. by talking not about the procedure tried to make the point that when you Is it good, is it bad, is it mediocre? itself, but the problem that it is de- make a direct comparison between It's really very hard to tell from one signed to solve. reproduced sound and the sound of sample, for which you have no refer- Suppose you were shown two color the live musicians you introduce a ence. Let us call this loudspeaker "X". reproductions of a Van Gogh paint- subjective element into the proceed- Now suppose you play the same is playing, one of which has a sky which is ings; that the existence of the concert - selection again, and while it obviously blue, whereas in the second, hall atmosphere and of the musicians ing switch from loudspeaker "X" to we shall the sky is almost orange. Now either induces in the listener what was called another loudspeaker which both of these reproductions are a "will to believe," an aura of accept- call "Y". grossly inaccurate, or one of them is ance. Therefore, said the writer, when Now we are a little better off-we right and the other wrong (or at you wanted to judge sound -reproducing have two things to compare. But still the least one of them is more right than equipment expertly, the thing to do one goes back and forth and may the other). I don't think that it takes was to use the so-called A -B test with- answer is not that clear. You a genius, or one who has written his out immediate reference to the origi- prefer one or the other. The fact is Ph.D. thesis in modern French paint- nal sound. that even with the most experienced ing, to devise a method of finding out I can imagine an Alice in Wonder- listeners who have worked both with which of these two reproductions, if land trial in which the jury is in- loudspeakers and with live music and indeed either one, is the accurate one. structed that a prerequisite to judging have heard the two together, listening We have only to compare them to a copy is making sure that the original for a period of time to sound with a the original painting and we will know. is nowhere in evidence. I am laboring particular coloration tends to make as at If I seem to be making an obvious this point a little because I want you one accept that sound right, or And so the demon- point I would like to assure you that to understand a thoroughly obvious least as "not bad." for your- it is far from obvious in the field of fact-we will never know which one stration you have just made sound reproduction. There are writers of the two color reproductions was self is commonly known as the A -B in the latter field who state, in pre- right until we take a look at the ori- test, and it has real drawbacks. sumably serious articles, that the way ginal painting, the original Van Gogh. The comparison of the two painting to judge sound reproduction and Yet this direct -comparison technique reproductions, too, was an A -B test. sound -reproducing equipment cannot is fought against by a fair number of You all knew what was missing there "experts" in the field of sound repro- -the original Van Gogh painting. *Acoustic Research, Inc., 24 Thorndike duction. What is missing from the A -B test of St., Cambridge, Mass. 02141. I am starting out with the assump- speaker sound is the original sound of

AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com the music you played from your REFER- record. ENCE It is not likely that you can produce the original musicians. My company U Wz and others have xz2 indeed staged live AMPLIFIER U O vs. recorded concerts where w we have aZZ had the live musicians on stage, but 0 0 0 0 0 0 w it is a very difficult and costly task. And so the procedure that I am going to describe is a simulated live vs. recorded test. In 1960 I presented a paper at an AES convention, in which I demonstrated a simulated live vs. recorded listening test for tweeters, using random noise as the basic sound source. Last year Consumers Union published an equipment review of loudspeakers and indicated that they had used a similar type of test, but with full -range speakers and with music. I have been given to understand o that their development of this 0000 I=1 test was independent of the test procedure that we used at our company, but I cannot claim independent de- Fig. 1. The record player, amplifier, and reference speaker make up a simulated "live" source. Recording system puts original electrical input to the reference velopment for the material of this speaker on channel 1, the reference speaker acoustical output on channel 2. writing. I had thought that the practical difficulties of making a simulated machine clanking away, or by a hum- source material) until it enters this live vs. recorded test with full -range ming bird, or by live musicians-is studio; and the sound of the record- multi -driver speakers would be too recorded anechoically, that is, in a ing must similarly be uncolored by great, but when I read CU I was in- dead environment without echoes. echoes until it enters this studio. trigued. We Question: What would be the tried it at AR and it Why must we record it anechoically? effect of worked. I mention recording not in an anechoic chamber, all of this be- Because the recording that we are cause I but in studio A and then conducting all feel that I should give credit going to use in the test must contain where it is due. your further tests in studio A? nothing but the sound of the source. Answer: It still wouldn't work. No And now we turn to the test itself. If the recording includes the rever- matter how you slice it the original In the simplest possible terms the beration and coloration of any partic- sound is projected into this studio staging of a live vs. recorded demon- ular hall, this coloration will be a false without any previous reverberation. stration consists of this: We record a element in the playback because that You must also project the recorded sound, a live sound, whatever it is. hall or studio isn't here, and so we sound without any previous reverbera- Maybe tion, or you get reverberation. it's a cricket, maybe it's a will not be able to match the refer- double mechanical device, Now whether we get the reverberation maybe it's a string ence sound. It would be as though quartet. of studio A plus this studio, or the re- We then take the same animal in comparing graphic reproductions or device verberation of studio A plus itself- or musician(s) that made against the original painting, we used that live sound, studio A twice-it would still be a put it on the stage a reproduction colored by the light false element in the recorded sound. here, ask it to make the sound again, and shadows produced by Question: It seems to me that there is and a particular try to imitate it by playing back exhibition hall. still a small error being made here. You the recording through different Question: You say you can use any cannot record the entire sound of the speakers. kind of speaker, which presumably might loudspeaker-you have to record it at The "live" sound that I will use have coloration. Why should it matter some particular position in space, that is, here is the output of a loudspeaker. whether the acoustical environment of you have to put the microphone at one It might help things if you didn't the speaker has coloration or not? point. It is a uni -dimensional signal, know what the loudspeaker Answer: Let's assume we record in whereas the sound emanating from a was, or loudspeaker unit in the anechoic cham- whether or not it itself had significant studio A. In order to compare our recorded sound with that ber is not. Do you put the microphone coloration. In any case we call this of the reference speaker, we are going to have to directly in front of the loudspeaker? loudspeaker a reference speaker. We recreate the reference sound here. We Answer: What you have done is call it a reference not because it has play the reference speaker here, re- merely to describe the difficulty of any standard of greatness, but because peating the sound that existed before this whole business, and rather than it is, literally, the thing to which we it was recorded by using the original answer this question now, the whole refer each time. electrical input, and this sound does substance of this paper will answer it. It is the major problem. I can tell you Figure 1 illustrates the electrical not, of course, have the coloration of elements studio A. But when we play the re- that it is not insurmountable, but I of the recording technique can also tell you that it remains the for the simulated live vs. recorded cording back through our speaker under test it would include not only the problem which makes this test less test. The sound of the reference sensitive than I would like it to be. speaker, which sound of the reference speaker but the you can call "Z" or sound of studio A. To continue, the sound is picked up anything you like-it could just as The reference sound is uncolored by by the microphone of Fig. 1 and is well have been produced by a weird any echoes (outside of the original recorded on channel 2 of the tape

34 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com The new Sony Solid State 350 adds professional performance to home entertainment systems

Selecting the brilliant new Sony Solid State 350 to fulfill pre -amps. Dual V U meters. Automatic sentinel switch. the stereo tape recording and playback functions of your Frequency response 50-15,000 cps -+- 2db. S.N. ratio professional component music system will also endur- plus 50db. Flutter and wow under 0.15%. Richly hand- ingly compliment your impeccable taste and passion for some gold and black decor with luxurious walnut music at its finest. With an instant connection to your grained low profile base. This remarkable instrument other stereo components, the versatile two -speed Sony is yours at the equally remarkable price of less than 350 places at your pleasure a full array of professional $199.50. Should you want to add portability to all features, including: 3 heads for tape and source monitor- this, there's the Model 350C, mounted in handsome ing. Vertical or horizontal operation. Belt -free, true dark gray and satin -chrome carrying case, at less than capstan drive. Stereo recording amplifiers and playback $219.50. For information write Dept. 17, Superscope, Inc., Sun Valley, Calif.

SONY SUPERSCOPE The Tapeway to Stereo

Portable Model 350C Check No. 72 on Reader Service Card, AUDIO NOVEMBER, 1966 37

www.americanradiohistory.comAmericanRadioHistory.Com N THE GOOD OLD DAYS this writer liked to listen to what comes out An Amplifier of a pair of triodes. There are triodes and triodes, all of which have fallen into disrepute. Everybody cleans up their distortion with ump- for the teen dB of inverse feedback; so beam - power tubes became the accepted thing. The main objection to triodes is that you need a lot of voltage to drive them and they are a little in- Armchair efficient. If all you need is Listener voltage, it isn't too hard to come by, and what's a couple more watts from the a.c. power R. E. BAIRD line? So we decided to go all the way. Now if you start looking for power triodes you will scan the tube manual In this day and age everybody advertises twenty -watt or fifty -watt hi-fi from cover to cover and not come up amplifiers. Actually the casual listener needs a fraction of one watt for with anything very exciting. If you the average living room. Distortionless listening with proper bass equali- pick something out of antiquity you'll zation for standard recording characteristics is of prime importance. probably come up with a filamentary type cathode. Nobody has built a modern triode with an indirectly heated cathode for audio purposes. There seems to be one outstanding exception which isn't listed in just any tube manual and this exception is primarily designed as a voltage regu- lator tube rather than a general purpose audio tube. The 6AS7G/6080 Fig. 1. The au- is a twin triode of rather massive thor's amplifier at proportions with a mu of 2 and a the "proving plate -to -plate resistance of 280 ohms. ground"-the test Using a standard push-pull output bench in the case transformer it would appear that this of amplifiers. tube couldn't care less what you hung on it for a load. It should be a natural for any kind of a changing load including a loudspeaker. So we decided to give it a try. Figure 2 shows the schematic of the finished product. The circuit is simplicity itself. A single 12AX7 supplies enough voltage to drive the 12AX7 02 6AS7G to comfortable living room C. r-, 6AS7G / 6080 C3 volume. If it were desired to drive the

1 0-1! 05 I 6AS7G to maximum output a larger \ / `_. I driver would be necessary (also more oR distortion would result). The circuit, 6 INPUT v 1 R3 N as driven, yields less than 1 per cent R8 R9 7 1500 PARTS LIST FOR FIG. Y 150 150 2 R2 .02 µF, disc ceramic S 5 óR7 6 Cs, C6 .05 µF, paper ONLY VOL C, 40 µF, 450 V. elect. o (I CONTROL C7 100 µF, 150 V. elect. .05 252 C6, C4, CRI, CR, 400 PIV, 500 mA silicon 6.3VAC diodes G R, 470k, 1/2 W. HEATERS 115-, R1, Q VAC- Rs 1500 ohms, 1/2 W. R,, R,, 0.22 Meg, 1/2 W. R6, R7 Rs B + L CR1 Ra, 150 ohms, 10 W. (or 300 ohms, 20 W. 5 R10 25 ohms, 10 W. potentiom- 40/450 eter. C> CR, LI 200 -mA filter choke, 30 H. C6 TI High -quality output trans- C7 í i former, 5000 ohms plate - 100/150 100/150 to -plate. NOTE: If chassis is grounded, it will be Fig. 2. Schematic of the power amplifier and power supply section of the armchair "hot." Isolate with 1-µF capacitor if it listener's amplifier. is to be exposed.

38 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com distortion from 20 Hz to 20 kHz. Frequency response is - 1 dB from The author subtitled this article "Something Old and Something 20 Hz to 20 kHz. Note, there is no New. " The first 6AS7G article to appear in Audio was in March, whatever. All meas- inverse feedback 1948, which is quite old. Everybody knows how new hybrid ampli- urements were made with a fifteen- however, that the power supply would make the dollar, twelve -inch, bass -reflex en- fiers are. Note, closed speaker as a load. input-and hence the phono turntable-"hot" to ground. Some Desiring to use the amplifier with a care should be taken in connecting to other equipment, as well as record player, the next question was in handling. Ed. what to drive it with? This time we decided to go for something new. An article appeared on noise performance of transistors in a late periodi- R12 +15V included a very in- cal' which also 100 _, R teresting equalized preamp for a +C6 N N The circuit included a Rl record player. C4 2N13082 100/15 Y2Ñ 308 loss, to take care of lot of treble TO INPUT modern recording characteristics, OF DRIVER E3 which we didn't go for. Unless you c, 5/15 Ø have a $150 speaker you can probably R9 use the extra treble anyway. So with .. ó a somewhat drastic modification we N O C5 2. 1 came up with the circuit in Fig. R Rll And we put a phase splitter on the end to drive the push-pull grids of the 12AX7. An added modification is 10,000 R18 the derivation of the d. c. supply for RF the transistor preamp by taking a 2200 R17 o portion of the cathode voltage from TO CATHODE ,., + the 6AS7G stage as a source. Since OF 6AS7G C9 this voltage was positive with respect -ä-- 100/50 to ground, NPN transistors were indi- 0 cated. The 2N1308 is available, low Tó priced, and does the job. Figure 3 B - shows the schematic of the modified voltage preamp. Bass equalization is achieved Fig. 3. The preamplifier section employs transistors, powered from the bias the output tube, a 6AS7G. through Cf and Rf. This yields almost of perfect 6-dB -per -octave from 500 Hz down. Figure 4 provides the over-all re- Cl 10 µf, 15 V. elect. R5 5600 ohms sponse curve for the preamp and final C7 15 µF, 15 V. elect. R5 2200 ohms 470 ohms amplifiers together. Frequency re- C5,º 25 µF, 10 V. elect. Re, R, R19 68 k ohms sponse was measured with a constant Cb 5 µF, 15 V. elect. 7 R8 490 ohms 15 millivolts input and the previously C5 100 µF, 6 V. elect. 100 ohms mentioned loudspeaker as a load. An C6 100 µF, 15 V. elect. R11 C8 100 µF, 25 V. elect. 100 k ohms audio voltmeter was placed across the R12 C9 100 µF, 50 V. elect. R18, Rib 2700 ohms voice -coil winding. Figure 3 also Cf .02 F. disc ceramic. R15, Rls 200 -ohm potentiometer shows the over-all harmonic distortion R17 10 k ohms Q1, Q2, Q.1 2N1308 of the system with speaker connected R1 150 k ohms Rf 47 k ohms and measured with a Heath Harmonic R, 10 k ohms All resistors 1/2 W. Distortion Meter. Measurement of dis- R3, Rr 4700 ohms torion was made at constant signal output (comfortable living room volume) . ó The results? All we can say is that I= fr we like the sound that comes out. We 02 VI have good solid bass, brilliant treble, ,-º-S1 Fig. 4. Response and a distortion level that is below o curve of the phono the perception of the ear. For living > (A) o amplifier, is tail- room volume and reasonable hi-fi it _ ored to provide certainly is an improvement over good solid bass some pretty expensive stock units on 20 from not-so-bassy the market. With the use of the volt- '4*.*Ns...... small loudspeaker age -doubler power supply the whole 10 enclosures. The THD curve for the unit is fairly low priced. Our future -6 plans include a complete second set amplifier is shown o at the top. up for stereo. Æ (B)

20 1W. A. Rheinfelder, Noise perform- 100 000 10000 '0x4 ance of transistors in audio circuits. Elec- FREQUENCY IN HERTZ tronics World, Jan. 1965.

AUDIO NOVEMBER, 1966 39

www.americanradiohistory.comAmericanRadioHistory.Com Equipment Profile

Fig. 1. The Sher- wood S-8800 Ster- eo Receiver.

SHERWOOD S-8800 There is none of that gritty "transistor contrary, we applaud it. There really is STEREO RECEIVER sound" here! no need for independent tone control The phono input is also an area where of the two channels in most modern in- Sales figures clearly place that com- transistor technology has been slow in stallations with identical speaker systems. ponent known as a receiver well out in equalling tubes. Sensitivity is quite high There is front of its more separatist relatives. one thing we do not like at -3.3 mV drives the unit to full output. all. S-8800 has That was true in the era of vacuum The permanently oper- Noise is a quiet 63 dB below this level. tubes when receivers were ating loudness compensation. True, it is on the dis- Resistance to overload depends on the advantaged side not excessive; at quite low settings there of quality, and it re- setting of a phono level mains true control (this is a maximum of 11 -dB boost at 100 today when the all -in -one also reduces sensitivity, of unit need not course). At Hz, but at typical listening levels the be inferior in any way to the worst, overload occurred at individual components. 62 mV. boost is on the order of 2-4 dB. Still, With the use of the control to turn down perhaps there are ears that do not quite This new unit from Sherwood is - all extra -high -output cartridges, Sherwood match what Fletcher and Munson found. transistor and all -silicon -transistor at that. has this problem very much under con- (Not that common practice follows the We will not enter into that argument trol. about silicons versus germaniums. F & M curves anyway.) We like our Let's The S-8800 struck us as a unit that is bass just leave it with the fact compensation defeatable. Call it that this unit stripped for most efficient action. Tone a personal perverseness employs silicon devices throughout. if you will, but controls are ganged for the two chan- that's it. There is that confusion with tran- nels. This is lower in cost than provid- The lovely sound sistor amplifiers regarding power output. of this unit is ing a total of four controls. We have more than just compensation. It has been our practice to measure all FM, both no quarrel with this practice. Quite the mono and stereo, is flawless. Stereo FM transistor amplifiers primarily with 8 - ohm loads. Now some amplifiers do best at this impedance with power dropoffs at 4 and 16 ohms. Others pour more power into lower loads, less into high. This latter case is true of this unit. So with both channels operating the S-8800 will deliver an honest 25 watts per channel at mid -band frequencies. (See Fig. 2 for the over-all power response.) There is more power to be had at 4 ohms. So we hooked up the receiver for listening tests to a pair of power- hungry, 4 -ohm AR -3's. There's power to spare here. High -volume listening does not audibly approach the clipping point of the amplifiers. The "typical" transistor amplifier IM curve, looking like nothing more than a single -humped camel back, has been proved unnecessary. This Sherwood model does not exhibit it. Figure 3 indicates the IM distortion characteristic, again with both channels driven into 8 ohms. At the low power level of 0.1 Fig. 2. (A). Power response of the S-8800. 0 dB equals 25 watts per channel into watt, IM distortion was 0.09 per cent. 8 -ohm loads with both channels driven. (B). 1 -watt frequency -response curve.

40 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com I i

5 SHERWOOD

S - 8800 ó_ 4

3 Fig. 4. The Stan-

2 ton 581EL "Long- hair" cartridge. S 1

o es M POWER OUTPUT- WATTS

Fig. 3. S-8800 IM distortion with both channels driven; 8 -ohm load.

comes in without background noise (we the Sherwood S-8800, priced at $359.50 degree, sometimes only subtly. But they employ a good outdoor antenna). A (less case; walnut case $9.00 additional) do sound different. In point of fact, we small indicator light ignites to show the will do the music lover proud. find some sonic differences from sample presence of a stereo broadcast. At the CIRCLE 1 to sample of the same model. But in same time, the circuitry is automatically products from reputable manufacturers switched to the stereo mode. The front - these intra-differences are small. panel mode switch has only one position The Stanton 581EL represents the top - of -the -line for a most reputable firm. As for the tuner-labelled FM. If you wish STANTON 581EL to defeat the automatic switching, pull can be seen from the illustration, the out on the balance control. This swings STEREO CARTRIDGE 581EL sports a moustache-a brush to the entire receiver to mono. We have a standard procedure that is sweep the record groove clean in ad- Tuning is accomplished with the aid followed each time a new cartridge vance of the stylus. The EL designation of a center -channel indicator meter. As comes in. It goes into a turntable and in the name details the fact that this we have noticed in the past, Sherwood we "live" with it for a while. Before model has an elliptical stylus; the car- put a degree of effort into providing ex- that the stylus went under the micro- tridge system as a whole is of the mov- tra smooth tuning action. It is a pleas- scope to ensure that no damage exists to ing -magnet principle. ure. ruin our records. Stanton has dubbed this model the by the piv- FM frequency response is ± 1 dB Living with a cartridge means using it Longhair, inspired no doubt from 30-15,000 Hz. So is RIAA phono to play those records with which we are oted brush. Perhaps what was meant is equalization. most familiar. In this way a general that this is a classic cartridge. As we There are two special niceties worth impression is already established before have come to expect from Stanton, this mentioning. Both are represented by we ever reach the test bench. is one of that select group of state-of- narrow adjustment shafts that protrude Cartridges have shown a steady and the-art cartridges. As with all the rest, from the front panel. The first men- significant rate of improvement over the it is not perfect. No cartridge is, nor tioned earlier, sets phono and tape-head past few years. It hardly seems that we anything else. But the 581EL does won- gain to match the FM level. The second settle on a favorite that seems to be "it" ders with a record groove. Look at Fig. is adjustable interchannel muting on but what someone else comes along and 5, the frequency -response and separa- FM. This is quite effective and can be upsets the applecart. tion measurements. These are as close set for maximum value against minimum Today there is a decent variety of to ideal as we could want. This over-all sensitivity loss. cartridges from which to choose. The smoothness is to be heard in the listen- All -in -all there is much to commend devil of it all is that the choice is no ing room. As with all cartridges to date, this unit. In the listening room it per- easier than that of several top -grade stereo separation diminishes as frequency forms splendidly. All sound sources are speakers. Our ears continue to insist rises, reaching a peak at the stylus - reproduced flawlessly. With its hand- that different cartridges sound unlike assembly resonance point. Nevertheless, some face and truly pleasurable sound each other, sometimes to a significant the effect of stereo is excellent; there is

Fig. 5. Frequency response and channel separation of the 581EL. The curves, derived from the CBS STR-100 test disc, are averaged for the two chan- Fig. 6. 1 -kHz square -wave response to nels. the CBS STR-111 test disc.

AUDIO NOVEMBER, 1966 41

www.americanradiohistory.comAmericanRadioHistory.Com no audible tendency for instruments to wander in position as they ascend or descend their range. The square wave is nearly perfect as cartridges go. The notch at the leading edge is likely to be the record rather than the cartridge. You would expect clean, sharp transients and you do get them. IM distortion was a satisfactorily Fig. 7. The BSR low 2.1 per cent on the +9 dB band of McDonald 500 au- CBS STR 111. (The square wave is tomatic turntable. also derived from this disc.) Output from 3.54 cm/sec recorded velocity at 1 kHz was 4.2 mV left and 4.4 mV right. This is ideal for tube and transistor preamps. The brush serves two functions. The first is the obvious one-it sweeps the groove. We have some qualms about the effectiveness of this type of brush as compared against something like the Dust Bug. So much so that we removed it, an easy thing to do. This revealed the second function. The brush helps hold the stylus in the groove. It is a flexible link from the arm to the groove so it aids in tracking and shock absorbtion. As a consequence, ideal tracking force with the brush is 1.25 grams; removing the brush requires 1.5 grams for the same tracking abilities. (Of course, we compensated for the physical weight of the brush itself.) Well, no matter. This is a longhair of a cartridge. It makes beautiful music Up to now, a high quality turntable worked, so we took the rest for granted. from those records that can. It does was an expensive item, but the Mc- With the right side raised 45 deg., the well with records we thought cannot. Donald 500 comes with a consumer unit tended to trip itself, starting the Finally, the list price is all of $49.50 as price of only $49.50, which puts it in record over and over. the elliptical EL, the 0.7 -mil 581A and reach of the most budget -conscious audio On the serious side, however, the the -mil 0.5 581AA. That's downright in- buff. Furthermore, most of the lower - turntable has all the desirable features, expensive. CIRCLE 2 priced record changers were usable only and some which we believe to be unique. as record changers, and were not equip- There is a cuing lift which will drop the ped with the niceties which the high- stylus back into the same groove from fidelity enthusiast has come to expect, which it was lifted. At the finish of the such as counterbalanced arm, fine ad- last record on a stack, the arm returns justment of stylus force, finger lift, and to its rest, gets latched in place, and the so on. motor shuts off. It can be set for any Neat and compact, the McDonald 500 of the four speeds or for 7-, 10-, or 12 - measures 141 by 13 inches, with an inch records. By placing the record over-all depth of 7 inches, and thus will stabilizing over -arm in its off normal po- fit into many of the smaller enclosures sition, the unit will continue to repeat which cannot accommodate the average the last record indefinitely. When the turntable. In styling, it is sufficiently unit shuts off, the motor shaft is disen- BSR "McDONALD 500" attractive that our art director stopped gaged from the idler. The four -pole at our desk to admire it without even motor itself is dynamically balanced and AUTOMATIC TURNTABLE being asked. well shielded to avoid radiating an ob- It is practically axiomatic by now that jectionable hum field. It employs a lightweight, counterbal- all high-fidelity automatic turntables come The McDonald 500 functions as a anced arm with the stylus force being from somewhere else-none is made in changer, accommodating a maximum of adjustable in 1/3 -gram steps from zero to this country. And the latest addition to eight records, and it also functions as 6 grams. The balance weight may the imported turntable category is from be an automatic single -play turntable, moved at will after loosening using Britain, and furthermore from the world's a knurled a separate spindle. knob at the top of the arm, and stylus largest manufacturer of turntables, rec- Wow and flutter checked out at 0.2 set -down is adjusted by another knurled ord changers, and tape decks-BSR Lim- per cent, while rumble measured 28 dB arm, so that no tools are required to ited. The American arm of the parent below a recorded velocity make the necessary adjustments. of 3.54 cm/ company is BSR (USA) Limited, which sec at 1000 Hz, which rounds off to is committed to a program of consumer One of the claims of the company is -38 dB when weighted with a 50 -Hz products in the high-fidelity field, with that the turntable can be played upside rolloff. Thus with any but the deepest- the McDonald 500 being the initial ven- down. It is so rare that this facility is bass loudspeakers, this should be recog- ture into these uncharted markets. Here- required that we didn't try it, but we nized as satisfactory in performance. At tofore, BSR products were available only did try it at extreme angles, like up to its price, it is much more than that. in complete phonograph systems. 60 deg. from the horizontal, and it still CIRCLE 3

42 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com The new KLH* Model Twelve is the result of some pointed questions about what kind of improvements might go into a speaker system designed for perfectionists.

The KLH Model Twelve is the finest speaker's overall sound quality-subtle moving -coil loudspeaker we have ever but important adjustments. Adjust- made. Not by a spectacular margin ments that would allow the listener to (there just isn't that much room for modify the speaker's musical balance improvement in today's best speakers), to account for differences in program but by some important degrees. material, associated equipment, room Before we began to design the Model acoustics, and personal musical judg- Twelve, we asked ourselves some ments. Instead of the usual mid -range pointed questions. We knew we would or "brilliance" controls, we could pro- not be willing to settle for just a set of vide the listener, for the first time, with more impressive measurements. What an effective way to tailor the speaker real improvements could we conceive of to his own needs. for a speaker designed unabashedly for This is why the Model Twelve comes perfectionists? Which of the improve- with a unique series of four multi - ments that we could make on paper position control switches. These adjust would, in fact, be audible and meaning- the level of broad segments of the fre- ful? Above all, how could we design a quency range: 300-800 cps; 800-2500 speaker that would be useful under the cps; 2500-7000 cps; and 7000-20,000 widest range of conditions? cps. They are housed in a remote switchbox (connected to the speaker by Suggested Retail Price: $275.00 A few answers a thin four -conductor cable) that can design) to cover a range at least an oc- be placed next to your favorite seat for tave short of their upper and/or lower We decided that there were a few and ease of use. improve upon maximum effectiveness limits. The mid -range drivers are absolute factors we could The amount of adjustment from each or change significantly in a system for housed in special sub -enclosures that switch is limited so that you can make are acoustic -suspension in principle. the perfectionist. We could supply a bit only meaningful adjustments. The response at extremely fre- The cabinet is made of one -inch ply- more low Model Twelve cannot be made to sound quencies. We could offer the potential wood, with quarter -sliced walnut veneer bad under any conditions. It can only for more very -high -frequency response selected for beauty and uniformity of be made better for your own require- use only with exceptionally good grain. The overall design of the 29" x -for ments. program material. We could make the 221%" x 15" enclosure has been under- overall impedance of the system eight Perfectionist's stated to make the cabinet as unobtru- ohms for optimum performance with speaker system sive as possible in any room. today's transistor amplifiers. we have done everything We think our approach to the Model We believe By using an acoustic -suspension en- can to make the Model Twelve the Twelve makes sense only for a perfec- we closure slightly larger than usual, we moving -coil speaker system we tionist's speaker system. And the Model best could also provide a bit more speaker have ever made. If you are an unabashed Twelve is just that. It will reproduce efficiency. The amount we could gain perfectionist, you should go hear the the highest and the lowest frequencies would be just enough to allow the Twelve. It's at your KLH Dealer now. any conceivable musical interest. Its listener a choice of many excellent of more information, write: KLH, 30 -high -frequency capabilities are ac- For amplifiers of less than super -power. very Street, Cambridge, Mass. 02139, tually in advance of most of today's Cross Dept. 700. program material; as the noise content A final step A trademark of KLH Research and Develop- drops on future recordings, the 7000- ment Corp. can be turned up for With the aim of usefulness upper- 20,000 cps control !me,' -irae most in mind, what else could we do? ever more realistic music reproduction. We could offer the listener the op- The Model Twelve's four speakers ''.. I..... I i portunity to make adjustments in the are used conservatively (in a three-way 30 CROSS STREET. CAMRRIDDE. MASS. Check No. 73 on Reader Service Card. AUDIO NOVEMBER, 1966 43

www.americanradiohistory.comAmericanRadioHistory.Com MUSIC AND RECORD REVIEW

Record Review Edward Tatnall Canby

the recording curtain (which is mostly Gold Curtain Pons' 1946 opening -night item, for sound -transparent these days). Third, it Opening Nights at the Met. (His- example, is represented by a record- features a youngish, up-and-coming cast toric Recordings of Metropolitan ing she made in 1930, and probably rather than a collection of international Opera Stars Re-Creating Their Cele- just as well. The recordings date famous names. For my ear, this is all brated Opening Night Roles.) from 1906 all the way up to 1958 to the good! And it does lower the RCA Victor LM 6171 (3) mono and were made in all sorts of places price. I like this team, German or no An actual hunk of the famed not including the Met itself. Most German. great golden curtain of the old Met are semi-coincidences, though Vic- Therefore this is as good a recording comes to you with this Limited - tor and the Met did, in truth, work as any by which to begin enjoying the Edition release. If that knocks you together like blood brothers over sizzling humor of this outrageous situa- for a loop, then the album is for many a year. It was just a matter tion -comedy. Phew! If you think Mo- you, definitely. But even if you are of matching up as many opening zart was a sissy with frills, just bury less than enchanted by a bit of ratty nights as possible to the existing re- yourself in the whirlwind, acid, sharp - old cloth-I think you'll enjoy the cordings in RCA's voluminous back edged gayety of this production via the whole thing, even though you can't files-and it's amazing how many excellent line -by-line, section -by -section tell a Mimi from a Sophie, a Sam- they could dig up to fit. But a translation (you never get lost). One son from a Sarastro, a Bjoerling good many of the yearly openers minute I'm thinking of Andy Hardy and from a Jeritza, or maybe a Galli- are missing, even so. No recording Bob Hope, the next it's "Who's Afraid Curci from a Gatti-Casazza. (How available. And/or the artist has of ..." etcetc-what a sardonic, worldly- many of us can?) since flown the coop, to other con- wise musical show this is-and how fast The reason is that even though tracts live or recorded. it moves! Unlike later operas, Mozart's are so full action the whole thing is obviously a pub- Don't expect any critical or his- of you are breathless licity tie-in with the opening of the torical evaluation of all this mate- trying to keep up. In this new Met at Lincoln Center this fall, rial. The atmosphere is the usual German version out of the it comes off-it really does. And one for the Met, a magic aura East, the orchestra plays a bit on the sur- hard the credit for that goes directly to rounding the endless parade of celeb- side-not bad-and the singers, the superb big 50 -page book accom- rities. But there's plenty of history perhaps rightly, are a bit soft, less crack- panying the records, featuring chat- to be inferred in the listening, just ling and sparkling that we expect in the ty, humorous, very readable notes the same. Not only the extraordi- usual high-speed Italian rendition. No harm done, though by Francis Robinson, who is 2nd nary change in singing styles over real some of the man at the Met and knows every- these years, but also a familiar arias will sound a bit strange to fine capsule who know thing. Don't be scared-he puts you history of the recording art, from those them well. It's a very knowing and at ease in seconds flat. the beginning of classical music re- enthusiastic vocal team, this, with a good mixture It's a gimmick. Of course, the cording straight down to the - tape of hilarity, sternness, 30 -odd artists didn't go out and "re- LP age and the verge of stereo. and an awareness of the deeper create" their roles for this album. Just sit back and listen-it's all subtleties behind all the In fact, some were pre -created; Lili there. fun-the amorous intrigues with their endless costume exchanges, the hidings behind chairs and in closets, the dis- coveries and the explanations-and Opera -at -Large Most such releases are oldies, reissued, through it all, the play of servant vs. have some Mozart: The Marriage of Figaro (in Ger- or other special reason for aristocrat, matching wits against author- the low man). Guedon, Prey, Rothenberger, price-not excluding a lousy per- ity. The Count, for instance, (Hermann Berry, Mathis; Dresden State Opera formance. This one isn't lousy at all. has precisely the There Prey) right easy-going Cho. & Orch., Suitner. are some good reasons for the condescension towards his mercurial me- price, as I figure it. Seraphim IC6002 (3) stereo nials, which can turn suddenly to hard Here's a relatively new stereo record- First, it's in German-and the proper authority with a quick change of voice ing of a famous Mozart opera and it's original language is Italian. This was for and tone. Excellent. on Seraphim instead of the higher -price local consumption, over there. Second, Yep-a bargain, if not the greatest Angel label. Howcome? it's out of Dresden, on the other side of performance on record.

44 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Timon in Fidelio. Kuchta, Patzak, to sink the lights down and so dim the ation (Purcell's Masque from Beethoven: the Beg- Orch. & Cho. Nord- stage.) Also, of course, the whole back- Athens) and went on through Rehfuss; Symphony and Rundfunk, Hamburg, Bam- ground of this opera and the complete gar's Opera and the era of glees deutscher through the Eighteenth berger. text in French and English. catches, and on And orchestral playing which goes century, until Handel's music slowly Nonesuch HB 73005 (2) stereo right along with the booklet. Excellent, brought propriety over from the conti- nent and launched oratorio to replace a first-rate "poor -man's Fidelio" and very knowingly worked out, down This is most opera, both lusty and high-toned. and, for that matter, a good one for any- to the last detail of elaborate. ornament. and yet As might be expected, the Purcell is body, at any price. It is another exam- A monumentally thorough job; (and the playing is always light and musical. the deepest (and musically the most se- ple of the important continental Others are alternative to the Alas, again, only the voices disappoint, rious) of these little works. especially German) but most -vehicle opera and the and they really fail quite miserably. The lightweight entertaining-Arne's high-priced star and Sally," or the Sailor's Re- this is the sort of ex- lead lady, Aricie, has a grainy, somewhat "Thomas star-studded cast: Henry Carey's "True Blue," James work -horse production that is course voice with a dreadfully uncon- turn," cellent Hook's "Musical Courtship," James Os- in the countries where the op- trolled vibrato and an indifferent sense common wald's "The Dustcart Cantata." eras originate and are still staple fare, of pitch; she tries hard but she is woe- the In its familiar manner, Everest mixes the type of performance designed for the fully inadequate. Her Hippolyte, up the cover of the album, omitting two local populace, who know the music hero, is better, but still a more or less to composer's names, changing the spelling cold. conventional singer, only half -adapted as that on the booklet; nor is there The singers are not big stars but they the Baroque style, singing mostly from - any indication as to whether the stereo are good singers and moderate stars. though this were just another Caruso voices is synthetic or "real". There should be. The orchestra is a good one and the style grand opera. Two solid bass But the music is worth it! conductor is excellent; all the principles add drama and authority at the expense wobbling, though it is know very well what "gives" in this mu- of a lot of heavy Caballe sings Songs of En- in essence. Montserrat sic. The result is not a star vehicle but musical enough rique Granados. Symph. Orch., Ferrer. voice is really first-class- an intelligent, unified, dramatic perform- Only one RCA Victor LSC 2910 stereo ance. I'm all for it and, indeed, would the lady villain, Phedre, sung by the a If you'd like to hear one of the most a lot rather hear this kind than the other American Janet Baker, Now there is voice-and a musical ear! She sings cir- recent voice sensations, and yet you are sort, which is all too often stylistically not exactly a grand opera fan, this is a hodge-podge-and deficient in singing cles around all the others. Her dramatic intensity rescues what otherwise would your chance. A lovely record. balance, as well, as between big and I sub- be a dull show. Granados died in a World War little names. sinking in 1916, just as he was adequate (Now if only they had taken on marine Technical quality is perfectly on the way to a biggish international and the stereo is serviceable. Philips' Heather Harper and Helen Watts, of the new British Messiah, for some career as Spain's great hope. Compared out great hope), Rameau: Hippolyte et Aricie (1773). of these ailing parts! Then we'd really to De Falla (Spain's other his music is now a bit tame and old Baker, Hickey, Tear, Shirley -Quirk; St. have some Rameau, worthy of the op- fashioned. But there is plenty of stuff Anthony Singers, Engl. Ch. Orch., Lewis. era's reputation.) of a great deal of this opera in some of it, notably the first set Fortunately, Amato- L'Oiseau -Lyre SOL 286-7-8 (3) stereo was stage spectacle, including plenty of songs here (Side 1), Canciones Love Songs. Fans of "grand opera" seem to think ballet and chorus music, so the big rias or, in simple English, is both more that opera began with Rossini and ended scenes are very much worthwhile in The second set, Tonadillas, (and Wagner, interpolated, terms, especially with the excel- popular and more dated-the consciously with Puccini musical sort we along with Gounod and Bizet from lent book before you to aid the imagina- "olden -style" music is not of a the folksy tunes are France). It didn't. Here is one of the tion. appreciate today and all operas, though un- a bit on the obvious side. most famous of with known to the Met. The highly researched The Intimate Opera of the Baroque All of these were originally set recording has a (Pergolesi, Purcell, Arne, Carey, Hook, piano accompaniments; RCA Victor is and carefully prepared mention solid value, unfortunately marred Oswald). Anonymous singers, Intimate less than candid in making no lot of or or- by mediocre solo voices in some of the Opera Society. of this, nor of the orchestrator parts. Everest 3138/3 (3) stereo chestrators. But the idea is OK-remove lead "recital" cate- this music is from the days of There's interesting and highly amusing these songs from the stuffy Though accompaniment Bach and Telemann in Germany, the material in this set, which Everest has gory implied by piano means pried out of British Decca (London). and put them squarely in the big-time style is altogether French-which RCA you have been catching up Though the designation is stereo, the opera -style gala performance. that, unless as its singer; the spate of new French Baroque curiously pinched, dry sound of the re- knows its audience, as well on voice that music of late, it will be a bit strange to cording implies an "oldie" (if it is new, Caballe has a big, flowery French went their own way then it is of course inexplicably sub- seems to have been destined for orches- you. (The the music. then, as now.) Potentially, it has better standard)-but the stereo presence is, tral accompaniment, whatever entertainment value than contemporary indeed, helpful to the dramatic presenta- (Oddly enough, the Spanish engineers -Italian Baroque opera; for the tion even if it is synthetic and the curi- have subdued the orchestra and brought German miking, so that variety of music and the continuity was ous tonal quality is not really unpleasant the voice forward in the than in the rela- if you are listening to the music. the accompaniment is actually less com- much more "stagey" on the recitative -aria operas out- The Intimate Opera Company was pelling than it would have been tively rigid the orches- France. founded in 1930, operated straight piano. The fault is partly in side the rhythmic But the special French mannerisms through the war and was then broadcast trations, which miss a lot of the typically profuse mu- to us, perhaps as a good example of vitality of the original piano parts.) and, notably, in its in both vocal and British "carry on" philosophy. The com- Caballe's voice is very beautiful sical ornamentation which are instrumental parts, makes for a lot of pany goes onward now-but, as I say, I middle and lower registers, shiny; her high trouble in a proper restoration. suspect this is an earlier manifestation. marvelously bright and go "white" got -up album does No matter. This is lusty, imaginative notes, somewhat surprisingly, This splendidly is excel- you could ask for singing, if by no very great voices, and and colorless. Her musical ear just about everything as De Los An- respects. A gorgeously com- the simple accompaniments are neatly lent, too-almost as good in most So is her plete booklet, with immensely interesting played. geles, which is saying plenty. of the Only Pergolesi's humorous "Music dramatic involvement and the sultry pro- material on the opera production music. some fascinating stuff Master" is familiar-but the somewhat jection of this often sensuous time-including recording is su- on staging and lighting. (Footlights via rakish style of the other works, all Brit- Very nice. The voice is out of that lusty period of perbly done. oil or tallow lamps floating in a trough ish, clearly 80) of water; the water could be drawn off, British music that began with the Restor- (Continued on page

AUDIO NOVEMBER, 1966 45

www.americanradiohistory.comAmericanRadioHistory.Com Columbia and Victor disc, Franz Allers leads the orchestra, Barbara Cook sings the part of Magnolia, and William War - field continues to chart the flow of the Mississippi, a task he began in the 1951 screen version of Show Boat. It's more LIGHT LISTENING than mildly instructive to listen to individual segments of these two discs on wide range equipment. Chester Santon It shouldn't be a total surprise to readers of AUDIO to learn that the newer version isn't neces- sarily the better sounding of the two. Taking the voice of Warfield first, his "01' Man River" on the Columbia stereo disc issued in 1962 has the presence one takes for granted when listening to a good system. The same presence is almost there in the RCA -Victor Dyna- groove version. What is missing is that touch of frequency range at top and bottom that the audio buff insists upon Marty Gold: Soundaroundus when selecting Any hobbyist or professional in the his playback equipment. RCA Any Victor LSP 3599 audio/visual field is acutely aware change in the voice of Barbara of the Cook This record arrived for review just as problem of choice when it comes is scarcely discernable. The RCA to miking the arrival of September was turning the sound -effect records. Even those blessed of her songs is closer than Co- lumbia's, thoughts of an audio buff to the New with a relatively lavish budget may find so much so that the intake of breath before York High Fidelity Show. It struck me it difficult to audition all the discs pres- a long phrase is much at the time as a reasonably good candi- ently listed in the Schwann catalog more apparent in her newer edition of under such date for turntable use in the 1966 ex- "Sound Effects," not to mention other great songs as "Make Believe," hibits using popular music to display releases of sounds too specific "You Are Love," and "Why Do I Love in nature You." their sonic wares. Since this review is to be listed under a catch-all heading. In the other leading role, baritone Stephen Douglass being written prior to the opening of Although many labels have been active exhibits an appealing the show, I have no way of checking on in taping sounds over the years, voice and style as the latest Gaylord only a Ravenal. my hunch that this disc might possibly few firms currently offer truly compre- It is no discredit to his performance to point change some minds in the industry about hensive libraries of sound effects de- out that John Raitt the sound of the Dynagroove process. signed to satisfy the needs of in the Columbia version delivers the home Ravenal This stereo record actually has some re- movie enthusiasts and others wishing to songs with a share more assur- spectable sound on it. It's not the best add sound to picture. Audio Fidelity ance. Constance Towers as Julie and and David record ever made but what pop record Elektra now offer the greatest array of Wayne as Cap'n Andy round out a cast is? Marty Gold is one of the select few discs for this purpose. In this new mul- that, although still better than av- arranger -conductor in the business with tiple album, Elektra has selected erage, does not replace the Columbia from version a genuine interest in the audio features its large library those sound effects most in my esteem. of his discs. In his apt latest release he to be used by someone starting a Edmundo Ros: Arriba seems to have persuaded his technical basic collection. Naturally, the pressings London Tape LPL 74080 crew to hold down the gimmickry in the are as up to date as modern technology No listener has ever been Dynagroove process to an absolute mini- can offer, giving a new freshness to lulled into slumber by a Ros recording and this mum. The result is a relatively straight- sounds that cover categories such as reel forward record that allows a good Forms of Transportation is no exception. The British maestro's home (land, sea, and Latin music system to work at its best in re- air), Machines, Sports, beat is as ebullient as ever in this Weather, War- varied producing a wide range recording. fare, and finally mere collection. Some of the selec- Household and tions Thanks to minimal tampering in the Human. try to resist conversion into Latin rhythm later stages of tape to disc transfer, one This is a handy package but Ros and his band of ar- that should rangers always can hear the truly impressive work of take care of anyone who hasn't gradu- have the last word. There is no sense of conflict in an today's better studio mikes, raw tape, ated to the really esoteric type of sound item such as and taping facilities. Perhaps the nicest effect currently available. "Siboney" which always sounds tailored - bonus in the disc is the chance to hear to -measure whenever Ros plays it in his well-oiled style. Noro Morales' widely - under proper conditions the outstanding Show Boat (Lincoln Center Cast) acoustics known piece, "Oye Negra," also gets of Webster Hall, scene of so RCA Victor LSO 1126 many good RCA treated in royal fashion with a glib ve- recordings prior to Revivals of this Dynagroove days. Jerome Kern classic, hemence that fast Latin tunes thrive on. This record proves onstage or in record once more that form, seem to come Among the definitely non -Latin composi- this fortuitous studio site along every few years. is one Now that Lin- tions, "Hello Dolly" does fairly well. of the very few in the business coln Center's where it's possible Music Theatre has mounted Only "Get Me To the Church On Time" to get lush close -to a new production of sound without running the show, the rec- from My Fair Lady hesitates in hitting the risk of sound- ord fan with a more -than -average ing cramped -for -space. The curi- its stride, what with an opening that con- stereo pat- osity in audio matters has a tern of miking unique op- tains pealing bells and a vaguely church - is unusual in the way it portunity to picks do some interesting com- like organ. Adding to the well estab- up solo instruments without losing paring of the smooth disc versions of Show Boat. lished appeal of Edmundo Ros' music cohesion and depth of the A few years rest ago, Columbia Records is- making in this release is the modified of the orchestra. Many of the se- sued an excellent lections are Show Boat recording nature of the London Phase -Four stereo sure-fire hits ("Shadow of with a cast assembled Your Smile," solely for the oc- process. The aural picture is not as dis- "Taste of Honey," "People," casion. Now Victor and "Walk in comes along with jointed as it has appeared in other re- the Black Forest") with a disc documenting the only electronic the revival that took cordings using this decidedly arbitrary trickery reserved for place this past summer "Bye, Bye Blues." at Lincoln Cen- process. Without strain to the imagina- ter. By a rare coincidence, these two tion, one can just about place all sec- leading versions of the show on records tions of the orchestra in one recording happen to offer the same leading lady, studio. No 133 Authentic Sound Effects imagination at all is re- the same baritone in "01' Man River," quired to appreciate London's Elektra EKS 7313 14 cleanliness and the same conductor. On both the of sound in this reel. /E 46 AUDIO NOVEMBER, 1966

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Check No. 76 on Reader Service Card. AUDIO NOVEMBER. 1966 47

www.americanradiohistory.comAmericanRadioHistory.Com David Blue Elektra Stereo EKS 74003 Both as a performer and as a song writer, Blue reveals exceptional talent and sensitivity. His lyrics present some of the most imaginative situations and poetic imagery that have been encoun- JAll and all that tered in the folk-rock movement. In addition, the instrumental backgrounds Bertram Stanleigh have color, variety, and vigor. And the recording is crisp, close-up, and evenly spread out. A first recording of this quality clearly indicates the arrival of an important new personality. The album includes a booklet with the lyrics of all of Blue's songs. They make fine reading as well as listening.

Billy Larkin and the Delegates: Ain't Bill Evans and Jim Hall: Interniodula- shall, trombone, Dave McKenna, piano, That a Groove tion and Bob Haggart, bass. Things are less World Pacific Stereo WPS 1843 Verve Stereo V6-8655 successful when the group, supplemented Billy Larkin's rock -blues -jazz organ This is by guitarist Bucky Pizzarelli, one of the most satisfying of turns to a is solidly supported by Fats Theus, tenor, recent jazz releases. bit of bossa nova. But the disc's high- Pianist Bill Evans, Jimmy Daniels, guitar, and Jessie Kil- and guitarist Jim Hall, are two perform- light-Daydreams whistled by Bob Hag- gart-ensures patrick, drums. This is an entirely new ers who use their easy going styles to that this one will be a bunch of "delegates" from those heard probe deeply into collector's item. the content of the on previous Larkin discs, and in my music they play. While each man has opinion, the change is a decided im- a strongly individual manner of com- Kai Winding: Dirty Dog provement. Eleven tunes get a vigorous munication, they collaborate superbly Verve Stereo V6-8661 workout; James Brown's Ain't That a without any apparent need to modify Groove, The free -and -easy trombone of Kai Larkin's own Where Did the their usual approaches. In addition to Blues Go?, and Ronnell's Willow Cole Porter's Winding is back again, this time with Weep I've Got You Under My for Me are particularly outstanding. The Skin and George Gershwin's My Man's three more slip horns played by Carl Fontana, Urbie Green, and Bill Watrous. stereo sound has body and an excellent Gone Now, the disc offers Hall's All spread. Across the City, Evan's Turn Out the With Buzzy Bavarian, guitar, Bob Cran- Stars, Angel Face by Joe Zawinul, and shaw, fender bass, Herbie Hancock, Claus Ogermann's Jazz Samba. Each piano, and Grady Tate, drums, they de- ESP Sampler piece is superb, and together they make liver a half-dozen swinging jazz per- ESP Mono 1033 a delightful program. The recording, by formances in a lively fashion punctuated This is the first of two new samplers by several Rudy Van Gelder, is on a par with the mumbled grunts, shouts, and introducing the ESP line. When a com- performances. Don't pass this by! other assorted asides. In addition to the pany specializes in the most advanced title tune, the selections include Sunrise, varieties of modern programming, record Sunset, Blinduran, Blindman, Something buyers may sometimes George Benson Quintet: It's Uptown be a trifle wary You Got, The Sidewinder, and Herbie about investing in entire discs Columbia Stereo CS9325 whose Hancock's Canteloupe Island. It's good contents are unknown. This platter A vigorous rock group featuring the to encounter the Hancock number again. should serve to overcome the problem. guitar of George Benson with Ron Cuber, It was originally heard in the pianist's It offers a total of 18 selections includ- baritone, Lonnie Smith, electric organ, brilliant Blue Note platter, Empyrean ing music by the Fugs, Omette Coleman, and Jimmy Lovelace and Ray Lucas Isles, and the very different perform- the Ayler Brothers, Pharoah Sanders, sharing the drum assignment. The music ance it gets on the present set is a mark Paul Bley, Giuseppi Logan, Charles Ty- is a mixture of Benson originals and of the tune's versatility and a demon- ler, Sunny Murray, and a performance such standards as Summertime, A Foggy stration of the relaxing influence that of Auld Lang Syne sung in Esperanto. Day, Willow Weep for Me, 2nd Ain't Winding emanates. Anyone who wants a one disc collection That Peculiar. The group works to- of far-out music couldn't make a wiser gether with well-oiled precision, and the Dick Hyman: Happening choice than this. results have power and a highly charged Command Stereo RS899SD blues character. The sound is close up Timothy and helps to get across the energy and Versatile keyboard performer, Dick Leary, Ph.D.: Turn On, Tune In, Drop Out excitement of this fine new quintet. Hyman, is heard this time on the harpsi- Guitarists of Benson's calibre are scarce, chord, and he sounds just as much at ESP Mono 1027 and this one will certainly bear watch- home with the style and technique of The subject of psychedelic drugs has ing. this instrument as he does in his usual frequently been linked in the press with performances on organ and piano. Ably jazz musicians, and it is consequently not abetted by a top-flight group that in- too surprising that an enterprising Yank Lawson: Ole Dixie record cludes Tony Mottola, guitar, Ernie Royal firm specializing in advanced forms of ABC -Paramount Stereo ABCS 567 and Doc Severinsen, trumpets, Bob Hag - jazz should devote a disc to a talk by Bob Thiele, producer of this delight- gart, bass, Phil Bodner and Stanley the former Harvard professor whose ex- ful novelty, has brought together a tra- Webb, woodwinds, Bobby Rosengarden, periments with such controversial items ditional dixieland group and three Latin drums, and Phil Kraus, percussion, Hy- as LSD, marijuana, and cannabis have drummers. The results of this happy man swings through a wide range of gained him a considerable amount of combination are some traditional num- items that includes the theme music notoriety as well as a couple of jail see bers like Fidgety Feet, Wolverine Blues, from Tom Jones and Zorba the Greek, tences. Dr. Leary presents the case foi and Muskrat Ramble played with fresh- Beatle tunes, Yesterday and Michelle, the employment, and enjoyment, of these ness and style. Chico Hamilton, Willie and the Ballad of the Green Berets with drugs in a quietly eloquent manner. One Bobo, and Victor Pantoja add their a vocal by a girl trio. The sound has wonders whether the Food and Drug familiar south -of-the -border accents to the characteristic brilliance and presence Administration may not decide that some the solid work of Yank Lawson, trumpet, that makes all Command discs excep- kind of cautionary warning should be re- Pee Wee Russell, clarinet, Cutty Cut - tional. quired on this fascinating disc. JE

48 AUDIO NOVEMBER, 1966

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www.americanradiohistory.comAmericanRadioHistory.Com Audio Measurements Course

NORMAN H. CROWHURST Part 10

While much of the measurement technique on tape recorders is "old hat," there are still a number of critical points which should be considered and not a few pitfalls which may not be well known at all.

WHILE TAPE AVOIDS the me- subject to variation from head to bands so the pattern appears to stand chanical problems of trans- head and tape to tape than is the in- still when viewed by a light operated duction inherent with phono- teraction between elasticity of the on standard 60-Hz supply (Fig. 10-1). graphs as a record medium, it poses phonograph record material and the With 92 uniform black and white measurement problems not present mechanical properties of individual bands, the pattern will appear station- there. The recorded groove in a phono- pickups. ary at 78.26 rpm, which is close to graph record can be checked physi- With these basic observations in the old standard of 78. For the new cally-most readily by optical (light) mind, the methods applied to tape standards of 331/2 and 45, the num- examination. Such a method is not follow procedures similar to those for bers of bands, 216 and 160 respec- directly available with tape, and the phonograph equipment. Different tively, result in stationary patterns only way to determine what is on the speeds have different equalization with exact correspondences. tape is to measure it with a playback characteristics, designed to optimize The same method is used with tape head. performance for each particular play- by applying a low -friction pulley of From this viewpoint, absolute standing speed. Standards are also set for known diameter to the tape. A standards are a little more difficult to special systems that may use a differ- ard diameter for the pulley is pre- achieve on tape. But from another ent combination of record/playback scribed in the NAB standard as viewpoint, the standard achieved is over-all result. 1.4305" +0.0002 -0, with 72 and more definite. Playback characteristic 36 equally spaced black and white is less dependent on interaction be- Speed lines or dots (Fig. 10-2). These will tween the record medium and the For correct results, both recording give stationary indications at the playback device. Some dependence is and playback must be performed at standard speeds of 17/8", 33/4", 71/2" possible, because presence of the mag- the correct speed. On phonograph, and 15" per second, when viewed by netic circuit of the playback head has this is checked by using a stroboscope a 60-Hz light. a temporary demagnetizing effect on disc on the turntable, with different Obviously, laying a paper disc on the tape. But this effect is far less numbers of black and white radial top of a phonograph test record will not produce any drag. But applying a pulley to a test tape may. One way VIEWED BY NEON OR to check whether or not it does is to FLOURESCENT play a recorded constant tone and LIGHT iutie check its frequency as the test pulley 111\\,11 /!l/% is applied. It may change momentarily while the pulley is engaging or THIS HAS 92 disengaging the tape: this does not matter. The frequency of the tone should be the same when the pulley THIS HAS 216 is steadily engaged or disengaged. Frequency Response THIS HAS 160 Apart from the chicken -or-the -egg problem, of where to begin, there is /11.Í Ï t11'1\,, a basic relationship to recognize I Me here: recorded signal is related to the signal current fed to the head, while playback is given in terms of voltage Fig. 10-1. The conventional stroboscope disc used for checking turntable speed on output from the playback head. phonographs. Check No. 77 on Reader Service Card.--,

52 AUDIO NOVEMBER, 1966

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The mew Miracord 50H achieves a playback quality It is also equipped with a dynamically, balanced tone beyond the capabi.i_ies of any other automatic available arm with interchangeable cartridge insert having a simple, today. And it accomplishes this with the mechanical re- slotted leadscrew control for precise stylus -overhang .ad- liability, record -handling gentleness and operating sim- justment. A retractable stylus -position indicator is locatel p'icity, characteristic of all Miracord turntables. on the turntable deck. The 50H embodies every feature known to modern The 50H also provides cueing facilities, anti -skate turntable design, ar.d includes several exclusive innova- compensation and direct -dialing stylus force adjustment tions of its own. lit is; strikingly handsome, trim and unclut- to less than V2 gram. tiered, and its very appearance reveals the care and atten- At $149.50, less cartridge and base, the Miracord tion lavished on _ts construction. 5CH is probably the most expensive automatic in the field. The Miracord 50H is powered by a hysteresis motor., This is entirely understandable when you consider it is assuring locked -.n speed accuracy. And it provides the also the finest. See it at your high fidelity dealer, or write. simple, geitle faci_ity of pushbutton operation. Benjamin Electronic Sound Corp., Farmingdale, N.Y.11'36.

www.americanradiohistory.comAmericanRadioHistory.Com the way, the equalization curves would be as shown at Fig. 10-.4. Practical record and playback heads are not perfect: there are both low - and high -frequency losses, as well as a general mid -range loss which we needn't consider here. So both record and playback equalization are needed to correct for these as well as the basic responses set by the NAB. The starting point recommended by the NAB is a high -quality playback head, the response of which is checked by stimulating it artifically with a constant -current magnetization of its gap, rather than using a tape. This enables the head characteristics to be sepa- rated from any characteristics in the test signal on the tape. Correction can be applied to the head so that its response to such stim- ulation, as measured at the equalized output from the amplifier, is equivalent to true constant -current excitation (voltage proportional to frequency). Fig. 10-2. Design for a pulley to check speed on tape, as specified in NAB standard. The next step is to apply further equalization so such simulated con- As magnetic flux on the tape is record current, producing constant stant -current excitation produces the basically related to magnetizing cur- flux in the tape. The playback charac- required playback characteristic (Fig. rent in the record head, and voltage teristic needs a 6-dB/octave rolloff 10-5) . If you are not concerned with is generated by the rate at which through this range. determining head losses for their own magnetism changes at the playback Below 50 Hz and above the upper sake, this final result can be the imme- head, there is a 6 dB/octave inherent turnover point, the characteristic diate target of equalization design. correction. If a tape is recorded at changes to constant voltage. Thus, as- With the head thus adjusted for constant flux density (constant mag- suming a perfect record head, fed playback, experimental recordings can netizing current) with frequency, then with a constant -current drive, and a be made until this response is again the playback needs a 6 dB/octave perfect playback head producing an achieved on playback, indicating that falling characteristic (Fig. 10-3). output from constant -flux recording the test tape has constant flux density. The conversion is not this simple, that rises at exactly 6 dB/octave all The record equalizaion is adjusted, because the recording amplifier would "rather" give constant voltage than constant current. Constant current would result in too low a recorded level of low frequencies and too high a Fig. 103. Basic level of high frequencies on the tape. "responses" per- On the other hand, constant voltage taining to idealized tape and would result in distortion at low fre- recording playback. Curve quencies, and excessive noise level "A" represents the (due to low recorded level) at high output from a con- frequencies. So a compromise is stant -flux record- needed, the exact choice depending ing. Curve "B" on tape speed. the offsetting Through the mid -range, from a low - equalization to frequency turnover point of 50 Hz to provide flat re- a high -frequency turnover that de- sponse. pends on speed -3200 Hz for 71/2 and 15 ips and 1800 Hz for 1'7/s and 33/4 ips-the characteristic is constant

54 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com N COMM MISE QUALITY increas- This combination of PAS -3X preamplifier, FM -3 tuner, plains why our limited product line has become kits are so easy to and Stereo 120 amplifier represents the highest level of ingly popular each year. It's why our service prob- quality which can be attained with high fidelity com- build; why maintenance is so easy; and our prod- ponents. It combines the virtues of both tubes and tran- lems so few. We constantly strive to improve when we do, these changes are avail- sistors in a flexible modular system without skimping ucts though, and at to squeeze it into one unit. able to our customers to update existing equipment Two of these components have passed the test of low cost. gives time years of increasing public acceptance. The Our detailed literature, available on request, - why the Stereo 120 is an all new design. All have been engi- the full specifications which help to explain and neered and produced with the same underlying Dynaco Dynaco components illustrated (PAS -3X, FM -3 philosophy of offering superlative performance at the Stereo 120) will provide the finest sound possible. Spe- spe- lowest possible cost-when you buy it, and as long as cifications are important, but the most complete Go to your you own it. Everyone recognizes that Dynaco is "best cifications cannot define truly superb sound. for the money." We know that it should be judged re- dealer, and compare Dynaco with the most expensive gardless of price-Dynaco quality has never been com- alternatives, using the very best speakers and source their promised by cost considerations. material you can find. Be just as critical, within Our sole concern is sonic perfection. We don't follow power limitations, of our best-selling Stereo 70, Stereo the herd in engineering, styling or promotion. Fads, 35 and SCA-35. status and "revolutionary new sounds" never enter our Of course, if you are now a Dyna owner, don't ex- planning. We avoid regular model changes and the pect us to convince you to replace what you already planned obsolescence they engender. We take the extra have. time to do things right the first time. That probably ex - But your friends might benefit!

OIL,II!aC0 INC. 3912 POWELTON AVENUE PHILADELPHIA, PA. 19104

Check No. 78 on Reader Service Card.

AUDIO NOVEMBER, 1966 55

www.americanradiohistory.comAmericanRadioHistory.Com without touching the playback equalization, until this is achieved. That's the "full treatment"-from scratch. More usually a constant -flux tape, made by these NAB standards, 20 will be used directly to give the re- Fig. 10-4. NAB standard equaliza- sponse of Fig. 10-5. Either way, when 10 PLAYBACK tions, for record this curve is produced CHARACTERISTIC by a constant I and playback at flux excitation, the response will be 0 3 I 71/2 and 15 ips. RECORD/ correct for playing tape recordings RACTERISTIC , The equalizations 1 with standard NAB equalization. /a shown for 33/4 and 10 1``/4 ` 17/8 ips are those i ti `-- commonly em- Distortion ------1/z, ployed 0 & 15 1..r.--. in current This is measured just as for phono- practice. graph reproducers. A test tape is - played and its output is analyzed. The » 10000 100 1000 10000 direct bridge method cannot be ap- FR. FREQUENCY IN HERTZ plied, because the original input is inaccessible. In measuring either tape or phonograph reproducers for distortion, flut- thus follow flutter, so a spuriously to reduce all readings-fundamental ter and wow can show up as distortion high reading will be obtained that can- and harmonics-similarly: the reading elements, unless specific means are not be identified by looking at the peaks up as the frequency taken to avoid such errors. goes The effect meter indication. However, looking at through the tune point, but the meter of such errors can vary with the the distortion residue on an oscillo- doesn't method have time to reach the true of measurements used. scope will tell (Fig. 10-6). Distortion peak -reading value. The conventional Probably the in- harmonic analy- elements will be represented by a validation of all readings zer, which removes fundamental is similar with single, clear trace. If either hum or and thus cancels out in a frequency -sensitive figuring dis- bridge circuit, flutter is present, this will show as a tortion as a percentage. But will go off balance due the rela- to the presence multiple trace. tive significance of the of flutter or wow, two methods thus leaking funda- Hum multiplies the simple distor- of measuring distortion mental, however carefully still follows the bridge tion trace, to look like parallel, the pattern discussed in an earlier is balanced. This will be more ob- crooked lines. Flutter changes the installment. vious on wow, because the meter shape of individual distortion traces, indication will fluctuate at the same according to the pattern by which speed as the wow, or maybe double the bridge is detuned by changing Flutter and Wow the speed. frequency caused by the flutter cycle. This is also measured in the same But the meter indication will not The use of a wave analyzer tends way as for phonograph reproducers. Tape recording is more susceptible to level fluctuations that occur due to varying tape contact against the recording head or due to quality variations in the tape, than phono discs are. So a flutter and wow meter Fig. 10-5. The needs more elaborate measured play. care to eliminate back response to amplitude fluctuations before meas- a constant flux uring frequency variations. tape, or to con- A flutter -and-wow meter for work- stant flux excita- ing on tape can (and usually does) in- tion, of a playback clude a 3000 -Hz oscillator to record head and ampli- the test signal on tape. This enables fier, equalized to the measurement to record over-all NAB standard for flutter and wow, from record to play- the two higher back. If the reading is speeds, and to higher than general practice it should be, you may want to deter- for the slow ones. mine whether the deviation occurs mainly on record or playback. Some units will produce about the same amount in both operations, so

56 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com not all cardioid microphones are alike ...

the S H V R E UN-1DM® III TRUE CARDIOID UNIDIRECTIONAL DYNAMIC MICROPHONE SOLVES ALL THESE COMMON MICROPHONE PROBLEMS!

PROBLEMS CAUSED BY INEFFICIENT REJECTION OF UNWANTED SOUNDS BY THE MICROPHONE

SITUATION PROBLEM CAUSES SOLUTION

off hard surfaces The Unidyne Ill rejects sound REFLECTIONS Feedback occurs where a Sound bounces so-called "cardioid" micro- on the walls, floor and ceiling, at the rear with uniformity at phone is used and the in and around the audience area all frequencies. Sounds bounc- speakers are placed to the and the microphone used is ing off floor or other surfaces rear of the microphone. A not effective in rejecting these are uniformly rejected. common occurrence in sounds at all frequencies, and churches, auditoriums, and in all planes about its axis. meeting rooms.

Unexplained feedback. Col- Feedback occurs when rear and The Unidyne III solves this side sound lobes of column problem because it has no rear COLUMN umn loudspeakers are used to distribute sound more speakers coincide with rear and or side lobes. Thus it rejects LOUDSPEAKERS evenly to the audience in side lobes of so-called "cardi- the side and rear lobes of the churches and auditoriums. oid" microphones. sound column speakers.

a A disturbing, echoing effect Low frequency reverberation and The Unidyne Ill maintains of low frequency sound often boominess occuring when mic- uniform pattern of sound re- even REVERBERANT found in churches, large au- rophone fails to retain unidi- jection at all frequencies, ditoriums, and arenas. rectional characteristics at low as low as 70 cps. The response frequencies. has a controlled roll -off of the low end-low frequency reverberation diminishes effect of hoomv hall.

SOUND PROBLEMS CAUSED BY THE MICROPHONE'S INEFFECTIVENESS IN PICKING UP THE DESIRED

microphone does The particular "cardioid" micro- The Unidyne III affords uni- GROUP COVERAGE A single with not provide uniform cover- phone used lacks a uniform form pickup of the group WITH ONE MICROPHONE a consistency in vol- age of a group. This is pickup pattern, so that persons resulting commonly experienced with in different positions within the ume and sound quality among +- ( "/ {(r] choral groups, quartettes, in- general pickup area of the the members of the group. strumental combos, and microphone are heard with vary- -rir/ speaker panels. ing tonal quality and volume. micro- The Unidyne Ill permits USING MULTIPLE Variation in the pickup level The pickup pattern of the phones used is too narrow, smoothness in pickup as true MICROPHONES and tonal quality exists throughout the broad area to causing "holes" and "hot spots." cardioid pattern gives broad be covered. This may occur The off -axis frequency response coverage with uniformity in stage pickup of musical of the microphones also varies. throughout coverage area. and dramatic productions, Eliminates "holes," "hot in sound panels and audience partici- spots," and variations pation events. quality, simplifies blending many microphones.

noise Long-range microphones are less Use the Unidyne Ill to gain DISTANT PICKUP Too much background with ef- or feedback results when directional with lower frequen- relatively long range of sound at working with microphone at cies. Lobes or hot spots allow fective rejection the rear of desired distance from sound background noise or feedback. all frequencies at \7j) source. the microphone.

SHURE BROTHERS, INC., 222 HARTREY AVE., EVANSTON, ILL. 60204 Check No. 79 on Reader Service Card. 57 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com the tape past the head (Fig. 10-7). Whether or not the motor maintains constant speed during the running of a tape, the tape speed varies on this type of machine. Usually it will vary somewhat similarly both DISTORTION on record and playback, so that tapes recorded PRODUCT ALONE on such a machine will play back without noticeable error in speed. Flutter and wow may be quite un- satisfactory for a professional recorder, but adequate for the special use, such as mobile reportorial jobs. Such a recorder cannot interchange tapes with other recorders-either to play back their tapes or to play recorded tapes-because of the unusual speed DISTORTION variations. Speech gets difficult to fol- WITH HUM low (these machines are completely impossible for music, anyway) when played at speeds approaching half or double that at which it was recorded. The next installment will start on measurements associated with acoustic transducers-microphones and loudspeakers. While waiting for it, why not consider how you would go about establishing a standard of conversion DISTORTION WITH from electrical to acoustical energy, or vice versa? FLUTTER OR WOW

FEED SPOOL TAKEUP SPOOL Fig. 10-6. Identifying distortion, hum, and flutter or wow, from the distortion residue obtained from a harmonic distortion analyzer: top, a typical trace due to distortion only; middle, a similar trace with some hum present; bottom, a similar trace when flutter or wow cyclically detunes the fundamental -nulling bridge. HEAD

the over-all result is likely to be provide for special recorders, where CAPSTAN -CONSTANT SPEED double the amount of each. But there the tape may not be recorded or may also be mechanical reasons why played back with the standard NAB either record or playback would pro- characteristics, but where the over-all duce more. To check this, tapes should result, from record to playback, may be recorded on one machine and yet conform to certain standards of played back on another, preferably frequency response, dynamic range. one with much lower flutter and wow and distortion. than the one being tested. By making The NAB standards on this still Takeup spool driven at the approx. constant speed. exchange each way, it is possible assume that speed is standard-one End almost twice speed to deduce where most of the flutter of the recognized speeds. Many of the of beginning and wow occurs. small portable recorders on the market do not conform to this: tape drive Fig. 10-7. Schematized arrangement of recorders: Special Recorders is not via -the conventional top, the professional type, capstan, whose speed In the foregoing we discussed meas- with separately controlled is controlled by a con- take-up and stant -speed capstan; bottom, the inex- uring tape machines against NAB rewind drive, but the take-up drive standards. pensive portables, in which the speed But the NAB standards also also serves as the "speed control" of is controlled by the take-up spool.

58 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Would you believe

...this is a hi-fi stereo speaker system?

A new sensation in sight and sound-a wholly new concept in hi-fi stereo speaker systems! Designed exclusively for Uni- versity by Larry Williams A.I.D.*, one of the country's leading designers of high quality furniture. University's exciting new Sor r er to is a bold example of perfection, styled and engineered for enduring use and enjoyment. The 4 -speaker system-Uni- versity's newest engineering development -produces the magnificent, live natural sound of music. Music as it is meant to be heard-at an original performance. The rich Seville blue finish of the Sor- rento is achieved by an exclusive glazing process and hand rubbed to fine furniture perfection. Natural slate top. Matching console mirror optional at extra cost. For complete literature write desk L-63. * Design associate.

LISTEN-UNIVERSITY SOUNDS BETTER SPECIFICATIONS: 12" ,'gh complante woofer. 8" sc id back mid -range speaker, patented Sphericon super tweeter, 31/2" rigid diaphragm direct radiator secondary tweeter - UNIVERSITY SOUND 20 to 40,000 Hz -40 watts IPM (Music Power) -8 or 16 ohms -1/4 section 6 db/octave I A OF LTV LING ALTEC. INC. electrical 1./C network 600 and 4,000 Hz crossovers Presence switch and con- t DIVISION - - x 163/e" 60 lbs. J 9500 W. Reno Oklahoma City, Oklahoma 73101 tinuously variable Brilliance Control - 261/a" x 221/2" - $369.50. Check No. 80 on Reader Service Card. AUDIO NOVEMBER, 1966 59

www.americanradiohistory.comAmericanRadioHistory.Com The Annual August Product Compendium Revisions

Any undertaking as extensive as our annual August undertaking must perforce contain some errors of omission and commission. So these pages must be construed as additions and corrections to your August file copies. Each group is referenced to the section and page on which it should be.

First off is Concertone-they were Electro -Voice 15 to 25,000 Hz and power -handling left out of the August compilations The RE -15 microphone listed on capacity is 100 watts. Impedance of altogether. So add this information to page 83 of the August issue is incor- the system is 8 ohms. Controls for the that which is found on page 66 of the rectly priced. It should sell at $153.00. mid and high frequencies are provided August issue. E -V tells us that all other specifica- on the rear panel. Weight is approximately 240 Concertone Model 803 tions are correct. pounds-depending on the Electro -Voice information-circle style of cabinet. The mediterranean This is a professional 36 -grade stereo style illustrated is the Model 1200- tape recorder fitted into a portable XLM. There are also contemporary case. The special feature of this unit and early American styles. All list for is the 3 + 3 Reverse-O-Matic opera- Jensen $895. tion. Both recording and playback Here again a major manufacturer may be accomplished in either direc- was left out of August. Their speaker tion. The unit operates at 33/4 and 71 systems would have gone on page 62. Jensen 700 XLW ips. Separate record, play, and erase heads are provided for each direction. Jensen 1200 XL Signal-to-noise is specified as 50 dB. Two each high -impedance line and microphone inputs are provided. The output from the all -transistor electronics is at 1 volt. Built-in controls allow for add -a -sound and echo as well as off -the -tape monitoring. Rewind is less than 45 second for 1200 feet due to the use of three separate motors. There are built-in power amplifiers. List price is $519.95. This large -bookshelf unit utilizes the The model 804B is identical except same deluxe components as the 1200 that it is a power -amplifier and case - series units except that there is only less deck version. List price is one woofer-and it is a twelve -inch $449.95. unit. Again there is a horn -loaded The model 805 is the deck plus midrange, a compression-driver, horn - Concertone's 30 continuous watt Nor- loaded tweeter, and the Sono -Dome ton amplifier. Two case-lid speakers super tweeter. Frequency range is are also included in the list price of stated as 20-20,000 Hz. Crossovers $589.95. are at 600, 4000, and 10,000 Hz. Power rating is 40 watts, impedance is Concertone 727 This is the top of a brand -spanking 8 ohms, controls for midrange and A stereo battery -operated portable new line from this venerable name. high frequency are provided. List unit. Four speeds from 71/2 down to These are four-way systems in furni- price of this walnut only unit is $275. 15%6 ips are offered on this a.c./d.c. ture enclosures and we can personally unit. Four-track recording with sepa- testify to their handsomeness. Each rate record, play, and erase heads are cabinet contains a total of seven speak- Jensen X-40 and X-45 also standard. Power is derived from ers arranged in a solid acoustic enclo- These are full -range, ultra -compact 6 "D" cells or 117V a.c. Signal-to- sure. Four of these are Flexair® systems. Both feature long -travel, low - noise is 45 dB and output power is woofers of 15 -inch diameter. There resonance eight -inch Flexair woofers. 2.5 watts from the transistor circuitry. is a compression -driver horn -loaded The X-40 uses a three-inch direct radi- Maximum reel size is 5 inches and unit that takes over about 500 Hz. At ator tweeter and the X-45 uses a weight is approximately 16 lbs. List 4000Hz a compression -horn super - compression -driver, horn -loaded tweet- price is $289.95. tweeter comes into play. This carries er. Both systems employ a high -fre- The SK88 Speakers-are matching on until 10 kHz when a direct radiat- quency balance control, both have units at a list price of $99.95 per pair. ing Sono -Dome® ultra -tweeter takes nominal eight -ohm impedances. Their Concertone information-circle 35 over. Over-all response is stated to be power rating is 25 watts. Both are in

60 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com When engineers open our catalog to select a Neumann microphone,

they don't know what they're getting themselves into.

ONES

41ONFS PHONE. YSTE !a SUPPLIES OPHONE ACCFSSORt. MIS and STANDS LICATIONS CHNICAL pApERS

equipment. To many sound engineers, Gotham studio and control room equipment. And test Audio means Neumann microphones. You'll find the names of Europe's best-known com- Period. panies on these products. EMT. Beyer. Studer. And, of of So, when they open our 188 page catalog, course, Neumann. You'll also find that our choice on ability to ad- they're in for a fascinating surprise. products is always based solely their Because, in addition to being the sole U.S. vance the technical excellence of American audio. distributor of the world's finest microphone, So, the next time you Gotham also offers more than 300 other quality need top -performance Gotham sound products and services.Tape recording equipment, sound equipment, open up Audio Corporation And disk recording lathes. Ana disk cut- one of our catalogs. You'll 2 West 46th St., New York,N.Y. 10036 for example. In Canada: JMar Electronics Ltd. ting systems. And disk reproducing equipment. And find it worth looking into. classifications in which you are interested. For information about any Gotham product, please write on company letterhead. Specify product 61 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com finished hand -rubbed oil -walnut enclo- UTC Sound sures. The X-40 has a suggested list UTC managed to get itself left out of $57.00 and the X-45 is $63.00. entirely from the August listings. Here- The Jensen line is extensive. We do with then, complete details on their not have space to list the many com- three most popular speakers. Add this ponent speakers in or out of cabinets information to page 65 of the August and in all price categories. listing. Jensen information-circle 37 Maximus 1 H. H. Scott

Model 2503 Model LT -112 This is billed as the "Smallest True There are no new products to add High Fidelity Speaker System in the to the August Scott listings to be World." 101/2 x 51/2 x 71/4 inches found in a variety of categories. Rath- but the sound belies the size. Two er our faux pas was to leave out en- drivers (the bass unit is air suspended) tirely information in the last column cover the claimed range of 45 to of each of these slots. That column 20,000 Hz. An LC crossover is ac- was Special Features, the column that complished at 1900 Hz. Impedance tells you what each manufacturer feels is 8-16 ohms, power handling is 15 is special about his unit. So here they watts maximum with 5 watts sufficient Model 388 are for Scott: to provide room -filling volume. Dis- tortion is stated to be less than 5 per cent at 45 Hz and below 0.5 per cent Tuners Add to above 150 Hz. Finish is oiled walnut. page List price is $59.50. Model LT -110B 44 Full color instruction manual, silver plated Maximus 5 front end. This unit is a compact three way Model LT -112C FET front end, all silicon IF, oscilloscope system with crossovers at 1800 and output. 8000 Hz. Bass is handled by a 12 -inch Model 312C FET front end, multipath meter, muting, pneumatic -suspension woofer. Mid- scope output. range passes to a direct cone radiator. Model 315 FET front end, all silicon IF. A similar driver is used for the highest Amplifiers frequencies. Over-all response is stated Model LK-60 39 Direct coupled silicon output. Heavy mili- to be 30-20,000 Hz with distortion be- tary type heat sinks, full color wiring dia- low 0.75 per cent from 50-20,000 Hz. gram. At 30 Hz distortion is stated to be 3 Model LK-72B Switchahle front panel headphone output, per cent. Impedance is 8 to 16 ohms center channel output. and power handling is up to 50 watts Model 260 Direct coupled silicon output, three position IHF power. A control allows upper pick-up sensitivity switch. frequencies to be tailored to match Model 299T Direct coupled silicon output, dual clutched room acoustics. Finish is oiled walnut, bass and treble controls. the grill cloth snaps in or out. List Modular Systems 48 price is $129.00. All Compacts feature separate guitar and microphone inputs with mixing, Maximus 7 front panel head -phone jack, tape monitor, slide rule dial, precision tuning This is the deluxe system of the meter, field effect front end (both AM and FM) separate bass and treble UTC line. Four drivers are employed. controls for each channel, acoustic suspension loudspeaker systems. A 12 -inch woofer operates from 25 to Receivers 1800 Hz. A pair of direct-drive cone Model 342 47 FET front end, direct coupled silicon out - midrange units with dispersion lenses put. operate up to 8000 Hz where a dome - Model 382 FET AM/FM, direct coupled silicon output, type super tweeter takes over. Over- Scott Signal Sentinel. all response is thus stated to be 25- Model 344B FET front end, direct coupled silicon out- 35,000 Hz. Distortion is less than put. 0.75 per cent above 50 Hz and 3 per Model 348 FET front end, direct coupled silicon out- cent at 30 Hz. Two controls, one for put. midrange and one for highs are pro- Model 388 FET AM/FM, direct coupled silicon output, vided to permit a wide range of acou- wide -narrow switching for AM band width. stic tailoring of sound. Impedance is Speakers in Enclosures 8-16 ohms, power handling capacity Model S-9 65 Each system features Scott's controlled Im- is 75 watts IHF. The cabinet is oil Model S-10 pedance design for optimum results with all walnut on all six sides with a snap Model S-11 amplifiers. Scott information-circle 38 on/off grille. List price is $189.00. Model S-12 UTC information-circle 39

62 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com With just a flip of a switch, the new Uher8000E tape recorder offers you 4 track stereo,monaural recording and playback, 4 speeds,4 heads, synchronous sound on sound, multiplay sound with sound,echo effects, exclusive built=in automatic slide synchronizer (Dia=pilot),optional sound activator, (whew) and a host of other fantastic features. (You'll also flip over its all new solid state circuitry.) If the above isn't enough reason to switch to Uher,® you should listen to its concerthall sound. 2339 South For a demo visit your hi-fi dealer or write for literature, Martel Electronics, Los Angeles: Lincoln Avenue. End wasted tape. Send for Ia4'marteLj Cotner; New York City: 1199 Broadway; Chicago: 5445 North MARTEL ELECTRONICS the new Martel "Tape Tabulator" for the timing of classical repertoires ($2.75 value). Dept. B, California office. Enclose 25 cents for postage and handling. Sound begins and ends with a Uher Tape Recorder. Circle 39 on Reader Service Card d-3

STEREO

L 014 -PILOT J www.americanradiohistory.comAmericanRadioHistory.Com Q that I cannot find any reference books that will show me how to design one. Books on audio design above the intro- ductory level seem to be nonexistent. Could you recommend some books that will help me? I am familiar with network synthesis. Would you please coin - ment on the soundness of my idea. A. I am not enthusiastic about your idea. As you know, treble boost is produced by reducing the middle and low frequencies. Accordingly the pronounced treble boost you are seeking at the high end entails serious reduction of signal level over most of the audio range, with corresponding deterioration in signal/ noise ratio. Sharp treble boost would entail a rather complex HERMAN network, and un- BURSTEIN less properly located and shielded it might be an additional source of hum pickup. Q. When I record and play sine wares Q. Instructions for my tape recorder Two discussions of equalization on tape, in high-fidelity I don't get a single sine wave state, "Connect a 100 -ohm resistor in se- components to which I on can refer the oscilloscope. 1 get several sine ries with the low side of the record you are: Norman H. Crow - waves hurst, superimposed on each other. What head." There are four wires-two white, Understanding Hi-Fi Circuits does this (Gernsback show? one black, and one red. What is meant Library), Chapter 7; Her- A. Your multiple sine waves atop one by the low side of the head? man Burstein and Henry C. Pollak, Ele- I don't get ments another indicate hum, which can be due as much bias voltage across the 100 -ohm of Tape Recorder Circuits (Gems- to one or more of several causes. Pos- resistor as specified by the manufacturer. back Library), Chapters 6 and 7. sibly hum is being picked up by the play- Also, my line voltage measures about 95 back head from the power transformer to 100 volts. Q. I am having trouble transporting tape across or the tape recorder motor. The trans- A. The low side the heads at constant speed. is the ground side. I have never port chassis may be improperly grounded This is presumably the white wire seen a detailed analysis of for the mechanics of tape to the tape electronics (do not use the each section of your stereo head. Each transport and would appreciate seeing signal lead for such grounding, but run white wire should go through a separate one. It seems to me the variables are: a separate wire between the transport 100 -ohm resistor to ground. Your failure surface of the and the electronics). Improper routing to obtain drive capstan; pressure of pressure roller the specified bias voltage across against of leads or cables may lead to hum the resistor under tape and drive capstan; deforma- this condition may be tion of pressure pickup. The playback head may be in- due to the low line voltage. roller against tape and adequately shielded against stray fields. drive capstan; angle of contact of tape And against pressure roller so on. Q. I have two AR -l's due to the line and two Radio joining the center of the pressure Shack Electrostatic (3) speakers; roller also two and drive capstan not being normal (at Q. I notice that the specifications given University N2B crossover networks. 1 right angles) to the tape as it is by manufacturers for the 3.75 would like to improve stretched ips speed the high end. from the last head or guide in their 8500 -plus tape Should I hook the to the drive recorders are bet- speakers to the 4-, 8-, capstan; the negative tension ter than the specifications or 16 -ohm amplifier or drag due for 7.5 ips in taps? On the N2B to the unspooling and their 8200 -plus machines. crossover I have friction across the Do these better a choice of either a 6 heads; the positive tension specifications at lower dB/octave or 12 due to the speed but higher dB/octave slope. On takeup spool; the friction of price reflect a truly superior or my AR -1's I have a choice the pressure equal of using the roller. Which of the above are critical, listening quality? I presume a manufac- 4 -ohm terminals or of switching in a se- and which ones have I missed? Can the turer uses the same ries resistor to present 8 methods of measur- an -ohm load. critical ones be quantified? ing performance What do you Do you have at various speeds and advise? any suggestions how various price levels. A. The amplifier I can measure them tap you choose will so that I can get optimum performance? A. Yes, it is possible make negligible for a high-priced difference in high -fre- A. As you yourself have tape machine to perform better quency response. If you stated, there at 3.75 use the 8 -ohm are many things to be ips than a low-priced connection on considered in one at 7.5 ips. the AR-l's, they will draw achieving constant tape While performance tends less power than speed. In addi- to deteriorate if you connect directly tion to the factors you mentioned, with reduced speed, to their 4 -ohm there neverless good de- terminals, resulting in rela- are several others, sign, parts, and construction tive emphasis such as a well-bal- can offset of the high -frequency anced drive motor; the inertia this tendency to an appreciable speakers (Radio Shacks). provided degree- Generally you by a flywheel on the capstan; the enough so that the state of art run into less problems with inertia today a 6 dB/octave provided by a guiding flywheel; the fric- permits close to excellent performance slope for the crossover network than tion or "stiction" of the tape with re- at 3.75 ips. While the differences with a 12 dB/octave slope. be- spect to the tape heads and guides and tween 3.75 ips and 7.5 ips are (The reader may be still meas- wondering what other parts contacted by the urable for a given machine, the above question tape; the these differ- and answer have to torque of the supply and ences are becoming increasingly do with tape recorders. takeup reels, less au- Nothing.) and so on. Between the two dible. In my own case, whereas of us we I once still have probably not listed all used to tape opera at 7.5 ips, the fac- I have now Q. As you know, microphones are tors involved. I cannot entirely committed myself quantify the fac- to 3.75 ips. somewhat lacking at frequencies above tors. This is about as In general I now far as I can go in do more recording at 10 KHz. What I plan to do is to add a answering your questions, 3.75 ips than at 7.5 ips. particularly On the other treble boost network to the mike input since the TAPE GUIDE is hand, I am better equipped dealing in first -generation on my machine. I do not want to use to deal with the tape, whereas recording electronic and magnetic companies and an ordinary treble control because this aspects of tape recording rather than others go through several copying the stages, would affect frequencies from 1 kHz up. mechanical ones. I suggest that you con- so that the listener ultimately winds up Instead I wish to match the treble boost with sult the book by W. Earl Stewart, Mag- third- or fourth -generation tape. network to the microphone, which has netic Recording Each stage involves Techniques (McGraw- some deterioration. fairly flat response up to 10 kHz. There- Hill Book Company, New Then it is York City), highly desirable to make the fore I need a network that will be effec- 1958, first recording Chapter 4, "Magnetic Recording at 7.5 ips and even 15 ips. tive only above 10 kHz. My problem is Mechanisms." Æ 64 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Now instant movies in sound start at $695. Tim new Sony Videocorder deck (model CV -2000D) is both compact and versatile. It's also quite reasonably priced, $695, It's just like current Sony Videocorder models, but without the built-in TV monitor. Using a separate monitor or TV set, yot can tape selected TV programs off -the -air. Add the optional Sony TV camera and you can tape "live" action in sight and sound. Play back your tape, and you'll see instant movies in sound. This new deck is small enough to fit on a bookshelf, as a part of your hi-fi component system. Light enough (only 44 lbs.) to take wherever you want it to perform. Adaptable a1 enough to use with any TV monitor, small or large screen (the new Sony 8"` -inch and 22* -inch receiver/monitors are perfect mates). It can be adapted to work with most home TV sets. Handsome too, in walnut -finish cabinet. Looking for a Videocorder with its own built-in monitor? Then meet -he rest of the Sony Videocorder family. TCV-2010 complete in its own carrying case, $995. The TCV-2020, handsome ail -finish walnut cabinet and with built-in timer to automatically tape TV programs while you're away, $1150. For taping "live" action, there is the Video Camera Ensemble VCK-2000 (camera, elevator, tripod, microphone) at $350. For an unforgettable demonstration visit your Sony Video - corder dealer today. For free :6 -page booklet write:

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they were both good, and some may pare to that the black have preferred one or the other. Now box trying to imitate itself. The sound I think there is no doubt as to which that you hear when you see the green of the two sounds was closer to the light over the black box is the original live original, and which speaker is a more sound as it existed at the recording accurate reproducer. This is a much session. When you see easier decision to make. You don't the red light over the black box you will have to bring into play your musical he hearing the black box playing the recording, taste (unless you must choose between trying to imitate itself, two types of inaccuracy). It becomes and the red light over the AR -3 obvious that certain factors sometimes will mean that it is trying to imitate the black box. claimed to be relevant-such as the I think that from what you fact that speakers don't sound the have already heard you should be same in different acoustical environ- able to predict which ments-have nothing will make a better imitation-the bet- to do with ter speaker. fidelity. And one old saw in particular, which is perhaps the most ridiculous I would like to point out one thing of all, that you can't tell which before I proceed. The problem raised speaker is earlier, of where to put the micro- best because we all have Fig. 3. Open-field recording setup. AR - phones, different ears and hear things differ- 4' reference speaker faces into a con- was especially difficult in recording ently, is exposed. It is of course true trolled solid angle of 180 deg. the black box. In the case of that we hear things the AR -4X it wasn't too difficult, since differently, but we another speaker with perfectly hear the live sound flat the dispersion pattern is not erratic; at the concert and response. The "flat" speaker will the reproduced sound then the treble gradually drops off at the in our own liv- sound just like the "skewed" speaker ing room with the same aberrations, sides, symmetrically in all directions. it is trying to imitate. The imitator The the same distortions-the same fact that it is a two-way rather ears. must itself be colorless. than three-way We also see things differently. You system helps. The off- So we buried the black box in the axis may be astigmatic, or you response curves of the black box, may be earth, to he recorded. What I will now however, myopic, but you see the original paint- bear little similarity to each show is the attempt of the AR -3 to other or to ing with the same kind of visual aber- the on -axis frequency re- imitate the black box, and I will corn - sponse curve. They rations that are operative when you develop peaks and look at the reproduction. One element in this simulated live vs. recorded comparison that may he confusing at first is the fact that a reproducing device-a loudspeaker- is used to create the original sound. If the original sound had been produced by live musicians there would be no problems: the loudspeaker that sounded most like the live musicians would he it. But when we use an original sound which is itself produced by a loudspeaker it takes some mental I KAM effort to unscramble things. Maybe the AR -3, which after all was designed by the same company, ought to sound more like the reference AR -4x than the black box which was designed by another company with a different design approach. The black box, inci- dentally, is one selected purposely as representative of the so-called "presence" speaker. To clear up this point, the next thing that I am going to do is to use the black box as reference speaker, to I demonstrate that similarities between Ill MIL the reference speaker and the speakers under test are irrelevant. We are testing the ability of any speaker to imi- 500 tate the reference, and whether 1000 5000 10 or not 000 20 000 the speaker under test is similar to the Fig. 4. Comparison reference has nothing to do with it. of frequency response curves of AR -4x reference speaker and black box, showing why the AR -4x If you have a speaker with a particu- was better able to imitate the black box than the latter was able to imitate itself. Measurements lar skewed response curve, the best were made in a reverberation chamber and represented integrated power output way to imitate the sound of speakers. Treble roll -off, of that caused by increasing absoption during multiple reflections, is typical of reverbera- speaker through a recording is to use tion measurements.

66 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com holes in different places. When we found the microphone positions that ACOUSTECH Introduces did the best job we could manage, there was one clinker, an exaggera- tion of a rattle that this particular "A the Art" speaker has. It's not a major rattle. State of Probably most of you have not heard it so far because you weren't listening for it, but the output of the black box FM Stereo Tuner at one particular angle, over a narrow cone of radiation, is out of this world. It may be as loud as the music. Since the microphone positions which were best able to represent the total color of this speaker were dan- gerously close to the rattle angle, I think you will notice that the recorded sound will have more rattle than the original sound. (The "rattle angle" is an advanced concept with which audio engineers are becoming more familiar.) What you should listen for is general color, and judge which speaker is able to better reproduce the :olor of the black box. Presenting the Acoustech VIII, the first all -solid state FM Question: It seems to me this test is stereo tuner of equivalent quality to Acoustech's highly ac- not absolute from the point of disper- claimed amplifiers and kits. At only $299 (accessory walnut the test speaker which sion, and indeed case $24.50), this unique instrument has many engineering best reproduces the reference speaker as and design achievements not available on other tuners far as dispersion is concerned is the one panel can- identical dispersion regardless of price. Its exciting see-through front that will have the To appre- angle, not some absolute version of not be adequately depicted in a mere photograph. what is best. ciate the Acoustech VIII fully, see your franchised dealer Answer: You are right in that this soon for an exciting demonstration (available November 15). test will not reveal with the same sensitivity defects in dispersion. Similari- to the reference may ties of dispersion Cascode F.E.T. front end - Acoustech engineers' even help the imitation somewhat. have developed an amazing front end using field For the demonstration using the effect transistors in cascode for remarkable sensi- black box as reference we recorded the tivity (better than 2 microvolts) and superior rejec-, same piece of music. tion of spurious signals. The first time that I heard an AR -3 sounding like the black box, the hairs on the back of my neck stood up. Re- member that you must limit your to which Modular IF with five stages of IF and four of limit- evaluation and your judgment design is to ing -a major breakthrough in tuner speaker makes the closer match reflected in the matchless performance of the IF the reference. strip. Excellent selectivity, low distortion, and full Apparently the black box being the limiting with signals as weak as four microvolts same as the reference speaker didn't are some of the characteristics. help it. In the first demonstration it was not able to reproduce the sound of the AR -4x without strong coloration, and when it reproduced itself Stereo headphone amplifier built in-for the first with that same coloration it was even time ever, an FM tuner with a built-in headphone favorite Koss the distortions were amplifier. Listen to stereo over your worse because low impedance phones without turning on your am- doubled. It was confusion com- plifier. Indeed start your music system with this pounded. superb tuner and a pair of headphones, adding amplifier and speakers later. A new approach to building economically a superior music system. Question: This then is like a third version of your orange -tinted sky, in which the orange is still snore so. Answer: Precisely. It would be as though we took our orange -tinted reproduction and reproduced it again through the same reproducing equip- ACOUSTECH, INC., div. KOSS ELECTRONICS ment. It might turn out vermillion or Dept.131)139 Main Street, Cambridge yellow. Mass. 02142

IMPETUS: 2 VIA BERNA LUGANO, SWITZERLAND Question: You say that it doesn't make any difference what reference speaker you use. In one respect it does. When Check No. 84 on Reader Service Card. 67 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com you are trying to test a wide -range quency extremes. Ideally, and some- switching speaker with a speaker whose from track A to track B? In range is day when perhaps we or someone else this narrower, you will case track A has been a direct elec- be able to ascertain improves this test, it will reveal color- trical how the wide -range speaker recording, and track B has been performs ation, frequency balance, frequency ex- through only in the frequency the anechoic room. range covered by tremes, range, and so forth and so on. the more limited one. Answer: You have described a sec- Question: Did you try other makes of ond test Answer: That is absolutely correct. speakers? method that can be used. You can simply If your reference speaker is chopped take one speaker, re- Answer: If I seem to be greeting your cord it, off top and bottom, then in play the recording back into compar- question with a blank stare, that is be- the ing the ability of other speakers speaker while it is still in the to cause I want to avoid getting commer- ground, imitate the reference you will not be record it again, and then see cial. We did try other speakers, and how much deterioration engaging their ability to reproduce top all I can say is there is after that when there is a the second, third, fourth, and bottom. Where this test method particular kind of and fifth coloration this test speaker recording and playback. really shows its worth is in revealing is very useful in revealing it. This is one of the things that I had planned the relative degree and especially the Question: Why did you need a refer- to mention towards the end of quality of positive coloration, elements ence speaker? Why not work with just this paper; the procedure exaggerates what- that usually have little to do with fre- one speaker under test, even your own, ever deficiencies a speaker has, and makes them easier to spot. Question: How much coloration do you think the microphones added? Answer: Not much. As you see, where we had a fairly close match in the first demonstration, the total difference was very small. Question: When you set up your speakers here, how did you determine your level and the damping factors that were used? Answer: They were all driven by Dyna Mark III's, and the damping factor is, I think, 10 or 15. Because it is that high it doesn't make much difference. As for relative levels, I stood in the back of the hall while some of my colleagues turned knobs until it sounded about right. The ob- BEYER jective sound levels of the different The Microphone That Picks Up Where Others Leave Off! speakers may not be the same, but I tried to adjust them so that the subjec- Beyer microphones are the world-wide standard by which others are tive level was about the same. That judged. Now, for the first time, the full line of Beyer microphones way you can concentrate on the color and accessories is available ih North America through the worldwide and not be influenced by loudness. sales and service facilities of Elpa Marketing Industries, Inc. The Question: Is there some correlation be- Beyer line covers the full spectrum of price and performance for tween measurements of separate drivers every need, in all types, ranging from heavy duty models for profes- in an anechoic chamber and a speaker sional broadcast and studio use, to popular-priced models for ham that sounds good when compared to it- or CB operator, student or audiophile. For faithful service and total self this way?. dependability, regardless of budget, the buy line is Beyer - now the Answer: The answer is, of course, new standard of quality in the U.S. "Yes, if you know how to make your measurements." The anechoic cham- See the Beyer Line at your favorite Hi-Fi dealer or write for literature to Dept. A411 ber will only give you measurements at one angle at a time, and so our ELPA MARKETING INDUSTRIES, INC. >< NEW HYDE PARK, NEW YORK 11044 anechoic chamber measurements are, as I think all such measurements should be, made as a family of curves, on and off axis. These anechoic measurements, as well as more direct power measurements in a reverberation chamber, showed the black box as having a "presence" peak of 13-14 dB (see Fig. 4) at about 1700 Hz, predicting the nasal, honky quality you heard here.

Question: If you had followed the earlier proposal and recorded over and played over the black box, but each time you moved the microphone to a little different place, then you might have not accentuated some elements. You may have picked a bad spot. I am saying that maybe to be fair to the black box you should try a little more integration. You might, for example, favor your own loudspeaker and pick a good spot for it and pick a bad spot for the black box. Answer: It is certainly possible, by Check No. 85 on Reader Service Card. bad choice or by biased choice of 68 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com "LE DÉJEUNER SUI L HERBE" by Picasso. An original linoleum cut 3/51-from the collection of James I. Lansing So -and, Inc. microphone positions and/or number of microphones to favor one or another speaker. Of course, if you do this, you render the test method useless, except perhaps for making an unethi- cal advertising pitch, and it is too esoteric a method to be really useful from that point of view. It is necessary to develop a method for getting a fair sampling of the reference speaker's output. I think this question really is: Could there have been a microphone position, or series of microphone positions, which would have made the black box do a more creditable job in imitating the AR -4x, and perhaps the AR -3 a worse job? There were microphone positions which would have made the AR -3 sound a lot worse in the imitation of the AR -4x, but we would not find positions which would make the black box do a better job in imitating the AR -4x. We tried, and we failed. Per- haps if we had used not two microphones but twenty, and had really covered the hemisphere around the speaker, we might have done better and might indeed have recorded sound that was more representative. Question: I was wondering whether you found the position of the speaker in the actual A -B listening test has an effect on all this? Answer: All that is important is that all speakers be pretty much in the same position. Now we will go hack to the AR -4x as reference, and I will play a few tapes with different kinds of music. During this part of the test, I never switched from A to B, but from a test speaker to the reference, and then to the other speaker. Any differences you hear between the two speakers under Three-dimensional objects expressed in flat, interconnectec test have no meaning without a reference. We go from speaker A to what planes; sickle -shaped curve!, surface profiles re-ezlin. facet: by definition is the truth-the refer- of structur complete mastery of traditional to speak- ence speaker-and then Art as technyues, then unceasing experimen: erB. Æ total with an endless variety of sty es and form: expression ... led to the dere.o2ment os "Cubism"- forme broken into planes aril volumes and portrayed as if seen fr:m several angles sir ultaneousl}.

The result is total visual txpressior.

JBL maintains a tradition of mar ifacturing the world's finest high fidelity equipment. Yet our engineers and craftsmen are cDnstantlq experimenting with new technicues, testing even the most radio-1 :nnovations in audit engineering.

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Fig. 5. AR's reverberant chamber for JBL 3249 Casitas Avenue, Los Angeles, California 90039 speaker testing. Check No. 86 on Readier Service Card. AUDIO NOVEMBER, 1966 69

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Scott Tuner in virtually any application ranging from that these units eliminate audio 'blast- the few feet of a swimming pool to deep- ing' commonly encountered with the sea probes at depths of up to 100 feet. rotary type switches. Frequency All connections in range is stated to be 50-20,000 and ont are made with Hz. with standard con- a sensitivity of 134 dB/watt. nectors. Operation is by positive Because of this high finger- efficiency and stand- tip action. List price of either model ard 16 -ohm impedance, ordinary ampli- is $49.50. CIRCLE 8 fiers may be used. The UL -2 has been The Scott 312C is the latest in a line Larger Reel of tuners from this venerable New Eng- Many land company. Many innovations tape recorders, notably the re are cent Magnecord claimed for the unit. These include: units, are able to ac- the Scott silver-plated commodate a larger than 7 -inch but 3 -field-effect tran- smaller sistor front end, all -silicon than 101/2 -inch reel. Magnecord IF section for has,in fact, improved stability and wide bandwidth, offered a blank reel in 81/4 - inch size. Now a front panel meter switch that converts BASF (Badishe Analin- & Soda -Fabrik, the meter to indicate signal strength, AG of West Germany) is marketing a line zero -center tuning, or multipath indica- of tape on this inter- tion; automatic stereo mediate size reel. Tapes now available switching not af- include fected by momentary signal -strength 1800 feet of 11/2 mil tape, 2400 feet 1 changes; interchannel muting; of mil tape, and 3280 feet of 3/4 separate mil stock. front panel outputs for stereo tape successfully employed as an underwater According to our information re- the entire line cording and an oscilloscope (for precise communicator with scuba divers and of BASF tape types will be available on this correction of multipath distortion. Us- research teams. It can be used without size reel. able sensitivity of the 312C is given as any modification as an underwater micro- CIRCLE 9 1.7 µV; cross modulation rejection phone as well as a speaker. Water con- is 90 The Disappearing dB; selectivity is 45 dB; stereo separa- trol of the unit is achieved by using a Dial highly -compliant tion is 40 dB. Price of the tuner is rubber bag which pro- ,Three new tects the receivers from Harman- $249.95. CIRCLE 5 diaphragm from water pressure. Kardon Pioneer offer peak -a -boo dials that van- states that this device prevents ish when any signal distortion the set is off only to reapper Top -Line Automatic which could be in all their glory caused by the voice when power is applied. coil going off its But the changes true axis in the magnetic here are not alone in field. The the face. They speaker may be used in fresh go far deeper. The FM or salt front ends employ water. It weighs 28 lbs. Cost is $275.00 metal oxide silicon field effect transistors (more easily list. CIRCLE 7 known as MOSFETs). H -K is claiming that these new devices surpass other FETs Speaker Switches with lower cross modulation and cross-

The new Miracord PW-50H features a completely new motor mounting and drive system to achieve inaudible rumble. Drive is from a newly designed Papst hysteresis motor. The PW-50H will track cartridges capable of operating as low as one half gram. At the opposite extreme, it will also accommodate cartridges that must track as high Switchcraft, who offers a variety of as six grams. The arm is in balance switching devices, as befits their name, with a vernier motion rear weight. The has announced the Sound Control Cen stylus and cartridge are adjustable by ters, models 641 and 642. Up to eight means of a leadscrew at the front of the complete stereo speaker systems may be cartridge head. An alignment gauge is controlled with these models. Thus the supplied. Other features include a cue- audio buff can virtually tailor-make his ing lift, positive anti -skating control, all sound distributing system. The basis for talk, superior sensitivity due to lower metal tone arm lock, illuminated speed both units is an eight -station switching inherent noise and improved rejection of indicator for all four speeds, and a di- device. Frequency response through the unwanted signals. The MOSFET also rect reading tracking force dial. The units is from d.c. to 30 kHz with negli- isolates the antenna circuit to provide an PW-50H is operated via the traditional gible switching losses. No external pow- improved match with the antenna. The Miracord pushbutton system. It lists for er is required for operation. Power han- three models break down as follows: $149.50 less base and cartridge. dling capacity is 100 watts maximum into model Two Hundred is an FM Stereo a 4 -ohm CIRCLE 6 load. The 642 model is for receiver with 50 watts IHF, priced at simultaneous distribution of sound to $239.50; the Two Ten is FM Stereo/AM more than one stereo Submerged Sound speaker system. and 50 watts IHF-priced at $269.50; The 641 is to be used when it is desir- and the 80 watt Presumably for Seven Twenty is FM the benefit of fishes and able to restrict sound distribution to one Stereo and priced at $369.50. Usable other underwater denizens, this Model stereo speaker system at a time. A posi- FM sensitivity on this last model is UL -2 from Pioneer Electronics USA tive interlocking feature between switch given as 1.8 microvolts. Full power Corp. has been specifically re- designed as stations insures that only one system at a sponse is stated as 8-40,000 Hz. an underwater speaker. It may be used time can be selected. Switchcraft states CIRCLE 10 70 AUDIO NOVEMBER. 1966

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Yale Audio of Florida is offering a fully automatic timer for switching on and off electrical products. Just the thing solid state cartridge for non -stay-at-home tape recordists. As many as 48 combinations of time inter- vals may be present to allow you free- dom from the chore of turning equipment on and off. There are many other with any other applications, of course. The timer is perfect for some kinds of time-lapse photography and for display lighting systems. Prices for the Yale Audio Func tional Timer start at $39.95; a.c. capa- stereo cartridge cities of up to 1000 watts directly are available. CIRCLE 11

Broadcast Console Insert The Universal Audio 610 amplifier module has a triangular shape that allows it to be installed on either the SONOTOBE sloped front of audio mixing consoles or vertically in a rack. The vacuum tube unit provides all the controls needed for low and high level input channels. An input selector switch allows the operator to connect the input circuit to either a microphone or a line -level bridging circuit. A second switch directs the output

Here's why you can't afford not to We're 99% sure you'll prefer the Mark V to all other stereo cartridges. But, just to be 100% sure, we'll allow you $2.00 toward its purchase price. onto any one of three program circuits. In every area, the Velocitone Mark V measures up to the best of today's An echo -send output, which is isolated fine stereo cartridges. from the program output and has its own front -panel gain control, is simul- And then goes them one better. taneously switched to one of three echo Like the Mark V's complete absence of magnetically induced hum. Fea- channels. The gain control is of the in- tures Sonotone's virtually indestructible Sono -Flex® needle in choice of terstage type, maximum microphone -input three fully ground, highly polished diamonds -0.7 mil, 0.5 mil and elliptical. gain is 63 dB, maximum high-level input Survives bends, bounce and mauling without loss of performance quality. gain is 25 dB. Power output is +18 dBm at less than 1 per cent distortion. nearby hi-fi dealer to demon- Ask your N E A blue-ribbon type connector facilitates strate it for you. Fits all high-fidelity SON OTO rapid installation or removal from a con- changers and turntables. From $32.50, audio products sole. The width of each unit is 3 inches, regular audiophile price. Simply send sale the long dimension is 14 inches and the receipt to us and you will receive your SONOTONE CORPORATION, ELMSFORD, N.Y. 10523 depth, when the front -panel is mounted ELECTRONIC APPLICATIONS DIVISION mail with our compliments INC., N. Y. C. 20 deg. from the horizontal, is approxi- $2.00 by return EXPORT: SINGER PRODS. CO., CABLE: EXREGNIS; N. Y. mately 5 inches. CIRCLE 12 for a wise choice. Check No. 87 on Reader Service Card. AUDIO NOVEMBER, 1966 71

www.americanradiohistory.comAmericanRadioHistory.Com AUDIOCLINIC some operating and monitoring con- poor. This is a matter of whether (from page 4) ditions. or Therefore, it is seriously ad- not you have output taken before terminals are connected similarly to vised that or you do not "normal" your after the de -emphasis network. If identical jacks. However, the station- tape the recorder. If you want to "normal" output is taken before the network, ary contacts of these jacks are then your tape player, go ahead. highs will be too strident. If you connected together. This means that Another took point to be considered is your output after the network, and the speaker and amplifier are con- the if matter of the TV receiver patch- the network is of poor design (normal nected together even when no patch ing arrangements. I do not like the for many sets), you will have insuffi- cord is plugged in to make the con- TV audio to be derived from the cient highs. You may have to "play" nection. If it is desired to feed an speaker terminals of the TV receiver. with de -emphasis values. If you external amplifier into your speakers, are The audio in such equipment is poor ahead of the network, try all you do is plug it into the speaker at 100 k best. You should consider taking ohms and 750/pF, with your output jack. This disconnects your internal your signal directly from the volume taken at the junction of the two amplifier and automatically connects control com- of the receiver in those in- ponents. The capacitor is grounded, the external amplifier to the speakers. stances in which this is possible. Some- while the free end of the resistor Conversely, if the internal amplifier goes times the volume control is located to the "hot" detector output terminal. is to feed external speakers, the exter- in some section of the set other than Your mixer can also be patched in. nal speakers are plugged into the in the detector stage-such as between Remember, however, to treat the amplifier output jack. This automa- the voltage amplifier and the power shields the same as you did the tically disconnects your main speakers, output pre- stage. Under those circum- amplifier. If the microphone connec- and allows the amplifier to feed the stances, you should make your con- tors are to be brought up the panel, external speakers. This "normaling" nections directly to the detector out- they should he insulated from it via can be done between amplifier and put and forget about the volume con- insulating washers. Better still, preamplifier. You might also wish to you trol. If you do use the volume control, should use the Cannon or Amphenol do this with your tuners. make your connections across the con- XL types which can be used for The rule here must he to avoid trol rather than between the arm of balanced line operation. This will overdoing the use of these "normals". the control and ground. In this way allow even more flexibility as your This can lead to trouble, especially you can turn down the audio coming system grows. High-level inputs of the when tape recorder inputs and out- directly from the speaker in the TV mixer can be treated as any other puts are involved. If you forget that receiver and permit only the audio high-level source-as discussed earlier. you have some "normals" on the of your high fidelity system to be Ground the mixer to the panel. board in these tape -recorder circuits, heard. Return all shields to the you are likely to make conections mixer ends You may find that the high -fre- of the cables. The "hot" leads which will result in feedback under only quency response is too great or too should be connected to the patch panel. ALL PHONE JACKS SHOULD BE DIRECTLY GROUNDED TO THE METAL PATCH PANEL. This will be the only ground return for these jacks. Should The world's you prefer to make your patch panel on a material other than metal, longest playing ground leads must he run to each of the jacks and the ground bus so audio tape formed must he grounded to some connection on your equipment, preferably to the preamplifier. In my own case, the equipment is contained MICRO in two standard utility racks, and the patch panel is made on a 7 -inch MEDIA 25 rack panel. There is another kind of patch you QUADRApIay should consider using. This is what is known as a "multiple." This is nothing more than four or five jacks which Now, .. enjoy a 31/4" reel that gives two hours are wired together. There is nothing external wired to them. These playing time in each direction at 1 %8 ips are very handy at times. Suppose you have a source having a low -impedance Micro Media 25 is the most advanced tape ever made available output-as from a cathode follower- for your listening pleasure. An exclusive formula combines a high which you would like to feed simul- density coating with a 1/4 mil tensilized Mylar° base to give taneously into a monitor amplifier and you more quality tape on every 17/e reel. At ips, the 31/4" reel the input of a tape recorder. This can provides over two hours play (1200 ft.) ... the 5" reel provides four be accomplished by connecting hours play (2300 ft.) ... the 7" reel provides over eight hours the output into play (4800 ft.) ... in each direction. Discover the new one of the "multiples" and connecting convenience of Micro Media 25 QUADRApIay - the monitor amplifier and it plays on and on where others end. the tape recorder input to two of the others in the string. There will be Available at audio and photo dealers throughout America no loss of performance. The devices Manufactured by MAGNETIC MEDIA CORPORATION are connected together 616 Fayette Avenue, Mamaroneck, N.Y, 10543 (914) 698-8660 in a very *Du Pont trademark simple way. See to it that all of your output Check No. 88 on Reader Service Card. sources are cathode followers or emit - 72 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com Use some sense when laying out the ter followers or, a least, of some low impedance output of the device feed- patches to enable easier memorization. impedance. This will allow you to ing the tape recorder. With the short- For instance, use all odd -number rows do something else which is very useful. ing deck disconnected, this will not left -channel connections; all even You can now remove the shorting happen. Further, because the output as numbered rows are reserved for right - feature from your preamplifier input - of the device feeding the recorder is channel connections. Group similar selector switch. This will permit you of low impedance, no leakage will things together. All inputs should be to switch the preamplifier from one be heard in the preamplifier. The mat- immediately followed by their out- source to another without shorting out ter of leakage is exactly the reason may find that the most the unused sources which might be why such switches are equipped with puts. You used patches should be feeding other switch positions of the shorting decks. frequently the left or the right edge preamplifier. This feature is especially Do not wire anything until you placed near the panel for more ready access. useful with the above - mentioned have made a complete chart of the of I do not know your back- monitoring scheme. Suppose you start proposed panel and the various patches Frankly, Hence, I may not have given out by wishing to monitor what is which will be used. Note on the ground. detail. Should this prove being recording on tape as described. chart what "normals" you will be you sufficient write to me again. I Then, while the recording is still in using. What I did was to number each to be the case, progress, you wish to monitor a TV vertical row A -F, and horizontal rows can then provide more information. detail program. You can do this merely by 1-17. You may not have 102 racks I have tried to comment in with the hope moving a switch on your preamplifier. on your panel. You will find, how- about your problem en- If the shorting feature were left in ever, that more will be needed than that you can proceed to wire your place, you would short out the low - you anticipate right now. tire system.

e . e and Now Our Finest Achievement: The SX-1000TA 90 Watt AM -FM Solid State Receiver your dealer doesn't carry the the finest AM -FM Solid State Receiver under Achievement"at your Hi-Fi Dealer. If Unquestionably send for more $500, the SX-1000TA has been rated by a leading testing labora- PIONEER line of quality components yet, please Pioneer Dealer nearest you. tory as the highest quality Solid State Receiver evaluated. details or the name of the Franchised We, of Pioneer, are extremely proud of this achievement. Its intro- P.S. We don't charge extra for the oiled walnut cabinet- net: $360. duction comes at a time when the audiophile can now select a it's included! The SX-1000TA-Audiophile Solid State Receiver with complete confidence, to upgrade his SPECIFICATIONS FM SECTION and begin a new adventure in sound reproduction by Noise (rated output); (IHF rating) hi-fi system Circuitry - Front-end using 3 gang variable Hum 8 - the mere flick of a switch. No matter what other components are capacitor.4 dual -tuning IF stages equipped TAPE HEAD: better than 60 db with muting circuit. MAG: better than 70 dD used with the SX-1000TA, their performance has to be superior. Usable Sensitivity (IHF)- 2.20 AUX: better than 85 db rated Signal to Noise Ratio - 60 db Inputs and Audio Sensitivity (for The SX-1000TA with both AM and FM bands, and advanced cir- Antenna Input - 300 ohms (balanced) output) - MAGnetic PHONO: 2.5 mV Multiplex Circuitry - Time Switching Circuit TAPE HEAD: 1.5 mV cuitry, has been engineered for more critical and satisfying per- equipped with AUTOMATIC MONO -STEREO CERamic 55 mV TORO:200 mV It a time switching circuit equipped with switching TAPE formances. contains Channel Separation -38 db (at 1,000 cps) Auxiliary: 200 mV automatic mono -stereo switching and provides 38 db channel Output Terminals and lacks - needs AM SECTION Speakers: 8 - 16 ohms separation. It is highly flexible in meeting the audiophile's Circuitry - Superheterodyne circuit with Stereo Headphones lack tape head auxi- tuned RF stage Simultaneous Tape -Recording jacks, with inputs for magnetic phono, ceramic phono, Usable Sensitivity (IHF) -18µV equipped with "TAPE MONITOR" switch. liary inputs, and outputs for stereo headphones. Has simultaneous Antenna Input - Built-in Ferrite loopstick Tape recording/Playback; (DIN standard) Antenna with terminal for external Antenna Equalization Curves - PHONO; RIM; tape-recording jacks and a tape monitor switch. Each channel has TAPE NAB AUDIO SECTION Filters LOW: dbt a db 0t cps) bass and treble controls. Ended Push -Pull circuit separate Circuitry - Single HIGH:: tut 11 db (at 10,,000 cps) (O T L) FM tuner has a sensitivity of 2.2 uy with abso- Music Power Output 90 watts total POWER SUPPLY. ETC. The front end of the - Switch (8 ohm load / IHF rating) Protection Circuit - Electronic by tuned intermediate frequency am- 115/230 volts lute selectivity assured four RMS Rated Power Output - 40 watts per Line Requirements - plifier stages, followed by a wide -band ratio detector. The precise channel (B ohm load) (switchable)1.8/1.9 amp. 50-60 cps. Harmonic Distortion - 0.5% (at 1 kc and (Max) automatic switching mechanism features a two-step discriminator rated output) Tubes75 watts 6CW4 (2) Frequency Response 20-60.000 cps Dimensions (Overall) - using a Schmidt trigger. A sharp reliable muting circuit eliminates (Over-all) 16" (W) x 534" (H) x 13'31" (D) noise when tuning from station to station. An easily readable, sen- Power Bandwidth (IHF) - 15-40,000 cps 405 (W) a 137 (H) x 350 (0) mm Weight Net 25 lbs. 5 oz./11.5 Kg. sitive tuning indicator and stereo indicator lamp make perfect Damping Factor - 30 (8 ohm load) - tuning easy. CORPORATION To fully appreciate the NEW, and exceptional AM -FM Solid State PIONEER ELECTRONICS U.S.A. N.Y. 10001 Receiver, we cordially invite you to listen and compare our "Finest "A MARK TO REMEMBER' 350 FIFTH AVENUE/NEW YORK,

Check No. 89 on Reader Service Card. AUDIO NOVEMBER, 1966 73

www.americanradiohistory.comAmericanRadioHistory.Com WORLD'S FET's (from page 30) FINEST 0 11111111 VOLUME MAX -LOUDNESS MAX .1111- VOLUME 5/4- LOUDNESS Hell _,.,11111,"1! 3/4 10 1IH .II- a-IIMfrckiee 111111 MIIIII 20'.,IIIII\fro4 Fig. 5. Response !i obtained with the IIIIIIIL3/4-z 00 IIIIII m... ;liIIIr Centralab C2-100 Pa 1111111 30 s-s Mil loudness control I minim anon as used in the cir- IIII cuit of Fig. 40 inm nu111111 3. 111111 111111 111111 5D UIII101IÌhIIIIf11111 Lao FREQUENCY IN HERTZ

volts ERSIX output was 0.06 per cent while C3-300 and C2-100). These even compo- the tube circuit was already in nents were' originally made heavy available overload. All measurements for a high -quality tube control MULTILORE were taken unit under identical equaliza- designed by C. G. McProud8. The tion and gain with all circuits adjusted circuit of the FET tone control to the optimum is (Table II). shown in Fig. 3 with curves in Figs. This phono 4 equalizer may be in- and 5. The circuit very much reminds stalled directly with the turntable (the one of a standard tube circuit, al- author's preference) with the tone though the self-bias resistors and are some- loudness control remote as a what larger. Also, due to higher separate, loop compact unit next to the gain of FET's, feedback circuits per- ONLY preferred listening 69C position. With this form exceedingly well. It must be re- concept, the critical cable BUY IT AT RADIO-TV PARTS STORES from cart- membered that FET's have a voltage ridge to equalizer is kept Check No. 90 short and gain of about 50 dB as compared on Reader Service Card. full control to from a listening position 40 dB for a pentode and 30 dB is possible. for a Two identical units are triode. As can be seen from New 514 -Page needed the for stereo. Up to 200 feet of curves, the performance of the unit /.I LLlt-a cable may be run from the equalizers is excellent. Gain at 1000 Hz was FREE 1967 Catalog 1 relative to V. rms. -1.5 dB due to the feedback with In all the other concept, the phono - controls set flat and volume maxi- equalizer is combined with the follow- mum. Noise level was more than 80 ing tone control in one chassis. Gen- dB below 1 V. Overload was 25.5 dB erally a remote d.c. power supply is above 1 V. at 1 per cent distortion. preferable to avoid magnetic hum This is still an excellent value as com- from power transformers to be picked pared to tube circuits, but it is some- up by the cartridge. what less than for the phono equalizer or the output stage itself. The distor- Tone Control Section tion was traced to diagonal loading of The tone control uses the Baxan- the tone control stage. Where an even dall7 circuit which features a variable higher output level is needed, the point of inflexion. It is a feedback - source follower may be directly type control of superior quality. The coupled to the drain of the tone con- design is greatly simplified by using trol unit with the 1 -Meg. and 3900 - Top Savings on Stereo special components available as low- ohm resistor of the source follower Hi-Fi and Tape Recorders cost printed circuits (Centralab parts removed and the 100 K resistor Buy from Allied-where more people buy +120V their stereo hi -fl than anywhere else in the ó world. Choose from world's finest makes .. . largest selection of tape recording equip- L-1.8-A ment... also famous Knight -Kit® build -it - 0 .05 yourself hi-fi. No money down...24 months to pay. Ió Mail this coupon today! I-o 1 i 1 50 ALLIED RADIO, Dept. A-10 P. O. Box 4198, Chicago, III. 60680 .05 C2-100 C3-300 º I+ Send FREE 1967 Allied Catalog 25 15K LOUDNESS -VOLUME TONE CONTROL N Name PLEASE PRINT Address

City State Zip L Fig. 6. Alternate circuit of tone control section, with relative locations of the com- Check No. 91 on Reader Service Card. ponents reversed.

74 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com changed to 15 K. The .05 µF coupling NEW ROBERTS 400X capacitor into pin 7 of the Baxandall unit is then removed from the drain of the first stage and tied directly to the source of the output stage. The OFFERS 'COMPUTERIZED' loudness -volume control must then be relocated to the input of the unit. This modification (Fig. 6) results in an overload of 30 dB above 1 V. STEREO TAPE However, the action of the tone control is not as correct at high volume settings because the Baxandall circuit works best from low -impedance gen- AUTOMATION erators (less than 10 K).

Application of FET's to Other Hifi-Circuits From the previous discussion, it is clear that superior performance is possible in all hi-fi circuits with FET's except where power is required since power-FET's have not become available as yet. The large dynamic range Plus 18 other has been used for superior micro- remarkable phone amplifiers9. The author has also converted various power ampli- features fiers to FET's with the exception of including the output stage itself. In push-pull 68 -watt all cases, superior performance re- sulted10. It was found that a FET solid state phase splitter could drive a pair of electronics EL 34's to 100 watts with ease (distortion out of the phase splitter at and 22,000 cps this level was 0.1 per cent). FET's Cross Field are applicable to all kinds of tape - Head* recorder circuitry with the exception 1. 22,000 cps of the bias oscillator. Also, superior Cross Field AM and FM tuners may be built with (*exclusive Roberts' design which uses separate FET's. Due to the different voltage head for bias, located so requirements, it appears that hybrid bias magnetic field will not affect the signal recorded design with transistors will be unsatis- on the tape, thus permitting factory, while hybrid tube designs are excellent frequency response The extraordinary new Roberts 400X stereo entirely possible. It is the author's at all tape speeds-even down to 33/4 ips). completely "computer- opinion that it will be only a few tape recorder offers you 2. Solid state electronics automated retrieval and playback of years until tubes and regular tran- 3. Automatic reverse play ized" and easy -to - sistors have been completely replaced 4. Automatic repeat play taped program material. Simply set an by FET's in all amplifier applica- 5. Automatic select play operate, built-in "computer" to perform what- tions. The cost of FET's while still 6. Four heads ever basic function you require: (1) Automatic 7. Three motors, synchronous higher than transistors at the mo- capstan drive repeat play, (2) automatic select play, or (3) ment, will drop sharply since there is 8. Push-button solenoid automatic reverse play. Further flexibility is than the new- controls no basic reason other 9. Two VU meters provided by the 400X "computer" to give you a device why cost should not ness of the 10. Two extended range choice of two types of automatic reverse play be on the order of 50c. It should be speakers 11. Three speed operation operation: (A) Pre -timed adjustable index sys- clear to the reader that an exciting (15 ips optional) or (B) precise tape foil sensor method. new era of solid-state design is on the 12. Electrical speed change tem, way, particularly in the hi-fi field. 7E 13. FM multiplex ready Ask your dealer to demonstrate the 400X, but 14. Records sound -on -sound don't expect him to know all the ways you can 15. Records or plays relative to 1 V. rms. sound -with -sound "program" this instrument - the 400X automa- OW. Rheinfelder, "Noise performance of 16. Theatre reverberation tion system is so flexible you'll discover some transistors in audio circuits" Electron- and echo 17. Four digit index counter new automatic operation tricks yourself. $199.95 ics World, Jan. 1965. 18. Adapters available for 7P. Baxandall, "Negative Feedback Tone lore reels Control," Wireless World, Oct. 1952, ABM I pg. 402. sC. G. McProud, Preamp with Presence, AUDIO ENGINEERING, Jan. 1954. the Pro Line 1ROBERTS 9"Professional Microphone Amplifier Division of Rheem Manufacturing Company FETs," Engineering Report 8. (ibid.) 5922 Bowcroft Street, Los Angeles, California 90016 19"Convert Your HiFi to Solid -State the THE WORLD Easy Way with FETs," Engineering RHEEM, AN INTERNATIONAL COMPANY WITH OVER 75 PLANTS AROUND Report 10. (ibid.) Check No. 92 on Reader Service Card. 75- AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com A convenient service to AUDIO readers.

ttppss Order your books leisurely by mail-save time and travel, we pay the postage.

Designing and Building Hi-Fi Furniture Maintaining Hi-Fi Equipment Jeff Markel HI -Fl TROUBLES Joseph Marshall Written by a professional By Herman Burstein hi-fi furniture designer HOW YOU CAN AVOID THEM A valuable reference for HOW YOU CAN anyone whose living who has taught furniture CURE THEM or Just published! At last, a hobby is servicing hl -A design at leading col- MU I leges, book which deals directly equipment. Outlines the this book is an au- with the problems thentic reference of value ;F(li\ 111; you face professional approach for in maintaining your audio servicing all types of hi- to the hi-fi fan and professional system in peak condition. fi components. Covers custom builder. Tells you how to locate trouble -shooting of elec- Covers everything from troubles, what to do about tronic, mechanical and types of woods to furni- them and how to do it-and, problems. 224 ture finishing for the just as important: what NOT pacousticages. mechanically adept; de. to do. Helps you to achieve No Paperback $2.90° sign principles, styles and the best in listening pleas- arrangements for the ure from your equipment. decor minded. 224 pages. No. 120 53.95 No. 79 Paperback $2.90*

The 5th AUDIO Anthology "?ho AUDIO Cyclopedia" 1280 pages The 6th AUDIO Anthology 3400 topics Edited by C. G. McProud, Howard M. Tremaine 1600 illustrations publisher of AUDIO. An an- Edited by thology of the most signifi- C. G. McProud, Here is one single volume cant articles covering: stereo publisher of AUDIO. Includes with the most compre- articles recording and reproduction; on the two most sig- hensive coverage of every nificant milestones stereo multiplex; measure- in the field phase of audio. Concise, of high FM ments; stereo fidelity: STEREO accurate explanations of technology, and TRANSISTORS construction and theory IN AUDIO all audio and hi-fi sub- - EQUIPMENT. A meaningful which appeared In AUDIO jects. More than 7 years reference for everyone in the during 1958 and 1959. The n preparation-the most fields of audio engineering, 5th is truly a collectors' item authoritative encyclope- recording, broadcasting, man- a dic work and valuable reference for ufacturing with a unique the professional engineer, and servicing of quick reference system for components and equipment. teacher, student, hobbyist and instant answers to any A necessary book for the hi-fi fan. 144 pages. question. A vital com- high fidelity enthusiast. 144 plete reference book for No. 125 $3.50 pages. every audio engineer, technician, and serious No. 130 $3.95 audiophile. No.123 $19.95° TROUBLESHOOTING High Fidelity Amplifiers Mannie Horowitz McProud High fidelity Omnibook SOUND in the THEATRE Prepared and edited Harold Burris -Meyer by First book of its kind . . . Written specifically for the C. G. McProud, publisher and nothing like it has ever been serviceman liiUBLf'. and audio hobby- of Audio and noted au- published beforel It is an ist who wants Vincent Mallory .. to get into the thority and pioneer In authoritative text on elec- í' profitable field _Sß00TiNC., of stereo hi-fi the field of high fidelity. tronic sound control for service. 12 fact -filled chap- Contains a wealth of theatres, auditoriums, con- Sigh - ters with a plain and simple ideas, how to's, what cert halls and other large Fidelity r=__ opproach to troubleshooting to's, and when to's, writ- enclosed areas where the all types of stereo and mono ten so plainly that both source and the audience are Amplifiers amplifiers-o direct text on engineer and layman can present together. Contains curing both, vacuum tube appreciate its valuable complete procedures: For and transistorized amplifier context. Covers planning, planning, assembling and 11 ...._.. I ills. Easy to read-includes problems with decoration, testing sound control instal- data on test instruments and cabinets and building hi- lations - Articulating sound procedures. 128 pages. fi furniture. A perfect control with other elements of production Operation No. 128 $2.95 guide. - No.113 $2.509 and maintenance of sound control equipment. Describes and illustrates 32 specific No. 126 SAVE MONTHLY SPECIAL SAVE $6.95 problems. Save over 35% with this collection of AUDIO books 5th AUDIO ANTHOLOGY ($3.50) - 6th AUDIO ANTHOLOGY ($3.95) High Fidelity Simplified McProud HIGH FIDELITY OMNIBOOK ($2.50) Harold D. Weiler TROUBLESHOOTING HIGH FIDELITY AMPLIFIERS ($2.95) Total Value All Four Books $12.90 The complete hi-fi story - ... answers oll questions about YOUR COST ONLY ... $8.95 POSTPAID in U.S.A. & Canada tuners, changers, amplifiers, tope recorders, speakers, CIRCLE 0S500 record plovers, etc. Lots of This Offer good only on direct order to the Publisher Ideas for custom Installa- tions. Tells how to achieve concert hall reception in your home. 216 pages. No. 142 $3.30 AUDIO Bookshelf 'All U.S.A. and Canadian orders shipped postpaid. 134 N. 13th Street, Phila., Pa. 19107

Getting The Most Out Of Your Tope Recorder Please send me the books I have circled below. I am enclosing the Herman Burstein

full remittance of $ (No C.O.D. or billing.) Written la "plain talk" for the man who has, or wishes 58 79 115 120 123 125 to buy, a tape recorder. It answers the myriad ques- TAPE RECORDER tions raised by tope record- 126 128 130 142 251 0S500 ing enthusiasts. Its chapters cover every phase or operation and maintenance-from NAME adding a tape recorder to the hi-fi system, to a thor- ADDRESS ough dissertation on microphones. Lots of practical Information on how to buy. 176 CITY STATE ZIP pages. No. 251 $4.25

76 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com A separate release has informed us early in 1966. The Jerrold Corp. is par- INDUSTRY that FRANK D. JOHNSON has joined Uni- ent company for both the HARMAN- versity as general operations manager. KARDON and JERROLD-TACO product lines. NEWS AND NOTES He comes to the company from a back- ARTHUR D. HALL, formerly with Bell ground rich in production supervision, Telephone Labs, has been appointed to most recently as production manager of the newly created post of vice president the aerospace division of Pacific Scien- and chief engineer of JERROLD ELEC- TANDBERG OF AMERICA'S parent firm tific Co. TRONICS Corp., the largest of the Jerrold in Norway has just completed a new subsidiaries. Mr. Hall will be respon- $2,800,000 plant. The facility will even- Changes at JERROLD. MILTON SHAPP sible for all aspects of engineering cur- tually employ 1000 people. Our release has divested himself of 516,351 shares of rently being carried out by Jerrold Elec- also reports that the actual completion Jerrold stock. (He is the Democratic tronics. This will include product devel- for CATV, educational televi- date was June 1 and that on the same candidate for Pennsylvania's governor- opment day, workmen began moving production ship). ROBERT H. BEISSWENGER has been sion, instrumentation, television recep- equipment into place. elected chief executive officer of the com- tion for home use, master antenna, in- mi- The TELEX CORPORATION of Tulsa, pany. Mr. Beisswenger has been presi- dustrial TV, closer -circuit TV, and Okla., has agreed to acquire the assets dent and chief operation officer since crowave. Æ and assume certain liabilities of VIKING OF MINNEAPOLIS, Inc., and an associated firm, VIKING TOOL AND DIE CO. This becomes all the more interesting when you are reminded that Telex also owns MAGNECORD, also a tape recorder manufacturer. However, we are told that the Viking products will complement the Magnecord line of professional tape recorders. Just what this means in terms What's New of overlapping products is not spelled out at this time. AMPEREX is expanding to meet the in- At Recent Hi-Fi Shows? creased requirements of its West Coast operations. A new office has been opened in Palo Alto, Calif. HANK STEEN- BEKE, recently named Western Regional Sales Manager, will head up the office. Back East now for latest news of AUDIO DYNAMICS CORP. PETER PRITCH- ARD, ADC president said that ground breaking has taken place for a major addition to ADC's New Milford plant. With operations in both Connecticut and Farmingdale, Long Island, this expan- sion will triple the size of the present Connecticut facility. The one-story building will house new ADC research laboratories, as well as manufacturing, sales, administrative, and engineering facilities. ELPA'S news is the formation of two divisions to handle their expanded product lines. The first is to be the Record Product Division headed by CARL CARL - SON, recently arrived at ELPA. STAN GROSSMAN, long with ELPA moves to head up the Tape Products Division. Product breakdown is as follows: Thor - ens, Ortofon, P -E, and Watts come under Carl's wing; Re Vox, Beyer, Editall and Editab belong to Stan. From UNIVERSITY comes word that It's the Sansui Model 3000, ABRAHAM B. COHEN has been promoted to vice president in charge of engineer- AM/FM Solid -State Multiplex Stereo Tuner Amplifier. ing. Mr. Cohen is no newcomer to Uni- True perfection in sound reproduction, which again sub- versity, having joined the firm in 1947. stantiated Sansui's world-wide reputation at the recent His position for the past several years National Hi-Fi Shows in Chicago and New York with the has been engineering manager. He has highest sound quality for its power output (110 watts). been instrumental in developing Univer- Listen to it, and let it prove itself ! sity's product line of public address and commercial sound products. In addition to his normal Oklahoma City -based engineering activities, he will co-ordinate the firm's technical research program LTV's re- with the overall parent -firm. SAN FRANCISCO OFFICE: 4203 Geary Blvd., search efforts in electro -acoustics. Abe San Francisco, Calif. Tel. 387-3300 patents in the elec- DISTRIBUTORS: Cohen holds several ELECTRONIC DISTRIBUTORS (CANADA), tro -acoustics field, he has been a prolific Sansui 949 Granville Vancouver 2, B.C. St., article writer and frequent lecturer. He SANSUI ELECTRIC COMPANY, LIMITED CALIFORNIA: TOKYO ELECTRONICS, Calif. 94115 is the author of the long -standard refer- 14-1, 2-chome, Izumi, Suginami-ku, Tokyo, Japan 2001 Filmore St., At Pine. San Francisco, ence "Hi-Fi Loudspeakers and Enclo- sures." Check No. 93 on Reader Service Card.

AUDIO NOVEMBER, 1966 77

www.americanradiohistory.comAmericanRadioHistory.Com Classified Order Form Classified Looking for hard -to -get equipment? Want Opportunities to sell a component? Looking for a lob in hi-fi? If so, your ad belongs in Audio. Rates are low, leadership is astoundingly FOR NEW AND USED COMPONENTS, high. Use this form to order a resultful HI-FI JOBS ad. AND EXCHANGE RATES: 10 cents per word per insertion OF SERVICES AND SUPPLIES for non-commercial ads; 25 cents per word for commercial ads (we reserve the right to determine this classification). Rates are net. Copy must be accompanied by remittance. Closing date is the 20th of EQUIPMENT WANTED POSITION WANTED the second month preceding the date of issue. WANTED: USED SCULLY LATHE. Age AUDIOPHILE for over ten years would and condition Please check one: not important. Peter J. like work in Audio and Recording field. Helffrich, Help wanted 419 W. 4th St., Bethlehem, Have FCC 1st class license, and Assoc. Pa. Situation wanted 18015. of Science Degree. Box AO -1. For sale D Equipment wanted WANTED: 601 or 602 Ampex Recorder SERVICES Services -full or half track in excellent condi- D Business opportunities tion. Richard Miles, 131 Farrington St., HI-FI SPEAKERS EXPERTLY REPAIRED (Attach a sepa rate sheet for wording for Wollaston, Mass. 02170. USED SPEAKERS BOUGHT your ad. Please type.) AUDIO SPEAKERS TECHNICS 22 Astor Place, New York, N. 10003 WANTED: One Berlant Concertone Y. Name 20/ AL 4-2140 20 Tape Recorder Carrying Case. Please state price and condition. Eugene TAPE DUPLICATING. Low prices. Any Address Weaver, 173 W. 133 St. Apt. 5F., New quantity. G&G Recording Service, York, N. Y. Box City 412, Peekskill, N. Y. 10566. WANTED: Fairchild 412, Electro -Voice HIGH FIDELITY SPEAKERS REPAIRED State lip 18" or 30" Woofer. Donald Bisbee, AMPRITE SPEAKER SERVICE 685 So. Roys Ave., Columbus, Ohio. 168 W. 23rd St., New York, N. Y. 10011 (Mail to: Classified, Audio Magazine, 134 43204. N. 13th St., Philadelphia, Pa. 19107.) CH 3-4812

STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULATION, Act of October 23, 1962; Section 4369, Title 39, United States Code). 1. Date of Filing, Oct. 1, 1966; 2. Title of Publication, AUDIO; 3. Frequency of Issue, Monthly; 4. Location of Known Office of Publication, Zeckendorf and Eastgate Bldgs., Garden City, N.Y. 11532; 5. Location of the Headquarters or General Business Offices of the Publishers, 134 N. 13th Street, Philadelphia, Penna. 19107. 6. Names and Addresses of Publisher, Editor, and Managing Editor: Publisher, C. G. McProud, 134 N. 13th Street, Phila., Penna. 19107; Editor, C. G. McProud, 134 N. 13th Street, Phila., Penna. 19107; Managing Editor, Larry Zide, 134 N. 13th Street, Phila., Penna. 19107. 7. Owner. North American Publishing Company, 134 N. 13th Street, Phila., Penna. 19107. I. J. Borowsky, 134 N. 13th Street, Phila., Pa. 19107. 8. Known Bondholders, Mortgagees, and Other Security Holders Owning or Holding 1 Percent or More of Total Amount of Bonds, Mortgages or Other Securities: None. 9. Paragraphs 7 and 8 include, in cases where the stockholder or security holder appears upon the books of the company as trustee or in any other fiduciary rela- tion, the name of the person or corporation for whom such trustee is acting, also the statements in the two paragraphs show the affiant's full knowledge and belief as to the circumstances and conditions under which stockholders and security holders who do not appear upon the books of the company as trustees, hold stock and securities in a capacity other than that of a bona -fide owner. Names and addresses of individuals who are stockholders of a corporation which itself is a stockholder or holder of bonds, mortgages, or other securities of the publishing corporation have been included in paragraphs 7 and 8 when the interests of such individuals are equivalent to 1 per cent or more of the total amount of the stock Fill in coupon for a FREE One Year Sub- or securities of the publishing corporation. scription to OLSON ELECTRONICS' Fantas- 10. This item must be completed all tic Value Packed Catalog - Unheard of for publications except those which do not LOW, LOW PRICES on Brand Name carry advertising other than the publisher's own and which are named in Sections Speakers, Changers, Tubes, Tools, Stereo 132.231, 132,232, and 132,233, Postal Manual (Sections 4355a, 4355b, and 4356 Amps, Tuners, CB, Hi-Fi's, and thousands of Title of other Electronic Values. Credit plan 39, United States Code). available. Av. no. copies Single issue each issue during pre- nearest to ceding 12 months filing date \. Total no. copies printed (Net Press Run) 40,833 40,000 R. Paid circulation 1. Sales through dealers and carriers, street vendors and counter sales. 8,296 8,913 2 .Mail subscriptions 18,727 19,264 If you hove a friend interested in electronics C. Total paid circulation 27,023 28,177 send his name and address for a FREE sub- D. Free distribution (including samples) by scription also. mail, carrier or other means 841 933 E. Total distribution (Sum of C and D) 27,864 29,110 F. Office use, left -over, unaccounted, spoiled after printing 12,969 10,890 G. Total (Sum of E and F-should equal net press run shown in A). 40,833 40,000 532 S. Forge Street Akron, Ohio 44308 I certify that the statements made by me above are correct and complete. Charles G. McProud, Publisher Check No. 96 on Reader Service Card.

78 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com FOR SALE -6-7.4 (-2Aezezezi iJCiirulfivi WRITE FOR LOW QUOTES, fast service, GGi everything in audio. Special Dynaco kits or custom wired plus walnut cases for complete Dynaco line. Kitcraft. 738A Washington Ave., Brooklyn 11238. THOFENSTURNTABLES REPLACE WORN LP JACKETS White 20c, Blue -Brown -Maroon 25c. NEW THORENS TD-150AB Samples 50c. A superb turntable in the world-famous Thorens Jackets Hillburn P.O. Hillburn, N. Y. quality tradition. Features silent, two -speed operation (331/3 and 45 rpm), plus integrated tone latest safety lowering de- saving stereo arm that incorporates FREE! Send for money vice with pneumatic damping action. Only $99.75 A9M and lowest quotations on catalog OTHER FEATURES INCLUDE: re- your individual component, tape Extra -light, low mass aluminum plug-in shell corder, or system requirements. Elec- with exclusive adjustable vertical tracking an- tronic Values, Inc., 200 West 20th St., gle. Adjusts to optimum playback stylus angle New York, N. Y. 10011. for any cartridge. 12 -inch, 71/2 lb. precision balanced, non-magnetic platter. MARANTZ 10B, Walnut Enclosure $550. 1-JBL D-130 $75. C. E. DiCini, 348 NEW THORENS TD -124 Series II Drive, Alameda, Calif. 94501. Maitland The Finest Transcription Turntable on the market today. TAPE RECORDERS, Hi-Fi components, A brilliant example of craftsmanship acclaimed Sleep Learning Equipment, tapes. Un- throughout the world. Unmatched for mono- or stereo -performance. Has more outstanding fea- usual Values Free Catalog. Dressner, tures, more built-in extras. Illustrated with the IMPORTANT! 15° STYLUS OWNERS! 1523T, Jericho Turnpike, New Hyde Ortofon RMG-212 Tone Arm. Only $125 N. Y. It is an ignored fact, that any record Park, 11040. that stacks changer or automatic turntable A "MUST" FOR RECORD LOVERS records on a turntable, the 15° stylus will 11011 10 have its greatest tracking error when used Want to get more out of your rec- !IF 1441,41,1 EXCELLENT CONDITION BROOK Pre - for single play because of the compromis- ords? Reduce surface noise? Get amp Model 7, Colbert Electronic Xover ing angle of its tone arm. longer record life? Learn profes- U.T.C. Transformers New LS92-LS72- Therefore, for correct tracking and opti- sional secrets of record care? Get mum playback performance, any stylus in- a copy of HOW TO CLEAN, MAIN- LS22. Andrew Beck, 4 Hurley Ave., cluding the 15° stylus should be used TAIN and PROTECT RECORDS by Cecil E. Watts. Only 25c. No. Plainfield, N. J. 07060. with a non -automatic turntable. Available from your hi-fi dealer or order book directly. KLIPSCHORN, Lacquered Walnut ELPA MARKETING INDUSTRIES, INC. Dept. 110A11 New Hyde Park, N. Y. $325.00. Fisher 80C Preamp $40.00. McIntosh MC30 Amp. $85.00. Walnut Available in Canada Cabinet w' turntable & ESL Arm Check No. 94 on Reader Service Card. $75.00. William Wilson, 1911 Marconi Road, Belmar, N. J. 07719.

HARPSICHORD: Same as owned by Philadelphia Orchestra and RCA Victor. In kit form for home workshop assembly, $150. Clavichord kit, $100. Free brochure. Write: Zuckermann Harpsi- chords, Dept. R. 115 Christopher St., New York, N. Y. 10014.

PROTECT YOUR LPs. Heavy poly sleeves for jackets, 5 cents. Round bot- Only from IRISH! tom for records, 3 cents. Minimum 100. May Assort. Poly Co., Hillburn, New York Post Office. FREE30" color coded leader and 30" trailer plus metal revers- MUST SELL: 7T, $250.00. Marantz 3, 5, 53/4 and plus these additional benefits Acoustech X's, $1190.00. Both almost ing strip with every Signature Binding handsome simu- new, perfect. Harman Kardon Citation i" reel. Identify tapes easily. - lated leather with gold writing foil to B, line you $190. Shure 330 mike, trans- Saves wear and tear, Gives index contents. former, $60. Both two years old, prac- extra usable tape footage. Auto- reel of Irish tape is uncondi- tically unused. Harrison Pope, Adams Every tape on tionally guaranteed. G-34, Harvard, Cambridge, Mass. matically reverses equipped machines. Irish - pioneers and still a leader in magnetic tape design and manufac- "CROWN" Professional Recorders: New AND NOW AVAILABLE ture. You can't buy a better quality and Wiegand tape. used. Reasonable prices. Irish Video Tape for home, industry Audio Labs, 221 Carton, Neptune, N. J. Every reel of Irish tape specially 07753. and educational use. treated with Ferro Sheená process for an extremely smooth surface. Mini- Irish lubricated tape for CARtridges mizes tape head wear. DISC RECORDING EQUIPMENT: Cutter - and endless loop applications. heads, Recording Amplifiers, and Lathes. New and used. From Rek-O- Kut to Scully. Send requirements. Wie- IRISH MAGNETIC RECORDING TAPE gand Audio Labs, 221tarton, Neptune, 458 Broadway, New York, N.Y. 10013 N. J. 07753. Export Dept. Morhan Exporting Corp. Check No. 95 on Reader Service Card. AUDIO NOVEMBER. 1966 79

www.americanradiohistory.comAmericanRadioHistory.Com Magnetic Cartridges are now obsolete Record Review (from page 45) Gluck: Orpheus and Eurydice; high- Only the lights. N uphonics Semiconductor Cartridge Streich, Klose, Schlemm; assorted orchs., Artur Rother. Retains intimate groove contact Heliodor HS 25005 stereo' at all audible Prevents chatter. Tracks second harmonic frequencies.* Stylus -groove resonance is pinch effects Nope, I don't much like these 47KHz, with uniform response of all fundamentals from 0-23.5 pot- beyond 50 KHz. Made possible by the low mass of the pourri collections by KHz. No magnetic cartridge approaches this active silicon Heliodor (out of requirement of noise -free, semiconductor element, which D -G), though distortion -free re- is smaller and lighter than the diamond the singers here are good production because of the mass of the iron tip and copper. itself. No magnetic can achieve this low mass. ones, as are the (4) orchestras. The opera is not well represented *The Office of Naval Research, as an entity- under Contract #1866 (24); has these are just the famous excerpts. More- shown that stylus -groove resonance over, they are done in the must be higher than 40KHz-or loss now-outdated of groove contact will result. Restora- Nineteenth-century adaptations of the tion of contact is in the form of music, including (if shock, producing impulse excitation I am right) the of the stylus system, with corre- "extra" music that Richard Wagner, sponding of chatter and noise. all people, wrote to liven up the tired ;Acoustics Research Laboratory, old Harvard University score! That's what he thought, anyhow. Miniconic delivers best bass in the world, because it responds uni- For singers and singer -collectors, may- formly down to DC. be yes. Good examples Miniconic of singing, along is inherently distortion - with the free, because it TK=15-LS Lab Standard Phono System. various familiar orchestral in- is based on the mass arm, TA -15 low - resistive principle. Magnetics are in- with U -15 -LS plug-in cartridge (biradial terludes-Dance of the Blessed Spirits, herently reactive and thus distor- diamond) and PS -15 power source. For magnetic or tion -prone. auxiliary inputs. USER NET of the Furies, etcetc. But in these days 87.50 of Miniconic is basically hum -free, be- TK -15-P Professional Phono System. As above, whole operas on tape and LP there's with U but cause it has 10,000 times the output -15-P cartridge and .5 mil tip conical diamond little excuse for this kind of disjointed of the best magnetics. stylus. USER NET 71.50 Miniconic CK-15-LS montage of bits and pieces, especially is flat to RIAA, whereas Lab Standard Phono Conversion Kit U -15 - in magnetics require up to 38.1 db of LS cartridge (biradial diamond) for standard heads, such out-of-date performance. equalization and PS -15 power to play RIAA. source. For magnetic or auxiliary Note that this is also in Miniconic is a modulator -valve, so inputs. USER NET 55.00 the "wrong" a small power source does the work, CK-15-P Professional Phono language. The first version, at Vienna, not Conversion Kit. As the delicate record groove. Mag- above, but U -15-P cartridge with .5 mil tip conical was an Italian opera; it was netic massive generators must be diamond stylus. USER NET later recast moved by 39.00 into French at Paris. the delicate groove at See your distributor German it never accelerations beyond 1000 G's-to or Write Dept. A-10 was. give a tiny output. uphonlcs MARKETING Write for'The Story of Euphonics Miniconie 173 W. Madison St., Chicago, Ill. 60602 Flute Concertos by Bach & Telemann. C EUPHONICS CORP. 1966 FACTORY: GUAYNABO, PUERTO RICO, U.S.A. Jean-Pierre Rampal; Saar Radio Ch. Orch., Ristenpart. Check No. 97 on Reader Service Card. Epic BC 1321 stereo Very interesting-at last we find old Live Better Electronically With Bach, the famous Bach, and the once - despised Telemann, both on the same LAFAYETTERADIO ELECTRONICS record. Good comparison. Telemann wins hands down here, though it isn't NEW! MODEL LR -1200T SUPER DELUXE 120 -WATT entirely Bach's fault. The two Bach Con- SOLID STATE FM/AM STEREO RECEIVER certos aren't really for flute at all, though they can be played that way. You'll recognize both if you know your Bach. One, BWV 1041 in A minor, is a violin concerto (though it might 25995 have been played on the flute) No and is Money Down also familiar in Bach's transcription for 99.0150WX* harpsichord. The other, maybe a violin concerto in the original (lost), is BWV 1056, a harpsichord concerto in F minor, as it is normally heard. This one just might have been for oboe, originally. Anyhow, in those days they used whatever instrument was handy, and the flute FREE is quite OK-except that on Side 2, Telemann writes so 1967 beautifully and clear- CATALOG NO. 670 ly for the flute's best range and tech- Over 500 Pages nique-just superb! It fairly blossoms under his treatment. Whereas in Everything in Electronics the Bach it labors along, never getting its For Home and Industry from the breath, generally in too low a range. It "World's Hi-Fi & Electronics Center" does the same in Bach's authentic flute works-the B Minor Suite, for instance. LAFAYETTE Radio ELECTRONICS Dept. Al -6, P.O. Box 10 Rampal, one of the great flutists of Syosset, L.I., N.Y. 11791 our day (and especially in Baroque music) is particularly good in the Telemann, Send me the FREE 1967 LAFAYETTE Catalog NEW! RK -815 SOLID 1 670 with its silvery high melodic lines. Ris- AK -6 STATE STEREO Name I tenpart and his orchestra play a vigor- TAPE RECORDER ------1 ous, if bouncy, accompaniment. I Address Note that these artists also appear ------1 on No Money Down low-priced City U.S. labels at less than half 99.1532WX* 129"1 Epic's regular price. The European *Imported State Zip source is identical; there's no really good 1 -mom ma am am ma me me - - m- reason for the differential. Check No. 98 on Reader Service Card. 80 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com CANADA High Fidelity Eaulpment Complete Lines Complete Service Audio ETC. Hi-Fi Records - Components and Accessories (From page 14)

E,LECTROI)O10ESOUND SYSTEMS Compatible Bandwagon? fAIRCNIID A mystery is developing in 126 DUNDAS ST. WEST. TORONTO. CANADA 3. slight my mind in respect to Philips' new com- Check No. 106 on Reader Service Card. patible World Series record, one disc for mono and stereo. The mystery is in the wording of the announcement, which leaves me at this moment completely SAVE MORE baffled. On HI -Fi "The new process rests on the prin- of 'phase control' The ups and COMPONENTS & TAPE RECORDERS ciple ... in both Easy-Pay-Plan-Up to 24 mos. to pay. downs of the musical waveforms 15 day money-back guarantee. stereo channels are electronically kept in 2 yr. unconditional guarantee parts and mutual interfer- labor no charge, at local warranty sta- phase. This prevents tion, factory or our service dept. ence of the two channels when played in Most items shipped promptly from our the stereo $250,000.00 inventory. mono but in no way lessens Trade-Ins-Highest allow-Send your list. effect .. . Shipments double packed & fully insured. (I can only say, in figuratively very Special consideration - Export & APO inqu iries. small type, that I used to think the stereo 21st yr. dependable service-World Wide. phase differences to Write for our price first. You'll be glad effect depended on you did. a very considerable extent (as well as 'We own the snarpest pencils In the U.S.A." on volume differences and differentiation of quality) and that two signals kept in HI -FIDELITY phase with each other tend to a point - 239 U East 149 St., source mono sound. No? Well, maybe -The Mouse ol LOr LO. P.oceti' New York, N.Y. 10451 like Li'l Abner. I'm all I'm confoosed, An electro -mechanical reverberation system set to find out about it-just thought I'd that adds dimension and extra listening level Check No. 102 on Reader Service Card. let you in at the beginning. Maybe I'm misunderstanding Philips' English.) to your sound. I should say that I've always felt we For complete details write: would sooner or later get away from the cumbersome dual -release structure, mono been feeling for a FAIRCHILD and stereo, and I've RECORDING EQUIPMENT CORPORATION soon the long time that maybe pretty 1040 45th Ave.. Long Island City 1. N.Y. price of stereo -compatible pickups-i.e. those which have adequate vertical com- Check No. 100 on Reader Service Card. pliance to ride the stereo grooves, mounted in adequately designed arms- would get down low enough so that even LEVELING the $14.95 phono portable would play any stereo record monophonically with- AMPLIFIERS too. out harm. Maybe the $4.95 phono, ae So even without a compatible process, stereo could win out 100 per cent, soon. Maybe the answer, aside from Philips, INOLJBTFaIES Co F1 F=1,. is a mild compatibility, calculated to FLUSHING, N.Y., 11356 match, say, 90 per cent of existing mono- ou.nt or[ ^^^^^ w,.. e.,. nouera+ Check No. 101 on Reader Service Card. type players at the moment-and grow- ing milder and milder as the players themselves grow more tolerant towards the stereo disc. But, any way you look THE at it, Philips may finally have broken the 2 -disc dam. If others jump on the Typical gain -reduction plot McPROUD band wagon, we'll have a stampede. Or HIGH maybe I mean a flood or something. (I can see that band wagon floating NO LAG FIDELITY along with the stampeded downstream, FLAT RESPONSE OMNIBOOK cows or buffaloes or whatever. Nothing like a mixed metaphor to nail down a REPLACES EXISTING $2.50 point on the nose! An unmixed blessing, LINE AMPLIFIERS definitely. ) North American Publishing Co. Wow-just think. If all the records LOW NOISE LEVEL 134 North Thirteenth Street now on the market in dual form, stereo Philadelphia, Pa. 19107 (real or synthetic) and mono, were to OVER 500 IN USE BY MAJOR NETWORKS releases, we would merge into single INDEPENDENT STATIONS 8, RECORDING Please send me copies have only half as many records to cope of the McProud High Fidelity with! Dealers, please take note. And STUDIOS

Omnibook. I am enclosing $ collectors, too. Our 8th Year Of Service To Industry (All USA and Canadian orders The economics of that possible devel- shipped postpaid.) opment are so prodigious that I'll just -TELETRONIX ENGINEERING CO.-- have to quit right here-my head is manufacturers of FM Broadcast Transmitters and RF Amplifiers Name spinning, my eyes are double-crossed Audio Relays, Solid State Remote Station Controls into reverse stereo, hopelessly incompati- Volume Levelers. FM Broadcast Antennae Calif. Address ble. Seeya next mo. .zfi 308 Monterey Road, South Pasadena, EXPORT: GOTHAM AUD. DEV. CORP. New York, N.Y. 10036 City State 7ip I 2 West 46 Street, Check No. 99 on Reader Service Card. AUDIO NOVEMBER, 1966 81

www.americanradiohistory.comAmericanRadioHistory.Com want quality? Advertising Index

Acoustech, Inc. 67 KLH Res & Dev Co. 43 Acoustic Research, Inc. 32 Koss Electronics 14 co e L_l-V Acoustical Mfg. 4 Alr Co. Allied Radio Corp. 74 SHERWOOD 8800 STEREO RECEIVER Altec Lansing Corp. 5, 7 Lafayette Radio 80 Ampex Corp. 35 J. B. Lansing Co. F,0 trade up to it at Audio Bookshelf 76 Audio Audio Dynamics Corp. 13 Exchange! Audio Exchange 82 3M Company 12 Trade in your old equipment and pay less for this Sherwood or any Magnecord Co. .. Coy lil one of thousands of new components! Choose too from our incom- Marantz Co. 11 parable selection of used equip- BSR 51 Martel ment. Write for free estimate on 63 what your old equipment is worth Benjamin Electronics Corp. 53 McIntosh and FREE Traders Handbook. 82 Beyer 68 Micro Media .. 72

WORSLD' FIRST AND FOREMOST >0.11/STEREO British Industries Corp. 3, 74 TR D IND ORGANIZATION Morhan Sales Co. 79 LoiocHanee 'e Multicore Sales .. 74 MANHATTAN: WILLOUGHSY, 110w, 32ND 51., LO 4.1600 PEERLESS, 43RD ST., LE%. AVE. MU 7.1000 JAMAICA: 153.31 HILLSIDEAVENUE, AT 7.7577 MIOOKLYN: Classified 78 1045 FLATSUSH AVENUE, IN 9-6200 WHITS PLAINS: 239 MAMARONEC% AVENUE, WH 3-3350 ROSLYN: 1040 NORTHERN SLVO., N.Y. SIR- MA 1.9297 STAMM:HIM SUMMER ST., RIDGEWAY SHOP. Olson CENTER Electronics . 78 Address mail to Dept. HF3 RI Jamaica Store. RE Dynaco, Inc. 55 Check No. 104 on Reader Service Card. Pickering & Co. 17

Pioneer Electronic Corp. 73

Eastman Kodak Co. 23

Electro -Voice, Inc. 1, Cov. IV Roberts 5 Elpa Marketing Corp. 68, 79 Robins Ind. Corp. 81 cpEE EMI/Scope 6 STEREO Empire Scientific Corp. 29 INFORMATION Euphonics Corp. 80 Sansui Electric 77 EV Sound Systems 81 H. H. Scott, Inc. Coy. ll

Sherwood Electronic Labs, . FM station directory . . , covers FM Inc 18 stations in U. S. and Canada. Factual Shure Bros. Inc. 24, 25, 57 equipment test reports. Test reports on tuners, preamps, poweramp/ Fairchild Recording Equip. Sonotone Corp. . 71 preamps. Find out what the experts Corp 81 think. A complete 36 page catalog Fisher Radio Corp. 15 Sony Corp. of America ...... 31, 65 tells about tuners, power amplifiers, preamplifiers, preamp/power amp Sony-Superscope, Inc. 37 combinations, and tuner preamp. Stanton Magnetics Corp. , R,R.. , , 47

Garrard Sales Co. 3

ALL FREE - Gotham Audio 61 JUST WRITE Teletronix Engineering Co. 81 TO: Thorens 79 McIntosh Lab.Inc. 6 Chambers St. Binghamton, N. Y. 13903 Harman-Kardon, Inc. 8, 9 NAME Hi -Fidelity Center 81 University Sound 59 STREET

CITY

STATE ZIP_ _ _ _ Irish Tape 79 Viking of Minneapolis, Inc. 27 Check No. 105 on Reader Service Card. 82 AUDIO NOVEMBER, 1966

www.americanradiohistory.comAmericanRadioHistory.Com DON'T MOVE UP TO A MAGNE C ORD.... START WITH ONE!

a Magnecord If you own another brand tape recorder /reproducer now, chances are you'll choose be conside-ing a when you trade up. But if you are buying your first hi-fi equipment, you may less expensive "beginner's model'" until you et the swing of it. less than People who won't compromise on sound soon find they aren't satisfied with anything Magnecord performance. If you're discriminEting enough to want true high fidelity reproduction to own a Magnecord. in your home recording and playbEck equipment, you are demanding enough your Magnecord You'll probably have one eventually ... so why not start with a Magnecord! See dealer or write for a free brochure today.

Telex Divisions Manufac- NEW 8 REELS' agnecord Other ture Telex Headphones and A Magnecord exclusive that e DIVISION OF THE Viking Tape Inst-uments increases playing time 50%. TELEX CORPORATION P. 0. Box 152E / Tulsa, Oklahoma 74101

Check No. 51 on Reader Service Card.

www.americanradiohistory.comAmericanRadioHistory.Com now has a staunch new companion!

Fy In just a few short months the boost when performers work ultra -close. ard mounting Electro -Voice Model stud and on -off switch. 676 has CV -D eliminates this "proximity effect" Either high- or balanced low -impedance gained quite a reputation as a problem so common to other cardioids. output can be selected at the cable of solver-no matter what the odds. Now Wind both microphones. the 676 and shock noise are almost has a teammate. The Model completely 674 has the shut out by the CV -D de- Choose the 676 or 674 in satin chrome same unique backbone that sign. Efficient rejects unwanted sound screening protects against or non-reflecting gray finish for just ...an exclusive damaging dust and magnetic with Continuously M. particles, $100.00. Gold finish can be ordered for Variable -D (CV-D)T. and guards against annoying "pops". microphones from Electro -Voice. And $10.00 more (list prices less normal As the improvement in performance is dra- for overall sound quality, only trade discounts). There is no better way matic. expensive professional models compare to stand up to your toughest sound with the 676 and 674. The exclusive pickup problems. Proof is waiting Troubled at with feedback or interfer- Acoustalloy® diaphragm gets the credit. your nearby E -V sound specialist's,. Or ing noise pickup? Most cardioid micro- It's indestructible-yet low in mass write for free catalog of Electra phones to -Voice cancel best at only one fre- give you smooth, peak -free, wide -range microphones today., quency-but CV -D* insures a useful response with high output. An important footnote: There is no time limit to cardioid pattern over the entire re- our warranty! The Model 676 slips easily into its 1" If an E -V microphone should fail, sponse range. And its small size means just send it to us. If there's even a hint that our work- stand clamp for quick, positive mount- manship or materials weren't the pickup is symmetrical on any axis. up to par, the repair is ing. The fine balance and shorter length no charge - even decades from now! Fair enough? Bothered by rumble, reverberation, of the 676, and absence of an on -off *patent No. 9.115,207 or loss. of presence? A recessed switch switch makes it ideal for hand-held or lets you attenuate bass (by 5 or 10 db suspended applications. at 100 Hz) to stop problems at their The Model 674 offers identical per- source. And there's no unwanted bass formance but is provided with a stand- 514,,Ce'rOICZ SETTING NEW STANDARDS IN SOUND

Check No. 52 on Reader Service Card.