NOVEMBER, 1960 504

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FROM RCA. MII msai ...I A NEW FAMILY OF DIODE-4-1Au0L. 6EQ7- 12EQ7 -20EQ7 specially designed for improved low -cost radios! AM- DETECTOR DIODE AND IF- AMPLIFIER PENTODE IN ONE ENVELOPE Each tube of this remarkable new family of broadcast receiver types represents a new arrangement of a diode and remote -cutoff pentode in a single envelope. One tube can serve as both AM- detector (diode unit) and if-am- plifier (pentode finit) thus replacing a 6BA6 and a semi- conductor diode at well under the cost of the two. In other applications, the pentode unit may be used as an rf amplifier; the diode may be used for ave. APPLICATIONS: RCA -6EQ7 and 12EQ7: in AM tuners of AM FM radios. RCA- 20EQ7: Makes possible a new "All- American Economy Four!" A 100 -ma- heater AC -DC AM receiver using only one 18FX6 converter, one 20EQ7 if- amplifier and detector, one 50FK5 power pentode and one 36AM3 -A rectifier, actually approaches the performance of a 5 -tube set! Improved internal shielding and wide lead spacing provided by the 9 -pin base assure low interelectrode capacitance, minimizing the possibility of instability. Diode plate Top shield Diode plate connector Pentode outer shield Bottom shield ADVANTAGES OF THIS NEW RCA DEVELOPMENT: @ Receiver cost reduction due to this successful combination of a diode and a remote -cutoff pentode. Relatively high transconductance with low values of grid -to- plate capacitance. Low interelectrode capacitance provided by ingenious shielding (see photo) and by 9-pin design. Grid -No. 1 -to- diode -plate capacitance is .0015 µµf maximum. High gain and stable operation with no need for a cathode resistor to provide degeneration. AVC output from the diode may be applied to pentode. @ Special basing arrangement provides separate pin connection for each electrode and for internal shield. Get the full story on this dramatic new development, and how it can benefit your receiver circuits. Check with your RCA field representative, or write to RCA Electron Tube Division, Commercial Engineering, Harrison, N. J. RCA ELECTRON TUBE DIVISION -Designers Entertainment Field Offices EAST: 744 Broad Street, Newark 2, New Jersey, HUmboldt 5-3900 MIDWEST: Suite 1154, Merchandise Mart Plaza, Chicago 54, Illinois, WHitehall 4 -2900 WEST: 6355 E. Washington Blvd., Los Angeles 22, Calif., RAymond 3 -8361

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www.americanradiohistory.com NOVEMBER, 1960 VOL. 44, No. 11

Successor to RADIO, Est. 1917.

AU D Io LNLINLLIiISG MUSIC SOUND REPRODUCTION

C. G. McProud, Editor und Publisher Henry A. Schober, Business Manager David Saslaw, Managing Editor Janet M. Durgin, Production Manager Edgar E. Newman, Circulation Director HERE! NOW! Sanford L. Cahn, Advertising Director FM /MX STEREO West Coast Representative - fames C. Galloway 6535 Wilshire Boulevard, Los Angeles 48, Calif. llidwestern Representative - =Mr= ,p Bill Pattis 4- Associates or-- 6316 N. Lincoln Ave., Chicago 45, Ill. $110.50"

CONTENTS only for those who want the ultimate Audioclinic-Joseph Giovanelli _ 2

Letters .. 6 Light Listening -Chester Santon 8 -- RWOOD -S -3000 III Audio ETC -Edward Tatnall C anby 10 Editor's Review .. 16 FM /MX STEREO TUNER Acoustic Matrixing--1 l ;ì ix l'.,r N,w l u)I peaker Developments- Norman The FM tuner that has everything ... 0.950 H. Crowhurst 19 sensitivity, Interchannel Hush noise muting An Engineer's S Belli -h..1. Greiner system, "Acro -Beam" tuning eye, cascode bal- In Two Parts -Part One 22 anced input, automatic frequency control. Level Test Tapes Aid Program Reproduction -Jay C. Abbott 28 "local- distant" switch ... now brings you Tape Guide -Stereo Considerations -Herman Burstein 32 the only Be Professional-Rack Mount-William G. Dilley 42 FM TUNER with "CORRECTIVE" Space Diversity Techniques Improve FM Reception-Daniel Von INVERSE FEEDBACK Recklinghausen and Martin L. Borish 48 Every high fidelity amplifier today incorpor- The Series -Parallel Speaker Array- Charles Mahler, Jr. 54 ates "corrective" inverse feedback for lower Equipment Profile -Tandberg Model 6 tape recorder -Shure M23.2 and distortion and improved response. Now, Sher- M236 professional tone arms- Garrard SPG3 stylus force gauge 58 wood brings the same performance benefits Record Revue -Edward Tatnall Canby 64 to the S -3000 Ill FM Tuner; these include and All That -Charles A. Robertson 'TO reduction of distortion due to overmodulation About Music- Harold Lawrence 82 by the FM station and better quality long - New Products 81 distance reception. New Literature 86 READY FOR FM STEREO.

Industry Notes and People 101 Stereo via FM multiplex broadcasting is just Advertising Index 102 around the corner. The S -3000 Ill contains COVER PHOTO- Arranged in the Chauncey, New York, home of NBC Special chassis space and all control facilities to plug Projects Director Robert K. Sharpe prior to being connected into a stereo system in a stereo multiplex adapter. Other features are the following items : Garrard 301 turntable, Shure M -216 Studio Dynetie arm include flywheel tuning. plus 7' expanded and pickup, Karg Futura FM tuner, McIntosh C -20 stereo preamp and MC -240 slide rule tuning scale, cathode -follower out- stereo amplifier, and two Electro -Voice Royal 400 speaker systems. Photograph put, and front panel output level control. by Mort Weldon. Sherwood Electronic Laboratories, Inc., 4300 N. California Ave., Chicago 18. Ill. AUDIO (title registered U.B. Pat. 02.) is published monthly by Radio Magazines, Inc., Henry A. Schober, President; C. G. McProud, Secretary. ExecuUre and Editorial Offices, 204 Front St.. Mineola. N. Y. Subscription rates - U. 8. Possessions, Canada, and Mexico, $4.00 for one year, $7.00 for two years. all other countries, $5.00 per year. Single copies 50t. Printed In U.S.A. at 10 McGovern Ave., Lancaster, Pa. All rights reserved. Entire contents copyrighted 1960 by Radio ( *) Other fine Sherwood Tuners: Magazines, Inc. Second Class postage paid at Lancaster, Pa. S- 200011 AM -FM Tuner $145.50 S -2200 AM -FM MX Stereo Tuner $179.50 RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y. Postmaster: Send Form 3579 to AUDIO, P. O. Box 629, Mineola, N. Y. fUN CUMCLEIL IECHNICAL DLIAILS WRITE DEPT. A -11. AUDIO NOVEMBER, 1960 1

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GIVES YOU JOSEPH GIOVANELLI REAL Measurement of Feedback 3. At this point, it may be possible to increase the amount of feedback and still Q. How does one measure the amount of be 6 db below the point of instability. feedback that an amplifier possesses? S. 4. Then further experimentation with the SATISFACTION Mogieleff, New York, New York. feedback capacitor is possible. A. It is very easy to find out how much feedback you are using. All you need to do Drift in FM Tuners is to connect an a.c. voltmeter out- to the Q. After purchase of my tuner I noted put of the amplifier and connect an oscil- that there was considerable drift for the lator to the input. The amplifier's output first 30 to 45 minutes of operation. Does should be loaded with a resistor whose this suggest that this tuner has defective value is equal to the impedance of the out- circuitry? If so, which circuit would most put transformer tap to which it is con- likely be involved? What suggestions can nected. Proceed as follows: you offer to ascertain the cause of such NEAT 1. Disconnect the feedback circuit at the drift is a new tuner that should have no Professional 4 speed turntable with hysteresis synchronous motor output transformer. drift according to the advertisements re- 2. Temporarily return this feedback cir- lating to it? What steps are necessary to cuit to ground. improve the situation? 3. Set the oscillator to 1000 cps and was led to believe that with this tuner gradually into I feed the tone the ampli- there would be no even from a cold fier until the mater reads full scale. In drift start. The tuner has operated perfectly in P -68 so doing, be sure that the amplifier is not producing more power under these con- all other respects. ditions than can safely be handled by I know that I should have notified the the tubes, output transformer, and ex- manufacturer of this defect during the ternal load resistor. warranty period, but I failed to do this 4. Without changing any knob setting, and it is too late now. Edgar E. Hamer, introduce feedback and read the voltage M.D., Downey, California. indicated on the a.c. meter. A. The drift of which you wrote is The ratio of the voltage obtained with- caused by improper temperature compensa- out feedback to that of the voltage with tion-at least that is the most likely pos- Specifications : feedback can be expressed in db when you sibility. When a tuner warms up, the grad- remember that db equals 20 times the log ual buildup of heat causes expansion of the Motor : of that ratio. Of course, if your a.c. meter elements of the oscillator tuned circuit. is 4 pole capacitor-start hysteresis has a db scale, all you need to do to This leads, in turn, to a change in circuit read that ratio directly in db. capacitance. The amount of this change synchronous motor. If you wish to know whether the feed- will determine the drift of the particular back is uniform at all frequencies, you may To of the tubes Turntable : circuit. add to this, heating apply the above procedure to any fre- (particularly the oscillator tube) will cause 12" diameter aluminum diecast- quency desired and note the different ratios. a change in interelectrode capacitance. ing. Even though this information is interest- This capacitance forms a part of the tuned ing to know, it is not important in evaluat- circuit of the oscillator and, therefore, is Speed : ing the overall performance of the ampli- contributory to the drift. 16-3, 33 -¡, 45, 78 r.p.m. fier. What's really important is that the To offset these effects, we usually add a amplifier should have a wide and flat f re- temperature -compensating capacitor either Power consumption : 15 watts. oueucy response, should be free from ring- across the oscillator section of the variable Recommended stylus force: ing, and should exhibit low distortion capacitor or as the grid leak capacitor, or What you must do to obtain maximum both. The capacitor placed across the vari- 15 gr. maximum feedback without amplifier instability is able capacitor should have a value of 1 or 2 to proceed as follows: mmf and should be negatively or positively S/N : 45 db minimum compensated according to the direction of 1. Adjust the value of the feedback re- flutter : Wow and sistor to produce feedback which is 6 db the drift. 0.25% maximum below the point at which the amplifier If the oscillator frequency increases with oscillates. temperature increase, it is an indication Frequency : 50 c /s. -60 c /s. 2. Then choose a value of capacitance that the overall circuit capacitance de- large enough to eliminate high fre- in To volts. creases with an increase temperature. Voltage : 90-117 quency ringing, but small enough to compensate for this a capacitor must be leave the upper frequency response un- added whose value increases with increas- as NEAT ONKYO DENKI CO., LTD. restricted to as great a degree possible. ing temperature. A capacitor designed for No. 4.1 chome, kanda Hatago-cho, Chiyoda -ku, -Tokyo, Japan 3420 Newkirk Ave., Brooklyn S, N. Y. this purpose is said to have a positive tem-

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During this past season Wharfedale, the name most highly regarded ing triumph of the W60, 74% of the new owners who returned the by music lovers and technicians in the field of high fidelity speakers, cards which register the Wharfedale guarantee, said that they had introduced the Wharfedale 60. purchased their W60 upon the enthusiastic recommendation of a The Wharfedale 60 was the first shelf -sized speaker to employ the friend who had experience and knowledge of fine audio equipment. exclusive sand -filled principle which achieves rich, non- strident high Now, in addition to the W60, Wharfedale brings you two other notes and glowing bass without electronic, mechanical or acoustical achromatic speaker systems, the WSO and the W70. tone coloration or false resonance. In every one of the achromatic systems, the speakers and the The Wharfedale 60 was the first compact speaker system truly to superb, handsome cabinet perform truly as a single unit. The repro- meet the uncompromising standard of high fidelity performance which duction is a perfect image of the music as it was recorded ... and, identifies all Wharfedale speakers. certainly as you wish to hear it. The W60, unmatched in its field for quality of sound, has won Today, with the advent of the new Wharfedale Achromatic Speaker amazing acceptance almost overnight. This success, in great measure, Systems, we have taken a giant step toward the goal of the perfect has been spurred by the unprecedented endorsement of qualified high reproduction of the sound of music. fidelity dealers, everywhere. May we suggest that you ask your dealer to demonstrate their But, above all, this adds to our pride and pleasure ... in the sweep- remarkable qualities.

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www.americanradiohistory.com perature coefficient. Conversely, if the oscil- lator drifts downward with increasing tem- perature, it indicates that the overall cir- cuit capacitance increases as temperature increases. This effect can be offset by the incorporation of a capacitor whose value decreases as temperature increases. Such a capacitor is said to have a negative tem- perature coefficient. These temperature -compensating capaci- tors are available in a variety of different capacitance values and in various degrees of compensation. To illustrate, a 1 -mmf capacitor would be designed to drift 0.001 mmf per degree centigrade; another might be designed to drift 0.0004 mmf per degree centigrade. The reference temperature is 20 i degrees centigrade. It is unlikely that this manufacturer failed to take this drift into account when designing your tuner. Probably one of the temperature -compensating devices in your tuner is defective. Curing the difficulty consists of trying capacitors having various amounts of com- Time to pensation until you hit upon the one which clean up stabilizes your tuner. Realignment of the oscillator will probably be needed with the your }srn...te introduction of each new capacitor. This, however, is not the only source of drift in an FM tuner. It is possible that the emission of the oscillator tube is falling off-changing as the tuner is warming up. ore%ö This will cause a change in the effective T -7 interelectrode capacitance and hence lead to drift. The cure for this is to replace the with voice -coil magnets of Ticonal-VII alloy (30% more efficient oscillator tube. than Alnico -V) Another possible source of drift stems GUILD -CRAFTED from a weak rectifier tube. Changes in plate BY voltage applied to the oscillator will cause PHILIPS OF THE drift. Bear in mind that any thing done to NETHERLANDS an oscillator circuit will alter the frequency to some extent. TO GIVE YOU 30% more efficient response to the full signal Noisy Power Transformers range of your amplifier ...whether its rated output is ten watts or a hundred ...at any Q. The power transformer on my power listening level from a whisper to a shout! amplifier produces a loud and annoying buzzing sound that I assume is due to a TO GIVE YOU loose lamination or winding. I cannot de- the audio realism you originally tect any vibration of the laminations by expected from your system! touching the outside of the transformer. TO GIVE YOU My attempts to tighten the lamination and mounting nuts have had no effect on the THE CLEANEST sound. I have never taken a power transformer SOUND apart and I wonder if by so doing I can locate the source of the trouble without AROUND ruining the transformer. This transformer has been in this condition since I bought my amplifier. H. H. Rosen, Montreal, Canada. A. Some transformers are extremely noisy when they are mounted on a steel chassis because of their high magnetic fields. These fields induce voltages into the chassis which cause an attraction and re- Ask for a pulsion between the transformer and the demonstration chassis. This condition can be cured by wherever mounting the transformer on spacers to good sound is sold, raise the transformer above the chassis, or write to: thereby cutting down on the attractive NORTH force between the two. AMERICAN Sometimes transformers are loose be- PHILIPS cause the core is not solidly held inside the CO., INC. coil. Frequently this condition can be cured High Fidelity by removing the outer shell and inserting Products Division fine wedges between the core material and 230 Duffy Avenue, Hicksville, L.I., N.Y. (Continued on page 100)

4 AUDIO NOVEMBER, 1960

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AUDIO NOVEMBER, 1960 5

www.americanradiohistory.com YOUR NEEDLE LETTERS

IS DESTROYING Silicon Diodes speaker; on the contrary, what we need iSIR: are records with more separa- tion. How often does it In his letter of comment on my Silicon happed that the speakers are placed 20 feet YOUR LP'S Diode article, Mr. apart and the Bruce R. Kaufman listening point is ten feet away from the brings out an interesting point. speakers, (if it isn't a Fidelitone Pyramid Diamond ) That will be almost the only The idea of matching rectifier diodes case where the third speaker will be neces- Ordinary ball point needles contact record micro - for use in series strings was considered, sary. This condition is very rare indeed. grooves at only two microscopic points. This but omitted from All the package causes a tremendous the article for prac- that I have concentrated pressure that heard with a third accelerates record wear, and ticable reasons. Today the manufacturers speaker have no stereo- reduces the life of phonic effect. What quality reproduction. of silicon diodes rate their products most little separation and spread of sound that they have had has Fidelitone's new Pyramid conservatively, and I feel the 1NT2071 Diamond, shaped like that been killed by the third speaker. the original recording stylus, is allows more sur- an outstanding example. I have yet DAVID FONSECA, face contact between needle and record. This to find one of these that will distributes not handle High Fidelity Advisory Service the tone arm weight over a larger a 600 -volt P.I.V. surface area, and lowers unit area pressure. Your In fact, In was recently 555 Notre Dame Ave., LP records will last many times longer. informed of a case where a series pair Chattanooga 11, Tenn. HERE'S WHY... handled an 1800 -volt P.I.V. for a couple Distant FM Reception of hours before one of the units failed. Six: Perhaps a matched pair would have gone In AUDIOCLINIC for January, 1960, under on much longer before both failed. the label "Pulling in the Weak Ones," John I still hold that the P.I.V. ratings of J. Haner of Galesburg, Illinois, brought multiple -unit strings are additive, but I up a very familiar problem. His problem was Riscording Stylus Ordinary N.,dl. Pyramid Diamond must agree that conservative operation that in trying to receive WFMT (Chi- cago), 98.7 mc, and about 150 miles Fidelitone's new Pyramid Diamond is shaped with an ample safety margin makes good to the east- northeast, he was similar to the stylus that recorded the original sense. It would seem to me that the in- interfered with by WHBF -FM (Rock Island), 98.9 mc, sound. It perfectly follows every tegrity of the manufacturer is important, contour created by the 40 miles north. During the last wl-.. recording although a 100 per year, I was stylus. cent guarantee would chief engineer at \\'RSB, a closed- circuit not make sense. Given a proper /"-1 In an unmodulated, design AM station at Shinier College in Mount or low fre- that includes a margin quency groove, the recording stylus for safety, diodes Carroll, Illinois. We received permission (A) cuts a groove (W -1) wide purchased "across the counter" should to rebroadcast \VFMT. Since our location enough to let an ordinary ball display an extremely high survival rate is similar to that of dr. Haner, (WFMT 46- point needle (C) and the Fidelitone without the need for selection. is 130 miles east and WHBF -FM is 50 Pyramid Diamond (B) track the miles B; L. B. DALZELL, southwest) we also had interference centerline of the groove accurate. from WHBF -FM. We solved the problem ly, and contact 1162 Fleetridge all recorded sound Drive, quite simply, with no special equipment. impressions. San Diego 6, Calif. We used a Sherwood tuner, a Taco 12- /A, As the groove is modulated by element Cabinet Credit broadband FM Yagi about 50 high tones, the groove width feet high and standard 300 -ohm twin lead. (W.2) cut by the recording stylus SIR: We get interference -free reception about (A -1) narrows. This causes Our cabinet appeared on your July cover 95 per cent of the time; the only time we the ordinary ball needle (C -1) and also was used as an illustration to rise and "pinch for get interference is when WFMT fades out" of an article by C. F. the record groove. Barton in August. out completely. Our Physics instructor It We are glad bridges modulation crests, to see you thought enough got the same results with the same equip- of our work mistracks centerline and to use the pictures in each ment and his antenna is about 20 feet case; we distorts sound impressions. would have been much happier lower. One of the other students who lives if we had The Pyramid Diamond (B -1), been given credit for the cabi- in Sterling, Illinois, (in about a straight because netry. of its new shape, stays line between Chicago and Rock solidly in the record groove, FRANK Island, RLSKAY, JR., President, though a little closer to Chicago) used two smoothly glides along the center- The Rus Lang Corporation, line positively six- element Yagis stacked, at about the driven by the 123 Hurd Avenue, 127 groove walls. Old Dyke Road, same height as our single 12- element Yagi Bridgeport, Conn. Trumbull, Conn. with substantially poorer results. (So would we. En.) MICHAEL T. VAUGHAN, Third Speaker 3443 Stettinius Ave., Cincinnati 8, Ohio. SIR: Tape Demonstration BALL POINT DIAMOND PYRAMID DIAMOND I have been reading Mr. Canby's articles on the third speaker, and in spite of his SIR: And the new shape of the Pyramid Diamond good intentions I have solved the allows to help people he has problem encountered more surface contact between needle and caused more confusion by J. Emmett Cade in his tape purchases, record, substantially reducing than we already contact pressure. have. To make matters worse, namely the reluctance of sales This greatly increases needle and record life. the amplifier personnel manufacturers have introduced as a sales to demonstrate stereo tapes. See your record dealer or hi -fi specialist today. gimmick that "connection My customers are welcome and en- Demand for a third the Fidelitone Pyramid Point. You owe speaker." And if we further add to couraged to audition stereo tapes it to your records and your this prior to listening pleasure. the innumerable ways that have appeared purchase. For the complete story on the revolutionary new in magazines of how to connect the third As soon as they leave the store I quickly Pyramid Diamond, or the name of your nearest speaker, the confusion becomes worse yet. rewrap the tapes they did not purchase dealer, in write Fidelitone, Chicago 26, Illinois. People are going around in circles asking Saran Wrap. This way, everyone purchases if they need the third speaker and how to "factory sealed tapes." connect it. The whole thing is preposterous WM. DRAWER, JR., and ridiculous. RECORDING, by Draeger, Fidelitone Of all the people who have stereo equip- 2712 16th St., "Newest shape on records" ment, 99 per cent do not heed a third Racine, Wisconsin

6 AUDIO NOVEMBER, 1960

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AUDIO NOVEMBER, 1960 7

www.americanradiohistory.com the disposal of Fennell's orchestra far more ebullient sound than Anderson has received from Decca on his disc recordings. With the appearance of this tape, the composer finally gets the break he has needed to put him out front on every count. The orchestra heard 1 here is considerably smaller than Fiedler's Boston Pops. The engineers work in close for maximum detail. (Note the "boinngg" of the snapped spring at the end of Syncopated ,fig HT Clock.) There is no contest between disc and r tape in this instance. If you like Anderson's - music, don't settle for less than this reel.

The Best of (Peter) Sellers iJENin9 Angel S 35884 Wackiness has had its share of supporters throughout the English -speaking world even CHESTER SANTON° before the word came into general use. The most recent explosion of same in the enter- tainment sponse, world has occurred in British comedy then the better of these Command films. It centers on a one -man acting academy The symbol tapes rates a score that averages out in the named Peter Sellers. Not Q indicates the United neighborhood of 90. too long ago, movie- Stereo Tapes 4 -track 71/2 ips tape goers in this country could take their choice number. When Mr. among five Sellers pictures playing here simul- Santon has lis- Stanley Black: All Time taneously. His tened to the tape Top Tangos and talent in mimicry is more than only, the tape Music of Lecuona sufficient to put him in a class with the old number is listed first. Otherwise, the master, London Alec Guineas. Although a good deal of corresponding tape number is fur- Q LPK 70035 the material on this record is primarily aimed nished by United Stereo Tapes. It's still surprising how sparsely settled are at the listener in the mother country, all of it some of the outlying areas in the catalog of will be seized by confirmed Sellers fans over four -track open-reel tapes. This is only the here. The several spoofs of "rock -n- roll" are the second commendable album of tangos to make most accessible items on the record. Lavish use of splicing enables Enoch Light: Provocative Percussion Vol. 2 its appearance on tape. Up till now, Audio Sellers to play a variety of Fidelity has had field roles in the sanie sketch. This, incidentally. is Command RS4T the pretty much to it- Q 810 self with a reel of tangos played by Pedro one of the rare humor records that requires Terry Snyder: Persuasive Percussion Vol. 2 Garcia. That album should have little diffi- stereo for optimum effect. At one occasion, Sel- Command Q RS4T 808 culty in continuing to hold top place with lers is heard at three distinct locations in the tango fanciers who insist on an authentic studio as he impersonates an old -maidenly One year has elapsed since a brand new South American atmosphere and an excep- press interviewer, a somewhat shady Major label came on the scene with an idea that is tional degree of crispness both in performance who operates a school for would -be rock-n- still having repercussions in the pop record and quality of rollers and finally one of the Major's less-than- field. sound. Stanley Black, in this Late in 1959, Command Records initiated newer tape, offers a good sampling of some of poised pupils. Other good items include a won- a series of percussion recordings on stereo the very derfully befuddled political speech and a truly disc best -known tangos La Cumpar- that added entertainment to what, up to Rita, Adios Muchachos, El Choclo, etc. These deadly take -off on a British radio program that time, had been the rather bleak chore of are titles that have always been in heaviest offering a round -table discussion by critics of channel balancing. The idea itself was not a demand. Black has the experience to maintain art, films, and hooks. The meticulous work of completely new one. Other nontechnical +de- an international flavor in his fairly straight- the staff engaged by Sellers shows up neatly in vices had been tried in stereo test and demo forward the job they do in a movie travelogue. The se- records arrangements. (Luckily, it's almost in an effort to help the listener attain impossible to fool around with the tempo of a lection of background music and its editing balance in response but this one really caught tango.) The other half of the reel contains ten reveal as many virtuoso touches as Seller's on. Quite a number of people in the record Ernesto Lecuona selections that include just dead -pan delivery of the script. Highly recom- industry (outdistanced competitors in particu- mended lar) about everything popular he ever wrote. These as a change of pace from our native have since been trying to duplicate the form the equivalent of a second complete al- nightclub- oriented comedians. Command formula. bum and may well be a deciding factor when The formula, as practiced in this reel, calls a tape fan finds himself at a dealer's counter for instantaneous switching of an instrument weighing in each hand tape's current Stereo Dialogue For Brass or group of instruments tango from channel to chan- repertory. Columbia CS 8290 nel under conditions of rigid control-acousti- cal as well as electronic. A stereo brass choir receives the Usually heard at the Parade Field in Stereophonic Sound key assign- beginning of a selection, this is an unadorned ment in this novelty record. Columbia has gone series of mollo sequences. The sane device ABC -Paramount Q ATC 806 to the trouble of evolving an idea that forms a when used later in the middle of a stereo plausible excuse for the severe separation de- interlude This is an ambitious project that attempts manded loses some of its stark characteristic to recreate the atmosphere these days by the novelty -minded cus- because the ear is slow of an army parade tomer. Twelve tunes by Rodgers, Berlin, Por- to relinquish its mem- ground as it may have sounded back in the ory of the stereo Illusion preceding it. I was year ter, Loesser, Loewe and others, usually heard not surprised to discover 1776 and as we know it in the present. as male -female duets, were selected for that the stereo seg- Although the reel boasts some interesting per- ments have better center fill than they do on formance by a bunch of in the right disc. Tape, touches provided by a drill team from First channel and a group In this instance, undoubtedly has Army Headquarters, Governor's of in the left another and more important advantage. Island, N. Y. channel. The Lew Davies' arrangements call It and the quaintness of 18th Century fife and for extensive should be easier to preserve the accuracy of drum music is use of mutes and cups by the the channel balance cleverly suggested. the overall brasses in simulating the dialogue. To main- in the production run of effect of the tape is diminished by a recording stereo tape than it was in the days when most tain an impartial element in the rhythm, each studio that sounds cramped by today's stand- channel has of the stereo demo discs were put on the ards. I could its own guitar. Vibes, xylophone market. Both of these be sensitive on this score after and bass share the center area. Drums and per- reels exhibit fine bal- spending some time this month with the out- ance on a system capable of delivering two standing cussion, for a change, have been relegated to equal sound sound of the Command tapes. This the background. channels. Given normal mainte- recording simply isn't in the same league with nance of the tape playback mechanism, there is every reason the best stuff being produced today. The rifle to expect that the tape version drill provides a good Finian's Rainbow: will hold this balance for expanse of unbroken Original Cast of 1960 a long tine. sound but the bugle calls and drum rolls would Broadway Production The Enoch Light reel is very impressive on have been a large just as effective in mono. It's the system with the Terry Snyder album old story -individual mikes feeding individual RCA Victor LSO 1057 just a shade behind. Light uses a more varied channels that do not assortment of always add up to a Finian is back on records with a new set of instruments-pitting bongos cohesive pattern of sound capable of trans- colors in his rainbow. Most, against piccolo in one of many studies in con- if not all, of the porting the listener to the scene of the event. credit for whatever interest this new trast while Snyder relies on grouping of three The album or four drummers. longer I lisen to stereo, the fussier I be- will arouse goes to the added presence of come when recreating a scene outside the con- stereo in a 1960 revival of a favorite United Stereo Tapes has put forth its finest cert hall. of the effort to date in the 1947 Broadway season. The original cast re- duplication of these Com- cording of the earlier production mand tapes. On the majority of systems, these (Columbia four-track reels should Leroy Anderson Conducts His Music OL 4062) is still available in mono and will deliver signal -to-noise probably remain the choice ratio almost equal to that of a good two-track Decca Q ST7 8954 of all serious fans of our musical theatre. The first cast of a job. One of my favorite two-track percussion Tape fantasy tapes is Tito Puente's "Top Percussion" can be quite a help when a composer as beguiling as Finian's Rainbow is on takes charge of his own music. bound to sound the only right one for RCA. reel APS 120. If we give the reference Although Ar- the score. Puente reel thur Fiedler and Frederick Fennell have had Since this holds true in the theatre, no one a score of 100 in signal -to-noise, their share of fun with will be surprised to freedom from distortion, and frequency most of the Anderson encounter the same situa- re- light classics featured in this recording, I've tion on records. Listeners who don't have fixed always entertained slight ideas on the sound of 12 Forest Are., Hastings -on- Hudson, a preference for the songs by Irish lepre- N.Y.N. composer's approach. I wouldn't attempt to chauns will take easily to this stereo produc- dispute the fact that Mercury has placed at (Continued on page 94)

8 AUDIO NOVEMBER, 1960

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AUDIO NOVEMBER, 1960 9

www.americanradiohistory.com of seniority here. But I must report that I'm running into mild FM tuning trouble already, undiagnosed but familiar. The tuning knob is rubbery; tune one direction and you get a station, tune the other way and it isn't there. The rubbery effect, I fear, is on the increase, but it may be a minor and correctible fault. (I'm out of an assistant, again. Will have to wait to check -but so would you, if you had run r into this trouble as an "Average home Buyer. ") In the country, my old Admiral gets the UDIO; expected heady jumble of a million- and -one AM signals, overlapping and static- ridden. What else, when you are in the crowded Edward ratnall Canby East but nowhere near a strong outlet? In the same spot, my Graneo got just one 1. THE IN- BETWEEN AREA versus wholes, and, especially, sales and FM station, a local outlet in a small town distribution. The item which follows below, a ways off. What more could you expect, The toughest sort of evaluation any of the Pilot PSV-3 speaker, falls into a simi- with no station nearer than around forty us must make, in this day of all -out super- lar category and is similarly interesting, miles? At least there was no static. latives and dangling comparatives, is that at a somewhat higher price level. My Admiral is reasonably definite as to which passes some sort of judgment on the I took a look at the little Graneo where on the dial a given strong AM sta- in- between equipment tuner which -to use two because it sells for slightly under $20. tion is best tuned in- sideband highs in- negative -type phrases -is built to a price, Crazy! Impossible! Nobody can sell a cluded, i.e., there's one peak tuning spot. designed for a market. When everything workable tuner these days for that price, My Graneo wasn't so sure. It acted, indeed, is better than ever, when nothing less than I thought to myself. If they do-and like the earliest and pioneer low -cost FM the finest is ever admitted in print, how are Graneo does -then what is it like? tuner, the original Pilotuner of 1946 or so, you going to talk about something that's How far could such a gadget go towards tuning a succession of "humps" with no good but maybe not beat good in its own meeting hi -fl minimum standards, since it very clear indication (to the average and terms? is physically an actual component in its uninformed user) as to which "hump" Ah for the days when verbal padding own right? It must, of course, play "into" would be best. This was, I gather, an effect was merely nominal! I remember with nos- something, an amplifier- speaker system; associated with the ratio detector circuit when it talgia there was a "standard" Chev- could be a genuine hi -fi component rig. used in the old Pilotuner. Maybe it's the rolet and a "standard" Ford, actually so But then again, it could also play nicely same here -I am not investigating at the designated, that were indeed nothing worse into a table model AM radio, or a portable moment. than a slightly substandard, stripped-down phono. How would it perform in this case, I tried a couple of diabolical tricks, on and using last year's body shell. The actual i.e., in comparison to mass- produced FM the other side of the fence, to put all this standard models, in those days, were equipment as built into standard small further into hi -fl perspective, too. At $20 merely called de luxe, a very mild sort of radios? Two standards of comparison, you or so this tuner clearly isn't intended to exaggeration compared to ours. see, and they were miles apart. match up with a couple of hundred dollars' So great is our current linguistic rate I am always aware, in the back of my worth of component equipment (here we of inflation that the only kind of stabili- mind, of the violently different standards go, calling spades spades). And so, patch, zation possible, in describing either top or of acceptably "good" performance that I tried it immediately. Well, given a good bottom value categories, is strictly dy- exist from one household to another in our FM signal, as in the city, the Graneo tuner namic; you must upgrade the entire set -up big country. I can go along with the differ- produces a fairly good sound via my sys- each year by at least one category. Thus ences myself, often enough. I understand tem, entirely listenable though noticeably awhile back Ford introduced a fancy model the good points of much mere appliance - less perfect than the sound of the same FM in the top bracket called Fairlane. Couple style home sound equipment. I can enjoy stations via, say, a $150 tuner. I'm not of model -years later, Fairlane had slipped Beethoven on a transistor pocket radio, analyzing, but remember that the basic down and there was something new on top and so can any musician. It all depends. FM advantage of low static and a steady -Fairlane 500. That held for a while, then For instance, my standard home AM interference -free signal applies here and everything slipped again and we had Fair - radio, that sits in the kitchen or on the is still a virtue, even at $20. The sound as lane 500 Galaxie on top, the others demoted breakfast table, is a truly superb plastic I heard it was perhaps a bit distorted but downwards, as befits their dynamic decline. job built by Admiral well before the war not unpleasantly so; it seemed, rather, to Pretty soon, if it doesn't just disappear, and bought new at that time by some vague lack response at the outer ends and it was the Ford Fairlane will hit the economy member of my family. We've sort of passed a bit wavy in the linearity -there was a bottom of the line (It has already, in the it around ever since and its early history is slightly hollow sound, as of a cavity reso- 1961 line. En.) lost in time's distant mists. It may have nance (but, I suppose, in electronic terms). Now, my friends, we have a four- cylin- been repaired in the past, but not since Not bad at all -and of course a far better der 1961 Pontiac, actually advertised as I've been using it, which is maybe ten sound than emerges from my faithful AM shorter and narrower than the wider -track, years. It has no AVC and when center -tuned set, out of its own little speaker and am- longer -look triumphs recent of eight- cylin- on any station it produces no highs (off - plifier. der progress! One cylinder does the work tuning brings out a bit of crispness along One more trick, that didn't work, I have of two -and we're right back to 1924 or with the static). But, long ago, my brother my well -tried FM /Q antenna on my roof so when, if I'm right, Buick still built a had a phono input installed, a plug with a in the country, now complete with a blind four -cylinder Buick, a highly desirable switch. I could (but didn't) just plug my rotator. (The meter went on the blink in economy model with prestige and quality little Graneo into that socket, and I'd have a thunderstorm and I rotate by guess -and- to go with it. What is going on1 FM -AM by Admiral -Granco. Could Granco deduce now. It works OK.) How about at- And so, on to hi fi and my problem, stand up to Admiral? taching Granco's other end to this fine bit which is to say useful things about a small Well, yes as to performance. Admiral's of hi -fi equipment? But I needed a dipole group of products that are neither the best AM set picks up all the connection and the tuner had only one an- nor intended to be the best. Puts me on a stations with its own flat-coil antenna tenna lead. Its a.c:d.c. My then new assist- dreadful linguistic spot, you see. How'm (highly directional). It's a.c. -d.c., of course. ant (who has had to give up, due to lack of I going to describe the darned things? I'll In the city, I can't get any AM station time) took over and applied a second an- be as dynamic as can. I further out than nearby New Jersey. Gran - tenna lead, via a capacitor to protect me co's FM tuner, in the city, similarly picks from fuse blowing and shock on the hot Granco FM Tuner up all the local FM outlets, pretty much side of the set. First a product I took on a dare -my parallelling the AM lineup. It, too, is lim- Well, it was a nice idea but so far it own. The little Graneo FM tuner is an item ited to city transmissions, via its unobtru- has got me nowhere. In fact at this point that to my mind falls into an extremely in- sive single antenna wire, which need merely the little Graneo produces nothing but a teresting and very important sales and con- be pulled a bit away from the set for good loud buzzing sound, whatever antenna I J sumer area, that which straddles our pres- results without even having to be stretched use. Something is wrong somewhere. I did, ent mass -production (retail) and compo- taut in a straight line. The Graneo is however, discover that the fancy FM /Q an- nent (audio fan) spheres with all that this a.c: d.c., too. tenna would add two or three stations to implies in manufacturing techniques, parts Whether Granco's FM tuner will still be the one -station maximum previously ex- pulling them in around 1980 I'm not in a perienced. That was all. "780 Greenwich St., New York 14, N. Y. position to say. Admiral has the advantage The factors involved are too much for

10 AUDIO NOVEMBER. 1960

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www.americanradiohistory.com UNI- me to sort out at present -there may be local scene. But can a real hi -fi component something wrongly figured out. But my honestly be designed to fit into the same tentative conclusion is that a tuner of this sales system? DIRECTIONAL simplicity, not more sensitive than is To put it more specifically, how about a needed in most city areas where FM sta- separate component system tions are close at hand, simply can't be that might bridge the frightfully large gap RIBBON expected to produce quantities of stations between the flimsy "detachable" hi -fi speak- in the distant "fringe area" even with the ers nominally supplied with most home help of a fancy antenna. This is strictly a stereo sets and the relatively huge, heavy, MICROPHONE big -city tuner. high -quality bookshelf models selling in the Again -what more can you expect? hi -fi component area? A tough design prob- And yet- believe it or not -my general lem, let me tell you, but this is Pilot's area feeling is favorable towards the Graneo, of interest and this, I gather, was their in- with reservations. It can do what it ought tention, mark -up or no. to do at the price. It is nice looking, com- Now right away you'll want nie to tell pact (about four by six inches, neatly you how the PSV -3 compares with a KLH, framed in gray plastic, with tuning and or something. I can tell you, but in all hon- 7%VM-18-S on-off knob, no pilot light, no volume con- esty- I think the comparison with any com- trol). It's lightweight and simple. It is an ponent -type speaker must be a qualified honest piece of component -type equipment one in view of Pilot's intended distribution in the non- component area, where such and sales. The comparison, if you wish, enterprise is rare and sorely needed, where must be two -way, with quality hi -fi com- a few more simple, low -cost, genuine com- ponentry and also with the appliance -type = VM-18-B ponents could do a world of good in educat- retail equipment that will be the main ing the mass public to the component idea competition. itself -in this specific case, a tuner instead In any case I had to wait for my own of just "a radio." evaluation. As you might guess, my proto- My reservations on Graneo, then, do not type hand -assembled models turned out to have to do with ideal performance as such. be atypical. Pilot sent their expert over to The unit can at best do as much as it fix them, in line with production standards, might be expected to. But I do feel that since set up. But even before this I had any piece of equipment, at any price -well, come to enjoy the speakers in other re- anything over five bucks-should be de- spects. signed to operate in a stable and reliable The PSV -3 -most people will want a fashion, within its area. The AM set has pair -are of a size and construction that been doing it for darned close to a quarter should prove extremely handy in plenty of century. I think that with a bit more pol- homes, quite aside from questions of mar- ishing and stabilizing, the Graneo FM keting and comparative sound. The little tuner might well turn out to be a highly speakers are in each dimension only about useful piece of equipment, in its rather un- half the size of the now -conventional book- usual niche in the total picture. Now if I shelf speaker of similar shape. They are can just find out why it's producing noth- truly bookshelf, these, but they can also ing but that loud buzzing sound.... sit or stand neatly on a table or on the floor- They are correspondingly modest in Pilot PSV -3 weight, easy to move and carry, taking little room in your compact's trunk or back And so we turn to another product seat. A nicely finished cabinet, obviously launched into the in- between zone, between well made, solidly sealed up in back with the component, audiofan area and the an open plastic grill material in front "mass- produced" appliance market. Pilot, (part of the acoustic system) makes an im- I must remark at once, has been very much mediate appeal to the eye-my eye, any- interested in this area for some years and, how- These boxes are clearly worlds ahead indeed, has been busy launching an assort- of the semi -cardboard affairs that often ment of interesting products that split the enclose the usual "detachable" stereo AIWA difference between hi -fi and component speakers. M I C R O P H O N E S straight home radio -phono equipment. In Don't forget, in this connection, that the Features: VM- my book "High Fidelity and the Music great fight for legitimate stereo, stereo 18- SVM -18 -B Lover," as published in the summer of Small size and slim shape facilitate handling from separated -and -equal sound sources, is 1958, I went into detailed analysis of sev- not yet half won. Keep in mind that the Comparatively high sensitivity and fine response eral Pilot music systems just on account public is still dismally confused as to characteristics of this very aspect -even then, they rep- stereo's values, how it should be set up, Sturdy construction with short ribbon diaphragm. resented an interesting new move towards where there can be compromise and where Humming minimized. the one -piece appliance -type machine with there cannot. It seems to me that even if separately described internal components. Equipped with a low frequency attenuation circuit. Pilot's little speakers sounded no better Since then, of course, the trend has con- than the cardboard "detachables," their Specifications: tinued, with much abuse (as with those size, convenience, good looks, and solid fur- misleadingly described "peak power" am- niture construction should nevertheless be Type: Ribbon Microphone plifier ratings in home equipment) but Frequency an immediate stimulus in the right direc- Response: 50-16.000 e, s ± 3 dB also with considerable useful progress. tion for the buying general public. More Impedance: 600 ohms ± 20'; (At 1,000 e/s Pilot's little PSV-3 speaker, of which I speakers of this sort are needed if we are at 0 point of the switch) got (unknowingly) a hand -assembled pro- to woo the supposedly adamant lady of the Output Level: - 75 dB (0 dB I V p bar 1,000 e /s) totype, fits squarely into this picture. It home into allowing two separated sound sells Mounting Screw: 5 8" 21 Threads at a relatively solid price mainly outlets in her precious living room. Directional through the so- called "music stores," the And how do they sound, these Pilot retail appliance dealers who purvey TV, Characteristic: Uni Directional PSV -3s? My first try was disappointing. radios, portables, and a very limited quan- The highs were shrill and strident, over- Noise Level: Below 30 dB tity of hi -fi componentry. balancing the bass end (which tends to Dimensions: VM-18 -S 1 1 Dia. 2' Length 9 1 /2" Limited, of course, because of harsh eco- make even clean highs sound distorted to Wt. 2 14 lbs w'0 staid nomic fact. These stores sell generally at a the ear). Turning down the tone controls

VM-18 -B Dia. I 1 2" Length 1 5/18" much higher mark -up than the component on my amplifier rolled off the highs, a mod-

Wt. 2 1 4 lbs. w o stand outlets. To sell through this distribution erate bass boost helped the balance further, Case: Satin Chrome Finish channel you must thus produce equip- and with this not -so-legitimate tinkering Complete with the connector for low frequency attenu ment at a remarkably low manufactured I managed to get a balanced sound, though any I still could hear highs, fion choke and 9.10 feet cord. cost if it is to have sort of home the unpleasant value at all. America still loves its music muted by the tone control. Not so good. stores and the big companies still can masa- But remember that these were the hand- AIWA CO.,LTD. produce low -priced equipment via this made, nonstandard prototypes. (Why do KANDA, CHIYODA-KU. TOKYO. JAPAN time -honored arrangement, to sell on the WC evaluators always get sent nontypical

12 AUDIO NOVEMBER, 1960

www.americanradiohistory.com Which cable has the

Both shielded cables have the same number of twisted pairs with identical AWG. But ... the cable with exclusive Belden BELDFOIL is smaller in diameter. What does this mean to you? It means that when you specify BELDFOIL, you are really buying extra space -extra conduit space, extra raceway space, extra console and rack space. A new development by Belden -BELDFOIL shielding is 100% effec- tive. It is a major development in quiet cables. BELDFOIL eliminates crosstalk and is superior for stationary or limited flexing at both audio and radio frequencies.

BELDFOIL shielding is a lamination of aluminum foil with Mylar which provides a high dielectric strength Folded Foil insulation that is lighter in weight, Mylar Tape requires less space, and is usually lower in cost. For multiple- paired Aluminum Foil cables, with each pair separately Insulated Conductors shielded, the Mylar is applied out- Drain Wire side with an inward folded edge." This gives 100% isolation between shields and adjacent pairs.

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power supply cords cord sets and portable cordage electrical 'Belden Trademark magnet wire lead wire automotive wire Reg. U. S. Pat. Off. Belden household cords "Patent applied for WIREMAKER FOR INDUSTRY and cable aircraft wires welding cable SINCE 1902 CHICAGO

AUDIO NOVEMBER, 1960 13

www.americanradiohistory.com early models, Manufacturers' over- eager- ness, quite legitimate on the part of any enthusiast for his brand new production.) The Pilot man duly arrived and went to You work on the prototype speaker. There are three interrelated cone speakers in this unit, a woofer, a concentric mid -range and Say a small cone -type tweeter' The hookup is elementary, using simple impedance values to shunt the proper frequency range to each. Somebody had goofed ; there was a AUDIO wrong capacitor or resistor (I forget just what) and the small cone -type tweeter, 3 -inch if I remember, was eating up too Is much of the signal. Too loud. A replace- ment fixed it in a few moments, reducing the tweeter volume to par. Publishing Now this, of course, nicely explained why I couldn't get the same results via ampli- fier roll -off. Simple-but who would think A of it, If you'll envision the performance - level of the three cone speakers as like three steps, let's say escalator steps, level Cookbook? at the top of the escalator rise, you'll understand me. Flat. (To be sure, in prac- tice the steps are rounded at the edges and overlap in their "curves." If one of those steps, the tweeter, is set Yes, AUDIO is publishing a cookbook - push himself away from the table before "fiat" but a number of db above the other not that we intend to extend the subject upsetting the daily calorie count." two in level, as my tweeter was, you'll get of gastronomy to include recipes in fu- shrill sound. But if you roll off the whole ture pages of AUDIO. Here is a cookbook that will enable you high end via your amplifier tone control to recreate in your own homes superb you will in effect merely tip the top step You may ask...why? dishes experienced only at the over, and the middle one too. The bump Mirror between them remains, though lopsided, And we would answer -Simply because Lake Inn -dishes like Lake Trout Baked and In Wine so does the unpleasant sound. we feel that people who read AUDIO, and Adirondack Apple Pie, rec- On the other hand, when the tweeter unit and enjoy the finest quality music repro- ipes for which are reproduced below - is brought into proper balance with the i duction also enjoy really good food on middle and bass speakers, the sound is LAKE TROUT BAKED IN WHITE WINE quite different and properly so. That's their tables. Remove heads and tails from a 2pound fish. Split open down what happened when the PSV-3 prototypes back and rinse well. Remove backbone and rub inside with lemon, ' Your next question may be...Is it a dif- salt, pepper and thyme to taste. were re- balanced to normal. A very signi- Knead I tablespoon of butter J ferent kind of cookbook? and anchovy paste the sine of a large pea; placing mixture inside ficant improvement. Bah. Place fish in a greased baking pan and cover with l4 cup Take note, while we're it, this Of at that course our reply would be-Yes! Oh, of white wine. Bake 25 to 30 minutes in moderate oven.n. 950 problem of "step" volume balance between it doesn't have a revolutionary format degrees. Baste frequently. Garnish with parsley and lemon speaker units in a system is by no means and it appears to look like any ordinary and serve with plain boiled potatoes. confined to Pilot's, nor to small systems. In fact have been rather cookbook. But, the secret of its goodness ADIRONDACK APPLE PIE I thoroughly both- I ered by the so- called "balance controls" is the recipes that fill its 148 pages... c. sutra 9 tbsps. white corn syrup 2 dups. sifted flour provided on many new speakers, recipes responsible for the heart 6 to S tart apples. thinly because I warm- 34 tsp. grated nutmeg have ing, flavorsome, sliced been aware all along that the adjust- homespun aromas expe- S4 c. orange juice pastry ments are often of this same step variety, rienced only in the kitchen of an Adiron- ;4 e. melted butter each speaker going up or down like my dack country Mix together the sugar. flour, nutmeg, orange juice, corn home. syrup step, its response "flat" at all levels of and melted butter. Add the sliced apples and mix thorough. volume. The name of the book ly. Butter a pie pan heavily before putting in your pastry. Fill the is PLACID pie shell with the apple Now we are all aware that tone controls, EATING, and is mixture and make pastry strips for the it chock full of palate - top which should be dipped in melted butter before putting on often elaborate and multipurpose on pres- tempting recipes compiled by Climena the pie. Bake in 400 degree oven for 15 minutes: reduce heat to ent stereo amplifiers, are mainly intended M. Wikoff, owner of the Mirror Lake Inn 250 degrees and hake 35 to 40 minute% longer. for adjusting speaker sound to taste and to ,,,at (you guessed it) Lake Placid, New acoustics. (Some say to pickup cartridges York. This colorful book, plastic bound for easy as well, though for me this is an inadmis- handling, will contribute many wonder- sible thought. Cartridges, at least, must be Actually, the first edition (now out of ful adventures in food for everyone in flat, period.) But these amplifier adjust- print) was discovered by Mr. AUDIO the family. Order a copy today, the Lady - ments are of the "leaning" variety, tipping (C. G. McProud) during of- the -house will the curve up or down; whereas the speaker his stay at Mrs. adore you for it. Inci- balance Wikoff's Mirror Lake dentally..,it makes a adjustments, provided for the self- Inn, where, in Mr. wonderful gift for same purpose, are of the step type, each McProud's own words -"... every meal is anyone. PLACID EATING, 152 pages, segment flat. so tasty that eating becomes a real joy, Plastic Bound: $3.95. Or are they? To tell the truth, I'm not where each night's dessert excels the one sure in every case that I've been involved from the night before, where one has to in. It takes quite critical listening to figure it out by ear on your own, tinkering with each speaker unit in turn. Some systems, moreover, give you "step" control of the RADIO MAGAZINES, INC., Dept. K99 mid -range but not the tweeter ; others com- bine tweeter and mid -range in a single bal- P.O. Box 629, Mineola, New York ance, not usually described with candor and clarity in the instruction sheets. ( "Just Enclosed is my remittance of adjust the balance control for the most please send me copies of pleasing sound.") PLACID EATING @ $3.95 each. There are so many possible combinations (No C.O.D., all books sent postpaid in U.S.A. and possessions, of "step" and "leaning" (rolloff) circuitry / Canada, and Mexico. Add 50c for Foreign orders.) in the speaker area that only a circuit - reader, who knows exactly what is in- volved, can be sure what is happening in NAME ADDRESS (Continued on page 87)

CITY ZONE STATE See "1.02 cubic feet and 45 cps," r AUDIO, August, 1960.

14 AUDIO NOVEMBER, 1960

www.americanradiohistory.com A MAJOR IMPROVEMENT in the

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I M U S I C T H E V E R Y B E S T N 15 AUDIO NOVEMBER, 1960

www.americanradiohistory.com EDITOR'S REVIEW

AUDIO ENGINEERING SOCIETY ward the practical creation of magnetic recording CONVENTION media." Fellowships in the Society were awarded to : W. J. Moreland, Edgar Villchur, and John G. Mc- PROBABLY THE MOST SUCCESSFcL of all of the twelve Knight. Audio Engineering Society Conventions was held This is the first year that the Society has operated in Hotel New Yorker from October 11 to 14, with its Convention entirely separate from the hi -fi in- a total of almost 800 visitors registering for the com- dustry, but it has proved that the twelve -year -old or- bined technical sessions and the exhibits of profes- ganization is now thoroughly capable of standing by sional equipment. itself. The caliber of the exhibits was highly technical, Dr. Harry F. Olson, incoming president, and for with a wide variety of professional equipment for re- the past year, vice -president -who, traditionally is cording and reproduction being shown. charged with the responsibility of securing the papers On the whole, the Society and those who made the for the Convention -is to be congratulated for the Convention and Exhibit the successes they were de- array of 83 papers which were presented during the serve considerable credit for the fine showing through- thirteen sessions occupying morning, afternoon, and out. We know how much work there is in such an evening of every day of the Convention except Thurs- enterprise, and everyone has apparently performed day when the Annual Banquet was held. beyond the call of duty. The new officers and governors for the coming year are : president, Dr. Olson; executive vice -president, OPEN HOUSE IN BOSTON Hermon H. Scott; Central vice -president, L. R. Bur- roughs; Western vice -president, Pell Kruttschnitt; secretary, C. J. LeBel; lit the abseuee of a hi -ii show in Boston this year, treasurer, Ralph A. Schlegel; two New governors, Murray G. Crosby, John M. Hollywood, England manufacturers have announced and Dr. M. R. Schroeder. Harry their co- operation in providing some hi -fi "show" of L. Bryant, the their own in out -going president, continues as a governor of the the form of an open house at their re- spective plants. These companies Society, and the other governors : are H. H. Scott, Inc. are William S. Bach- and Acoustic man, Sherman M. Fairchild, Donald J. Plunkett, Research, Inc. and the dates for their event are November 17 -19. Both factories will be William B. Snow, and Edgar M. Villchur. . open to visitors, with plant tours and demonstrations, Frederick V. Hunt, Rumford Professor of Physics and and Gordon McKay Professor of Applied Physics at engineers will be on hand to answer questions Harvard University and to show how their products are constructed, was the guest speaker with an tested, packed, address entitled "Needles the Groove and shipped. -in or in a To anyone who Rut." He referred to the "hare-brained fringe of has never visited either type of respectability plant this should be a very interesting experience. We and prevailing ignorance" of its field have that exists throughout the phonograph industry, and always been fascinated by the workings of these offered types of plants because the methods of making loud- a cure which involves the launching, through speakers an agency such as the RIAA, of "an industry -sup- differ considerably from one plant to another and the testing of amplifiers and tuners in a modern ported program of basic research into its livelihood" high -quality on the order of other large industries. electronic factory tends to demonstrate better than anything else can just how much care goes The John H. Potts Memorial Award, furnished an- into nually since 1949 by Audio Magazine, the products we finally bring into our homes and was given to lives. We believe Dr. S. J. Begun "in recognition of more than that the open house idea should be thirty followed often by years of research and engineering in the science of and a wider segment of the indus- try, for most of the plants we have visited have in- electronics, magnetics, electrostatics, and mechanics, creased toward more perfect sound transmission and record- our respect for the companies' products. ing." The Emile Berliner Award was presented to Rene Snepvangers "in recognition of his contribu- ERRATA tions to fine-groove disc recording." The Audio En- gineering Society Award went to Harvey Sampson, An eagle -eyed author, D. E. Johnson, has spotted Jr., "in recognition of unstinting devotion of time two errors in his paper "The Musical Scale as an En- and energy to the indispensable tasks of the Society." gineering Tool," which appeared in the September Honorary Memberships in the Society were given issue. On page 23, the word "progress" appearing in to Miklos Rosza "as an outstanding composer -con- the fifth line above Fig. 1 should have been "pro- ductor, devoted to the new art of music especially gressed," and on page 58 about half way down in for the medium of recording "; to Otto W. Kornei of the third column, the second formula should read, IBM "in recognition of basic physical research in

16 AUDIO NOVEMBER, 1960

www.americanradiohistory.com : t-S.,

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two...perfect for stereo Perfect Stereo- mates` for the best Stereop layer ever/ Silent partners ...the 198 and 800 reproduce only the music in a record.., perfectly... faith- fully ... without adding a whisper of sound. The Stereotable -Gyropoise 800... Here is responsible performance -for all who the only magnetically balanced high fidelity turntable...actually revolves can hear the difference. From a gentle pian- on a cushion -of -air. Without a trace issimo to a resounding crescendo -every of rumble -horizontal or vertical - the Gyropoise 800 is the perfect - movement of the stylus reflects a quality mute in a Stereoplayer, keeping the touch possessed only by the Stanton Stereo record in quiet motion at precisely Fluxvalvet. 331 rpm. less base $66.00

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www.americanradiohistory.com WHAT GOES ON HERE?

41-1/ry

Bell Telephone Laboratories' new electronic In one experiment at Bell Laboratories, a network of artificial neurons is subjected to a stimulus from light "nerve cell" is a step toward finding out through a set of photocells. The network can distinguish specific patterns of light and dark, thus duplicating roughly One fascinating area of communications has long re- some of the eye's basic reactions to light. Similar studies sisted exploration -what happens inside the nervous system are underway to explore our hearing processes. when you see, or when you hear. At present, too little is known about neural action to permit exact electronic duplication. But experiments with This area is of special interest to telephone science; artificial neurons can provide suggestive clues, contributing knowledge of how the nervous system handles sound and to a stimulating interplay between electronics and neuro- can is picture signals help determine what information physiology which may help workers in both disciplines. essential to perception. This in turn may lead to more efficient communication instruments and systems. The human nervous system, including the brain, is the most efficient and versatile data processing system known; To probe the mystery of nerve activity, Bell Telephone and data processing is an essential part of communications. Laboratories scientists have developed an electronic model The artificial neuron provides a new approach to investi- of a living nerve cell or neuron. Consisting of transistors, gating and understanding basic nerve network functions. resistors, capacitors and diodes, the "artificial neuron" It is a fresh example of how Bell Telephone Laboratories exhibits many of the characteristics of a living neuron; for constantly explores new frontiers to improve America's instance, "all -or- none" response and fatigue. communications system, now and in the years ahead.

II'J.i!!7.À$s`áM Network of neurons is assembled by L. D. A single artificial neuron. It delivers electri- Harmon of Bell Laboratories, the initiator of cal impulses when stimulated, like a living this new research. Many kinds of assemblies cell. Neurons are also being used for research are possible. into hearing.

BELL TELEPHONE LABORATORIES WORLD CENTER OF COMMUNICATIONS RESEARCH AND DEVELOPMENT

www.americanradiohistory.com Acoustic Matrixing -A Basis For New Loudspeaker Developments

NORMAN H. CROWHURST'

Through acoustic matrixing control is exercised over the direction of particle velocity as the sound wave leaves th3 speaker to achieve wide sound coverage. In application this concept provides a system with unusually fine stereo sound -from a single cabinet.

We've heard a lot about electrical, Two such loudspeakers, using a stereo or electronic, matrixing recently. (left and right) source will radiate two particularly in relation to stereo sets of spherical diverging waves. The broadcasting. While there are some simi- stereo illusion, if it is achieved at all, is larities in the acoustic variety we shall the result of the difference between the discuss in this article, it should be stated way these two sets of divergent spherical at the outset that it is not an acoustie waves combine at the listener's two ears. way of doing the same thing. e There are certain disadvantages to this In electrical matrixing, the quantities method, which account for many of the to be matrixed are scalar; voltages or dissatisfactions experienced with stereo currents specified completely by instan- reproduction. taneous magnitude and polarity. An Ignoring at first the effect of reflec- algebraic sum and difference process 2. vertical tions, the pressure and velocity due to a will convert Fig. A line of loudspeaker "left" and "right" channels units will approximate cylindrical radia- spherical wave decrease in proportion to into "mono" and "stereo" by this process, tion with a vertical axis. distance from the source. If the listener or vice versa. is at a distance greater from each loud- In acoustic matrixing two additional speaker than the loudspeakers are from -w features complicate matters : propaga- each other, the difference in intensity tion and space. Not only does the origi- EDGE -ON UNIT received from each will not be too nal scalar quantity, DELIVERS "STEREO" converted into an (DIFFERENCE) great. Thus far, we might conclude that acoustic wave, take time to reach any SIGNAL a scaled -down theater system would specific point, determined by propaga- achieve equally good effect in a living tion velocity and distance; the quantities CONVENTIONAL room, FRONT -MOUNTED throughout an area corresponding themselves do not remain scalar. An _8 x SPEAKER DELIVERS to the part of a theater occupied by the acoustic wave is possessed of pressure L J "MONO" (SUM) SIGNAL audience. But now we take into account and velocity components that are not the effect of reflections. simple counterparts of voltage and cur- Fig. 3. Basic loudspeaker arrangement In an auditorium, the distances are rent in the electrical analog. While the used in some of Lauridsen's experiments. such that the direct waves from the loud- instantaneous sound pressure at a point speakers reach the listener with a per- is a scalar quantity, particle velocity at loudspeakers whose radiation is pre- ceptible lead time before any conflicting a point is possessed of direction, which dominantly longitudinal and relatively reverberant waves, wherever the listener may or may not coincide with the di- nondirectional. Within certain limits, a is located. Also the difference in distance rection in which the wave is propagating. loudspeaker with enclosed back (includ- traveled by the two groups of waves is ing bass reflexes, which are effectively such that the direct wave maintains a Spherical Waves closed back at most frequencies) radiates substantial intensity difference above It seems as if, so far, most people waves of a diverging spherical character. that of the reverberant ones. concerned with applying loudspeakers to stereo have avoided any deliberate use of acoustic matrixing. They have utilized

216 -18 40th Ave., Bayside 61, N. Y. Fig. 4 Construction on which CBS "iso- phonic" demon - station was based: dashed lines rep-

THIS THIS resent polar pat- ENTIRE ENTIRE terns of individual WALL WALL isophonic units; RADIATES RADIATES "LEFT" BOTH END WALLS "RIGHT" dot -and -dash lines SHOULD BE 100% link at ABSORBENT TO points INCIDENT SOUND which received in- tensity from the two units is equal, Fig. 1. A hypothetical way of achieving when they radiate stereo by radiating plane waves from equal power. opposite walls of the room.

AUDIO NOVEMBER, 1960 19

www.americanradiohistory.com listener positioning than in the large Plane Waves auditorium. Some have said that headphone listen- This last statement is true for two ing is the ideal way to hear stereo. This reasons. To get separation, the loud- transmits the sound pressures directly speakers need to be further apart in to each ear via the short auricular canal. proportion to the major room dimen- If the sound from each loudspeaker Fig. 5. Each unit will be free from trans sions. Consequently altering one's loca- could be transmitted to each ear without verse components only along the axis. tion can make the distance ratio from loss or intermixing, either with sound the two loudspeakers change to a greater from the other loudspeaker or with re- In a smaller room, such as more nor- extent. verberation effects from the room, the mally used for home listening, a differ- The second reason is that spherical stereo illusion would be improved. ent relationship obtains. The shorter radiation reduces its intensity more A plane wave, as opposed to a spheri- distances serve to "catch" waves radiated rapidly than the direct inverse square cal one, transmits sound with virtually in all directions from the loudspeakers, law at first. At greater distances, both no reduction in intensity. A hypothetical reflecting them inwards again, so the pressure and velocity diminish in inverse method of utilizing this form of radia- listener at almost any location hears the proportion to distance. In the shorter tion would be to have the two opposite reflected sound with little time delay or distance range, the velocity component entire walls radiate sound, each handling intensity loss from the direct sound. of the wave decraeses in inverse propor- one channel of the stereo (Fig. 1). If Also the relative intensity difference be- tion to the square of the distance. So each of these walls could also be rendered tween direct waves from each loud- deviation of effect with listening posi- 100 per cent absorbent to waves from speaker is apt to be more dependent on tion may be even greater in small rooms. the other side, a very good stereo system would probably result. wall RESULTANT 1 Fig. 6. At the in- However, practical surfaces

T ef, N FFr tersection of axes would produce a high degree of reflec- the pres- RESULTANT (Fig. 5) tion, especially to a wave striking them sure and particle "full on" So, even assuming the whole velocity (magni- wall could be rendered into one large A. IN PHASE , PRESSURE B. PHASE OPPOSITE , C. PHASE QUADRATURE, tude and direc- MAX., VELOCITY EQUAL PRESSURE ZERO, VELO- MEAN PRESSURE, VELO- transducer, the reflection aspect would PATH tion) depend on TO EACH COMPONENT. CITY J3 TIMES EACH CITY ELLIPTICAL probably negate its apparent advantage. COMPONENT. EQUAL TO EACH COM- the relative phase PONENT. of signal from the two units. Cylindrical Waves Splitting the difference, so to speak, between the spherical and plane wave, is the cylindrical wave. In a sense, this is SPEAKER UNIT (ELLIPTICAL) plane one way and spherical the other. ED PACK So a wave propagated from a vertical line source will travel a given distance BAFFLE with only half the reduction in intensity BOARD (measured in db units) suffered by a spherical wave. This will have three ad- vantages for stereo in a normal -sized listening room. First, the intensity of the direct wave will be greater relative to reflected re- verberation components at almost any location. SOUND WAVES FROM FRONT SOUND WAVES FROM BACK COME THROUGH HOLE WHERE RADIATE FROM VERTICAL Second, the difference between the in- SPEAKER IS MOUNTED ON BAFFLE SLITS AT SIDES tensity from two loudspeakers due to BOARD different listening locations will be re- Fig. 7. Cross-section through one of the Heath "satellite" units, showing how the basic duced. CBS isophonic is modified, physically. And third, reflections from floor and ceiling will be practically eliminated, be-

o° cause the waves do not radiate towards 1o° 10° them. Thus the increase in ratio of the zo° z0° direct wave intensity over reverberant confusion is considerably increased. One way to achieve this effect is by approximating the line source with a vertical line of loudspeaker units on 50° 50° each channel (Fig. 2). Another method approximates a similar effect by using controlled radiation, as in the Jim Lan- sing "Hartsfield," spreading sound hori- zontally and restricting it vertically. 1 1000 -5000 cycle WARBLE (SIMPLE DOUBLET) Transverse Waves -- - - 3000 -7000 cycle WARBLE (SIMPLE DOUBLET) But we still have essentially pressure - - THEORETICAL OPEN BACK (BIDIRECTIONAL) - - or longitudinal radiations from each Fig. 8. Directional pattern achieved by the unit of Fig. 7. (From data supplied by loudspeaker. We have not yet introduced Heath Company.) the piece de resistance of this article.

20 AUDIO NOVEMBER, 1960

www.americanradiohistory.com At the beginning we pointed out that particle velocity at a point may not co- incide with the direction in which the wave is traveling. When two radiations of the same frequency combine by inter- section from widely separated sources, the particle velocity is a resultant due to both waves. Its magnitude and direc- tion will vary quite rapidly with loca- tion, and beyond a simple vector sum (as does the pressure component). Even without taking reflections into ac- count, this can become a highly compli- cated wave pattern at different fre- quencies. Fig. 9. The pillar of sound: (a) placement in room; (b) cross- section, showing position of speaker groups. The acoustic matrixing concept does not utilize the same kind of longitudinal mally occupied) it is inversely propor- transverse component will be too strong radiation, but controls the direction of tional to distance squared. From a nor- (which may give accentuated separation particle velocity as the waves leave the mal longitudinal radiator with spherical effects!). If you get too far away, the loudspeaker(s). The first experiments distribution, it is inversely proportional separation will diminish, as it also will that deliberately applied this principle to distance squared for small distances, by moving to the side. were those of Lauridsen, who used it, not becoming inversely proportional to dis- Widening the Control for true stereo, but a form of pseudo tance directly at greater distances. Thus, stereo, delaying the signal fed to one of regardless of wavelength and distance, One method of overcoming this objec- the units. The same method has been the transverse propagation reduces its tion uses separate loudspeakers that do tried with M -S type stereo. In this, an intensity at a more rapid rate than the utilize other than the simple transverse edge -on unit radiates the "stereo" com- longitudinal components. radiation effect. First in this group was ponents, while the "monophonic" comes This means the correct stereo illusion the experimental system developed and from a conventional pressure radiator can only be achieved over a relatively demonstrated by CBS Labs. As there 4 at the same location (Fig. 3). In Laurid- small area in front of the loudspeaker was spacial separation, this system used sen's experiment the same audio was fed combination. If you get too close, the (Continued on page 77) to the "stereo" unit but with a time delay. When used on M -S stereo program material, the transverse radiation propa- gated by the edge -on unit, which be- haves approximately (over a limited frequency range) as a doublet sound source, combines with the longitudinal Fig. 10. Variation propagation from the front -on unit, to of velocity com- ponents with dis- D control particle velocity orientation rela- tance, using cylin- eer tive to the direction of propagation at drical or spheri- all points. The much more complicated cal radiation. In- pattern due to special separation does creased rate of not build up. very change for ú At the listener's head, and in the mid - short distances is frequency range, the obstacle effect uti- not shown. -Zii:i` lizes the pressure gradient coincident with the oblique -angled particle velocity N to produce a pressure difference at his ears. This generates "left and right" \. pressure components at the respective 3 4 5 6 7 8 10 30 ears. FEET FROM SOURCE- DIRECT WAVE ONLY While this method works, it has limi- tations too, otherwise everyone would probably be using it by now. The limita- tions can be seen by looking at the prop- erties of a doublet source. First, the transverse component is strongest at the edge -on position, which becomes the center in Lauridsen's arrangement. Fig. 11. Relative front of Moving to the side reduces the magni- motion units' cones when a sig- tude of the transverse component re- nal is applied ceived from the "stereo" unit. from "left" chan- Second, the intensity from a trans- nel only -no out- verse radiator falls off more rapidly put from "right." with distance than does that from a longitudinal radiator. At short distances from the radiator, the transverse velocity is inversely proportional to distance cubed. At greater distances (more nor-

AUDIO NOVEMBER, 1960 21

www.americanradiohistory.com An Engineer's High Fidelity System

R. A. GREWER

We have all read about, and have seen, many decorator- oriented systems in recent years. Here is the system of an engineer who compromised appearance for the sake of the ultimate in sound.

I N TWO PARTS -PART 1

Tii r. SYSTEM to be described in this and corded source material, we find that we succeeding parts of this article must are dependent upon the availability of truly be called an engineers high fi- high quality turntables, pickups, and delity system. It is a laboratory instru- tape transports. It is indeed fortunate ment which has not been designed to that there is available on the market a look beautiful. That is, it is not con- large quantity of very good equipment tained in a series of French Provincial of the sort needed. The only price to cabinets. It has however a beauty of its be paid is, of course, the high dollar own-that of perfection. Or, at least a cost. The point is that the best turn- degree of perfection seldom found in tables and tape transports are good audio systems. enough so that they do not in any way I will describe in the first part the limit the performance of the overall general arrangement of the system and system. In fact there are several tape the details of the loudspeakers. The elec- machines which sell for under $1000 tronics will be described in part two. which are good enough for even the There are fundamentally three parts most critical applications -(scientific as to the sound system. First, we have the well as audio.) sources of sound and the associated It would seem from this writer's ex- equipment which is needed to change perience that there is still a way to go this stored information into electrical in the area of pickup improvement. signals. Second, there is the electronics While the very best pickups are good, which modifies the electrical signals to they do not match the quality of the suit the desires of the audiophile. Finally tapes. It may be that we are close to a there is the loudspeaker system which fundamental limitation of the phono- must change the electrical signals into graph pickup and for this reason prog- useful acoustical energy so that the au- Fig. 1. This jack panel is the heart of the ress has been very slow for the last diofan may enjoy it. versatility built into the system. several years. The disc is after all a very Let us first consider the sources of crude method for storing information. of sound. Live sources broadcast at the ber prerecorded tapes which fall into The mechanical- electrical systems for time of the performance are generally this category. It must be expected that both recording and playback the high fidelity are now rather rare. In any case, one is then fully enthusiast will make highly refined and further progress may every effort to select the very dependent upon the quality of the pick- best be expected to be very slow. quality of source material. Unfortunately up, of the transmission, and of the AM There is no doubt that tape can the desired choice of music and per- or FM receiving equipment. The only achieve truly superior results if the cost formance are not always found on the control of quality that can be exercised of the medium is not of primary con- discs and tapes which are technically the by the listener is to use the best tuner cern. However it is clear that the cost best. There is some possibility that the available. (And to write strong letters to of tape is of importance or the tape music lover will have access to original the broadcasting station. ED.) market would not be as small as it is. tapes or first generation of The two common recorded sources are copies mas- One can only conclude that the number ter tapes. This is a most desirable po- of course discs and tapes. In either case of persons interested in the best quality sition. The most avowed audiofan will we depend upon the manufacturer to is so make small that they are not worth produce a high fidelity record. There an attempt to supply himself with live recordings. This situation is the worrying about as far as the commercial are a number of modern discs which recording companies are concerned. can be considered of high engineering most satisfying of all in this writer's opinion. Some compromise in perform- There is adequate evidence that this is excellence and a somewhat larger num- ance is a fair price to pay for the not an idle statement. For example, tape

University of Wisconsin, Department truly superior quality of live tapes. copies can be very close in quality to MIS of Electrical Engineering. Turning our attention to playing re- the original master if they are dubbed

22 AUDIO NOVEMBER, 1960

www.americanradiohistory.com O VU level and fed to the jack panel shown in Fig. 1. From here, the signals are plugged to the remote control am- plifiers, to control amplifiers in the relay rack, or to one of the other signal processing chassis. The remote control amplifiers are located in the main listen- ing room and allow control of the main sound system from that room. Only a single turntable and tuner are located in that room with the main speaker sys- tems. The details of this remote control arrangement will be described in part two. After suitable control of gain, loud- ness, bass, and treble response, the signal is returned to the jack panel and plugged to the appropriate power amplifiers. The main power amplifiers consist of Fig. 2. Main elec- two groups. There is the amplifier rack tronics of the sys- for the main system which is shown in tem with the cov- Fig. 2. The service covers are shown ers removed from removed. There are four completely in- the power ampli- dependent amplifiers each of which can fier rack. deliver 50 watts. A pair of electronic crossovers are located directly above the amplifiers and are arranged to drive the two main speakers with 100 watts each. An additional pair of amplifiers (Dyna- kit "Stereo 70 ") is used for monitoring in the control room. Additional single - 4 channel amplifiers are used to drive re- mote loudspeakers. There is enough equipment and versatility available to handle three independent stereo channels at one time. In addition one can dub disc -to -tape or tape -to -tape at the sanie time. The panel above the jack panel de- serves some mention though it is de- scribed in detail in part two. It is used to at a reasonable speed. All the same any of the professional tape machines control the inputs to the tape recorders. there are almost no tapes available are desirable. All important switching is performed which sound like master tapes. The There are some things which must be on this panel along with the generation reason is probably that there are few done to the source material and some of a "third channel" made up of the persons willing to pay the price. Tise things which are a matter of opinion. sum of the program material on the recent change to four -track tapes is An individual may, it seems to me, want two stereo channels. This channel may further proof of this. the orchestra to sound twice life size, or be fed to a third speaker in the main So as not to slight the disc manufac- have more brilliance, or have more bass listening room or used to provide bal- turer, I would like to note that the than is in fact present in the live or- anced listening at a single-speaker re- sound quality of most modern discs is chestra. I shall not argue such matters mote location. surprisingly good. In fact it is so good but only describe a system of electronic Complete control of the line power that tape may never again come to the controls which gives the audiofan for the entire system is incorpprated in fore. There is not much difference be- rather complete control of the variables the power amplifier rack. The-line eon - tween a good record and a four -track in the system. He may then use his own trol at the top of the rack is used mainly tape. discretion on the matter of knob twist- to insure the correct operating voltage Despite shortcomings in the quality ing. for the tape recorders which do not at of the source material commercially It is relatively easy with modern feed- present have electronically regulated available, it is still worthwhile attempt- back electronics to make controls and power supplies. There is a single power ing to process the source signal in such amplifiers which have essentially no dis- supply in the control rack which sup- a way as to not distort it any more than tortion compared to the recorded sound plies plate and heater power to all of it already is-and thus be ready when a and loudspeakers. The equipment de- the control and special purpose chassis high fidelity signal conies along. My scribed in this and the following parts in the two racks. Thus any piece of system for accomplishing this consists of the article has a distortion level which equipment which is designed for per- of: (1) Rondine Deluxe turntable, (2) is hard to measure with standard labora- manent rack mounting need not have a Shure stereo and monaural pickup arms, tory instruments. (Under 0.1 per cent power supply of its own. (3) Berlant and Concertone tape re- total harmonic distortion and noise com- Finally, and certainly not least, there corders (4) An adequately thick pile of bined.) The power amplifiers are not is the main loudspeaker system to con- discs and tapes of carefully selected quite that good but are under 1 per cent sider. The details of this system and quality. There are many other similar at full output. the experimentation through which it pieces of equipment on the market which All of the input signals from the was arrived at is dicussed in the fol- are about as good in quality. Certainly several sources are preamplified to the lowing section. Figure 3 shows one of

AUDIO NOVEMBER, 1960 23

www.americanradiohistory.com and construct a power amplifier with loudspeakers are at present made only a rating of 50 watts and with such a in small sizes and with enclosures of small amount of distortion that it takes such a size that the airload at high pow- the finest laboratory instruments to de- er- levels is not compressed adiabatically tect the distortion. With the loudspeaker and thus some nonlinear distortion is in- the distortion problem is so severe that troduced. There are other difficulties if a manufacturer could produce a loud- which arise when small cones are used speaker capable of an accoustical watt for a wide range of low frequencies as of power with a distortion of less than will be seen later. In the search for two per cent he would be very happy. In high power -handling capacity at low fact, distortion is usually not mentioned frequencies, low distortion, uniform fre- at all. This should not be taken to mean quency response, and good transient re- that loudspeaker manufacturers are not sponse, several large -loudspeaker sys- trying very hard to make a good prod- tems were constructed. uct, or that they are not very clever. Over the past ten years a variety of The true difficulty with the loudspeaker horn -type enclosures were designed and part of the system is simply that it is built. Several models of a corner horn.' an extremely tough acoustical and me- were built. Eight -, twelve -, fifteen -, and chanical problem to change an essen- eighteen -in. varieties of this horn were tially perfect electrical signal into an built with apparently good results. acceptable acoustical signal. The con- Horn -type enclosures are well suited to stant work which is going on should corner placement. The advent of stereo give us continued improvement. One has however brought about some drastic Fig. 3. Front of one of the main loud- speakers. The front panel is painted with 2 -14" CIRCLES slate -colored blackboard paint. SECTION A -A A 24" the main loudspeakers. There are two 36 identical loudspeakers in the stereo setup. Each loudspeaker consists of two 15 -in. woofers, two 6 -in. midrange speakers, and an array of eight tweet- ers. A variety of smaller loudspeakers is used for monitoring and for the "third channel" of the main system. 24"

Large Loudspeaker Systems First let me warn you that I am an advocate of large- loudspeaker systems. There are many good reasons for my stand which are based on sound acousti- cal principles. I will mention several of the arguments in the following discus- sion of an adventure in the construction of a large- loudspeaker system. The loudspeaker is one of the weakest links in most audio systems. There is good reason for this to be the case. One may compare progress in producing ALL PIECES ARE 3/4" THICK 1 A quality loudspeakers with progress in the electronic part of the system by not- Fig. 5 Plan for horn -type enclosure to be placed against flat wall. ing that it is relatively easy to design must "make do" with the loudspeakers changes in the placement of loudspeakers which are available. in the listening room. It is very ap- The loudspeaker is by nature a very parent that the placement of the speak- nonlinear device. The mechanical sus- ers in the corners of the room is not at pension is the major nonlinear element all satisfactory. The corner of the room in most loudspeakers. The force- ampli- is the best from an acoustical viewpoint tude response of a loudspeaker cone will because the best coupling is obtained be- be something like that shown in Fig. 4. tween the speaker and the room. If one It is clear that only small excursions of uses a two -channel system however it is FORCE the cone about the zero position will give not desirable to excite the room in a linear response. Thus one solution to the uniform manner with both of the chan- distortion problem is to keep the cone nels because the directionality of the motion as small as possible. There are sound sources is lost and a huge jumble many modern loudspeakers which are of sound results. Instead, the purpose reasonably linear when used at power of speaker placement is to obtain a f levels well within their ratings. The only sound pattern in which distinct source innovation in recent years has been the areas are perceptible. The very best Fig. 4. The force -amplitude response of a acoustic suspension which has a larger typical loudspeaker. Note curve is linear linear region near the origin than most 1R. A. Greiner, "A folded horn design," only near the origin. ordinary speakers. Unfortunately these AUDIO, December 1956, pg. 40.

24 AUDIO NOVEMBER, 1960

www.americanradiohistory.com BASIE ROSE l COUNT WASHING GTON pP^ I GERRY MULLIGAN KPFAIPN

Nb11 3aVlsd A3113HS I p yì Z HHNVäd a3lN`1W S03NOr Or Nd í 3N008 lVd I 8.01415

Any number ...any recording artist. With 30 recording companies making more and more of their libraries available on 4 -track stereo tape - you can pick your favorite musical number, recording artist or type of music from 4- track's growing list right now! And, because of the long -lasting fidelity of tape, it will always sound as good as the day you bought it. Your local hi fi salon, music store or tape machine dealer has the full story on 4- track's ICLASSICAL winning combination of quality- variety -and economy. For catalog, write: 1024 Kifer Rd. , Sunnyvale, California, UNITED STEREO TAPES Sri

MUSIC SOUNDS BEST ON TAPE /and you can prove it to yourself... hear it

www.americanradiohistory.com stereo results are obtained with the as far as frequency response went, it large distances to reproduce low fre- usually recommended placement of the was quite unsatisfactory as far as the quencies while it is at the same time loudspeakers along a flat wall and not sound went. Because of the resonances, reproducing high frequencies. This latter adjacent to other walls. it had the typical horn sound. There was effect is not one that the speaker manu- In view of the above requirement on huge bass and very poor transient re- facturer can avoid. It is a purely linear loudspeaker placement an attempt was sponse due to the driver unloading at effect and even a perfectly linear sus- made to construct a horn -type system the resonant frequencies. The sound of pension will cause Doppler distortion. which would be suitable for placement this loudspeaker became intolerable after It is in fact this type of distortion which on a flat wall instead of in a corner. only a few weeks and it was discarded. is the limiting factor in the development The configuration chosen was a back Another attack on the problem seemed of small speaker cones with very large loaded horn driven by two 15 -in. woof- essential. throw. There is no doubt that a 10 -in. ers. The design of such an enclosure is The approach to the problem which speaker can reproduce an accoustical relatively straightforward and has been finally succeeded was to use direct ra- watt at 30 cps. There is, however, also used in small theater systems for years. diating loudspeakers. In retrospect it the certainty that it can't reproduce any Figure 5 shows the plan for the horn does not seem very surprising that this other frequency more than two or three which was constructed. The most ob- should be the case. The fact is that all of octaves higher without serious Doppler vious fault of this structure is that the the people whom I have known for years, distortion. The best solution to the dis- circumference of the mouth is only 10 and who's opinions I regard as very re- tortion problem is to choose a loud- feet. Without the helping effects of cor- liable on audio systems, have ended up speaker which is specifically designed to ner loading there is an abrupt discon- with direct radiating systems. Thus the cover a relatively narrow frequency tinuity at the mouth of the horn and type of system which I will rescribe is range and to use a sufficient number of strong reflections occur at the mouth not at all new. However the exact combi- such loudspeakers in each range so that with attendent peaking of the response nation of components and the details of linear operation is obtained. at the low frequency end. The require- the structure will, I think, be of interest. The low frequency end of the loud- ment for smooth response for a non - There are several serious difficulties speaker system consists of four woofers. infinite horn is that the mouth have a to be met in using direct radiating loud- These are 15 -in. loudspeakers and are circumference greater than the wave- speakers. Fortunately they can all be placed in two separate enclosures for length of the lowest frequency to be overcome with brute force methods. The use with stereo sources. The total ex- reproduced. To obtain smooth response efficiency of the system is very low. That cursion for two of these speakers, in with a horn on a flat wall to the low can't be a real objection since it is so their own infinite baffle enclosure, is audio range requires a mouth of unrea- easy to use a high power amplifier. The about 0.1 inch for a full acoustical watt. sonable dimensions. Despite the indica- main problems are acoustical in nature. Thus the speakers are operating very tions that the horn would have seriously The response of a loudspeaker falls off near the origin of the curve shown in peaked response in the 30 to 100 cps rapidly at frequencies for which the Fig. 4 and are behaving like very linear range, it was constructed. This speaker wavelength of the sound is greater than transducers. At the same time Doppler was called the "monster horn" because the circumference of the loudspeaker. distortion becomes negligible with the everyone who saw it would say, "What Thus, to obtain uniform response to very small excursions involved. Large speak- a monster." The horn behaved exactly low frequencies the cone must move in- ers which are made specifically for low as expected. The power handling ca- creasingly large distances as the fre- frequency operation may not be used pacity was adequate with the two 30- quency decreases. The final result is dis- above about 600 cps so other speaker are watt woofers. The low frequency re- tortion because the nonlinear suspension provided for the remainder of the range. sponse extended to 24 cps but there were mentioned earlier. There is another kind A midrange loudspeaker specifically serious resonances in the 29 and 65 cps of distortion, called "Doppler distor- designed to cover the range from 300 to regions. While the horn was satisfactory tion," which occurs if the cone must move 3500 cps was used for the frequencies from 500 to 2000 cps. A standard tweeter array of high quality was used A SECTION A -A for the frequencies from 2000 cps and up. Two midrange units and eight tweet- ers are included to match the power han- dling capacity of the woofers. An elec- trostatic array could as easily be used for the high end. It is very important to maintain com- plete electrical control over the speaker system at the extremes of the operating range as well as in the midband. Both electrical and acoustical damping are needed to insure good transient response. 48 Electrical control is especially needed if some sort of tuned port or vent is used in the baffle since this technique of ob- taining low frequency response intro- duces resonances at the low frequencies. It is essential that a minimum number of electrical elements be introduced be- tween the amplifier and the loudspeak- ers. Resistors, inductors, capacitors, pads 36. and other junk should be avoided at all 1 costs. For this reason, the loudspeaker A ALL PIECES EXCEPT FRONT PANEL ARE 3/4" THICK Fig. 6. Plan for direct-radiator speaker system. (Continued on page 80)

26 AUDIO NOVEMBER, 1960

www.americanradiohistory.com LET'S ENJOY THE 4 INTERMEDIATE RANGE MORE FULLY!

Is your speaker system a two -way one ? Or a three -way one? If you are now using a woofer of ten inch or larger for low frequency range in your two -way system, you are likely dissatisfied with the tone quality of inter- mediate frequency range. Aren't you? It's very difficult to reproduce the middle range satisfac- torily if a speaker of large caliber is employed for low frequency range in a two -way system. Can't a two -way system be converted into a three -way system easily and simply? Yes, it can be done by making use of a PIONEER Speaker Model PM -16B, which is shortly to be placed on the market, together with a PIONEER Crossover Network Model DN -5. When constructing a new three -way system, a combina- tion of Model PM -16B and Model DN -5 also comes in very handy.

CONE -TYPE SPEAKER MODEL PM- 16B FOR INTERMEDIATE FREQUEN- CY RANGE WITH BACKLOADED CASE

PIONEER Model PM -16B is a new speaker which is made by thoroughly improving the intermediate -range speaker Model PM -16B sold hithertofore. The frequency range of Model PM -16B is 400 -6,000 cps, reproducing the intermediate range only, but it has an extremely smooth characteristic within its range of reproduction and enhances the pleasure of truly enjoy- ing the beauty of middle frequency range. Model PM -16B is provided with a back -loaded case, its rear being hermetically sealed. Therefore the back of speaker needs not be enclosed in another box, enabling it to be mounted in any type of cabinets just as is. SPECIFICATIONS Voice coil impedance: 8 or 16 ohms Crossover frequency : over 500 cps Resonance frequency: 350 -420 cps Power Input : 25 watts Frequency range: 400 -6,000 cps Sensitivity : 104 db!watt TWO- AND THREE -WAY CROSSOVER NETWORK MODELS DN -S, DN -6 AND DN -7 A crossover network is a 'must' for constructing a multi -way system. The three kinds of crossover networks Models DN -5, DN-6 and DN -7, newly placed on the market by the PIONEER, can be expediently used in either two -way or three -way system by means of a slide switch. Especially the Model DN -5, in addition to two -way or three way selection, is provided with a switch for choosing the impedance of either 8 ohms or 16 ohms as occasion demands. Those, who have a two -way system at present and desire to convert it into a three -way system, can do so very simply by just using a Model PM -16B together with any one of these networks. SPECIFICATIONS D N - 5 Model No. DN -S DN -6 DN -7 Attenuation : 6 db /oct. 12 db /oct. 12 db /oct. 4,000 cps for two -way 4.000 cps for two-way 4,000 cps for two-way Crossover frequency: 500 cps and 4,000 cps 500 cps and 4,000 cps 500 cps and 4,000 cps for three -way for three -way for three -way (selected by slide switch) (selected by slide switch) (selected by slide switch 8 or 16 ohms Impedance: 8 ohms (selected by slide switch) 16 ohms Maximum transmitted power: 30 watts 30 watts 30 watts FUKUIN ELECTRIC, LIMITED pioneer 5 Otowacho 6- chome, Bunkyoku, Tokyo, Japan

AUDIO NOVEMBER, 1960 27

www.americanradiohistory.com Level -Test Tapes Aid Program Reproduction

JAY C. ABBOTT

Wide differences in level from tape to tape have plagued the broad- caster as well as the serious tape recordist for a long time. Here is a pro- posal, which, if universally adopted, may well eliminate the problem.

THE ALMOST UNLIMITED level range of modern recording tape unfortunately is a contributing factor towards sadly disappointing the listener when tapes which sounded brilliant at the time of recording are played over radio or trans- ferred to disks. The lack of positive levels that would apply to all tape recorders, regardless of make or working condition, would, from the experience of this writer, seem to be the factor needing correction. Perhaps this would then be a good time for tape recordists to give thought to the plight their work has brought to the broadcasting and recording industry. For example, the working day of the station engineer finds him faced with an endless stream of records and tapes which he must get on the air, often while dubbing as announcer, phone-answerer and general office boy. Many of these same factors apply to commercial rec- ord companies who have daily produc- tion quotas to consider. While commercial records in general are recorded within basic db level ranges, the tapes an engineer can encounter in Fig. 1. Marking the level -test tape. a day might vary from a whisper to the roar of a hundred jets on take -off. gap. There is a twofold purpose in hav- master. This dynamic concert favorite Considering that a radio station disk ing level test tapes : the first being to opens with a soft roll of the snare drum jockey, who nowadays often doubles on establish the general level used by the and plucking of the harp. For five min- the controls, might be clear across the operator in recording his program ; the utes this beat is exchanged among the room engaged in the lawful pursuits that second is to establish a known working various instruments of the orchestra with management has also found to occupy level of the recorder being used. It is little increase in overall volume. Then his time, it is no wonder that tapes con- amazing the variance of zero db levels the roof begins to bulge and the operator taining a wide range of sound levels that one can encounter going from one is faced with a db meter that doesn't often come over the air with disastrous tape recorder to another, even of the seem to know any limit to its rise. At results. same manufacture. the end of twelve minutes the operator Record engineers have the struggle of Factors controlling this variance can generally has overcome the single effect compressing tape sounds within the db be bias level at the moment of recording, the conductor and orchestra have labored range their equipment is capable of tube and component conditions, tape and so hard to create -that of a constantly transferring to records. Within either in- surface condition of the record and play- rising crescendo of sound, climaxed with dustry the transfer of program material back heads. Level -test tapes allow for all a loud discordant noise marking the end. tape -to -tape, to the air, or record sur- these variances and permit, when dupli- With level -test tapes the operator can faces often ends up in a game of Rus- cating or broadcasting, operation at the within seconds adjust his equipment so sian Roulette due to the lack of known highest possible signal level without fear as to completely preserve the musical levels. of overload or change in volume level text indicated by the composer and win Level -test tapes made at the time of during the run. for himself the applause of listeners recording can do much to correct this Consider for a moment an engineer everywhere. .x.254 Audobon Dr., S.E., Grand Rapids, faced with putting a live tape recording The problem of established levels for Michigan. on Ravel's Bolero, on the air or a record tape recording was encountered by the

28 AUDIO NOVEMBER, 1960

www.americanradiohistory.com CLASSICS THAT MADE THE HIT PARADE

-a new bonus reel from Audiotape DETAILS OF THE PROGRAM Some of our greatest popular songs - hits like "Full "Classics that Made the Hit Parade" includes Moon and Empty Arms," "Till the End of Time," these popular symphonic themes: "Stranger in Paradise " - took their melodies from the Borodin . Polovtsian Dances from Prince Igor classics. Eight of these lovely themes -in their original (Stranger in Paradise) classical setting -are the basis for "Classics that Made Tchaikovsky Symphony No. 5 in E (Moon Love) the Hit Parade," a program with strength, variety, and, Waldteufel Espana Waltz of course, rich melodic beauty. (Hot Diggity) This unusual program, professionally recorded in Chopin . Polonaise No. 6, in Ab Major RIGHT (Till the End of Time) sparkling full fidelity on Audiotape, is available Tchaikovsky Symphony No. 6 in B Now from Audiotape dealers everywhere. (And only (The Story of a Starry Night) from Audiotape dealers.) Ask to hear a portion of the Rachmaninoff . Concerto No. 2 in C Minor program, if you like. Then, take your choice of a half - (Full Moon and Empty Arms) hour of two -track stereo, or 55 minutes of four -track Chopin . . . Fantasie Impromptu in C# Minor (I'm Always Chasing Rainbows) stereo or dual -track monaural sound - all at 7% ips. Tchaikovsky . . Romeo and Juliet Overture Don't pass up this unique opportunity. (Our Love) "Classics that Made the DETAILS OF THE OFFER Hit Parade" makes an ideal This exciting recording is available in a spe- addition to Audio's first two cial bonus package at all Audiotape dealers. bonus reels, "Blood -and- The package contains one 7 -inch reel of Thunder Classics" and "High Audiotape (on 11/2 -mil acetate base) and the valuable "Classics that Made the Hit Parade" Spirits," still available at

program (professionally recorded on Audio- Audiotape dealers. tape). For both items, you pay only the price of two reels of Audiotape, plus $1. And you have your choice of the half -hour two -track stereo program or the 55- minute monaural or four -track stereo versions. il speaks for itself See your Audiotape dealer now. AUDIO DEVICES, INC., 444 Madison Ave., N. Y. 22, N. Y. In Hollywood: 840 N. Fairfax Ave. In Chicago: 5428 N. Milwaukee Ave.

www.americanradiohistory.com level -test tapes will permit an adjust- ment to be made to correct for the natu- ral loss that is encountered when half - track recordings are being played on full -track equipment. The second track naturally being blank. In practice the system offered here is :u'hieved in the following manner, how- ever, the individual recordist can easily alter the system to fit his individual needs. While these notes refer to symphonic AANNIEG WARNING EARNING recordings, all procedures also apply to TO AIL TATIOJ ENGINEERS 14 esTAILLLEIRG recordings of popular music, group or LEVEL Or THE PROGRAM MATERIAL GOrTAIRED IN TMI3 single performers, any recording where A 1S SEOOED EICORDIA:, LEVEL TEST RECORDING IMMEDIATELY it is desired to preserve the full range ' THE ACTUAL PE$E1: BROADCAST MATERIAL. THIS of tone used by musicians, actor or RNPaCIER3 RECEDING TP.R IuUDRR PASSAGE TRAT speaker to his D:'PL4R MILL ErCOl7TptED present performance to THE NB%ADCAST ARD A LEVEL THAT M;LL IC? the public. ,DEM. PILG.9AM HE IX? REATI,.1' AND TIMING The symphonic series I have men- TH CAM Ba P,aD i +' SN;CSD TIMINI L.,;JNa 1ICU PULLq/li -Ara. THE B&B tioned is first taken on what is called TRANE Y;: D, the music master tape, which is edited to the time limits of the program. Voice announcements are then added to, and in cases over, the music on a first dupli- cation process. Either during initial editing or when dubbing voice, careful note is made of the dynamic range of the symphony, con- certo or suite being worked. The selected Fig. 2. Flyer is packed with tape to inform broadcast engineers about test tape. This passage is duplicated making sure the will prevent him from inadvertently putting the test tape "on the air." controls are set so as to duplicate ex- writer during production of a radio station engineer or recording studio actly the volume intensity. series featuring a 90 -piece symphony could set their equipment for the loudest During the second editing on what has orchestra. A group of this size is capable known signal they would encounter in now become the "program master" tape, of producing levels that can exceed even the program which followed. the selected passage representing the the db level limits of tape. Add to this Later another procedure was developed loudest part of the program is attached orchestra a 600 -voice festival choir and which accomplished the same results to the lead of the tape with appropriate the stage is set for a tape broadcast that without the time -consuming process just leader strips. would tax the ability of all but the most described. The revised system however The program master tape is now ready experienced engineer. requires audio signal generating equip- for duplication in the required number Let an inexperienced person happen ment and for the benefit of those lacking to accommodate stations carrying the to be at the controls for such a broadcast such equipment or for those who would symphony broadcast. The same test level however, and you can imagine the dis- find such practice not practical "in the added to aid radio stations now serves to aster that would result -and did! This field," the first procedure is described in assist the duplication service, if em- then is the reason for the effort that went full. ployed, in quickly and accurately adjust- into formulating this proposed idea for To create a level -test tape without the ing their equipment. Further, by record- level -test tapes. laid of audio signal generating equipment ing at the highest possible level through The solution which is offered here to the recordist selects that passage he the test level system, a considerable drop correct the problem of tape level has knows to contain the loudest db level in tape hiss has been noticed in the dupli- been taken in part from a practice fol- range. This is then recorded for approxi- cated tapes. lowed by news services in the transmis- mately 15 seconds, making sure that the Where master tapes are released for sion of wirephotos throughout the world. controls are not changed after being set. use and duplication not employed the Preceding each picture transmission, a An error at this stage can throw the same procedures would apply with the brief interval is taken to transmit a entire procedure off balance and destroy test strip applied to the beginning of sending level to which each set on the the intent of level -test tapes. the program. network is then adjusted by the receiving We first employed this system in pre- By specific instruction duplicated operator. Through this method the oper- paring symphony recordings and the en- tapes are returned with the test level ator in Grand Rapids, Michigan; Spo- thusiasm with which it has been received strip intact. However leader strips must kane, Washington; or Atlanta, Georgia by station engineers has been most en- be placed between the test and program received identical reproductions of the couraging. The finished product on the material and so noted. (See Fig. 1.) The transmitted image. All variations are air has become a true presentation of first leader strip is carefully marked in eliminated. the program material contained on the crayon or ink, "15 second test -level re- Following the suggestion of creating tape with absolutely no evidence of cording." On the second leader strip im- a tape recording test signal we turned overloading or a rush to adjust receiver mediately preceding the actual broadcast to the musical score being recorded and volume. All of the dynamic range so required program information and tim- decided to employ the loudest passage favored by musicians is preserved espe- ing is noted. 1 contained in the recording and to copy cially when heard on FM transmission. As a final step in packaging the pro- this signal for approximately 15 sec- While most stations prefer full -track gram a flyer is attached so as to lie over onds. By inserting this special recording recording, when necessary or the occasion the program reel. (See Fig. 2.) Sug- as a leader to the actual recording the demands, anything will do. Here again, ((" ,,tinned on page 92) NO.

30 AUDIO NOVEMBER, 1960

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www.americanradiohistory.com Stereo Considerations

HERMAN BURSTEIN

For those considering the purchase of a stereo tape machine here is an informed discussion of the merits of four -track tape systems.

MOST OF WHAT has been said in pre - vious articles applies to mono and stereo tape operation alike (unless specifically directed at one or the other). However, stereo recording and playback entail certain special questions, which are Fig. 2. Four -track tape. the concern of the present article. The stereo topics to be discussed here are four - track versus two -track stereo, the tape cartridge, coordination of the two chan- nels, and conversion for stereo.

Four -Track Stereo stereo was first introduced, When tape spaced about 11/4 -in. apart, and posi- a reliable and not overly expensive de- it employed the same track arrangement tioned so that the gap of one head vice. Thus the staggered -head arrange- as half -track mono tape, shown in Fig. spanned the upper track while the gap ment, innately a clumsy one, became ob- 1A, except that the lower track (for a of the other spanned the lower track. solete, and so did the tapes that had been tape running from left to right) was Use of separate heads permitted indi- recorded by this method. It was not feas- used for the second channel. Originally, vidual adjustment of azimuth of each ible to use an in -line head to play a tape a staggered -head arrangement, shown in gap, assuring maximum treble response with a displacement of 11/4 -in. between Fig. 1B, was used to record and play on each channel; and it avoided the channels, corresponding to a time dif- 2 -track stereo tape, but this eventually problem of crosstalk between heads, ference of 1/6 second at 7.5 ips and 1/3 gave way to a single in -line head, shown namely the appearance of the left signal second at 3.75 ips. in Fig. 1C. The staggered arrangement in the right head and vice versa. Two -track stereo tape ran into prob- employed two conventional mono heads, With improvements in manufacturing lems of tape economy and convenience *280 Twin Lane E., WVantagh, N. Y. techniques, the in -line head proved to be (Continued on page 35)

A e C HALF -TRACK MONO TWO -TRACK STEREO TWO -TRACK STEREO STAGGERED HEADS IN -LINE HEAD 100 mils GAP 50 mils y__ -4 LEFT CHANNEL

¡j TRACK 2 Viiy 4 RIGHT CHANNEL f 4. 100 mil, DIRECTION OF TAPE

Fig. 1. Head configurations for half-track mono and two -track stereo tape.

32 AUDIO NOVEMBER, 1960

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ADVANCED FEATURES AND OPTIONS technical advances permit combination of complete. pr onal stereophonic and monophonic record and repro- duce at little more cost Char monophonic alone. The versatile PR -10 -2 provides 1) complete stereophonic record and repro- EXCLUSIVE ELECTRODYNAMIC CLUTCHES for fast, gentle, error -proof tape handling duce, 2) monophonic record and reproduce with many of the EXCLUSIVE AUTOMATIC TAPE THREADING ACCESSORY introduces "No Hands" tape new two -channel techniques now being used, 3) conventional handling for speed and convenience 'optional) monophonic use (r/z track). In addition, separate-track erase head in combination with new PROFESSIONAL PUSHBUTTON RELAY SOLENOID CONTROLS for rugged, positive, "record- safe" selector permits half-track recording of either convenient operation track, sound on sound. cue tracks. and other special effects. Full -track playback applications can also be met with full -track COMPLETE REMOTE CONTROL of ALL functions permits expanded use of recorder playbac ALL NEW COMPACT ELECTRONICS with many advanced design features PR -1 ADVANCED DESIGN 4- POSITION HEAD ASSEMBLY (erase, record, playback, -f- space PHONIC MODEL for extra head) permits changing heads in the field for special requirements II advanced fe ' electronics PLAYBACK WHILE RECORDING for on- the -spot quality assurance with a built -In mixer that can mix line and microphone or two microphones (by using a plug -in preamplifier). Later conversion 4 -TRACK STEREO PLAYBACK (optional) for fourth head position to two or more tracks is accomplished by changing full -track MINIATURIZED "PLUG -INS" for flexibility of equalization and input characteristics head stacks and adding an electronics. (The half -track version is originally equipped with stereo heads.) HYSTERESIS SYNCHRONOUS MOTOR for timing accuracy PORTABLE OR RACK MOUNT AVAILABLE ON BOTH MODELS TWO SPEEDS: 15 and 712 fps or 7/2 and 33,4 ips As a portable, the PR -10 offers performance found only in units twice is size and weight. For rack installation, either the RUGGEDNESS AND DURABILITY of overall design to outlast a succession of lower monophonic or stereo units require only 19" wide by 14" high ost units mountings - a space occupied by many older recorders, permit- ting easy replacement without disruption of equipment racks.

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Rigid, noise -insulated top plate of Hysteresis, synchronous motor for special aircraft style construction in- timing accuracy. Reserve power in- sures permanent alignment of all com- sures against stalling or overloading ponents for precision tape handling Exclusive electrodynamic drive as- Shielded, hinged head fully cover sures permanent, adjustment exposes heads -free for easy tape editing tape handling Head alignment "locked" to elimi- Each transport component (clutch- nate periodic need of head adjustment es, motor, solenoids) is unitized, Error-proof pushbutton operation plugs into color coded socket on control Simple, guided, straight -line tape box threading All new compact electronics with new, low noise and Tape lifters permit touch cuing on circuits many operating features and fast wind and rewind conveniences Safe -Record Positive, dependable speed change selector protects against accidental erasure Provision for fourth head (four - Two 3" side -by -side VU meters track stereo, sync head, etc.) .,:e. permit simultaneous reading and bal-

Motor cuts off to permit "stand- , ancing of channels by" position when safety switch arm r All electronic alignment controls is released C\_1 [\_'-1 accessible through exclusive front Lifetime, solenoid operated self - panel door, eliminating need to re- regulating brakes never need adjust- .--z1 move unit from case or rack ment r- 44 r Individual A -B switches on each 1 channel for quick comparison be- t tween original and recorded program

ASSOCIATED EQUIPME GENERAL PERFORMANCE CHARACTERISTICS AND SPECIFICATIONS IMPORTANT: optional at extra cost AS PROFESSIONAL EQUIPMENT, THE AMPEX PR -10 SERIES OF RECORDERS IS DESCRIBED BY SPECIFICATIONS LISTED BELOW WHICH ARE ACCURATE MEASUREMENTS REQUIRED BY PROFESSIONAL STANDARDS AND DO NOT INCORPORATE EXAGGERATED SALES CLAIMS. THESE ARE FOUR POSITION TWO -CHANNEL, MONOPHONIC/STEREO MIXER THE The MX -10 mixer was designed to extend the flexibility and operation of the GUARANTEED MINIMUM PERFORMANCE SPECIFICATIONS THE CUSTOMER PR -10 recorders, permitting up to four microphones, or two mikes and two lines, CAN EXPECT IN LONG -TERM OPERATION. to be controlled and fed to either or both output channels. Request Bulletin No. 211 for full details.

PROFESSIONAL SPEAKER AMPLIFIER MONITOR SYSTEM The finest. most flexible unit ever designed for professional monitoring. Prov quality, power, and overload characteristics essential to critical listening, evaluation. Powerful 40 watt amplifier with new stabilizing power demands FREQUENCY RESPONSE: 30 - 18,000 cps ± 2 db at 15 fps cuitry and efficient, long excursion speaker in special completely separate tuned 40 - 12,000 cps + 2 db at 71/2 fps duct enclosure assure lowest distortion at critical low frequencies. Available for 40 -8,000 cps -.-2db at 33/. ips portable, rack or wall mounting. Request Bulletin No. 214. SIGNAL TO NOISE Better than 55 db at 71/2 and 15 ips RATIO: 50 db at 33/. ips REMOTE CONTROL FLUTTER AND WOW: Less than 0.15% rms at 71'2 and 15 ips Greatly expands use of recorder. Plugs into receptacle provided and permits 0.25% rms at 33/4 ips recorder to be controlled from any desired location. Duplicates all functions of TIMING ACCURACY: Within + 0.25% record, play, fast forward and fast rewind buttons on tape Record transport. OUTPUT: -t- 4 dbm into 600 ohm balanced or unbalanced button prevented from functioning when record selector is in "safe" position. load. Cannon XL connectors. Single and two - Available as a boxed or flush plate unit. channel headphone jacks provided. INPUTS: PR -10.1 single -channel model with two inputs: TWO- SECOND AUTOMATIC TAPE THREADING No. 1 - Low impedance microphone input stage. Exclusive Ampex Professional accessory allows two -second threading without bel No. 2 - Unbalanced bridging with provisions for touched by hand. Kit is either factory-installed or can be added later by user. plug -in balanced bridging transformers or low impedance plug -in microphone preamp. Individ- PLUG -IN EQUALIZERS ual gain controls on each. Interchangeable units provide NAB, AME or CCIR curves appropriate to tape speed PR -10 -2 two -channel model with one input per channel: Unbalanced bridging with provisions used. Equalizers for other curves to meet special requirements available on for plug -in balanced bridging transformers or special order. low impedance plug-in microphone preamps. The MX -10 accessory mixer is designed to feed un- PLUS-IN INPUT UNITS balanced bridge inputs. Interchangeable units match various Inputs such as zero loss transformer for SPEEDS: 71/2 and 15 ips, or 33/< and 74 ips balanced bridging; 40 db microphone miniaturized preamplifier for close pickup POWER REQUIRED: 117 volts AC - 60 cycles, 1.84 amps (215 watts) conditions and,or high output microphones 60 db - miniaturized preamplifier RACK SPACE: Transport 83/a" x 19" x 6" D. for distant pickup conditions or low output microphones. Electronics 51/s" x 19" x 57/a" D. WEIGHT: Unmounted 44 lbs; Portable 53 lbs.

STUDIO CONSOLE PERFORMANCE AND FEATURES AT HALF THE WEIGHT, HALF THE SIZE AND HALF THE PRICE: PR -10 -1 Monophonic recorder $845 AMP1Ex PR -10 -2 Stereo Monophonic recorder $945 MX -10 Stereo /Monophonic mixer $395 SA -10 Speaker/Amplifier $295 AUDIO PRODUCTS DIVISION AMPEX PROFESSIONAL PRODUCTS COMPANY Prices are for unmounted models 934 Charter Street Redwood City, California EMerson 9-7111

SEE YOUR AMPEX PROFESSIONAL DEALER FOR COMPLETE DEMONSTRATION. ASK FOR A NEW FULLY ILLUSTRATED EIGHT PAGE BROCHURE.

www.americanradiohistory.com FOR COMPLETE DEMONSTRATION OF THE TAPE GUIDE PR -10 (from page 3.2) of operation. In the case of mono half - SEE YOUR AMPEX PROFESSIONAL DEALER track operation, one could record or play

the tape in one direction, reverse the ALABAMA ORLANDO Pecar Electronics OREGON reels, and promptly continue operation BIRMINGHAM East Coast Radio of Orlando 11201 Morang SALEM Shgh Acts Radio Supply Co. 1012 Blvd., S.W. Reiss Public Address Systems Cecil Farnes Co. in the other direction. But two -track 3101 . 4th Avenue 7629 E. Jefferson So. PENSACOLA 440 Church N. E. stereo permitted the tape to be used only Grice Electronics Inc. GRAND RAPIDS 300 E. Wright St. in one ARIZONA Kaminga Electric Company PENNSYLVANIA direction, which was wasteful of TAMPA 1337 Judd Avenue S. W. PHOENIX PHILADELPHIA tape, particularly for commercial appli- Burdett Sound MINNESOTA Austin Electronics Inc. Bruce's World of Sound 3619 Henderson Blvd. 2711 E. Indian School Rd. MINNEAPOLIS 1421 Walnut St. cations. In the case of prerecorded tape, Lew Bonn Company Radio Electric Service Co. of Pa. 7th and Arch Sts. the tape itself presents a major item of GEORGIA 1211 LaSalle Ave. CALIFORNIA ATLANTA ROSLYN cost, whereas in the case of a phono- EL MONTE Ack Radio Supply Co. MISSOURI Grove Enterprises Audio Supply 331 Luckie St., N. W. KANSAS CITY 1383 Easton Rd. graph disk the vinylite material is a mat- 543 So. Tyler Ave. Electronic Equipment Inc. BA Hi Fidelity 301 East 55th St. ter of a few cents. Moreover, after a two - FRESNO 526 Plaster Ave.. N. E. RHODE ISLAND Burstein.Applebee Company Tingey Co. PROVIDENCE track tape has been recorded or played, 847 Divisadero St. 1012 McGee St. HAWAII De Mambro Radio Supply it is necessary to rewind it in to HOLLYWOOD 1292 Westminister St. order HONOLULU Franklin Electronics NEBRASKA John J. Harding Co., Ltd. get it back on its original reel; this is 1130 El Centro St. OMAHA 1514 Kona St. SOUTH CAROLINA Ralke Co. House of Hi Fi not the case for mono Precision Radio Co. half -track tape, 849 No. Highland Ave. 4628 Dodge St. COLUMBIA 1160 So. King St. Dixie Radio Supply Co. where half the width of the tape (ap- LONG BEACH NEVADA 1700 Laurel St. Scott Audio Co. proximately) is recorded in one direction 266 Alamitos St. ILLINOIS LAS VEGAS CHICAGO Rugar Electronics and the other half in the opposite direc- LOS ALTOS SOUTH DAKOTA Allied 517 Tumbleweed Lane Audio Center, Inc. Radio Company SIOUX FALLS 100 N. Western Are. tion. 293 State St. Warren Supply Co. of So. Dakota Fried's Incorporated NEW JERSEY 115 S. Indiana Ave. The problems of tape economy and LOS ANGELES 3801 W. 26th St. CAMDEN Arco Electronics Newark Electronics Corporation Radio Electric Service Co. convenience of operation were solved by Ill So. Vermont Ave. 223 W. Madison St. of New Jersey TENNESSEE California Sound QUINCY 513 Cooper St. MEMPHIS four -track stereo recording, as shown in 310 No. Hoover St. Gates Radio Company PATERSON W 8 W Distributing Co. Craig Corporation 123 Hampshire 644 Madison Ave. Fig. 2. Tracks one and three are recorded 3410 So. La Cienega Blvd. Magnetic Recording Co. 344 Main St. Kierullt Sound Corp. NASHVILLE (and played) in one direction, and, after 1015 So. Figueroa St. INDIANA Nicholson's High Fidelity Center 113 - 19th Avenue So. the reels are reversed, tracks four and Magnetic Recorders Co. INDIANAPOLIS NEW MEXICO Melrose Ave. 7120 Radio Distributing Company SANTA FE PALO ALTO 814 N. Senate Sanders 8 Associates TEXAS 70 West Marcy St. Mardis Co. SOUTH BEND ARLINGTON 2115 El Camino Real Colfax Company. Incorporated Audio Acoustic Equipment Co. 747 SACRAMENTO S. Michigan NEW YORK 130 Fairview Drive BUFFALO McCurry Co. DALLAS 8th & I St. Buffalo Audio Center IOWA Audio Acoustic Equipment Co. 161 Genesee St. SAN DIEGO CEDAR RAPIDS 5645 N. Central Expressway Collins Radio Company NEW YORK CITY Radio Parts Co. EL PASO 2060 India St. 5200 C Avenue Camera Equipment Co. Sanders & Associates 315 West 43rd St. SAN FRANCISCO 1225 East Vandal! St. Harvey Radio Magnetic Recorders Inc. Co. LOUISIANA 103 West 43rd St. HOUSTON 1081 Mission St. BATON ROUGE Lang Electronics Busacker Electronic Systems Inc. SAUGUS Southern Radio Supply Co. 507 Fifth Ave. 1216 W. Clay St. Sylmar Electronics 1112 North Blvd. Sonocraft Corp. Gates Radio Co. 26000 Bouquet Canyon Rd. NEW ORLEANS 11s West 45th St. 2700 Polk Ave. South Radio Supply Co. Visual Electronics MIDLAND 1909 Tulane Ave. 356 West 40th St. Midland Camera Co. 250 5 10 15 20 25 30 3 COLORADO 317 N. Colorado St. ROCHESTER AZIMUTH MISALIGNMENT -MINUTES OF ARC DENVER MARYLAND Rochester Radio Supply SAN ANTONIO Davis Audio Visual Inc. BALTIMORE 600 East Main St. Modern Electronics Co. 2149 So. Grape 2000 Broadway High Fidelity House SYRACUSE Electric Accessories 5127 Roland Ave. 1260 Blake W. G. Brown Sound Fig. 3. Signal losses due to azimuth mis- 521 East Washington St. UTAH alignment at cps a MASSACHUSETTS TUCIeAHOE SALT LAKE CITY 7500 at tape speed CONNECTICUT BOSTON Boynton Studio Standard Supply Co. of 7.5 ips. 10 Pennsylvania Ave. NEW HAVEN De Mambro Radio Supply 225 E. 6th Street South Radio Shack Corporation 1095 Commonwealth Ave. 230 Crown St. NORTH CAROLINA two are recorded in the other direction. Radio Shack Corporation VIRGINIA 730 Commonwealth Ave. WINSTON.SAL EM NORFOLK. RICHMOND - ROANOKE The major disadvantage of four -track CAMBRIDGE DaltonHage Incorporated Radio Supply Co. Inc. DISTRICT OF COLUMBIA Hi Fi Lab 938 Burke St. compared with two -track tape is a reduc- WASHINGTON 1071 Massachusetts Ave. RICHMOND Shrader Sound, Inc. NEEDHAM HEIGHTS OHIO J. M. Stackhouse Co. tion in signal -to -noise ratio. The tracks 2803 M Street, N. W. Industrial Electronic Supply CINCINNATI 5803 Patterson Ave. Wilson Gill Inc. 150 A Street Customcrafters Audio, Inc. of the former are about half the width I Thomas Circle, N. W. SPRINGFIELD 2259 Gilbert Ave. WASHINGTON of the latter, so that there is a propor- Del Padre Supply Co. COLUMBUS 999 Worthington St. Electronic Supply Corporation SEATTLE tionate reduction in the amount of signal FLORIDA WELLESLEY 134 E. Long St. Electricraft. Incorporated 1408 - 6th Ave. that is recorded. Consequently the signal I NOIALANTIC Music Boa DAYTON Western Electronics Supply Co. McHose Music 58 Central Ave. Custom Electronics Incorporated 717 Dexter St. level obtained from the four -track tape 145 Filth Ave. WORCESTER 1918 5. Brown St. JACKSONVILLE De Membro Radio Supply Srepco, Incorporated SPOKANE in playback is about 6 db less than the 222 Summer St. Sales Inc. Fidelity Sound Inc. 314 Leo 20th Century West 1621 First Ave. signal from a two -track tape. This means 1427 Landon Ave. TOLEDO Southeast Audio Co. MICHIGAN Warren Radio that the ratio of audio signal to noise 1125 Roselle St. ANN ARBOR 1002 Adams SI. WISCONSIN MIAMI Wedemeyer Electronic Supply MILWAUKEE and hum produced by the tape recorder East Coast Radio of Miami 215 N. 4th Ave. OKLAHOMA Beacon Electronics Division electronics is decreased 6 db. 1900 N. W. Miami Ct., N. W. DETROIT NORMAN 715 N. Milwaukee St. Flagler Radio Co. K.L -A Laboratories, Inc. Thomson Sound Systems Steffen Electro Art Company However, ways are being found around 1068 W. Fleeter St. 7375 Woodward Ave. 315 W. Boyd 5101 W. Lisbon this problem. For one thing, tape elec- tronics today tend to be less noisy than those of yesteryear due to improvements AUDIO PRODUCTS DIVISION in circuit design and in tubes or tran- sistors. another, is AMPEX PROFESSIONAL PRODUCTS COMPANY For it possible H AMPEX through skillful design to produce play- 934 Charter Street Redwood City, California back heads with increased output for a

AUDIO NOVEMBER, 1960 35

www.americanradiohistory.com track, with a consequent reduction in sig- however, that eventually all houe ma- F OUR-TRAC K nal -to -noise ratio. chines will permit four -track recording. TWO -TRACK STEREO HEAD STEREO TAPE Some tape machine manufacturers (As a side note, it is of interest to ob- have chosen to accept this limitation on .serve that the four -track head makes t~ signal -to -noise ratio of one of the chan- possible four -track mono operation, TRACK I -LEFT nels. Others, however, have incorporated thereby doubling the playing time ob- a mechanical device for shifting the head tainable from a reel of tape. The re- TRACK 2 -RIGHT up and down. For four -track tape, run- cording or playback sequence is : tracks ning from left to right, the head is one, four, three, and two. A number of GAPS shifted up. It is shifted down for two - tape machines, through extra switching track tape. There is some danger of im- facilities, take advantage of this oppor- pairing azimuth alignment as the head tunity. Switching must do the following : Fig. 4. Mismatch between the lower gap is shifted up or down. Consequently in (1) In recording, it must channel the of a four -track stereo head and the a few high -price machines a separate input signal first to one section of the lower track of a two -track stereo tape. head has been introduced for playing head (for tracks one and four) and then two -track tapes. to the other section of the head (for given amount of signal recorded on the Most home tape machines use the same tracks three and two). (2) At the same tape. Third, there have been continual head for record and playback. Such time, in recording, it must shut off the improvements in tape quality, and it is machines, perforce, permit four -track bias current to the record head section reasonable to believe that time will bring recording as well as playback. However, not in use and it must shut off the erase improvements with respect to the amount the higher -price tape machines usually current to the erase head section not in of signal that can be recorded on the employ separate record and playback use. (3) In playback it must channel the tape without increasing distortion or heads. Some of them use two -track re- signal first from one section of the head other undesirable effects. In sum, one cord heads, while others provide four - and then from the other section to one may look forward to eventually achiev- track record heads. It would appear, of the playback amplifiers. If one uses ing a signal -to -noise ratio on four -track track that approaches the ratio achieved in the past on two-track tape. On the other side of the coin, four - track stereo tape has two positive ad- vantages over two -track tape. One is the fact that azimuth alignment becomes less critical as track width is decreased, thereby reducing treble losses due to slight departures from exact azimuth. Figure 3 suggests the benefits obtained from narrowing the track. It compares azimuth losses for a half -track mono re- cording with those for a full -track mono recording. Obviously, much greater azi- muth misalignment, in relative terms, is tolerable for the narrower track. The benefits obtained by going from two - to four -track stereo are comparable with those indicated in Fig. 3. The second advantage of four -track tape lies in the greater separation be- tween the two gaps of the in -line head. Hence there can be greater separation between the two sections of the head, re- sulting in less crosstalk. Comparison of Figs. 1C and 2 shows that there is 50 mils (thousandths of an inch) separation between the gaps of a two -track stereo head, compared with 93 mils between the gaps of a four -track head. Although it is indicated that four -track stereo tapes will supersede two -track stereo tapes, there will remain the prob- lem of playing valued two -track tapes purchased or recorded in the past. There- fore the manufacturers of tape machines have sought to make it possible to play two -track stereo tapes with four -track heads. The problem lies in the fact that

the lower gap of the four -track head does not lie fully within the recorded area of the lower track of a two -track tape. This is made clear in Fig. 4. The fact that part of the lower gap spans unrecorded space means less output on the lower Fig. 5. The RCA tape cartridge.

36 AUDIO NOVEMBER, 1960

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AUDIO NOVEMBER, 1960 37

www.americanradiohistory.com gaps, to preserve frequency response do not claim high fidelity performance substantially out to 15,000 cps, closely at this speed, the results are surprisingly rivalling the performance at 7.5 ips in good. For example, they can reproduce this respect. Still, in terms of distortion music quite satisfactorily for background TILTED GAP and signal -to -noise ratio, 3.75 ips record- or party purposes, where the presence of GREATLY EXAGGERATED) ings lag behind those at 7.5 ips. To competing sounds makes it pointless to achieve response out to 15,000 cps or strive for high fidelity. But the 1.875 ips thereabouts at 3.75 ips, it is necessary cartridge proposes to go a major step to reduce bias current fed to the record forward by lifting the quality at this head below the value employed at 7.5 speed to meet at least minimum high ips, thereby reducing treble losses due fidelity requirements. Fig. 6. Stereo head with tilted gap. to bias erase. The decrease in bias cur- rent results in an increase in distortion. Coordination of Channels double-play tape at 1.875 ips, it is pos- The increase in distortion can be offset A unique problem of stereo tape ma- sible to record as much as 17 hours of by lowering the recording level. But the chines is that of properly coordinating program material on a 7 -in. reel.) latter measure means less signal on the the two channels in various respects. tape and therefore a lower signal -to- This problem may lie with the manufac- The Stereo Cartridge noise ratio in playback. In practice, the turer of the machine, with the user, or It has long been the goal of a section course usually followed is to accept some partly with both. of the tape industry to simplify the play- increase in distortion and some decrease 1. Co- Linearity of the Stereo Head ing of prerecorded tape to the point in signal -to -noise ratio, rather than just Gaps. One of the problems of manufac- where this is just as easy as playing a one or the other. turing a good stereo head is to insure phonograph disc. To this end the tape As stated just before, response to that the gaps are in exactly the same cartridge has been introduced. First on 15,000 cps is feasible at 3.75 ips. But to straight line. If one gap is tilted with the scene was the RCA cartridge, shown achieve such response, greater attention respect to the other, as illustrated in Fig. in Fig. 5, which houses the tape in a must be paid than at 7.5 ips to factors 6, then it is not possible to achieve cor- plastic container with apertures that that can adversely affect treble response: rect azimuth on both channels simul- permit the tape to contact the heads, too wide a gap in the playback head; taneously; hence high frequency re- capstan, and guides. It is merely neces- incorrect azimuth alignment; poor tape sponse will suffer on one channel or the sary to position the cartridge on a tape to head contact because of dirt, brittle other, or both. If one gap is displaced machine designed for the purpose and with respect to the other, as illustrated push a button, whereupon the machine in Fig. 7, then the time relationship be- takes over without the need for the oper- tween the left and right signals will be ator ever to touch the tape. Some car- altered. Some experts have claimed that tridge players are designed to stop the extremely small changes in the time rela- tape after it has played in one direction, tionship can significantly alter the stereo while others will reverse the tape and effect. play it back in the opposite direction LOWER GAP 2. Equal Playback Levels. One section against another head, after which the SHOULD If a stereo playback head may produce BE ON THIS LINE tape is automatically stopped. a few db more signal output than the The RCA cartridge can hold up to other for the same amount of signal level 600 feet of tape, which at 7.5 ips affords recorded on the tape. Or one playback Fig. 7. Stereo head with displaced gap. a maximum playing time of 32 minutes amplifier may have more gain than the if the tape is operated in two directions. tape, improperly adjusted pressure pads, other. To determine the relative play- But to be competitive with the stereo etc.; excessive bias current to the record back levels on each channel, set the play- disc, the stereo cartridge must be able head ; improper record or playback back gain controls at the position most to provide up to an hour of program equalization. apt to be used, and play a full -track test material. Therefore it is necessary to re- Although the 3.75 ips speed has only tape. Compare the signal levels with a duce the speed of the tape cartridge to quite recently, and after much striving, VTVM or by ear, assuming in the latter 3.75 ips. In sum, the RCA tape cartridge proven capable of good quality, the case that the channels of the rest of the and the 3.75 ips speed go hand in hand. 1.875 ips speed is hard on its heels in audio system are balanced right through Fortunately, improvements in tape vying for serious consideration. The to the speakers. Adjust one of the gain heads, in other components, and in tech- further reduction in speed would make controls on the tape machine for equal niques have made it possible to obtain prerecorded tapes still more economical volume on both channels. If the tape good fidelity at 3.75 ips. Thus it appears and would permit tape cartridges and machine does not have separate playback that the tape cartridge will prove to be cartridge players to be more compact. gain controls for each channel, then it a suitable medium for popularizing pre- Along this line CBS and the 3M Co. re- becomes necessary to use the input level recorded tape. While the 3.75 ips speed cently announced a tape cartridge de- sets, if any, on the audio system ampli- may not be suitable (yet) for truly high signed to be operated at 1.875 ips. fier to equate the signals. If there are fidelity, it is still good enough to pro- While commercial production was esti- no input level sets, then the balance con- vide pleasurable reproduction of music mated to be several years distant, demon- trol of the stereo amplifier must be used to the many persons who own moderate - strations to the trade were convincing as for this purpose. It is then necessary to price sound systems and who do not de- to the possibilities of good results at this take note of the balance control setting mand the ultimate in available quality. speed. Moreover, the machine designed to which achieves signal equality on tape On the other hand, for those who de- play this cartridge incorporated a playback. mand the best it appears that for some changer mechanism, putting tape fully 3. Equal Recording Levels. Some tape time to come the 7.5 ips speed will be on a par with the phono disc for sim- machines use a single switched record used, combined with four -track stereo plicity and convenience of operation. level indicator for both channels, while recording on open reels. It may be added that a number of others use separate indicators for each At 3.75 ips, it is possible today, owing open reel tape machines already incor- channel. The fact that both indicators to playback heads with extremely fine porate the 1.875 ips speed. While they (Continued on page 95)

38 AUDIO NOVEMBER. 1960

www.americanradiohistory.com This Christmas you can afford an Ampex (Now priced from $349.50 to $595)

The work of science no longer is costly. The 960, in portable case, records mon- recorded tapes are available now - 10 Ampex prices are down, but the quality ophonic and stereo, plays single, 2- track, times as many as last year. And don't of its tape players and recorders remains and 4-track tape. Reduced from $650 to forget the recording fun of starting a brilliantly Ampex. At last these coveted $495. The 952, unmounted deck, records new kind of souvenir -the family album instruments are within reach of every stereo, plays single and 2 -track tape. on tape for hours of pleasant playback. stereophonic high fidelity enthusiast. Reduced from $595 to $450. The 902, un- Tape players and recorders by Ampex, The 970, in portable case with built -in mounted deck, records monophonically, world leader in magnetic recording, at speakers, records monophonic and plays single and 2 -track tape. Reduced your dealer everywhere. See and hear stereo, plays single, 2- track, and 4 -track from $449.50 to $349.50. them today. Ampex Audio - AMPEX tape. Price reduced from $750 to $595. For listening, more than 1,000 pre- Company, Sunnyvale, Calif.

AUDIO NOVEMBER, 1960 39

www.americanradiohistory.com CTHE ITATION

SOUND" "... FOR THE SAKE

"Over and above the details of design and perform- -When we first heard the Citations our immediate reaction ance, we felt that the Citation group bore eloquent was that one listened through the amplifier system clear back witness to the one vital aspect of audio that for so to the original performance, and that the finer nuances of many of us has elevated high fidelity from a casual tone shading stood out clearly and distinctly for the first time hobby to a lifelong interest: the earnest attempt to ... bass is clear and firm, and for the first time we noted that reach an ideal -not for the sake of technical show- the low frequency end appeared to be present even at low manship -but for the sake of music and our demand- volumes without the need for the usual bass boost ... The kit ing love of it." is a joy to construct." C. G. McProud, Editor, Audio Magazine

A truly remarkable commentary about a truly remarkable "The unit which we checked after having built the kit. is group of products -the Citation Kits by Harman -Kardon. the best of all power amplifiers that we have tested over the Mr. Reid's eloquent tribute to Citation is one of many past years ... none have had distortion that was quite as low extraordinary reviews of these magnificent instruments. We as we found in this new Citation II ... the amplifier should are proud to present a brief collection of excerpts from Cita- provide the very finest in hi -fi stereo reproduction . . ," tion reviews written by outstanding audio critics. William Stocklin, Editor, Electronics World

PRESENTING THE 1961 CITATION LINE FEATURING

The CITATION Ill The CITATION II The CITATION I Professional FM Tuner Stereophonic Preamplifier 120 Watt Stereophonic Control Center Power Amplifier Citation Ill is the world's most sensitive tuner. This remarkable instrument has a peak power But more important -it offers sound quality never Here Is the first brilliant expression of the before achieved in an FM tuner. Now, for the first advanced design concepts which sparked the new output of 260 watts and will reproduce frequencies as low as 5 cycles virtually without time Harman -Kardon has made it possible for the Citation Kit line -the incomparable Citation I, phase shift, high kit builder to construct a completely professional Stereophonic Preamplifier Control Center. The and frequencies as as 100,000 cycles without any evidence of instability or ringing. At normal tuner without reliance upon external equipment. Citation I consists essentially of a group of circuit listening To meet the special requirements of Citation blocks termed "active" and "passive" networks. levels the only measurable distortion Ill, comes from the laboratory test equipment. a new FM cartridge was developed which embodies The "active" networks are treated as one or two Video output level most of the critical tuner elements in one compact stage amplification units, flat over an extremely pentodes are used in all low stages for wide frequency unit. The cartridge is completely assembled at the wide frequency range and each is surrounded with exceptional response and low distortion. Multiple feedback loops for factory, totally shielded and perfectly aligned - a feedback loop. This results in levels of distortion increased degree of usable feedback (30 db eliminating the difficult problems of IF alignment, so low as to prove unmeasurable. The "passive" overall) result In lower distortion oscillator adjustment and lead definition. networks provide precise equalization with no without sacrificing sta- bility. The power supply consists of four silicon The Citation Ill's front end employs the revo- phase shift. diode rectifiers, choke, heavy duty electrolytics lutionary Nuvister tube which furnishes the lowest The use of professional step type tone controls and potted power transformer for precise regula- noise figure and highest sensitivity permitted by overcome the limitations of continuously variable tion and long life. The use of rigid component the state of the art. A two -stage audio circuit pat- potentiometers. Each position on a step control is boards, heavy duty components, special Cable terned after the Citation 11 is employed. By utiliz- engineered to perform a specific function -which Harness assure the kit builder that the unit he ing a high degree of feedback and providing a fre- Is absolutely repeatable when necessary. The many constructs will be the exact duplicate of the quency response three octaves above and below professional features and philosophy of design ex- factory built Instrument. Because of Its absolute the range of normal hearing, the Citation sound pressed in Citation I permit the development of a reliability and exceptional specifications the Cita- quality is maintained and phase shift is eliminated. preamplifier that provides absolute control over tion II has gained widespread acceptance among The Citation Ill is styled In charcoal brown and any program material without imparting any color- professionals as a laboratory standard. The Citation gold to match all the other Citation instruments. ation of its own. Citation 1- Factory Wired $159.95. II- $159.95. Factory Wired-$229.95. Metal Enclo- Citation 11 I- $149.95. Factory Wired - $229.95. -$249.95. Walnut Enclosure, Model WCI, $29.95. sure, Model ACII- $7.95. Walnut Enclosure, Model WC1- $29.95.

40 AUDIO NOVEMBER, 1960

www.americanradiohistory.com OF MUSIC AND OUR DEMANDING LOVE OF IT."

"Its listening quality is superb, and not easily described "Specifications published by the manufacturer are so in terms of laboratory measurements. Listening is the ulti- astonishing that our sister publication, Electronics World. mate test and a required one for full appreciation of Citation has subjected them to critical examination and found per- ... there is a solidity, combined with a total ease and lack of formance wholly consistent with claims . . Nothing can irritation which sets this amplifier apart ... The more one faze it ... we have heard this particular amplifier loaded listens to the Citation II, the more pleasing its sound becomes with four big speaker systems glide over the steepest orches- ... Anyone who will settle for nothing less than the finest tral hurdles without the slightest trace of strain . , . The real- will be well advised to look into the Citation II." ism of the virtually distortion -free music was nothing less Hirsch -Houck Labs, High Fidelity Magazine than startling. Our initial amazement soon gave way to an "At this writing, the most impressive of amplifier kits is easy, relaxed enjoyment that was sustained for hours without of known as "listening fatigue." Here without doubt the new Citation line of Harman -Kardon .. . a trace that tension their design, circuitry, acoustic results and even the manner was a sound system that fulfilled the most difficult of all high : music. of their packaging set a new high in amplifier construction fidelity requirements to provide an awareness only of ti and performance, kit or no .- and oblivion of technicalitie-.` Norman Eisenberg, Saturday Review Herbert Reid -Hi Fi Stereo Review

THE NEW CITATION III PROFESSIONAL FM TUNER

CITATION KITS harman kardon The CITATION V CITATION IV The 80 Watt Stereophonic INCORPORATED Stereophonic Preamplifier Power Amplifier NEW YORK Control Center PLAINVIEW, The Citation V Is a compact version of the pow- Is a compact stereophonic The new Citation IV erful Citation II. Designed with the same lavish designed in the best Citation tradi- preamplifier hand, it is conservatively rated at 40 watts RMS and features rivaled tion. It offers performance per channel with 95 watt peaks at less than 0.5% wave tracings at 20 and For complete information only by Citation I. Square distortion. between the re- 20,000 cycles reveal no difference The availability of rated power at the extreme on the new Citation Kits, sponse of the Citation IV and the signal generator. ends of the frequency range enables the amplifier including reprints of inde- The Citation IV provides separate bass and to effortlessly drive any of today's most ineffi- treble tone controls for each channel which may cient speakers. It clips clean without breakup. The pendent laboratory test output stage consists of two 7581's per channel be switched out of the circuit completely to elimi- reports, write to: Dept. operating conservatively in a fixed bias, ultra - nate phase shift and transient distortion inherent A is stati- In all tone controls. D.C. on all heaters and the balance circuit. bias meter provided to All, Citation Kit Division, pair of output use of low noise resistors in critical places reduce cally and dynamically adjust each tubes. The supply consists of four Harman -Kardon Inc., thermal agitation and hum. A zero to infinity bal- power silicon and heavy duty elec- ance control allows complete cut -off for either diodes (hermetically sealed) Plainview, New York. 8 regulation and long speaker. Military type terminal boards make for trolytics for excellent rigid, professional appearance and facilitate con- life. This results in instantaneous recovery time All prices slightly higher in and superb transient response. struction. The control over program material pro- the West. vided by the new Citation IV enables the user to Here is an all new power amplifier which truly perfectly recreate every characteristic of the orig- reflects The Citation approach to audio design: inal performance. The Citation IV is handsomely no compromise in quality regardless of cost. The styled in charcoal brown and brushed gold. The Citation V is styled in charcoal brown and brushed Citation IV -$119.95. Factory Wired - $1$9.95. gold. The Citation V- $119.95. Factory wired - Walnut Enclosure, WCI- $29.95. $179.95. Metal Enclosure, ACV -$7.95.

AUDIO NOVEMBER, 1960 41

www.americanradiohistory.com Be Professional-Rack Mount

WILLIAM G. DILLEY

If you would rather put your money into equipment than cabinets -rack mount. You may then be able to afford that new piece of equipment you've been wanting.

ost serious audiophiles are easily tor. Units may double as portable com- identifiable by the constant chang- ponents when removed and placed in a M ing of equipment that occurs portable housing. (See Fig. 1.) Also, the within their homes-either expanding use of rollers or casters on racks, makes their capability and performance, or ex- possible ease of movement of the entire perimenting with new equipment or de- equipment from one room to another as required signs. Even the newcomer, who retains for recording, patio music, etc. his interest, goes Accessibility /Serviceability: All com- through the evolution ponents are readily of improving his exposed by opening initial installation a door in the back of the the number of - rack for tube changes being limited changes, rewiring, lead changes, etc. The only by his enthusiasm and his pocket- individual units are easily removed from book. the front for inspection, repair, and /or The effect of all these changes is usu- modification. As one who is constantly ally reflected in the additional expense removing the efforts of amateur cabinet required to revamp the equipment cabi- makers from mazes of wires and wooden net, the cramped quarters, the increased platforms, I cannot stress too emphatic- amount of heat, ally the importance of accessibility a reduction in functional (upon electronic efficiency, performance). The ac- or at the very least, exposed tion of successfully components stuffing all wires into because of insufficient hous- a hole, just prior to sliding in the com- ing. Nothing is quite so disheartening as ponent, is just not compatible with good to own an expensive console or built -in electronic performance. cabinet that has been rendered function- Convertibility: Herein lies the great- ally obsolete by changing requirements. est saving to the individual who is con- In fact, decisions to make necessary stantly making changes and who houses changes often are avoided his equipment. Control functions may be because of a added, reluctance to deleted, or moved without chang- rebuild beautiful but out- ing the basic moded cabinets. equipment by simply re- placing the front panel at very Such a small problems, decisions, and expense cost. Inter -unit wiring changes are fa- can, for the large part, be avoided by cilitated by complete accessibility to all rack mounting your components. The units from the rear. Obviously, such advantages of rack mounting are nu- changes in a furniture -type housing can merous: flexibility, accessibility, serv- be quite costly. iceability, and convertibility, not to The disadvantages of rack mounting mention such by- products as improved are two : Women are inherently opposed ventilation, and professional appearance. to such items in their household (my wife Equally important to the audiophile, refers to mine as "The Iron Monster") however, is the added advantage of the and if you should feel inclined to sell availability of necessary materials and your equipment, the buyer's wife may de- the ease of construction required to pro- feat you for the same reason. duce that professional appearing equip- For those dedicated individuals who recognize the merit of such an installa- 577 East Avery Street, San Bernardino, tion, and who would like to rack mount Calif. their equipment, in spite of the disadvan-

Fig. 2. Record /playback unit illustrating the use of blank panels pending further expansion.

nient. A few highlights of these advan- tages are: Flexibility: Rack mounting allows complete freedom of component place- ment in a vertical direction. Units may be changed from top to bottom merely by removing panel attaching screws. Units may be interchanged as required Fig. 1. Six -position stereo mixer that for specific uses thus permitting the use Fig. 3. Portable mixer removed from doubles 7 as a portable unit. of only one rack where economy is a fac- cabinet and ready for rack installation. 42 AUDIO NOVEMBER, 1960

www.americanradiohistory.com 0 IVEWW a ° [1L] 0 fl LE*LOUDSPEAKERS SERIES

For commercial sound applications Cl 2-RC Super -shallow depth 2-SC Cl New SYNTOX -6 F Ceramic Magnets

These new 8- and 12 -inch ruggedly dependable speakers are especially designed for all PA and sound reinforcement applications, yet are economically priced. They are ideal choices for schoolroom, office, store, restaurant, supermarket, and all similar applications. Extended high frequency range, smooth response and wide angular coverage for excellent music reproduction as well as voice. The new Jensen SYNTOX -6

ceramic magnets give 1/2 to 1 db more acoustic output than speakers employing 4.64 and 6.8 oz. Alnico 5 magnets. Extremely shallow 8 -inch units permit in -the -wall mounting. Moisture proofed cone and voice coil plus corrosion resistant treatment of metal parts for maximum

reliability. 1 -inch 8 -ohm voice coils. Transformer mounting facility. O

CB-RC C8-SC

MAX. DIMENSIONS MAGNET WT. NOM. POWER NET LIST MODEL SIZE RATING DEPTH MAGNET SVNTOX -6 EQUIV. AL 5 WT. PRICE J D C8 -RC 8" 12 watts 8W 3" 31/I6" 10.0 oz. 6.8 oz. 2 lbs. $12.50 C8 -SC 8" 11 watts 81/3" 215/16" 3W 6.0 oz. 4.64 oz. 13/41bs. 10.35 C12-RC 12" 14 watts 12W 41/2" 31/46" 10.0 oz. 6.8 oz. 5 lbs. 16.00 C12-SC 12" 13 watts 121/8" 41/46" 31/4" 6.0 oz. 4.64 oz. 43/4 lbs. 14.75 NOTE: Mounting holes conform to all existing EIA standards. T.M.

THERE IS ALWAYS A BETTER /MANUFACTURING COMPANY LOUDSPEAKER FROM .. engen DIVISION OF THE MUTER CO, 601 S. Laramie Avenue, Chicago 38, Illinois In Canada: Renfrew Electric Co., Ltd., Toronto In Mexico: Universal De Mexico, 5. A., Mexico D. F.

AUDIO NOVEMBER, 1960 43

www.americanradiohistory.com tages mentioned, a typical installation manufactured side plates of heavy gauge will be described. steel may be purchased, or the builder The initial decision in rack mounting may construct his own of light alumi- is one of determining the total space re- num. Straight side plates may be used quired to house all of the components. for most chassis, but if weight is a con- Racks are available in various heights sideration, a 90 degree bend of 1/4- to from approximately 36- to 77 -in. in a 1/2 -in. on the top of the plate will pro- standard width sufficient to accommodate vide the necessary strength to support a 17 -in. chassis. When the height has all but the heaviest of components. (See been decided upon, it would be well to Fig. 3.) add a margin for error-and expansion. The panel supports the entire assem- You will surely need the additional space bly when suitably connected to the chas- once you embark on the road to rack sis and attached to the rack. mounting. Blank panels preserve a neat Control identification can be ap- appearance for any unused portions proached in two ways: panel marking to until filled (see Fig. 2). Panels (19 -in.) indicate function; or placement, direc- are available in various sizes from 1% tion of motion, and coloring to indicate to 21 -in. in height. These panels are function, with no markings required. aluminum and are easily worked. Even This latter method is usually referred to a wood file can be used to cut the mate- as function determined by association. rial. Standard 17 -in. rack chassis are Panel marking materials available to available in heights of 2- to 4 -in. and in the home constructor are rather limited depths of from 4- to 13 -in. and may be broadly classified in two gen- It is a simple matter to connect the eral categories : "hard" and "soft" type chassis to the front panel. Commercially markings.

Fig. 5. Rack -mounted stereo record /play- Fig. 4. Rack - mounted sound back system constructed by the author. distribution sys- tem by Al- used types to metal, plastic, lied Radio Cor- "Ilard" refer poration. or fiber plates or disks that are attached to the panel front by mechanical means (screws, nuts, bolts). Metal dial plates for various functions are fairly abun- dant, but specific control marking plates are almost non-existent. The constructor may, of course, make his own with pho- tographic paper covered with plastic or other such methods. However, an eco- nomical and effective method is to use engraved plastic door markers, made to order in most dime stores. "Soft" types of markings refer to painted or direct application markings. Most common in this category are de- cals such as "Techni- cals." They are available in white, black, and gold and are purchased in book form for specific mommial uses, such as: Communications, Audio, Workshop, and etc. Panels are available in three standard finishes-gray wrinkle,

44 AUDIO NOVEMBER, 1960

www.americanradiohistory.com from McIntosh ... the finest performance available the MacKit 30 A 30 -Watt Unity Coupled Amplifier Kit*

*Identical to the renowned McIntosh MC -30 Amplifier Price $120 Enjoy the wonderful experience and satisfaction of putting the finest amplifier together yourself.

A "Mark of Excellence" Product by flI4ntosh LABORATORY, INC. 4 Chambers St., Binghamton, N. Y. Now available at Franchised McIntosh Dealers

AUDIO NOVEMBER, 1960 45

www.americanradiohistory.com NTRODUCING ALTEC ' STEREO AM -FM TUNER -AMPLIFIER

Advance with Altec to the new, true sound of music -the kind which created the matchless sound of Cinerama larger -than -life sound of stereo at its finest! The all -new and Todd -AO for theatres, the speaker used by almost Altec 707 Stereo AM -FM Tuner -Amplifier brings you Altec all major broadcast and recording studios. engineering at its best -the same engineering which has Enjoy the sure made Altec sound the universal standard of theatre and simplicity of professional controls, the broadcast sound. Here is that all -in -one control unit unequalled performance of the 707 in your own stereo every stereo enthusiast has demanded -but one which set -up. Compare the specifications, then listen to it at makes no sacrifice in circuitry or component perform- your Altec dealer's. Experience that great moment when ance. In the 707, there is no compromise with quality! you are introduced to the true sound of music -the Altec It took Altec speaker engineering to turn the trick -the sound of music. Priced at only $387.00.

NOW AT LAST, a home -sized 800 cycle speaker with components similar to those used in the world- famous A7 Altec "Voice of the Theatre" system.

Visit your Altec professional high fidelity con- sultant and ask him to demonstrate the new 837A "Avalon" speaker system and the new 707 Stereo AM -FM Tuner -Amplifier, that will bring the full range and dynamics to your living room.

The 837A "Avalon" is a professional 2 -way sys- tem with frequency response of 40- 20,000 cycles. 25 watt capacity. Dimensions, 293/4" H by 35" L by 173/4" D.

Other complete speaker systems from $89.50.

Compare ALTEC advances and superior specifications at your ALTEC DEALER'S. ALTEC offers you the most complete line of quality stereo and mono high fidelity amplifiers, speakers, and systems in the world. Write for descriptive brochure. Address Dept. AD -7D

ALTEC LANSING CORPORATION, a subsidiary of Ling -Temco Electronics, Inc. 1515 S. Manchester Avenue, Anaheim, California 161 Sixth Avenue, New York 13, New York

46 AUDIO NOVEMBER, 1960

www.americanradiohistory.com THE ALL NEW

Tt c ,121 .140 160 KC 60 70 80 90100 AM 5 111911111 t11111iii211i511111{111511IICtttltlll . MC 92 94 96 98I0010210I(108 Fir! 88 90 .

FM AM Antenna: Standard 300 Ohm. Antenna: Built -in Ferrite Antenna, plus external antenna con- Maximum Sensitivity: 2 Microvolts. nection. Quieting Sensitivity: 2.9 Microvolts for 20 db. Maximum Sensitivity: 3.2 Microvolts. 7.0 Microvolts for 30 db. Loop Sensitivity: 35 Microvolts per meter. Frequency Range: 86.5 to 109 mc. Frequency Range: 537 to 1630 kc. Image Rejection: 45 db. Image Rejection: 65 db. IF Rejection: 55 db. IF Rejection: 50 db. Detector Peak Separation: 450 kc. Selectivity: 6 db bandwidth, 13 kc "Broad ", 6 kc "Sharp ". Frequency Response: ±1 db 20- 20,000 cps. Whistle Filter: 10 kc Attenuation better than 40 db. Antenna Radiation: Meets FCC Requirements. GENERAL AUDIO Front Panel Controls: Input selector switch, channel balance Power Outputs: 80 watts Stereo Program Peak Power (40 control, Dual gain control, Dual bass control, Dual treble con- watts per channel); 48 watts Music Power Output (24 watts trol, AM Broad -Sharp selectivity switch, FM AFC defeat switch, per channel); 40 watts, rms continuous, Stereo or Monophonic Stereo -Monophonic Mode switch, Stereo Standard - Reverse (20 watts per channel). switch, Loudness contour switch, Rumble filter switch. Distortion: Less than 1% THD at 20 watts, 1,000 cps, each Internal Control: Squelch threshold control. channel. Inputs: 9, Stereo or Monophonic- Magnetic Phono, Tape Frequency Response: ± .5 db 20- 20,000 cps at 1 watt. Head, Tape Machine, Multiplex Input, FM antenna, AM Tone Control Range: ± 12 db at 50 cps, 12 db at 10,000 cps. external antenna. Rumble Filter: 12 db per octave below 30 cps. Outputs: 6, Stereo or Monophonic -Channel A and Channel Input Sensitivity for 20 watts output: Tape, Multiplex -350 B Recorder, left and right speaker, Center speaker, Multiples my 1 kc; Magnetic Phono -3.0 my 1 kc; Tape Head -1.5 my Outputs. 250 cps. Tubes: 1 -6GY8, 1 -6AL5, 5.6BA6, 1 -68E6, 2 -EM84, 1- 12AU7, Input Impedance: Phono -47,000 Ohms; Tape Head - 5- 12AX7, 4 -7355. 47,000 ohms; Multiplex- 100,000 Ohms; Tape Machine - Power Consumption: 145 watts, 117 volts, 60 cps. 100,000 Ohms. External Power Available: One AC outlet controlled by power Load Impedance: 4, 8 and 16 Ohms. switch. Noise Level: Phono -55 db below 20 watts; Tape Head -52 Color: Platinum gold or platinum pink. Weight: Apx. 35 lbs. db below 20 watts; Tape Machine -78 db below 20 watts; Dimensions over knobs and antenna: 57/8" H x 15" W x 125/8" D. Multiplex -78 db below 20 watts. ntifir 1960 Altec Lansing Corporation ALTE[ THE TRUE SOUND OF MUSIC AUDIO NOVEMBER, 1960 47

www.americanradiohistory.com Space Diversity Techniques Improve FM Reception

DANIEL VON RECKLINGHAUSEN and MARTIN L. BORISH Having trouble with signal fading on your FM tuner? Two or more tuners connected together can improve your reception and may entirely eliminate fluttering of the signal caused by moving planes, other objects.

MPROVED FM reception, especially in fringe areas where signal strength I is extremely low, is now practical through use of space diversity techniques with two or more H. H. Scott 310 -D FM tuners. Adaptation of this technique to FM allows the critical music listener to obtain usable FM even though he is lo- cated in areas where ordinary tuners would fade frequently. Diversity reception is familiar to many professional shortwave operators. It has received considerable publicity for its use in tropospheric scatter transmissions such as used on the DEW line as well as in transoceanic communication. However, to our knowledge very little has been Fig. 1. H. H. Scott 310 -D Wide -Band Broadcast Monitor FM Tuner which can be done with diversity techniques for re- connected for dual- or triple- diversity interference -free reception. ception of standard FM broadcasts. Cer- s tainly the H. H. Scott 310 -D Wide -Band as expected.' The average measured field It is obvious that one does not have Broadcast Montior FM tuner, Fig. 1, is strength of a 30 -foot receiving antenna to be far from the transmitter for signal the first commercially available tuner to placed in a variety of locations is as strength to be quite low on occasion. have provisions for diversity reception much as 20 db below computed values This can also be due to attenuation built in. based on standard formulas using the re- caused by the terrain (hills, buildings, To those unfamiliar with diversity, it fractive index of atmosphere, conductiv- and so on). The appearance of short - can be described simply as a system of ity of ground, and the dielectric constant term fading on top of this causes the two or more antennas as far apart as of the earth? signal to drop below the threshold of possible, supplying signal to two or Long -term fading further complicates usability of even a sensitive wideband more tuners. The tuners in turn feed the this picture.$ Ten per cent of the time tuner. At distances far removed from the playing system. The unique feature of the signal may be as much as 13.2 db transmitter, these problems become more the 310 -D switch diversity system is that below the average (exceeded 50 per cent severe and more common. if one of the tuners is receiving a poor of time) field strength. One per cent of The greatest single cause of short - signal it will immediately switch out. In this time, the signal may be 25 db lower. term fading is reflection from moving cases of short term fading it may often Minute variations in the location of an objects on the ground or the air. Ground happen that only one antenna at a time antenna will also cause changes, due to reflections from cars, trucks, and so on gets a good signal. Using 310 -D's only reflection_ from, ground or other nearby disturb the field of the receiving an- the tuner receiving a usable signal will objects. Most people do not live near tenna only slightly. It is the reflections feed the amplifier. The automatic switch- smooth ground which is one of the as- from flying man -made objects (as op- ing between tuners can occur as rapidly sumptions used to calculate field posed to flying saucers) which are the as forty times a second without any ad- strength. major factor. In Fig. 2 we have a typi- verse effects (such as low- frequency cal situation. The plane is somewhere transients) audible in the speakers. ' Phillip L. Rice, "Tropospheric fields near the path between the transmitter Thus, the problem of signal fading can and their long -term variability as reported and the receiving antenna (it does not be considerably improved. by TASO." Proc. I.R.T., Vol. 48, pp. 1021- have to be directly between). The 1029; Tune, 1960. amount of signal reflected by the plane The Problem of Fading 2 Alfred H. LaGrone, "Forecasting tele- and picked by vision up the tuner may be as service fields." Proc. I.R.R., Vol. 48, strong as that from Just how serious is the problem of pp. 1009 -1015; June, 1960. the transmitter, de- pending on path fading in regular FM reception? Many G. Birnhaum and 11. E. Hussey, "Ampli- length. If the signal tude, scale and spectrum of refractive in- along path A and listeners are near the transmitter and that from path B + C dex inhomogeneities in the first 125 meters arrive in phase, should receive a signal of considerable the resultant signal at of the atmosphere." Proc. I.R.E., Vol. 43, the tuner will add. If they arrive strength. Investigation discloses that the pp. 1412 -1418; October, 1955. out of phase the signal will subtract and, thus, field strength may not be nearly as great 3 G. R. Sugar, "Some fading characteris- tics of regular VHF ionospheric propoga- may cancel completely. H. H. Scott, Inc., 111 Powermill Road, tion," Proc. I.R.F.., Vol. 43, pp. 1432 -1436; As the plane moves, the signal at the Maynard, Mass. October, 1955. tuner will increase and decrease rapidly

48 AUDIO NOVEMBER; 1960

www.americanradiohistory.com any 2 different HI-FI programs to several places in the home simultaneously all thru one BOGEN-PRESTO instrument!

M. ONLY OV N CO PAN DOES IT! Operating ANY 2 DIFFERENT HI -FI PROGRAMS -Family music and entertainment ALL THRU ONE BOGEN- PRESTO INSTRUMENT - tastes can be satisfied -really satisfied -with SoundSpan. Pop tunes for SoundSpan is simplicity itself. Programming Selectors direct mono or the youngsters -while the grownups listen to classical music -from stereo programs to either or both channels. A lighted panel indicator AM or FM radio, records, tape, TV sound -any two, and at the same shows the program sources and channels in use. Your choices of these time! No longer need the family be bound by the personal tastes of programs are directed to speakers individually controlled by a simple one of its members. With SoundSpan you have music to suit the indi- switching arrangement. Only the RP -40 or AP -40 with SoundSpan can vidual taste -entertainment when you want it. channel two different mono programs -or one stereo program to several loudspeakers located anywhere in your home... and without input SEVERAL PLACES IN THE HOME SIMULTANEOUSLY -Whether you program limitations. Owning the RP -40 is like having two independent live in a 3 -room apartment, a suburban split level or a very large home, high -fidelity systems in your home -for the price of one. Send for free you'll find SoundSpan versatility the perfect answer to your family needs. literature; get the whole story on SoundSpan and the many other won- Think of it- Mother can enjoy FM in the kitchen while the children derful features incorporated in the model RP -40 Receiver and AP -40 dance to records in the playroom ... thru one system! Later the whole Amplifier. family together can thrill to stereo in the living room. The bedroom, den, and the patio or terrace are other places you might locate loud- speakers operating from BOGEN- PRESTO's SoundSpan RP -40 Receiver or AP -40 Amplifier. There are four controlled output lines. How you use them is entirely up to you.

(1 i'

WATT AM -FM AP -4040 WATT AMPLIFIER TP -40 AM -FM TUNER NEW BOGEN -PRESTO RP -40 HOME MUSIC CENTER -40 LESS ENCLOSURE. $199.50 LESS ENCLOSURE $189.50 LESS ENCLOSURE STEREO RECEIVER WITH SOUNDSPAN: $329.50 BOGENPrices slightly higher in the West -PRESTO A OF THE SIEGLER CORPORATION DESK A -110, PARAMUS, N. J. DIVISION 60 -7

www.americanradiohistory.com will be identical and in phase. There is no correlation between the background noise so the total noise of the two tuners in parallel, assuming identical noise level, will be 3 db below that of either one. If one tuner is noisy and one quiet, the background noise will be up to 6 db below that of the noisy tuner. This is f not desirable since Fig. 2. Cancella- the poorer signal con- tion effect due to trols the quality of the resultant audio different transit output. It is therefore necessary to have times of direct automatic means of control of the audio and reflected sig- output of each tuner actuated by the sig- nals. nal available to each tuner. One approach is known as "Combiner Diversity." This procedure, much used in scatter propagation, has the tuner with the poorer signal simply fade out, while the one with the better signal stays in. The controlled devices are bass -band amplifiers with variable output imped- (a plane moving ances actuated by the at 300 mph may vary the correlation between the signal reach- amount of noise the signal between detected. This method provides zero and 100 times ing the two antennas is up to 50 per perhaps per second). In the least resultant signal -to -noise a strong signal area, cent. However, if the separation is in- ratio. with a high-quality However, it also creates wideband tuner, the creased to 61/2 wavelengths, the correla- low-frequency output of the transients that would tuner is independent of the tion decreases to 30 per cent. It is under- be disastrous in signal strength. wide-range music systems. The AGC and limiting stood that it is desirable to have as dif- In scatter re- action of the ception, a typical system tuner are the only con- ferent a signal as possible reaching the may operate trolling factors. down to 300 cps, Therefore, there will be different antennas, so the with the combiner cut- correlation ting off no audible fading. However, there will should be as low as possible. at 100 cps to prevent transient be an increase Correlation problems. This in background noise dur- will not be greatly affected by the is not satisfactory for ing this period. direc- high fidelity performance. tion of the line between the receiving If this same fading occurs at the antennas. If only two are used, it is best threshold of the Switch -Type Diversity tuner's sensitivity, there to keep the line normal to the signal will not only be an increase in noise, but from the transmitter. As a rule of The best method for quality perform- also moments when the signal becomes thumb, let us say that at a frequency of ance is to arrange it so that completely unusable. the tuner about 100 me for FM, the separation with the poorer signal is To the discriminating of switched out. listener this is the two (or more) antennas should be a This is referred to as "Switch -Type a most objectionable situation. Di- The per- minimum of 35 feet, and preferably sev- versity." It can be done with tuners that son adding to his tape library by record- eral times this amount. Here it might he incorporate "squelch" circuits. With a ing off the air can have a valuable re- remembered that our wavelength at 100 squelch circuit the tuner is set so that cording completely ruined. For the mo is approximately 10 feet. the audio output will be turned off if various FM networks the that are linked to- The second requirement is to combine signal strength falls below a certain gether by means of off -the -air reception, the outputs of the two or more tuners value. All tuners to date do this by fading is a major difficulty. used. means of a tube. In this case the tran- The simplest method is to connect the sient created by turning the audio out- Requirements for Diversity outputs in parallel. The audio output put on and off causes an enormous low - The first requirement frequency pulse to be transmitted to the for diversity re- 4 G. L. Mellen, W. E. Morrow, A. J. Pote, ception is a tuner with exceptionally W. H. Radford, and amplifier. This pulse can be as much as J. B. Wiesner, "UHF twenty good usable sensitivity. This is a basic long -range communication systems." Proc. times as strong as the audio out requirement for good performance I.B.E. Vol. 43, pp. 1269-1280; October, put from a 100 -per cent modulated sig with 1955. or without diversity. Other necessary (Continued on page 90) design features have been clearly speci- fied in the report on diversity prepared by a research team at the MIT Lincoln Laboratory. "These design features in- clude wide -band high -speed limiters and wide -band high-linearity discriminators. Receivers embodying these features have superior performance Fig. 3. With two under multipath spaced antennas conditions.14 It comes as no news to be and two FM tun- told that the H. H. Scott 310 pioneered ers, connected as these very features years ago. described, only the The next requirement in diversity re- output from the ception is to locate the antennas as far usable signal is apart as possible. Under these conditions, fed to the ampli- it is not likely that the signals reaching fier. the two antennas will be cancelled at the same time, as can be seen from Fig. 3. With antennas 35/2 wavelengths apart,

50 AUDIO NOVEMBER, 1960

www.americanradiohistory.com STEREO SYSTEM FOR A MILLION- AIRE: 4 SELECTIONS Gentlemen's Quarterly magazine asked James Lyons, editor of The American Record Guide (the oldest record review magazine in the United States), to poll hi -fi authorities on which audio components they would choose for the best possible stereo system, without any regard for price. Three writers in the audio field and one audio consul- tant made up independent lists. The ideal systems they projected in the April, 1960 issue of Gentlemen's Quarterly are suitable for discriminating millionaires-one of the systems, using a professional tape machine, would cost about $4000.

ACOUSTIC RESEARCH AR -3 loudspeakers are included in three of the lists,* and these are moderate in price. (There are many speaker systems that currently sell for more than three times the AR -3's $216.) AR speakers were chosen entirely on account of their musically natural quality.

Literature on Acoustic Research speaker systems is available for the asking.

In two cases alternates are also listed. For the complete component lists see the April, 1960 Gentlemen's Quarterly, or write us.

ACOUSTIC RESEARCH, INC. 24 Thorndike Street Cambridge 41, Massachusetts

AUDIO NOVEMBER, 1960 51

www.americanradiohistory.com The PR -500 Turntable ...

. a single speed (331h -rpm) turntable with an integrally

mounted arm . . . employs a somewhat unconventional drive system which results in a to- tally inaudible rumble level, and low wow and flutter. The arm is simple yet effective, with a mounting system which REVIEWS makes the unit relatively insen- sitive to shock and vibration." "The arm tracks well at the lowest stylus forces recom- mended by the cartridge manu- facturer."

"The hum field surrounding the PR -500 is very low, and no dif- ficulty should be experienced from this source even with LIKE poorly shielded cartridges." . . . the Stromberg - Carlson PR -500 performs in a manner comparable to that of the most expensive turntables and arms, yet sells for much less."

"The PR -500 is an excellent value at $69.95." Hir ,.h -Houck Laboratory - THESE... Hlgh Pidrlity ,lingn.iar, Mn y 'Go)

...hint at the performance of new

New Amplifiers ... New Speaker Systems

ASR 660 -an extremely clean, beautifully de- ASR 220C - an unusually versatile medium Three new, wide range speaker sys- signed stereo amplifier Continuous power: power stereo amplifier Continuous power: tems. A new elliptical tweeter with 36 watts (18 watts per channel) Music power: 24 watts (12 watts per channel) Music power a heavily silver -plated voice coil pre- (IHFM standard): 44 watts (22 watts per chan- (IHFM standard) 28 watts (14 watts per chan- vents harshness caused by cone nel Total harmonic distortion: 0.6 °', at 18 nel) Total harmonic distortion: 0.7% at 12 breakup in conventional circular watts per channel Intermodulation distortion: watts per channel lntermodulation distortion: speakers. Woofers of extra -heavy cone 1°, at rated (4:1 output ratio, 60 and 7,000 cps) 2 °b at rated output (4:1 ratio, 60 and 7,000 cps) stock are capable of long, linear ex- Frequency response: -± 0.5 db, 20- 20,000 cps Frequency response: ± 0.5 db, 20- 20,000 cps cursions for outstanding low fre- Separate channel, - clutch type bass and Separate channel clutch - type bass and quency power handling without dis- treble controls Scratch filter (18 db.'oct); treble controls Scratch filter (18 db /oct); tortion. Tweeter level switches Rumble "Twin filter T" filter, null at 20 cps Rumble filter "Twin T" filter, null at 20 cps included on all models. Enclosures Loudness contour switch; Balance control; Magnetic phono pre -amp with new, low noise are carefully matched to the woofer. Channel reverse switch; Program selector; tubes A plus B center -speaker terminals. Master gain control DC on pre -amp heaters Suggested Audiophile net: $119.95 Suggested RS511 59.95 to 84.95 for low Audiophile net: noise; A plus B center speaker (prices vary RS514 74.95 to 99.95 terminals. with finish) RS516 105.00 to 135.00 Suggested Audiophile net: $149.95 For the sheer joy of listening ... "There is nothing finer than a Stromberg- Carlson"

52 AUDIO NOVEMBER, 1960

www.americanradiohistory.com The FM -443 Tuner ... The ASR -880 Amplifier ...

"The Stromberg- Carlson FM -443, . a compact integrated stereo one of the least expensive FM amplifier rated at 32 watts per chan- tuners on the market, nel. Noteworthy . it exceeds its approaches the performance of rated power substantially over most range, has more expensive equipment. It of the audio excellent power - handling capabilities at both is therefore an especially good ends of the spectrum." value for anyone who wants to obtain the highest level of per- "Each channel delivered 50 watts at 2% harmonic or 48 watts formance in a moderate -priced distortion, system." at 1% distortion. This is unusual in an amplifier rated at 32 watts ..." "The distortion at 100% modu- The distortion of the ASR -880 is very lation is about 1% for signals low at usual listening levels when stronger than 10 microvolts." correctly operated ... it has a rare "The sensitivity measurement combination of very high gain and very of the FM -443, according to low hum. The amplifier has a number IHFM standards, is amazing. Its of special features, such as center usable sensitivity is 3 micro- channel output and a very effective volts, a figure not usually found channel -balancing system, as well as in tuners in this price range. the usual stereo control functions This high sensitivity has not found in all good amplifiers." been obtained at the expense Only 0.6 or 0.7 millivolts at the phono of IF bandwidth." inputs will drive the amplifier to 10 "The tuner sells for ;79.96." watts output per channel. At normal

gain settings . the hum level is Hirsh- Houck Laboratory - Hiyh Fidelity Magazine, Junr'60 better than 70 db below 10 watts even on phono input. This is completely inaudible."

"With a listening quality matching its laboratory response, the Stromberg- Carlson ASR -880 must be considered a very good value at its $199.95 price." Hirsh -Houck Laboratory - High Fidelity Magazine. Sept. '60

Stromberg- Carlson components like these:

New Tuners

FM-443A -an improved version of the highly SR- 445A -a combination of the FM -443A and All the new Stromberg- rated FM -443 New, high- accuracy, precision an entirely new, wide -band AM section. FM Carlson components have so dial Precision components in de- emphasis specifications: identical to FM -443A AM fre- many impressive features, network, giving improved frequency response: quency response: Broad: 25 to 9,000 ± 11/2 db ± you'll find a visit to your 20- 20,000 cps ± 1 db Sensitivity: 3.5 micro- Sharp: 25 to 2,500 cps 11/2 db AM noise Stromberg- Carlson dealer volts for 20 db quieting Improved local - level: 60 db below 1 volt output AM harmonic most rewarding. He will be distance control in RF stage for lowest distor- distortion: less than 1% at 100% modulation tion and best signal -to -noise ratio on both Separate tuning Indicators for AM and FM. glad to demonstrate either local and distant stations Total harmonic Suggested Audiophile net: $139.95 an individual component or distortion; less than 1% full deviation. a complete Stromberg- Suggested Audiophile net: ;79.95 Carlson Component En- semble. See him or write: Stromberg- Carlson, 1,118- 011 North Goodman Street, Rochester 3, New York, STROM BERG -CARLSON A DIVISION OF GENERAL DYNAMICS

AUDIO NOVEMBER, 1960 53

www.americanradiohistory.com The Series -Parallel Speaker Array

CHARLES MAHLER, J

The multiple- speaker system using an array of small speakers has stirred up a great deal of interest ever since this author introduced his system in AUDIO last year. Now we present his latest improvements plus some thought about using this system for stereo.

WE CONNECT speakers in a

-.cries-parallel array we must mod- TEST CONDUCTED OUTDOORS WITH ify our conventional ideas. Prac- SPEAKER 60 FEET FROM NEAREST RE- tically all loudspeaker theory has been FLECTING SURFACE IN FORWARD \ DIRECTION WITH BACK OF CABINET 11 written about single units and how they AGAINST WALL. MICROPHONE 15- IN. FROM GROUND FOR FREQUEN- react under various operating conditions. Fig. 2. Frequency CIES BELOW 2000 cps, 30 -IN. FOR These writers have been talking about a response of series - FREQUENCIES ABOVE 2000 cps. MIC- 15 ROPHONE 36-IN. OFF AXIS. single unit or at best a two- or three - parallel array us- way system. Therefore it is not difficult ing 22 six -inch 14 six to understand why there has been so speakers and 13 four -inch tweeters. much interest in the series -parallel array. 12 This type of array, besides being differ- n ent, eliminates many of the speaker problems that have been confronting 10 engineers for years. It clearly puts a 9 whole new on slant loudspeaker system row 100 10000 design. FREQUENCY IN CYCLES PER SECOND The series -parallel speaker array con- sists of a large number of inexpensive fraction of an inch in the magnetic field 3. Outer rim suspension and spider de small speakers so connected as to work available at the voice coil. At no time sign. in unison (in phase). The purpose of does the cone move in a nonlinear 4. Cone resonance at low frequencies. 5. Eliminating peaks this arrangement is to move a large fashion. This fractional movement of the and resonances at wavefront of air at the low frequencies. higher frequencies. cone prevents the cone material, which 6. Magnet arrangement and shaping. Because the output of the is amplifier is generally a paper substance, from 7. Increasing efficiency at lower fre- distributed across all the speakers, each buckling or distorting in its movements. quencies. speaker is required to do a very small Thus expensive and sophisticated speak- 8. Voice coil wire size, shape, and ar- part of the overall job. If the number of ers are not required for the array. rangement. 9. Extending high frequency response. the speakers is large enough, the inter - Practically all loudspeaker design in modulation distortion and frequency the last decade or longer has been con- doubling effects are almost entirely elimi- cerned with one or all of the following Perfection in the loudspeaker system nated. This is explained has been elusive and costly. The type of by the fact that problems : each speaker in this array is moving a systems offered to the public today are L Cone material breakup. still a long way from ideal. Because of 2. Linear movement of voice coil in mag- 958 Arguello Drive, San Leandro, Calif. netic field. the audio engineer's failure to solve com- plex obstacles in system design, the pub-

lic has had to compromise. At least at. ...8 the price it is willing to pay. As a re- ... sult, the sound he listens to is a core- - I promise. SPEAKER A The series -parallel array conies closest. to solving all these problems. Fig. 1. Illustration We must keep in mind all loud- of how resonant that impedance is speakers, regardless of who makes them,. u smoothed when consist of a vibrating diaphragm which. is very I two speakers with a basic and simple thing to con- different resonant struct. The reason so many speakers - points are con- sound different is primarily due to the - nected in parallel. change "A * "B each designer makes in this sim- e. ple vibrating diaphragm. i: IN PARALLEL Some design- ers put metallic domes or phenolic cone - l..e=e.u e..!_ -- cc2o6271'Wu.- extensions on this diaphragm. This must alter the sound in some manner. The metallic horns, which are popular, use a vibrating diaphragm loading into a metal or other type horn. This horn in-

54 AUDIO NOVEMBER, 1960.

www.americanradiohistory.com

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A highly 535A POWER SUPPLY Compact, highly 458A "PLUG -IN" PREAMPLIFIER An extemely 459A "PLUG-IN" PROGRAM AMPLIFIER reliable, low noise amplifier with exceptionally reliable, the 535A is the DC power supply for simple, highly reliable, low noise preamplifier, the 458A program voltages to the cross -neutralized large power capability, the 459A consists of a 2 -stage furnishing the operating incorporates a single stage push-pull 459A amplifiers used together coupled to source and push -pull circuit with a balanced negative feedback loop. Altec 458A and vacuum tube circuit, transformer SU Console. Externally are Push -pull operation of all stages provides reliability, inter. with the Altec 250 load. Maximum reliability with unfailing performance hum, the 535A employs featuring fewer com- changeability with preamplifiers for added gain and power. mounted to preclude achieved through simplified design rectifiers in both the filament and accurate balance of input and out- Superior overall performance results from special input and silicon ponents, extremely balance combined "B" supplies. The 535A connects to the 250 put and premium quality pre -aged, shielded output transformer design of ultrafine transformers, tubes. Program SU by means of a 4 -foot multiple conductor tubes. The failure of either tube will not cause loss of with premium quality pre -aged shielded is not interrupted by failure of either output cable terminated in a type P306CCT Jones program. transmission receptacle tube. plug which "mates" with a Jones Console. A single screw frees GAIN: 40db unterminated input, in the 250 SU SPECIFICATIONS the power supply unit from its mounting 34 db terminated. POWER OUTPUT: dbm at less +20 input, 50 bracket for inspection. than .5% THD 50 to 15,000 cps. -4-25 dbm at less than SPECIFICATIONS GAIN: 56 db unterminated POWER OUTPUT: dbm at less than 1% THD at 1 KC. FREQUENCY RESPONSE: + 1 db 20 to db terminated. +30 1% THD 20,000 cps. SOURCE IMPEDANCE: 150 or 600 ohms .5% THD 30 to 20.000 cps. +35 dbm at less than +1 to 20,000 cps. SPECIFICATIONS POWER OUTPUT: 275vdc 600 ohms). LOAD IMPEDANCE: 150 to 600 at 1 KC. FREQUENCY RESPONSE: db. 20 (centertap for at 275ma. At 275ma ripple is .02v peak to ohms (centertap for 600 ohms). OUTPUT IMPEDANCE: SOURCE IMPEDANCE: 150 or 600 ohms (centertap for 600 ohms). LOAD IMPEDANCE: 150 or 600 ohms (centertap for peak max. Equal to load impedance. NOISE LEVEL: Equivalent input INPUT: 117v 600 ohms). NOISE LEVEL: Equivalent input noise: -126 1.5v peak o3peak max. POWER noise: -126 dbm. POWER SUPPLY: 15ma at 275vdc and RECTIFIERS: dbm. POWER SUPPLY: 40ma at 275 vdc and 1.6a at 6.3vdc. 50 -60 cps 245 watts at full load. .7a at 6.3vdc. TUBES: 2- 6072/12ÁY7. DIMENSIONS: 2. Cir- 12BH7. DIMENSIONS: 1 be" W Silicon. CONTROLS: 1. Power Switch. 1 W x 3 15/16" H and 9 11 /16" L. COLOR: Cad TUBES: 1- 6072/12AY7, 2- 3/4" (Push to reset). 3.4 Position tap WEIGHT: 3 1/2 lbs. (including x 3 15/16" H x 9 11/16" L. COLOR: Cad plate, dichromate cuit Breaker plate, dichromate dip. adjustment of voltage by tray). SPECIAL FEATURES: Push buttons for individual dip. WEIGHT: 3 1/2 lbs. (including tray). SPECIAL FEA- switch (provides to accommodate 2 to 1 40ma dc can be to center taps for TURES: Push buttons for individual tube test. 40ma dc can autoformer action tube test. applied Dark Green. WEIGHT: ACCESSORIES: 13225 Rack Mounting Assem. be applied to center taps for simplexing. ACCESSORIES: range of loads). COLOR: simplexing. MOUNTING: 7 3/16" W bly (for 9 units). 13401 Mounting Tray Assembly. 5981 13225 Rack Mounting Assembly (for 9 units). 13401 Mounting 16 pounds. SIZE AND Tube Test Meter. 535A Power Supply. Tray Assembly. 5981 Tube Test Meter. 535A Power Supply. x 9 5/8" H z 7" D overall.

ALTEC LANSING CORPORATION Ling -Temco Electronics. Inc. Dept. ADB -2D A subsidiary of a @1960 Altec Lansing Corporation 1515 Manchester, Anaheim. Calif. 161 Sixth Avenue, New York 13, N.Y

AUDIO NOVEMBER, 1960 55

www.americanradiohistory.com troduces an effect of its own into the nature of the sound being generated. In spite of all these refinements and gim- micks, the direct radiator with the com- mon moulded-paper cone is still the most accurate and popular vibrating dia phragm. Because of its simple cone ma terial, the direct radiator reproduces sounds with practically no coloration as compared to some of the brassy and me- tallic sounds which are generated from so- called high- fidelity speakers using metal horns and diaphragms. The big problem with the direct- radia- tor speaker has been relatively low power - handling characteristics. The sound is good at low volume but poor at higher volume levels. One reason is that the travel of the voice coil within the mag- netic gap becomes nonlinear. To reduce _,. ,-,. these problems, the manufacturers have .. had to make heavier cone material, larger voice coils, heavier magnets, and less rigid -, » .., ., . . I spider and outer rim suspensions for the cone. The only difference is that these sophisticated radiators can now be oper- tP a s t". ett* ated at louder volume levels and at lower t .. frequencies with less distortion. But the , vibrating diaphragm has not changed in t" At. t"/ t"' bG basic theory or application. The inex- . pensive six -inch speaker, as an example, when used at low volume levels, has ex- tremely low distortion and excellent fidel- ity. Because of the limited piston area, A however, a single six -inch speaker cannot Fig. project the lower frequencies so that the 3. Layout of speakers as seen from both front and rear of baffle. human ear can hear them. The series - parallel array allows us to use this sim- pedance change that the amplifier sees. course, it is important to note ple that both vibrating mechanism to an advan- To illustrate what actually occurs you speakers had different tage. resonant points. can see that speaker "A" in Fig. 1 has If they were the same then we could not With all due respect to G. A. Briggs, a resonance at 60 cps. (We are looking at shunt out the impedance humps. With who has done tremendous work in the the output of the amplifier and not the different resonant characteristics the audio field, I must take exception to his output of the speaker.) Speaker `B" speakers are unable to resonate because remarks about multiple speakers. In his in Fig. 1 has a resonance at 100 cps. If the amplifier will not see the impedance book, "Sound Reproduction," he says, these two speakers were connected in change. Therefore the amplifier does "The main not objection to such speakers series, the amplifier would see two increase its output at this resonant (inexpensive fre- multiple speakers) is the humps; one at 60 cps and the other at quency; a very simple, but highly sig- fact that the cone resonance is high." 100 cps resulting in two resonant points. nificant, occurrence. This statement is true to a certain ex- But if we connected these two speakers This "resonance shunting" effect is tent. But I can demonstrate how this oh- in parallel, we have changed the im- the reason why the response curve of a jection can be eliminated. Perhaps a dis- pedance load to the amplifier. Perhaps series -parallel array is unlike any other cussion of resonance is in order at this we can explain what happens by illus- loudspeaker system curve. there time. If are trating with resistors. Suppose we con- any "peaks" or "valleys" in any individ- As we know, resonance is a condition nect a 100 -ohm resistor across the out- ual speaker of this array, they are lev- which occurs when the moving system of put of the amplifier ; now, the amplifier elled by this series -parallel connection. a loudspeaker resonates sympathetically sees only the 100 -ohm resistor. Now let us This has the desirable effect of reducing at some fixed frequency. This resonance connect in parallel with this 100 -ohm re- the violent dips and peaks so common to causes the amplifier to see an increase in sistor a 20 -ohm resistor. Now the ampli- most loudspeaker systems. By careful electrical impedance. So the amplifier fier does not see the 100 -ohm resistor. and painstaking selection of speakers it output is increased at this resonant fre- Instead, it sees sonic value less than 20 would probably be possible to eliminate quency. This results in an increased audio ohms. This is simply an application of all response curve variations. However, output from the loudspeaker. The result Ohms Law. The important thing to re- it is not necessary to go to this great a is a "boom" or "roar" at this frequency. member, however, is that the 100 -ohm degree of selection to obtain results as Since we cannot easily change the reso- resistor is still there, but the amplifier shown in the response curve of Fig. 2. nant frequency of a loudspeaker, then cannot now see it as well. The lower When you consider that this response we must change what the amplifier sees. value resistor takes practically all the curve does not vary more than 2 db If the amplifier were to see no increase output of the amplifier. When speaker from 20 to 15,000 cps, you can appre- in impedance at the resonant frequency "A" is shunted by speaker "B" the same ciate the significance of this series- paral- then there would be no resonant "boons." thing happens. We have shunted the lel array principle. The more speakers By a certain arrangement of an array of speakers so that they cannot resonate at loudspeakers we can eliminate this im- their natural resonant frequency. Of (Continued on paye 99)

56 AUDIO NOVEMBER, 1960

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AUDIO NOVEMBER, 1960 57

www.americanradiohistory.com TANDBERG MODEL 6 EQUI PMEN't TAPE RECORDER SHURE M232 AND M236 PROFESSIONAL PICKUP 001 ARMS .0® e®o GARRARD SPG3 STYLUS FORCE GAUGE PROril E

TANDBERG MODEL 6 crophone plug disconnects the other two way, so that rapid starts and stops are pos- TAPE RECORDER sources from the recording amplifier. sible without noticeable slurring. Other features include: separate "magic Four additional pushbuttons plus the The 1'aadberg Model 6 is a light, com- eye" record -level indicators for each chan- start -stop button control electrical opera- pact, handsome, versatile, three -speed tape nel, with a "floating action" circuit to fa- tion. Two buttons, one for each channel, machine with separate record and playback cilitate reading transient peaks; automatic are for recording, and the other two for heads for four -track stereo and mono oper- demagnetizing circuit for the record and playback. The record buttons are linked ation. There is no head -shift device for erase heads which operates whenever the with the tape motion lever so that they can playing two -track stereo tapes, now becom- record buttons are released; provision for be locked down only when the lever is ing semi -obsolete; such tapes may be automatic shutoff at the end of a reel, re- moved into normal forward position. Put- played nevertheless, although at some loss quiring attachment of a metallic leader to ting the lever into neutral causes the rec- in signal -to -noise ratio ou the right chan- each tape; a four -digit tape counter with ord buttons to pop up. nel. In the main, design and construction reset knob; a jack for attaching a remote The pushbuttons provide a fascinating are of professional caliber and so is per- on-off foot -pedal control; cathode follower example of switching logic. With only the formance at 7 i ips. In the machine tested outputs in playback; d.c. on all tube beat- left record button down, all input signals, there was some question as to frequency ers except the oscillator; easy removal of whether fed to the left or right input jacks, response and equalization at the low end. head covers for cleaning and demagnetiz- are routed to the left tape track, and simi- The price is approximately $500. ing heads anal other parts; azimuth ad- larly for the right record button. But with justment screws; head- height adjustment both record buttons down, left and right Features and Functions se rows. input signals are routed to their respective A "tape motion lever," tracks. The playback The operating in a buttons work in an Model 6, shown in Fill. 1, operates T -slot, puts the machine into the rewind equally logical manner. With only at 7'%, 3%, and 1% the left ips. It permits sound - mode, fast- forward mode, or else in a pre- button down, the left playback signal goes on -sound recording without the necessity set position for normal forward to both output for an operation. jacks, and similarly for the external mixer, echo effects, A -11 A stop -start pushbutton actually starts or right button. But with both playback but- monitoring, and mixing of input sources. stops the tape when tons For the lever is in the nor- down, each playback signal goes to its each channel there are sparate gain mal forward mode. The lever moves the respective ouput jack. When the playback controls for recording and playback-four pressure roller within about % -in. button for a given in all. of the channel is up, the in- Each channel has a microphone in- capstan and allows the motor to come up put signal for that channel is routed put and two inputs to the for medium and high - to full speed. Then the start -stop button output jack. Thus an A -B comparison can level sources. However, insertion of a mi- moves the pressure roller the rest of the be made during recording by alternately releasing and depressing the playback but- ton for the desired channel. Signal routing operates as just described when the start -stop button is down and the tape is in motion. But with the button up and the tape at rest, the incoming signal is directed to the output jacks. The high -level input jack provides about 18 db attenuation compared with the me- dium -level input jack, to prevent overload- ing the first two recording stages. The medium -level jack presents an impedance of about 100,000 ohms, which may be too low for certain signal sources, such as a piezoelectric cartridge. The high -level in- put impedance is about one megohm. Pe:formance The measured signal -to -noise ratio was 52 (lb on the left channel and 51 db on the right at 7% ips while recording a 400 -cps tone at 3 per cent harmonic distortion. This is excellent for quarter -track opera- tion. Tape hiss was much more predominant than machine noise. On each channel, the "magic eye" closed exactly at the 3 per cent harmonic distor- tion level, which is as should be. The wow and flutter characteristics are excellent at 7%F. ips. A professional tape editor, musically trained, lent an ear in this test and observed on listening to a 3000 -cps tone being recorded and played back that the Tandberg's Fig. 1. The new steadiness of mo- Tandberg Model 6 stereo tape recorder. tion equalled or possibly surpassed some of

58 AUDIO NOVEMBER, 1960

www.americanradiohistory.com ELECTRO -VOICE MODELS 636 AND 630 eliminate critical placement ... assure remarkable fidelity. Omnidirectional from all points. For truly uniform microphone response -for slim -trim case styling -for complete application versatility, the Electro -Voice Model 636 Dynamic is unsurpassed. Designed especially for public address and general purpose applications, the Model 636 blends easily, unobtrusively into PA stagings, eliminating placement problems and improving audience enjoyment. The baton design provides a convenient, easy -to- handle shape for hand carrying. This modern, streamlined model measures only 1iú inches in diameter, yet provides output levels equal to microphones four times as large. Other Features: Exclusive E -V Acoustalloy diaphragm. Adaptable to either high or low impedance inputs; convenient ON- OFF switch for instant control; uniform response from 60 to 15,000 cps; wire mesh grille to minimize wind and breath blasts; tiltable through 90" arc toward sound source. List price (less stand). Satin Chromium Finish -$72.50; Gold Finish -$77.50.

Omnidirectional also describes the performance of the popular ElectroVoíce Model 630 Dynamic Microphone. Designed by the same top acoustical engineering talent that devet. oped the slim Model 636, this versatile microphone also provides optimum performance for an unusually wide range of professional, commercial, and personal applications. An exceptionally rugged instrument, the Model 630 may be mounted on a floor or desk stand or it may be hand held. List Price (less stand) $52.50. ',id! Products Division Complete specifications available upon request. For a trial demonstration of either of ELECT/20-VOICE. INC. these fine, omnidirectional microphones, visit your ElectroVoice dealer- today. MODEL 630 Dept. 11A Buchanan, Michigan

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$ -5 $ 5 -

I 10 LEFT CHANNEL I IO // LEFT CHANNEL 2 s 5 5 o o +s '+s - 3

5

10 RIGH CHANNEL 1 RIGHT CHANNEL - ItItf 1 ION FREQUENCY IN CYCLES PER SECOND FREQUENCY IN CYCLES PER SECOND

Fig. 2 (left). Frequency response curves for the Tandberg Model 6 at 71 ips. Fig. 3 (right). Response curves for 33/4 ips. the professional machines he works with. suit of treble boost in playback (obtained small coupling capacitor between the first At 3% ips, wow was barely discernible on by resonating the playback head with a and second stages produces a bass rolloff a sustained tone-still very good. But at capacitor) and partly to smaller playback commencing (3 db down) at approximately ] T/s ips wow became definitely apparent. bass boost (which is equivalent to smaller 65 cps. Yet in the next stage, feedback Speed measured 0.6 per cent fast; pro- treble cut). Here is a machine that is very equalization produces just enough bass fessional machines usually claim 0.2 per well designed and constructed, yet gives boost to bring response up to or slightly cent accuracy. Under 1 per cent is very scant support to the thought that 3% ips above flat. good. is suitable for high fidelity. In playback, equalization is claimed to Figures 2, 3, and 4 show the frequency The Model 6 requires about 85 seconds be NAB at 77,E ips, and a reading of the response measured at each speed while re- to wind or rewind a 7 -in. reel bearing 1200 schematic indicates this is so. Measurement cording at a level 25 db below "magic eye" feet of tape, which is about medium, which shows that equalization conforms to NAB closure on a 1000 -cps tone. At 7% ips, re- is to the good, preventing tape stretching above 1000 cps, except for about 3 db too sponse was within 3 db of flat from 80 to and stresses leading to distortion. Profes- much treble in the region of 10,000 to nearly 15,000 cps on the left channel; on sional machines usually take about 45 sec- 14,000 cps, not a serious fault. But below the right channel, tre'ile response was onds; the average "hi -fi" machine is nearer 1000 cps there is substantially less bass greater, with a slight tendency to "peaki- two minutes. boost than called for by NAB. Bass boost ness" in the 10,000 to 14,000 cps range. comes to a halt at about 100 cps, reaching Perhaps there was somewhat less bias cur- Construction and Circuitry a maximum of 14 db. The NAB curve calls rent in the right channel section of the for 19 db boost at this frequency, and 23 record head. Parts are of first quality, neatly laid out, db at 50 cps. The major difference in frequency re- and readily accessible on four printed cir- The fact that response, nevertheless, is sponse at 7% ips occurred at the low end, cuit boards: record amplifiers, playback down only 3.5 db at 40 cps at 77,E ips with a dip, in response between 50 and 70 amplifiers, oscillator circuit, "magic eye" makes it appear that the contour effect is cps. On A -B testing through a fine audio circuits. One motor is used, a hystresis syn- employed to maintain low- frequency re- system, this made a significant change in chronous unit. Low -noise resistors and her- sponse. The contour effect refers to the fact the "color" of both voices and music. More- metically sealed capacitors are liberally that at low frequencies the whole playback over, it seems, the lack of bass caused the employed. The power transformer has tor- head, particularly a small one, behaves in apparent signal -to -noise ratio to sound lese oid windings to minimize its external hum the same manner as the gap, augmenting than the measured ratio. That is, fuller field. response at some bass frequencies and de- bass would have masked tape hiss to a There are four separate amplifiers -two creasing response at others. greater extent. for recording and two for playback. Each The Model 6 has a profusion of internal At 3% ips, high -frequency response amplifier has four triode stages, employing controls that permit the technically quali- held up very well to 10,000 cps. Bass re- ECC83's, with the exception of ECC82's fied individual to adjust performance to sponse held up reasonably well to about (12AU7's) for the last two stages of each optimum. Each channel has the following 50 cps on one channel and 60 cps on the playback amplifier. Feedback equalization five internal controls: recording level pot, other. At 1T/e ips, response was good from is employed both in recording and in play- providing the proper amount of signal to about 60 to 4000 cycles. back. For treble boost in playback at 3% the record heads at a given distortion It must be stated that the measurements and 1% ips, resonating capacitors arc level; playback level pot, permitting the are definitely better than the listening at switched across the playback head. playback output signal to be e9uated to 3% ips. This appears substantially due to Some questions are raised by the equali- the input signal for A -B comparison; rec- an increase in tape hiss, partly as the re- zation characteristics. In recording, a ord -level indicator pot, causing the "magic eye" to just close at the 3 per cent har- monic distortion level; bias level pot; vari- able inductance, forming part of a resonant trap to keep bias current away from the +5 "magic eye" tube and elsewhere. There are o three more controls which affect both chan- nels: bias -frequency adjustment; variable ß s capacitor to ground, to keep bias current

I 10 LEFT CHANNEL out of the wrong places; balance control in oscillator, 2 the grid return of the push -pull 5 for obtaining the purest possible bias wave- o Fig. 4. Response form and thereby minimizing noise in re- curves for 1,8 ips. cording. +5 Accessories available for the Model 6 o include microphones, a footpedal for re- mote start -stop control, a carrying case, sr and headphones. (H.B.) L-21 10 RIGHT CHANNEL NOTE: Recent shipments of the Model 6 have been corrected as to the low -frequency I so response at 7% ips. Mr. Burstein will re- loo test a later unit and the results will ap- FREQUENCY IN CYCLES PER SECOND pear next month. En.

60 AUDIO NOVEMBER, 1960

www.americanradiohistory.com "Theoretically, and in fact, it is impossible to reproduce, totally intact, the sound of a pipe organ in the home. Yet, it has been my observation that loudspeaker systems made by James B. Lansing Sound, Inc., come close to doing the impossible. In the course of my professional i activities I believe I have investigated all transducers commercially available. Perhaps I prefer JBL products because there are so many apparent parallels between these loudspeakers and a well -wrought pipe organ. Neither is mass produced. Each is the product of skilled hands. Their excellence is the result of painstaking attention to details both conspicuous and unseen ... the result of following without compromise the route to perfection laid down by the accumulated precepts of experience guided by the cold eye of science:' - JUSTIN KRAMER

Justin Kramer. Mus. M., A.G.D., musician, musicologist, campanologist. theology student, inventor, acoustical consultant, designs and installs pipe organs. Mr. Kramer personally attends to the final voicing of each pipe. At left, with Mrs. Kramer, he inspects the instrument he installed in the Church of St. Paul the Apostle. Westwood. California. ...choice of the talented listener

Hear the speakers preferred by talented listener Justin Kramer in the demonstration room of the JBL Signature Audio Specialist in your community. Write for his name and address. Ask, too, for the will to the speaker system d guidebook that lead you d that meets your own standards of perfection, JBL Catalog SC508.

P ODUCTS OF JAMES B. LANSING SOUND, INC., ARE MARKETED BY JBL INTERNATII LOS ANGELES 39, CALIFORNIA

www.americanradiohistory.com GARRARD SPG3 STYLUS FORCE GAUGE Most gauges for measuring stylus force have been makeshift devices-some deriv- ing directly from some other application, and others designed for indicating a single predetermined force. The Garrard SPG3 gauge appears to have been designed for one specific purpose, and it fulfills that one purpose excellently. It consists of a molded Fig. 5. Shure M232 professional tone arm. plastic housing which encloses a calibrated dial which is turned by an external knob to a desired setting anywhere from 0 to SHURE M232 AND M236 method of adjusting the arm is to pull the 12 grams in alignment with a setting line PROFESSIONAL TONE ARMS stylus force adjustment knob forward and on the transparent cover. Extending from down, which releases the spring tension, the right end of the case is the scale arm Incorporating most of the features then turn the balance knob to obtain a to which is attached a swinging balance which have been considered essential in static horizontal balance. After this is lever, and at the bottom of the lever is a high-quality phono arms, these two units done, the stylus force adjustment knob is plastic scale pan. To use, the calibrated by Shure Brothers are attractive in ap- slipped back into its recessed slot and the dial is first set for the desired stylus force pearance, easy to install and adjust, and knob turned to give the required force as and then the unit is placed on the turntable effective is operation. indicated by the pointer. and the stylus simply placed in the depres- The two models Both horizontal and vertical pivots em- sion in the plastic scale pan. A red pointer are similar in appear- ploy precision ance, differing only in length and such ball bearings for minimum should then move to the setting line if the other parameters friction, and limiting stops are provided stylus force is that to which the dial is set. as may be governed by inside length alone. The M232 has an over -all the main pivot post so that the arm If it is not, the force adjustment on the length of 1211/,. can be set so as not to allow the stylus to arm is changed so the red pointer moves in., and is thus intended for contact use in high -quality home systems. The the turntable spindle. A plastic arm exactly to the setting line. M236 is 141/2 rest with provision for height adjustment While this may appear to be somewhat in. long. Our own observa- is tions refer to the M232. furnished with the arm. At the bottom complicated, there are reasons for this type These arms of the main pivot post is a 4- terminal of construction. To make an accurate meas- are mounted by means of socket which carries a phenolic base, using three wood or ma- three leads from the urement at the actual point where the arm chine screws cartridge -the common sides are connected will be operating, it is necessary that the as the motor board requires, together in the arm at a distance of in. from the turntable -and a fourth lead scale pan be at a certain height above the 81/2 which connects to the metal parts of the With center. The M236 is to be mounted 101' /a turntable surface. this design, when in. from arm. A 4 -foot connecting cable is furnished the force exactly balances the indicated the spindle. Both can be mounted with the plug for the arm from the top of the motor board, with only already attached, value, the pan must be at the same posi- and with two phono plugs and a single tion at all times, regardless of the force a single plug at the bottom of the pivot wire poet carrying all necessary at the other end for plugging into required. To make sure that the downward connections. the preamplifier jacks. The The pivot post may be adjusted over single wire con- pull is applied to the same point on the a nects the metal parts of the arm to the scale arm at all forces within the range of height range up to 21/2 in., and is locked amplifier ground in place by a single and thus eliminates static the gauge, the balance lever must be free set screw. An anodized pops caused by touching the aluminum disc covers the mounting screws. arm. The sig- to swing. The position of the stylus pan is nal leads are separately shielded, and a thus exactly the same distance above the The head of the arm is removable, with plastic jacket covers contacts the two shielded leads turntable every time, which ensures accu- four carried through to the cart- and the ground lead, making a single cable racy of measurement. ridge. The cartridge itself is attached to for the connections. a mounting plate, using the hardware One further refinement is the provision fur- The M232 arm is thus seen to be very of a 5 -gram checking weight which is car- nished. Some cartridges require spacers, of easy to install, which and equally easy to adjust ried in a small compartment of the housing two lengths are furnished, and for for various conditions. The supplementary and kept in place by a sliding door the very light cartridges it is necessary so to use instruction sheet for mounting the car- weight need never be lost or misplaced -it two mounting plates -both of which are tridges is furnished. Explicit one of the most complete and is always handy when desired to cheek the instructions are fur- most specific we have ever seen. In accuracy of the gauge. nished for practically every opera- currently avail- tion, the arm works smoothly and consist- To determine the accuracy of the unit, able cartridge so that the weight will fall ently within the range even at stylus force adjustments we checked it first with the 5 -gram weight of the balancing adjust- around 1 2 grams, ment. The or and the scale was and found it "right on the nose." Then we cartridge mounting plate is at- found to be within 0.5 grams at any point. tached to the head by a single screw which checked with a set of photo -scale weights While no pickup available for the testing at every gram from 1 to 12 and still found allows for about 1/2 in. backward and for- would ward adjustment operate properly at the extremely it exactly right at each point. Beyond the of the exact stylus posi- low stylus forces, we found reliable tion, which is indicated by two and most important element of accuracy it can small pro- satisfactory operation at 3 grams with jections molded into the head, thus making a be said that the method of use is simple Shure M3D and at 5 grams with a Shure and convenient, making it ideal for origi- sure that the stylus overhang is exactly M7D. correct. The M232 arm is a handsome addi- nal installation as well as for the ocea Only in such a manner as this can tion to any turntable, and it works as the user be sure the well sional check that the careful audiofan gives that tracking error is as it looks portend. L -22 his equipment. L -23 held to the minimum designed into the arm by the manufacturer. In many arms, the actual position of the stylus is dependent on the physical relation between the stylus and the mounting holes in the head, and since these are actually not standard (al- though there are presumed to be some standards about this spacing), it becomes necessary to mount the arm on the basis of stylus overhang rather than to a fixed posi- tion of the arm pivot with respect to the Fig. 6. Garrard turntable spindle. With such a construction, the optimum position of the stylus may not SPG3 stylus force be attained as cartridges are changed un- gauge. less the arnt mounting is changed to fit the required overhang. Referring to Fig. 5, a short calibrated scale will be noted on the body of the arm, with a knurled knob at its left. Under the rear of the overhanging portion of the arm body is a weight to counterbalance the en- tire arm. This weight is adjusted by a r knurled balance knob under the arm. The

62 AUDIO NOVEMBER, 1960

www.americanradiohistory.com "REK -O -KUT "- the safest word you can say to your dealer For sixteen years, Rek -O -Kut has been synonymous with quality and integrity in the design of turntables. As other brands have risen, fallen and even completely dis- appeared, Rek -O -Kut has won consistent acclaim as the overwhelming choice in its field. In performance ratings and engineering contributions to the art of turntable design, Rek -O -Kut has compiled a record unchallenged by any other turntable producer. Now, this tradition is again emphasized by the introduction of the magnificent new N -34H StereoTable ...a professional quality two -speed (33t/á and 45 rpm) turntable. Quiet power is furnished by a Rek -O -Kut hysteresis synchronous motor and an efficient new belt -drive system. Speeds can be changed even while the table is rotating, merely by pressing a lever. The N -3411 is a symphony of crisp, clean lines accentuated by the unusual deck design. Mated with the new tapered base, the N -34H becomes one of the proudest and most beautiful components ever to grace a home music system. Insist on seeing it at your dealer's. N -34H STEREOTABLE only-S79.95 net. Shown with new Rek -O -Kut Micropoise Stereo Tonearm, Model S-220, $29.95 net. Tapered base in hand -rubbed, oiled walnut, $14.95 net. A NEW DIMENSION IN TURNTABLES -12%" x 19 "- DESIGNED TO FIT NARROW CABINETS AND BOOKSHELVES!

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AUDIO NOVEMBER, 1960 63

www.americanradiohistory.com RECORD REVUE Edward Tatnall Canby *

REAL CLASSICS . . . starting in the last century, depicts little version is the most compelling I've heard Bruno, Bruuu the wavy -haired boy, the ear- since Mengelberg -and that's a lung time. It Dvorak: New Word Symphony (No. 5). nest young man, the young papa with heard, combines the passionate intensity of the older London Symphony, Leopold Ludwig. the still -young conductor (without beard), conductorial master with the economical and then onwards, Walter sitting, standing, drive we favor Everest SDBR 3056 stereo today, for an almost definitive cutting with practically Everybody in music expression of the music in terms of 1960. One hears rumors of changes at Eter,st -even Tosc:uuhn! (twice 1. First- person com- \fengelhcrg's poetic, rubato -laden version lately -and the news is the more disturbing ments by the daughter are nicely Germanic: (styled out of the turn of the century) made because of such imaginative recordings as "Perhaps my favorite, this so Victorian photo- the great love tune its high point. Markevitch this, which could so easily have been just graph. My father was seven.") The booklet turns his version ou the loud and violent pas- another potboiler to fill up a prestige lime. continues with a long British essay on the sages -which so often today seem like so plugging standard items. This Is surely n numerous orchestral works (Neville Carlos) much orchestral mumbo jumbo, noise, sound standard item, but the playing is far more and a tribute to the Hollywood players, tech- and fury ! Hero, these tremendous passages interesting than such works usually receive ideally n pickup orchestra, who have worked take on an extraordinary intensity which is from our overworked orchestral musicians together with Walter long enough to have not mere outward drama; the playing itself and conductors. And as usual, the Everest become in fact a major symphony orchestra does the trick, the intensity of shape and stereo recording is no less than splendid, both as well as an orchestra in name. phrase and rhythmic Impact that must be in terms of technical hi -fi and in the musical This is no place for au analysis of these credited to Markevitch and to the superb sound itself. moony performances, nor as n music listener orchestra that works with him. It's a spell- Dvorak's big works have three particular myself run I sit down right now and play the binder of a performance and I recommend it aspects that are, all of them, increasingly dif- entire urehestral works of a major composer if you want to know how Tchaikowsky can ficult to get across today. One, of course, is at 0 sitting for the sake of a few brief com- come to life in modern terms. the sweet, lilting Czechish lyricism, the melt- ments here! The album is of course of phono- ing graphic importance, further documenting songfulness of "Goin' Home" in this sym- the Respighi: The Fountains of Rome; The phony (a title after the fact, of course). The Inter phase of this man's long and musically second, and n less well understood aspect, is vital service to orchestral performance in Pines of Rome. London Symphony, Sar- the tortured violence of intensity that appears terns of Columbia's quite definitive stereo gent. Everest LPBR 6051 (mono) in many pages -expressed in what are for us technique. Everest has got the mistaken idea I now such dated orchestral terms that we tend (The four syniphonles were recorded in that want the version I to find them merely noisy, unless the playing mono by Walter some years ago. A musical mono-that's listened to is unusually comparison with the new versions might be for this recording. But even in nano form the expressive and well managed. It marvelously- high quality of Is -here. The third element, of course, is that interesting but, I suspect, would not reveal the sound Itself any startling Innovations nor is entirely evident. There is no doubt that at of startling harmony -and here, too, we easily deteriorations. the moment miss the impact of 'l'he old man Is still full of musical vigor.) Everest is leading the industry in sudden harmonic changes pure sound terms. at least in that in his day were strikingly effective, with In general terms, you can count on Bruno the wider classi- a thrill of modernity. Walter for a sane, balanced, somewhat old cal field coal in terms of over -all batting fashioned but thoroughly "authentic" Brahms, average. As with any well written music, Dvorak's 'l'he fountains and is open to informed interpretation that can with a minimum of fancy personal idiosyn- pines of Respighi have still bring crasies, a maximum of plain, common -sense never alone touch for my musical ear and I out these features, even to us with am likely to he our radically changed ears. The effects are high musicianship in the portraying of the inattentive even to the most eloquent This 0110. In addition more than mere show. They are part of the Brahma style. This music is Walter's own performance. fabric of music home language; it comes from the same place to flue sound, boasts a modest, well shaped the and if the musical sense and careful playing of both works so is projected whole, the original impact cub be and tithes as he does himself, speaking that the felt again. broadly. And so it is both impeccably styled tired car is more titan likely to he refreshed, not blasted. Good. Even eternal Just try the opening slow introduction to and deeply traditional. A very far cry from, that recorded nightingale is unobtrusive -- where do they dig World" say, Toscnini's Brah m s, bui probably more this "New to see what I mean. Per- him up. year year, such haps Dvorak himself would find it strange important, even so. after for perform- (but, ances? This one appears to he nhodetu 111-fi then, he would be stupified by any bird, probably very autlenti, laird watchers phonographic hi -fi sound, after all ...). Yet please check me. in terms of our day and of the recorded Tchaikowsky: Romeo and Juliet; Nut- medium -this Is it. The dark. bleak, terrify- cracker Suite. Philharmonia Orch., Mar - ing side of the Dvorak expression is right kevitch. Angel 535680 stereo Beethoven: Symphony No. 1; Symphony there, and convincingly. Even so simple a No. 2. Detroit Symphony, Paray. touch as an extra-intense roll The intense youngish conductor of from the tim- this Mercury SR 90206 stereo pani can do it (with such lovely transients, recording has developed into a powerful and too). earnest interpreter of ballet and pictorial I'd rate this tops in sheer hi-it quality, good The other aspects, as per above, receive a music. You can hear in seconds of listening in other respects but subject to arguable similarly reasoned, expressive and effective that he will never do a pot boiler of the differences of opinion. In this it is like other treatment In this Anglo- Germanic collabora- blandly effective type we get so often on records in the Mercury- family. tion. I'm all for it. records. These arent, decidedly. It isn't easy to judge this sort of disc as The Nutcracker isn't too successful here, to the impact of the original performative in for that very reason. is Bruno Walter Conducts the It full of interesting musical terms -for so touch is involved in Orchestral phrasing, lively and well balanced on the the recording technique that is used. Music of Brahms. (The four Symphonies; whole: but there are numerous momenta of Here, for example, the strings, especially the Overtures; Variations on a Theme by what can only be impatience, as though to the fiddles, are heard close -to and sharply Haydn.) Columbia Symphony. get the job ou and over. Thus the opening of separated in space, the ever -working first the miniature overture is hasty bit violins ; Columbia M4S 615 (4) stereo and a out almost obstinately to the left the of time, but quickly it solidifies into a lilting surrounding liveness is small. The violin (mono: M41 252) production such as the piece seldom gets in sound, in this environment, is brilliant but more conventional versions. Still-this isn't scratchy -not via distortion, but through The first thing that will catch your eye in Markevitch's this new Columbia "spectacular" is the pic- meat, this little suite. faithful reproduction -and the individual vio- What really counts here is the enormously lins do not blend into a butter -smooth en- ture layout entitled "Bruno Walter, an bigger "Romeo," Affectionate Portrait," by his daughter, Lotte surely one of Tchalkowsky's semble, as they theoretically should. It is an Walter Lindt. The Walter family album, most intense, cogent works of musical con- effective sound and "faithful" to the mikes. struction and drama. It has challenged all the But is this the "live" sound that Party, the great conductors; few can make it sound conductor, thought he had achieved? Is this 780 Greenwich St., New York 14, N.Y. today more than effectively rhetorical. This the recorded sound that we ourselves, as

64 AUDIO NOVEMBER, 1960

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listeners, find most effective In projecting Beethoven's meaning? Let's remember that we are not reproduc- ing the concert hall, nor Beethoven's "live' music, but are, always on records, reinterpret- ing that sound in terms of a new medium. It is the wonder of the phonographic art that this reinterpretation, for the living room, can be so widely successful in so many musi- cal areas, that, indeed, it offers such ex- traordinary flexibility of means, to stilt n thousand different situations, periods, com- posers. Mercury is on entirely solid ground, then, as far as principle is concerned. There is only a question of aesthetic values within the phonographic medium. It is wholly legitimate to work towards a phonographic sound that will project Beethoven effectively via those very new transducers, the stereo loudspeak- ers. I am all for Mercury's point of view and only disagree, mildly, on the type of new sound that might project Beethoven's sense most imaginatively. The Detroit is not the world's finest en- semble yet, nor is Party a Beethoven spe- cialist of world repute. It is, thus, a question here how much of the slightly uneven string ensemble is the orchestra's and how much n purely phonographic magnification, via the close -up mikes. The same with that slightly scratchy fiddle sound. My feeling is that, for Beethoven at least, a warmer, more reverberant, less sharply sep- arated mike pickup would produce a better Beethoven product from the same original performance. But this, of course, is a matter for aesthetic argument and personal pref- erence. Mercury's hi -fi does pretty well for itself among record buyers. Having said all this, I must add emphat- ically that there are aspects of the interpre- tation that do come through direct from the players and conductor, mikes or no mikes. That curiously French ability to play down counterpoint in the German manner, to hit for the main tune, is nicely evident here, and would be with any mike set -up ! You'll hear it, for instance, in the counterpoints, the added melodic figurations, that surround the main tune of the Second Symphony's slow move- ment- played down, somewhat indifferently phrased, where more Germanic -minded con- ductors play up the double melodies for their undoubted architectonic strength. Subtle, but a profound difference, and Beethoven is weakened here in terms of his own intent, phonographically or no.

Sound Off! Marches by John Philip Sousa. Frederick Fennell, Eastman Wind Ensemble. Mercury SR 90264 stereo (mono: MG 50264) I was really astonished by this record -or rather by John Philip Sousa. Here are no less TD -134, $59.95 net. Optional base, $6.00 than a full dozen Sousa Marches one right after the other with no more than the regu- lation five -second pause between each (and It's the Thorens TD- 134 -one hi -fi bar- tracking ability and distortion charac- one quick record flip) ; and yet I listened gain that's really a bargain. teristics to equal straight through both sides and was ready those of much more for more at the end. Buy a Thorens TD -134, and you get costly separate arms. The fact is that, within this very special the matchless Swiss -precision crafts- Last but not least, TD -134, like all the medium, Sousa was an expert and authorita- manship tive composer, of an almost limitless imagi- that make the superb Thorens TD family of fine turntables, is backed nation and freshness as well as concentration. TD -124 His grasp of form was impeccable, he never turntable the talk of hi -fi circles, by the Thorens one -year guarantee .. . here and abroad. Your dealer invites you lacked new ideas for more march material, his a feature that gives you confidence in rhythmic sense is terrific-even in the one, to examine the mirror- finished, precision your decision to buy any Thorens turn- same march tempo, over and over-and above machining that contributes so much to table. all, he knew how to achieve tight harmonic contrasts. the smooth -running, low- rumble charac- See the TD -134 at your franchised In these respects, Sousa is right up with teristics of all TD- series turntables. Thorens dealer's today, and, while you're two other earlier pops men (if you will) - You Johann Strauss, Jr. and Offenbach. Sousa has save with an integral, built -in, there, get acquainted with all the fabu- taken his technique from both of these, the high -performance tone -arm that has lous TD turntables. You won't regret it. semi- rondo, endless -chain of lilting episodes 0.4 from the Strauss waltz, the zippy, peppy snappiness from Offenbach. You can hear Guaranteed for full year. both of these Europeans whenever you want one to in Sousa. But you can also hear America Sold only through carefully selected franchised dealers. singing, all the time. The Fennell "wind ensemble" makes a good Sousa band where in other popular wind music SWISS MADE PRODUCTS it has for my ear played with a too -precise HI -FI COMPONENTS . LIGHTERS and rather academic stuffiness. The reason SPRING -POWERED SHAVERS might seem clear enough -these are profes- THOItE MUSIC BOXES sional conservatory musicians who must cover NEW HYDE PARK, NEW YORK the whole of music ; they are aware that

66 AUDIO NOVEMBER, 1960

www.americanradiohistory.com Sousa's work is a lung cut above most march material and they play it with both respect and enthusiasm. rood stuff. SEVERAL LINES OF THOUGHT 14 ASSEMBLY MANUALS Andar Foldes plays Beethoven. (Wald- :;:MODEL SA -40 stein, Appassionata Sonatas). 40 -watt stereo preamp -amplifier in Deutsche Grammaphon kit form. Harmonic distortion, less DGS 712021 stereo s. than 0.5% 14 controls. Hum and noise inaudible. (mono: DGM 12021) MODEL SA -40 -Kit 5 79.95 MODEL SA -40W -Wired $129.95 It's good II) hear from my ample Hungarian friend Andor, he of the enormously powerful hands and driving technique, housed In a big, friendly frame of fat with an energy -less voice suggesting indolence and comfort! To look at him, you'd think piano playing was more than he could rouse himself to try. To listen to him, you'd think the devil was let loose at the ENGINEERING keys. :Lndor Foldes travels. these days, a million miles and a thousand concerts a MODEL ST-45 year. His records drop in every so often, be- AM -FM SIMULCAST stereo tuner in tween postcards of the "wish you were here" %Aic-- kit form. Sensitivity -.2 pv for 30 type -plus postscript telling of his latest im- db quieting. MPX facilities. portant dates. He keeps us informed. MODEL ST -45 -Kit $94.95 ST with be MODEL -45PA - Semi -Kit, This would seen to a kind of Hungarian AM and FM tuner sections wired, temperament, this smouldering, volcanic per- prealigned and calibrated $99.95 sonality, highly educated and urbane, yet ever MODEL ST -45W- Wired, aligned, cal- near to violence of a sort. Bartok had it, and ibrated. ready to operate .$134.95 showed mainly chill to the outside world (though anybody could see the fire In his face and eyes). The genial Dohnanyi played like a joyous fiend in his 82nd year -then died. In any other national guise, Foldes would surely be a merely aimable pianist, in such n body. STYLING As a Hungarian, he is formidable. Not a warm, though severe, player, like MODEL ST -35 Schnabel, not n cloudy planistic Byron. like %Aie- some of the big Germans. nor a sentimental FM TUNER KIT. Sensitivity, 2 Av Romanticist In the sweet Viennese manner, for 30 db quieting. Easily adapted Foldes plays hard and cold, expressively, over- for MPX and stereo. MODEL ST-35 -Kit $59.95 poweringly just the same. He hardly makes MODEL ST-35PA - Semi -Kit, tuner for easy -going listening, but he does give you section wired, prealigned $69.95 a potent insight into major aspects of Beet- MODEL ST-35W -Wired, aligned, cal- hoven structure and emotional content, not ibrated, ready to operate $89.95 the bigness of Beethoven but the enormoo- inner intensity. k4-9t/ SAVINGS

A Memorial Album: Ernst von Dohnanyi Plays His Own Music for Piano. Everest SDBR 3061 stereo This is quite an ext rwrdinary 'luvuorial. both in the sound and in the ci reum s to 'lees. It will have considerable appeal simply as a MODEL L -2 tine piano recording, and as a testimonial to 2 -WAY. SPEAKER -SYSTEM SEMI - the amazing powers of an 82- year -old Hun- factory wired you wire - KIT. 10" Jensen woofer and horn- garian pianist. $129.95 YOU SAVE type tweeter. Response, 45 cps to The strangest aspect of this recording is 15 Kc. 231" W x 13" D e 12" H. $50.00` MODEL L- 2U- unfinished birch that the man died almost immediately after $59.95 completing it (heart attack, complicated by MODEL L- 2F- walnut, furniture -fin- ilu) -and as you listen you will be tempted to ished. $69.95 feel that it wasn't surprising. Such fabulous planistic energy as is here displayed is hard to believe! But surely it was his own pleasure to play in this fashion ; he was not in any mood to spare himself, and the triumphant feeling of success that the old man must have felt at such performances for hi -fi posterity shows itself in every measure. It is an exu- berant record, from beginning to end, and a happy memorial as well as a truthful one. MODEL L -1 The Dohnanyi music is of the late -Romantic THAT ULTRA.COMPACT SPEAKER SYSTEM school, like Rachmaninoff but lighter, more P A Q o SEMI -KIT. Excellent sound in mini- airy, far less inhibited. It isn't great music, HIGH FIDELITY KITS mum space. Response, 50 to 14.000 and a few pieces go a long way, for most of cps. 151" W x We" D x 81" H. our MODEL L -1U - sanded (unfinished) ears. But in these all -out and authentic OUTSELL walnut performances, limited only by a finger stiff- $24.95 ness FACTORY -WIRED At that the old man is simply determined to leading hi -ti ignore, and does, you will find a tributors dealers gusto and COMPONENTS ... where and electronic truthfulness in the Romantic vein Plate you can dis - that isn't line also see at all common more. test, the corn - any I'd recommend the equipment kits.PACO marine disc for almost anybody who likes musleal and ham gusto. For comp /eue catalog, write: Ede Zathureczky. (Franck: Sonata in A. Beethoven: Sonata in G, Op. 30, No. 3, ELECTRON Bartok- Zathureczky: "For Children ".) Ede CO., INC. Zathureczky, violin, Menahem Pressler, PRECIS/ON Kit Division Apparatus of piano. Vox EZ-1 mono 70.31 84th Company. Street, Glendale /n.-. This memorial album Is (Subsidiaries 27, L I part of the last of PACOTRONICS, N. concert of a top Hungarian violinist, colleague Inc.) of Bartok, Kodaly, and the rest, who died suddenly in this country in early 1959. The

AUDIO NOVEMBER, 1960 67

www.americanradiohistory.com record consists of a portion of a "reference It was good that Vox could undertake its pro- All in all, a noble but not too successful ex- tape" made at the concert, which took place duction on its regular label, for wider avail - position of French music. at Indiana University, and it poses some abitity. interesting questions. On Its face value (for those not present on the actual occasion, or Ravel: String Quartet. who do not know the man's work as a whole) Franck: Sonata in A Major. Prokofiev: String Quartet »2. Carmirelli it is quite disappointing. The faults are both Debussy: Sonata in G Minor. Isaac Stern, Quartet. London CS 6174 stereo musical and technical. adding up to what is violin, Alexander Zakin, piano. undoubtedly u misleading surface impression. I like the way this forthright group of And yet -who is to say that a man's last con- Columbia MS 6139 stereo Italian players tackles the familiar music of cert is not a fitting memorial, at least to all (ML 5470 mono) Ravel and the folkish, Russian -bear Quartet of who did know his greatness and can discount l'rokofieff. The group seems to have its own the shortcomings of n single recorded occa- These day-.s, it big perforating artist is sup- rather individual approach to what are, by sion? posed to be able to play the whole repertory this time, pretty much standard items in quar- M usleally, it is evident that at this time of music In his field for sing it), whateter the tet literature. They have an Italian sense of Zathureczky must have been very tired and /or style or nationality. This is not good, for it drama and lyricism, warm and positive but a ill; the playing is highly musical but phys- militates against individuality and, in fact, bit on the soft side. They avoid very thor- ically- weak, full of tell -tale slurred passages. against style itself. oughly that academic "quartetty" sound that uneven intonation, tired entrances, a thin. Isaac Stern plays everything ; but the Stern - many- players feel is somehow the mark of quavery tone. This is heightened by casual Z.akiu team seem to me to be best in the more good quartet playing. Maybe so, but imagina- Germanic types miking- mostly his own fault ; he sways from of music. Their Brahms, for tion counts heavily, when well applied as here. side to side, in and out of mike range. (Re- Instance. is superb. This foray into two French The Ravel is all mystery in its more Itnpres- member that this was merely a "reference works is, as I hear it, a slightly qualified suc- sionistic parts, sounding really like the fresh, tape ".) In contrast, the immovable piano's cess-good, for both musicians are top- drawer, enthusiastic early work that it was when com- sound is much better and Its impact is height- but still not what it should be stylistically. posed. The I'rokofieff, however, is quite unlike -mean- ened by a powerful and intense player, Mann - Even the recording interferes, with well other recent performances I hare heard. The hem Pressler, who practically- carries the ing intent. Too fancy in the sound. taut, hard, intense quality, the gutty expres- fiddle along with Ids own energy. Too much The Franck sonata Is overly eloquent and sion. Is largely missing in favor of warmth plano. forceful. as though it were a German work, and song -whenever I'rokafieff allows it. Some The inadequate recorded effect, then, is a thereby somehow dampening that fresh, pastel - well known passages just seem to mystify these product of circumstances -a specific tinte and like and almost naive Romanticism that was players, judging by the sounds they make; but place. Good recording, we most remember, is Franck at his best. Too complicated, this they have n good try at them anyhow, in their always timeless, without reference to any spe- playing, too involved In "meaning," where the best Italian manner, and the results, while not cific occasion; it must sound out strictly on piece is best played impeccably, yet simply. exactly Russian in flavor, are winning and Its own built -in merits. And so this is not a And as for Debussy, the playing again is )octal to hear. good recording, though it may be a naming full of fire and "meaning," recorded in a huge memorial to a great nun. big liveness; and once more. it seems to me, So -so editing doesn't help. Applause is shot the essentially dry sound of this work of Debussy: String Quartet at you like a gun burst (cut in without fade - craftsmanship is made tun expressive and Ravel: String Quartet. Juilliard String up) before each piece--quite unnecessary since thereby loses its best strength. Moreover, the Quartet. RCA Victor 1SC 2413 stereo the music begins and ends without applause Debussy work is above all a piece of intimate overlap. There's nothing wrong with well - chamber music, at its best in close proximity, I played this record just after I had spent managed applause to indicate that a concert without liveness. The big sound Columbia ap- it morning in I 'h lladelph la and the same after- is taking place; hut it must be tailored to the lilies here gives an unduly symphonic effect noon in New l'ork. No doubt about it -this recorded medium. This isn't, by a long shot. that is quite out of style. dull ha rd Quartet Plays in the tempo of New These technical nutters will not bother In both works it seems to me that the im- York. those for whom the memorial is Intended and portant piano part Is subordinated to the fiddle In Philadelphia I had a feeling that people the friends and admirers of a notable violinist in the mike set -up, for still another stylistic walked just a trifle slower, cars waited a bit will surely want to own a copy of the record. fault. Not serious. but noticeable, nevertheless. longer at the light (and honked less when

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68 AUDIO NOVEMBER. 1960

www.americanradiohistory.com held up), the cops were more suave and un- two sirens, that dates from the late Twenties or has Columbia made the usual boo -boo? It's hurried, there was always a bit more room to -the music, not the record; it was 1950. Here Edgard, not Edgar. move around in than in my normal place of it Is in stereo, and added to it for a represen- Y.S. There's a Folkways mono recording of residence, . If the Juilliard Quartet tative survey of the man are other works "Ionisation," same conductor as the old EMS can be taken as standing for American music - from the sane incredibly remote period, plus 401 (Folkways 6160), with Juilliard School making versus European, I think their Impec- his latest opus, tape -composed, the three-chan- players. Folkways ignores us, here at Aumio, cably "Manhattan" intensity is perhaps typi- nel "T'o'me Electronlqué' that was assembled so I haven't heard it. Also a withdrawn cal of our way, in contrast to that of, say pat Philips in Holland) for the 1058 Brussels Crania, in both stereo and mano. The original Vienna or London. World's Fair and projected there in a building EMS record included four of the works on this Both of these works are given fast, in- designed by Le Corbusier, via some 400 built - new Col bin record. tense, highly charged performances, beautifully in loudspeakers. worked out, driving but never less than smooth Maybe Ita literal prejudice -I've heard him in ensemble. They are, if you wish, musical before-that makes me feel that the "live" La Harpe: Classique et Moderne. Marcel chrome plate, but a solid, enduring layer of it, portions of this record are a bit less healthily Grandjony. Capitol SP 8514 stereo good for the ages. "Our tempi are generally energetic than earlier versions I've experi- faster than fifty years ago because the pace of enced as led by other conductors than Mr. \I. CraandJaity Is use of the greatest and life is faster," says the first violinist of the Craft. I lis somewhat chilly intellectualism most not tical harpists of all time and at com- is ensemble in the album notes here. That's pre- gives us superbly accurate playing bas far as municator of the harp's musical idiom who cisely the idea. This is modern playing, ex- I can tell) but omits a certain zest that is in- so magnetically persuasive that ninny of us pressing 1060, for better or worse. herent in every Varèse prodnetion, as in the who would not look a horn or an oboe in the irrepressible man himself. But the essential face will listen endlessly to his harping, no potency of these works will fascinate and matter how corny the substance -land corny Music of Edgar Varèse. (Ionisation; Den- shock you even so. This Is a real screamer, it often is. sense I bn't be misled by that pretty word sity 21.5; Intégrales: Octandre; Hyper - controversial in the finest imaginable. You'll be violently pro, or insanely against; "moderne'; look the other wily when you prism; Poème Electronique.) Robert Craft you won't stay neutral; you can't. I think the read "Jazz Band" as one of the Included ti- conducts woodwinds, brass, percussion. man is a real genius of his sort. I suspect he tles. M. Grtndiany's modern music might con - Columbia MS 6146 stereo is so far the only big musical mind, at least ceivably hate sounded modern hack In the depths of the Impressionistic age, which is (mono: ML 5478) of an older generation (who knows yet how the youngsters are endowed) so far to have the modern harp's true home anyway. As for Its You've 11141141. and you remember. the fam- invaded the electronic field. Jazz, the harp is the harp and jazz isn't ous EMS -401 hi -fi recording of "Ionisation," Only one small question in my mind -hms forte. Not under this man's fingers, anyhow. that fascinating collection of noises. including Varìse dropped the odd last letter of his name. (Continued on page 76)

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www.americanradiohistory.com enjoying the benefit of Lave Hancock's engi- neering are Morning Air, Rippling li'ater, and 7'ango La Caprice.

Les McCann Ltd: The Shout Pacific Jazz 7 Rarely lias a new jazz pianist caught on as quickly with the public as Les McCann, whose first album deals with "The Truth" and be- came a best -seller overnight. Its success stems in about equal measure from his persuasive pianistic powers and a capacity to create ec- static neo-gospel themes, especially in waltz tempo. Recorded just before McCann was about to take his trio on a cross- country tour. the present album is a revelation of the whole croup's ability to grip the attention of an audience and hold it. The location was The luit, n coffee house on Hollywood's Sunset strip, and Dick Bock's engineering of the trio, in stereo, proves it to be as finely balanced as any now working. The dynamics are wide- ranging throughout, and the speaker system CHARLES A. ROBERTSON that can handle Leroy Vinnegar's sixty- fourth bass notes Is one worthy of the name. McCann uses choice humor to introduce several numbers and almost bursts into song STEREO his former boss and the sound of his new band on the title tune, his sole original of set. is fresh and vital. the Ernie Wilkins: The Big New Band Of The Vinnegar is a powerhouse on C Jam Blues, There always will be a touch of the Basie and Ron Jefferson Everest SDBR1104 lets loose a masterful drum '60s tradition in everything Wilkins does, which Is roll on Night in Tunisia. The lead is shifted as it should be. On three originals, prepared In the midst of a thriving career as ar- from one member to another often, always for the second LP, he comes nearest to open without a hitch. The audience can hardly con- ranger for several bandleaders, Ernie Wilkins competition, but then dodges the issue by giv- is dangerously close to assuming the full re- tain its enthusiasm. When the pianist fades ing two principal roles to Yusef Lateef, who is down to a whisper on But Not For Me, how- sponsibility of an organization of his own. A best known for such exotic excursions into Asiatic ever, the drop of a pin would be audible. good excuse for contemplating a risky mush,. The multiple reedman from Detroit en- step is the success of his first effort for Ever- livens Fresh Flute, and turns to tenor sax for Count Basie: Not Now, I'll Tell You When est, "Here Comes The Swingln' Mr. Wilkins idiomatic statements on Ernie's Blues. An- (SDBR 1077)," which introduced him to the other tenor player, Seldon Powell, underlines Roulette SR52044 pleasures of assembling a big band and taking .4 Swing Serenade, while still a third, Zoot The album title refers to Count Basie's prac- complete charge in the studio. The current re- Sims, propels Gershwin's Fascinating Rhythm. lease results from a return invitation and 1s tice of occasionally cocking a warning finger parts are assigned to a trio of equally at an expectant soloist. His other methods even more promising. Unless the urge is con- varied soloists. with Charlie of quered, Wilkins may leave security behind and Shavers featured signaling the band include arched eyebrows, on Satin Doll, in addition to his own Unde- distinctive piano chords, and his private ver- realize an expressed desire to venture out on cided. Clark Terry, a Basle graduate, the road at the head of a similar group. is lyri- sion of the Benny Goodman eye. This time cally expressive on Very Much In Love, and his instructions remain secret, however, as \Vilkins grew to maturity as an arranger switches to fiugelhorn for Lover Man. Richard during a four year period in Count Basie's sax they were used to extract a sheaf of arrange- Williams, one of the most promising of the ments and new numbers from various mem- section and learned a great deal from studying newer brassmen, is heard on Get By. The the Inner workings of the band. When he left Ill hers. Trumpeter Thad Jones proves to be the mellow of Henderson Chambers is hardest worker, coming up with the title five years ago to devote all his time to writing, just right for Speak Low. it was because he had the Basle style down pat piece, Sweet And Purty, and also rescuing Leading the reed section is Earl Warren, a Jule Styne's Mania's Talking Soft, a catchy and was hard pressed to meet all the demands melodic alto saxist who held the same post for his work. Besides doing scores for Quincy tune cut from "Gypsy" at the last moment. with Basie for more than a decade. The band Frank Wess provides his own flute settings on Jones, Harry James, Ted Heath and Dizzy executes unison voicings with the ease Gillespie, he has kept close to the creative and Blue On Blue, and Swinging At The Waldorf. repressed power of a 70 -watt amplifier han- Frank Foster contributes Rare Butterfly, and source of jazz since then by assisting many dling the dynamics of a Meyer Davis dance small groups on record dates. One of the rea- the pivot man in the rhythm section, guitarist set. Appropriately enough, Wilkins seems to Freddie Green, is the writer of the pulsating sons why he has escaped settling into a rigid be aiming at those Meyer Davis followers mold derived from soloists at who Daly Jump. These are the sort of compositions is the stimulus like to be adventurous once in awhile. A these sessions. Wilkins, who learned long ago the Basie team does best, and they sound all spirited rhythm team, sparked by the supple the better for originating within the band. where productive ideas may best be found, guitarist Kenny Burrell always gives credit to former Basic colleagues and drummer Charlie The Count adds a characteristic opus him- Persil), should start them swinging again. self, called Back To The Apple. Sonny Payne for inspiring a number of his themes. Armchair listeners, immersed in While boasting a reputation founded on an the aural encores his showpiece, Old Man River, but the satisfactions of amply proportioned stereo, other members, instead of walking into the ability to project the relaxed swing and en- will be impelled to resume foot tapping. semble impact of the Basie band, Wilkins also wings, remain on the stereo stage for the rec- is noted for his skill at mixing modern over- ord, and bis drum solo is nicely integrated tones with the basic riffs of Kansas City jazz. with the full band sound all the way through. Luckey Roberts 8, Willie 'The Excellent examples of how he has branched Lion' Smith: Credit the engineers for an unusually good a. out in recent years are his big band settings Harlem Piano Good Time Jazz 510035 -ist in the studio. for Sonny Rollins, available on the M -G -M The dean of Harlem piano demoutrates the Ray Bryant: Little Susie label. An extensive work surveying the his- art of piano assisted on the program of jazz on a tickling, tory saxophone, done commission by a robust and swaggering cub from the litter Columbia CS8244 from the Monterey Jazz Festival, permitted which included P. him to write for Ornette Coleman as well as James Johnson, Fats The best all- around pianist to develop in Waller, and Duke Ellington. Luckey Roberts, recent years is undoubtedly Ray Bryant, who the veterans Ben Webster and Coleman Haw- who school, kins. Continued growth as a composer since helped found the learned to play can sit in with traditional or modern groups by ear at the turn of the century and worked and have something to say in either context. Basie days, however, is only a partial solu- in a carnival the age of six. He rose to tion to the problems Wilkins will meet as a at the Approving audiences welcome him at The leader. top of the heap by World War I and wrote Roundtable, a dixieland outpost on Manhat- several ragtime hits. Less adept at self-pro- tan's East Side, or at Birdland Monday nights. Too much a product of the Baste organiza- motion than certain other pianists, he appears tion to be called an imitator, Wilkins also His reputation as a composer is also growing. for the first time on LP playing his own tunes. largely due to Little Susie. Written and named knows that any new band following the style Quite a bit of plano history is covered on the too closely will run second for a long time to for his daughter, it holds rhythmic appeal for six chosen, from Nothin', an acrobatic exer- teenagers as well as middle-aged admirers of come. If Wilkins goes to the other extreme and cise of fifty years ago, departs from the Basle style completely, he to the contemporary two -handed piano. Before Columbia signed Outer Space. Stately waltz themes are heard him to a contract, at least two other com- will no longer be doing what he is trained to on Inner Space, while alone do best. The planning of the two Everest al- the titles explain panies had already paid him for recording the Spanish Fandango, and Railroad Blues. Luck - tune. Columbia outdid the others by pushing bums indicates how he intends to disentangle ey's powers seem undiminished he himself from this predicament. As a starter, and strides the single version, however, and now Susie, along in line two -handed fashion. It will be newly framed in stereo, is ready for further the lists were ransacked for show tunes and one of the tragedies of jazz he pop standards not usually included in the if never records adventures. the rest of his compositions. With all the The program also uncovers two other Bry- Basie book. Soloists were judiciously picked to money floating around for less useful projects, fit each tune, but few are Basie alumni and ant originals in Big Buddy, and Blues For someone might set up a Harlem Piano Founda- Norine. His affinity for the blues is well estab- none is a member of today's band. Conse- tion to preserve some of quently, Wilkins avoids direct comparison with the vast repertoire. lished, but he proves equally attuned to Misty, Willie "The Lion" Smith has recorded most So In Love, and Oreensleeves. Brother Tommy of his works before, but never in stereo, or in is on bass, and Eddie Locke and Gus Johnson 732 The Parkway Mamaroneck, N.Y. sound anywhere near as good. Among the titles alternate on drums.

70 AUDIO NOVEMBER, 1960

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www.americanradiohistory.com Andre Previn: Like Previn! NO BETTER SOURCE FOR SPECIALIZED Contemporary 57575 TRANSFORMERS THAN THE EXPERTS Dinah Shore: Dinah Sings Previn Plays AT Capitol ST1422 It would be a remarkable LP that contained all aspects of the musical personality of the multi -talented Andre Previn. The first pre- sents him as jazz pianist and writer of eight originals in the company of bassist Red Mit- PEERLESS chell v and drummer Frankle Capp, the regular members of his trio. Three tunes are named for the musician's wives, but the leader also takes recent jazz trends into account and Since 1935, Peerless has been the makes one a blues waltz, adds a camp -meeting pioneer - designing and manufacturing flavor to another, and then shows off his bal- transformers of the highest reliability to most- exacting specifications of the lad style. While not of the roistering school and of humor, Previn strikes a witty vein on Tri- electrical electronics industries. A policy of creative engineering, pre- cycle, and comes back for an encore during cision construction and rigid quality control has given Peerless acknowledged brisk exchanges on Three's Company. The leadership bassist's solo on Rosie Red, dedicated to his - particularly in the design of specialized units. Pioneering in helpmate, explain why he is the pride of the miniaturization, Peerless has also established the industry standards for Mitchell household. Dinah Shore joins in on a relaxed session reliability in sealing and ruggedness of packaging. Products range from that allows Previn to display his considerable skill as accompanist and weaver of units 1 /10 cubic inch to more than 20 cubic feet, from fractional voltages romantic moods. The rhythm men take a breather on to 30,000; from less than 1 cycle to almost a half megacycle; in 1, 2 and several tunes, on which just the singer and 3 -phase or phase -changing configurations. Constructions cover the range pianist together create a quiet and timeless feeling. It makes quite a change from her ap- from open -frame to potted, hermetically -sealed and vacuum- impregnated pearances before television cameras. Among units. Whatever your transformer needs, Peerless the songs given the casual touch are The can design to your specifi- Man I Love, Melancholy Baby, and That Old cation and deliver in quantity. In addition to the units shown here, Peerless Feeling. has solved these special problems: Cannonball Adderley: In Chicago IMiniature Inductance Unit, 4.85 henrys (' 7 %) at 150 ma, DC Mercury SR60134 Miniature 400 -cycle Filament Power Transformer for airborne operation When still working for Miles Davis, during an engagement Miniature Power Transformer, 3- phase, 400 cps to 1, 2 and 3 -phase at Chicago's Sutherland Hotel, Cannonball Adderley took Miniature Audio Input Transformer, low -level input the rest of the leader's sidemen into the studios in February. Miniature Hermetically -Sealed Output Transformer, 400 cps, high level 1959. Both he and John Coltrane, the group's tenor sexist, had attained a pinnacle In their careers while with Davis and would soon set out on their own. The was ripe .,c..,m,, ç?.. . time for a joint discussion of their experiences together, and a new revelation of progress LOW VOLTAGE, HIGH CURRENT made. The AUDIO breezy Chicago atmosphere also seems to have OUTPUT TRANSFORMER 16595 affected Adderley, who wastes no effort in purposeless rhapsodizing on Limehouse Blues, Single - phase, oil - immersed unit rated at and Stars Fell On Alabama. Ills alto -sax play- power level of 26KVA. Frequency response ing follows direct and functional lines on Wabash, a composition of his own. Coltane of .5 db from 20 cps to 5 KC. Above reso- contributes Grand Central and The Sleeper. nant frequency, at 28 KC, attenuation slope Rather than depart on unexpected tangents, each is content to work as a team and feed and phase shift are smooth and without the other ideas from a bountiful supply. irregularity. Suited to such applications as Pianist Wynton Kelly spins a balladic tale on You're A Weaver Of Dreams. Paul Cham- driving high -power shaker tables. bers, bass, and drummer Jimmy Cobb com- plete the quintet. Bernie Clapper, of Universal Recording, provides a stereo setup that never renders asunder what Miles Davis put to- gether. 20 -20 PLUS SHIELDED INPUT Johnny Griffin: The Big SDul -Band TRANSFORMER K -241 -D Riverside RLP1179 Small size for such superb performance. Frequency Every good big baud hopes eventually to response, 1 db: 10 to 25,000 cps. Primary bal- play with relaxation and flexibility of a small band. When good fortune strikes anced to attenuate longitudinal in and every- currents excess thing begins to move at once, it usually hap- of 50 db. Secondary may be used single -ended or pens late at night after the members have worked in push -pull. months together. Most musicians en- Electrostatic shield between primary gaged to fill studio dates have experienced the and secondary has 90 db electromagnetic shield- feeling, at one time or another, and are hired because they can stir up a semblance of

ing. ! Maximum operating level, 8 dbm. the real thing on short notice. The occasions when ten men catch fire with the intensity of Whatever your transformer needs, Peerless engineers can design those surrounding Johnny Griffin are so rare, however, that it is difficult to believe a studio to any military or commercial specification and manufacture in group is involved. It is even more difficult to any quantity. See REM for complete catalogue of standard units think of his fiery "soul- band" in conventional or write for information to Dept. AD-11. big band terms. While the liner notes stretch a point by in- sisting no one else thought of welding gospel fervor with full band sound before, this is the first LP to be quite so thoroughly steeped in the subject. Norman Simmons, a young Chi- cago arranger and composer who served a stretch as Dakota Staton's pianist, sets older PEERLESS spirituals and new originals as texts for the leader's sermonizing tenor sax. In addition to three of his own compositions, he provides ELECTRICAL PRODUCTS full -scale scorings of Bobby Timmons' So AL A DIV /S /ON OF ALTEC LANSING CORPORATION Tired, and Junior Manse's Jubilation. His Los writing, aside from evoking the gospel spirit 6920 McKinley Avenue, Angeles 1, California in a fresh and novel manner, never impedes the band and each declaration seems wholly

72 AUDIO NOVEMBER, 1960

www.americanradiohistory.com spontaneous. Even Charlie Persip, on Medita- tion, is allowed to preach to the congregation in a drum part that almost talks. Griffin is the main soloist, taking several -kit© packed on knightPRODUCT OF ALLIED RADIO emotion choruses all numbers, and does the best work of his career. His fluent delivery has frequently lacked the sense of direction which Simmons supplies ou Wade a pleasure to build and you own the best In The Water, Nobody Knows, and Deep River. Griffin attacks each with a personal urgency that drives the band full tilt. Clark Terry, you get more with a Knight-Kit: Matthew Gee and Timmons also have solo roles. The arrangements demand much call custom quality...exclusive design developments... and response from the sections, and engineer Ray Fowler tosses the exchanges back and maximum savings...supreme listening enjoyment forth in faultless stereo.

George Shearing: On The Sunny Side Of The Strip Capitol ST1416 Despite all the efforts with surrounding strings, woodwinds and voices, the George Shearing Quintet still performs best unencum- bered and before n live audience. Capitol made this discovery when the pianist was recorded in concert at Claremont College, and again when he accompanied Peggy Lee before as- sembled disk Jockeys. At last, the microphones follow him to a more customary habitat on Hollywood's Sunset Strip, permitting the cash customers at the Crescendo to be heard en- joying a typical program of ballads and mod- ern Jazz standards. Emil Richards, vibes, and Toots Thielemans, guitar, give expert assist- ance on ordu, Confirmation, Bernie's Tune, and Joy Spring. The leader, aided only by bassist Al McRibbon and drummer Percy Brice, charms old and young lovers every- knight -kit Stereo Tape Record -Playback Preamp Kit where on The Nearness Of You. Complete record -playback preamp The concluding number of each side brings new for any 2 or 3 head stereo tape transport. on conga drummer Armando Perrazza, whose Separate dual -channel recording and playback preamps. Permits tape Latin rhythmic effects are a treat for stereo and monitoring, "sound -on- sound" and "echo" effects. Features: Accurate VU listeners on Mambo Inn, and Ernesto Grenet's meters; adjustable bias and erase voltages; concentric clutch -type level controls Drums Negrita. Capitol engineers have devel- exclusive for mixing of mike and auxiliary Inputs on each channel, for channel balance oped a real aptitude for location work and and for master gain adjustment; 6- position selector switch selecting every turn in an excellent recording. possible stereo and monophonic function. Printed circuitry for easy assembly. Extruded aluminum panel in Desert Beige and Sand Gold; 4'/, x 15'/, x 9'. : Newport Suite Shpg. wt., 15 lbs. 83 YX 929. 55 Down. Only $79.95 (less case). Roulette SR52047 A mischance resulted in the title Newport wide choice of money- saving stereo hi -fi knight -kits Suite, which is actually a blues -based piece of slightly more than average length, and only by virtue of an interpolated I.1,--=..-,r7.1---73.03 + waltz theme does It become a suite. Still un- named when the band arrived for the 1959 `_ Jazz festival, it was christened and launched O on the spot because Maynard Ferguson learned IS at the last moment that a blues program was 70 -Watt Stereo Amplifier Kit scheduled. It builds, like any proper 20 -Watt Stereo Amplifier Kit blues, 83 YU 934 $119.95 through a series of minor explosions to a 83 YX 927. $39.95 point where the listener is thoroughly pre- pared for the final climactic detonation. Frank Farrell, tenor sax, and Jimmy Ford, set the stage for the leader's entry, and his solo heightens the sense of anticipation by under- statement before ascending ultimately to the upper reaches of the trumpet. No doubt the time elapsed between Newport and the studio 40 -Watt Stereo Amplifier Kit 32 -Watt enables Stereo Amplifier Kit the band to offer an improved perfornr- 83 YU 774. $76.95 83 YU ance-a powerful one in every respect. 933. $59.95 Although Ferguson describes all seven num- bers on the LP as "applause- getters," an ade- quate amount of space is allotted to something besides pyrotechnical displays. His attitude is thoughtful and profound on Sometimes .1 Feel Like A Motherless Child. Hampton shares the writing chores with Bill Maiden, a fel- low bandsman of humorous Stereo FM -AM Tuner Kit bent. Maiden's Prices Include case FM -AM HI -Fi Tuner Kit idea of a good time is to inveigle his boss 83 Y U 731, $87.50 83 YX 928. into playing , and then match $49.95 him with baritone -saxist Frank Hittner for some eventful stereo sounds on The Jazz FREE 1961 Knight -Kits are products of and Bart'. Ferguson should try to get as much fun ALLIED CATALOG Jump unconditionally guaranteed by out of a trumpet once in awhile. See the complete Knight - Irnolos Kit line of hl -fi compon- ALLIED RADIO June Christy: The Cool School ents. For everything in 1 build -your -own hi -fi, for ALLIED RADIO, Dept. 138 -L Capitol ST1398 everything In Electronics, 100 N. Western Ave., Chicago 80, III. The headmistress of the cool school of vo- get the 444 -page 1961 Ship the following Knight -Kits calizing opens the fall term with a lesson in Allied Catalog. Send for fundamentals, designed especially for new Free copy today. s enclosed aspirants and older students in need of a re- fresher course. Because June Christy starts Easiest Terms: Sand FREE /N1 Catalog faatudng Knight -Kits. right out with a review of first principles, the Only$5.00 down (or less) Name LP should be forwarded to graduates who on orders up to $200; up now believe their personal mannerisms are to 24 months to pay. Address more important than the substance of a song. Not only does teacher know that a distinctive : Knight -Kits are style depends upon City Zone _State the ability to sing, she : available in Canada L -J

AUDIO NOVEMBER, 1960 73

www.americanradiohistory.com shows how on Gershwin's Looking For 4. Boy, column. There is no disputing the validity of niques employed. By keeping earphones within Swinging On A Star, and Scarlet Ribbons. any of his statements, but the fact remains reach, the listener can satisfy his curiosity But the main part of the Christy message that such aids are a necessity to many listen- and obtain two distinctly different kinds of is aimed at a younger generation. As though ers. Quite a few people were distressed when dual -channel sound without rising from his to prove her point, she romps through such Permafiux stopped making them a few years easy chair. juvenile favorites as Ann Ronne11's The Magic ago. (They still make them -see New Products It would seem that the creation of true Window, Small Fry, Give A Little Whistle, in the October issue of AUDIO, ED.) stereophones is within the grasp of Dr. Amar and Kee- Mo- Ky-Mo. By scarcely bending a note Earphones, however designated, are selling G. Bose, the M.I.T. professor whose design of along the way, she makes the practice seem almost as fast as Kingston Trio albums this a new speaker system is about to be placed elementary and surprising once again. Joe season. With the return of tape for home on the market. His invention calls for twenty - Castro, playing piano and celeste, heads the listening and the advent of FM- multiplexing, two small speakers vibrating together on the accompanying quartet which consists of Leroy the demand is likely to gain greater momen- curved surface of one -eighth of a sphere, Vinnegar, Larry Bunker, and a guitar manu- tum. Aside from the obvious reasons of neces- with a radius of twenty inches. Resembling a facturer by the name of Gib Fender. sity and convenience, one incentive for the section of honeycomb in appearance, it can be purchase of this piece of accessory equipment placed in a floor or ceiling corner and is The Kingston Trio: String Along Is plain, ordinary curiosity. Audiofans wait- reputed to reproduce low bass frequenciés ing for further improvements in stereo com- without distortion clue to the vibrations of Capitol 5T1407 ponents suddenly decide to try earphones for the whole surface. There being little new to say at this late want of anything else to buy. All Dr. Bose needs to do now is reverse date about the Kingston Trio, whose albums While all the shortcomings mentioned by the position of a proportionate number of sell like hotcakes anyway, let it suffice for this Mr. Canby quickly become evident, earphones speakers and extend the sphere into the dome review to say that the boys seem twice as ram- often remain as a handy adjunct because of shape of a space helmet. Plexiglas might bunctious through binaural earphones. The these same characteristics. Where the proper vibrate as effectively on bass notes as the copy writers insist on calling then stereo - room placement of speaker systems conceals unspecified material used in Dr. Dose's new phones, and Mr. Canby has expresed his views the means of achieving stereo effects, ear- system. It Mr. Canby, or anyone else, turns on the subject in September's AUDIO ETC phones clearly define the engineering tech- purple at this suggestion, they are hereby nominated to become the first to don a Man - from -Afars globe. Deluxe models might be air conditioned and completely enclosed, with air intake from an oxygen tank. Oxygen is a sure cure for hang- GRADO "Truly the world's finest... over and should lessen any vertigo induced by kettledrums reverberating from channel - to-channel and back again. Regulations in pub- lic places would require that all transistor radios be contained in portable models -a real boon for captive audiences at beaches and ballparks. Mention should be made in passing of sev- eral new additions to the Kingston repertoire. Jane Bowers, the guardian angel of the group and Dave Guard, are credited with When I Was Young, and Buddy Better Get On Down The Line. Other trio members assisted on Who's Gonna Hold Her Hand, and The Tat- tooed Lady. Carl Sandburg, Cisco Houston, Bobb Gibson, and Lee Hays are among the composers of the remaining tunes.

Perez Prado: Big Hits By Prado RCA Victor LSP2104 This is one of the happier results of the practice of bringing hit recordings up -to -date by means of stereo. Not only is the sound benefited enormously, but Perez Prado takes the occasion to review his blockbusters of the past ten years with a calculating eye and improves upon many of the original perform- ances. The smouldering trumpets burst into flame on Cherry Pink And Apple Blossom White, and compulsive rhythms charge through Mambo Jumbo. The arrangements of the Cuban pianist are especially suited to the panorama of stereo. At the same time, his custom of interjecting guttural cries seems less forced, and the electric organ less over- bearing on Patricia. The engineers do a splendid job of handling both the organ and rampaging brass.

MONO Shakey Jake: Good Times Prestige /Bluesville 1008 Besides bringing back some of the older blues singers, plans for the Bluesville serles Gunstock walnut wood Vertical azimuth adjustment evidently extend to younger men not recorded Smaller in size and mass Interchangeable cartrdges before. Shakey Jake currently sings weekends on Chicago's South Side, works the rest of the Vertical balance adjustment Adjustable overhang alignment time in a gas station, and earned his nick- name while shooting craps to further supple- Lateral balance adjustment Completely wired to preamp ment his income. Although he was born Jim- cable mie Harris in Arkansas, sharecropping forms Tracking force adjustment Ultrafine shielded no part of his past and most of experiences are urban. He came to Chicago as a boy dur- ing the depression and learned about the blues there, listening to other singers and studying the harmonica style of Sonny Boy Williamson. While of uneven quality, all the tunes are Custom Cartridge $32.50 - Master Cartridge $49.50 - one Arm $29.95 his own and several of the dozen heard can stand beside the best in the genre, notably Just Shakey, and the title tune. No great shakes as a vocalist yet, he does know how to create a real blues feeling and will un- For further information write: GRADO LABORATORIES, INC. doubtedly improve. His harmonica playing, however, is more powerful and plumbs deeply 4614 Seventh Ave., Brooklyn 20, N. Y. - Export - Simontrice, 25 Warren St., N. Y. C. on Jake's Blues, and Sunset Blues. Bill Jen- nings, guitar, and Jack McDuff, organ, assist admirably.

74 AUDIO NOVEMBER, 1960

www.americanradiohistory.com Jazz Scene 1 Epic LA16000 Jazz Scene 2 Epic LA16001 The aim of this series is to include "artists who bave influenced jazz growth and the di- rections it would take." Some of the choicest items to appear on the old Vocalion label are reissued on the first volume. Along with Bunny Berigan's I Can't Get Started, there are four Ellington small groups under Rex Stewart, Johnny Hodges, Barney Bigard and Cootie Williams. Most significant are Jones. Smith, Inc. playing Lady Be Good, the number which introduced Lester Young to jazz listen- ers, and Roy Eldridge's Heckler's Hop. That Eldridge forged the connecting link between the trumpet styles of and Dizzy Gillespie is best observed on four sides recorded at this 1937 session. The remaining three should be considered for future releases in the series. While the first volume is essential for clos- ing a gap in many collections, the second con- tains items from LP's still on the market. Its value depends entirely on the individual col- lector's stock of Ahmad Jamal, Herbie Mann, and Conte Candoli.

The Happy Jazz Of Rex Stewart Prestige /Swingville 2006 Feeling that jazz needed a little fun and frolic for a change, Rex Stewart remembered the record sales of Red McKenzie's Mound City Blue Blowers during Prohibition Days and decided the group's high spirits might be worthy of revival. The popularity of this type of music is now largely confined to England, a country where skifile bands sprout at the end of every hedgerow. But McKenzie's knack of blowing choruses through comb and tissue paper has eluded musicians on both sides of the Atlantic. The more prosaic kazoo is sub- stituted on this session, with Stewart and John Dengler taking turns at imitating the en- raged buzzing of a swarm of angry honeybees. In addition to filling the breach with accus- tomed cornet solos, Stewart is encouraged by the general informality to vocalize on Red Ribbon, Nagasaki, and Four Or Five Times. Dengler rumbles like a bear after honey on bass sax, and settles the hive by beating on a washboard. Wilbur Kirk's harmonica is sooth- ing. while two guitarists and a drummer help out. The LP might serve at a party as a change from dixieland fare. Mound City tunes re- claimed are San, and One Hour. The group performed best when Coleman Hawkins and This dramatic 5- minute test -demonstration Pee Wee Russell were present. Perhaps Stew- art will invite them to the next outing. will prove the most compelling musical expe- a concert hall King Pleasure: Golden Days rience you ever enjoyed outside Hifija:z J425 Any Spacial Fidelity dealer will be happy to give you this cv. icing 5. minute demonstration. He will first select a famous, brand -name speaker system in hi- stock, or you may suggest one. A prophet and philosopher under the name select a Fidelity system. Both will be connected to a high fidelity music of Clarence Becks since the age of six, King He will then Spacial Pleasure later adopted the avocation of show system so that he can switch instantly from one to the other. business, but abandoned it in 1956 to reclaim Your dealer will then play a high fidelity monophonic record through the first speaker. After his real identity. The formulation of a new about one minute he will switch the music to the Spacial Fidelity system, so you can hear the Planetism has re- theory of existence called difference. There will be no mistaking it. quired all his attention since then. From a partial outline of his findings noted on the So startling is this difference in performance between Spacial Fidelity and conventional speaker liner, it is easy to believe that earlier studies systems, that in similar test -demonstrations for random groups, eight out of ten listeners identi- helped him to think of his voice as a disem- fied the monophonic performance of the Spacial Fidelity speaker system as stereo. object in space. In any event, he bodied Your next question will probably be about stereo. Your dealer will point out that a Spacial Fidel- learned to play on his vocal chords as he is a complete stereo reproducer in a single cabinet enclosure -and might on an instrument and was the first to ity speaker system actually develop the idea of setting lyrics to impro- that if, at some later date, you convert your high fidelity system from mono to stereo, no addi- vised jazz solos. Most singers would envy his tional speakers will be required. To demonstrate this point, he will play a stereo record or tape vocal projectoin and control, but the King through the Spacial Fidelity speaker system. himself a singer and always speaks never calls If you have ever attended a concert, an opera, a musical -any live performance-you know the of his work as interpretation. dimensional quality which the environmental surroundings impart The popularity of the Lambert-Ifendricks- sensation, the unmistakable can you no more Ross Trio has created a new demand for this to the music. Stereo Spacial Fidelity offer -only the delightful realization that style of vocalese and snatched the King from you can now recreate this experience-at will -in the comfortable privacy of your own home. momentarily. Restored are his his research The Classic (illustrated a stately decorator piece designed by Petruccelli - captures the justly famed Moody's Mood For Love, and luxurious warmth and elegance of the formal drawing room magnificently handcrafted and Mood. Also explored are solos origi- - Parker's in $765. models from $225 to $795. nated by Stan Getz and Illinois Jacquet, while superbly finished. Available red or brown mahogany, Other the title tune is based on Pleasure's own Prices slightly higher in West. theme. Undoubtedly a jazz musician at heart. Arrange today for a personal 5- minute test -demonstration of Spacial Fidelity. For the name of the King is right at home as part of a sextet the dealer nearest you, and descriptive literature. write to: Dept. A -11. headed by Gerald Wiggins, which includes Harold Land, Matthew Gee and Teddy Ed- IS AUDIO PRODUCTS DIVISION, RADIO FREQUENCY LABORATORIES INC., BOONTON, NEW JERSEY wards. .PE

AUDIO NOVEMBER, 1960 75

www.americanradiohistory.com DESIGNED FOR RECORDS (from page 69) A wee, thin trace of semi -syncopation. a few STEREO "dissonant" sweeps of the hand over high -7/ strings, serve to give this mid -twenties "jazz" i piece its jazziness; it is just another nice salon opus. But such limpid, liquid, wonderfully Intel- ligent playing! Almost beyond belief. I love P \TANNOY/ and always will. (And note that the harp sounds really good in stereo. Surrounds it with what it needs, a plastic sense of space The NEW, COMPACT and liveness.) 'MONITOR' DUAL CONCENTRIC, Marcel Moyse, Flutist. "The French School Type III LZ at Home ". A Marcel Moyse Flute Recital. Sixteen Classical Selections From a line of for the Flute. laboratory standard speakers comes the 10" Dual Con- Marcel Moyse, Blanche Honneger -Moyse, centric - not an adapted speaker but one designed specifically to operate flutes; Louis Moyse, piano. in small enclosures, yet provide the extended range integrated sound Marcel Moyse Records source with incredibly low harmonic distortion already acclaimed out- (183 Western Av., Brattleboro, Vt.) standing features of the larger 15" and 12" Monitors. Here are three LP's out of a series of musical documentaries -documenting one of Here is a speaker with ALL the basic attributes of larger systems: superb the great flute players of a past generation, transients good, solid, fundamental bass (not cabinet-simulated who brings both the techniques and the atti- - sound) tudes of the age of French Romantic flute - sustained mid and upper range frequency response smoothly maintained playing to our ears today in hi II sound. beyond audibility the TANNOY formula for unparalleled Don't let me carry you away ; you'll have to - presence. love the flute dearly to get through this wealth of flute, flute, and more flute (with Also Just Released the Tannoy `CADET' Enclosure Designed for the more to come, I expect). Nevertheless, every flute student, every historian of instrumental 10" Monitor Dual Concentric size 23I" x 134" x 11" music, every lover of high instrumental tech- nique, will want at least one of these. Not to mention all the music schools in the country Write for details to: -they'll need 'em all. As for the music, it's mostly so much senti- Tannoy (Canada) Limited Tannoy !America! Limited mental doggerel. If not that, then It Is classic 36 Wellington St. East, stuff played in a fine Romantic way. A Bach P.O. Box 177, and a "Haendel" on the classic disc display Toronto 1. Ontario East Norwich, L. 1.. N. Y. two flutes-lovely but in snail's pace fashion Circle 76A a short Beethoven item is nearer to the mu-

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76 AUDIO NOVEMBER. 1960

www.americanradiohistory.com slcal norm ; a hundred odd show pieces and arrangements fill out the rest of most sides, Just as in every specialized instrumental re- cital that comes along on records. DIFFERENCE': If you want incredible flute acrobatics, try "RESEARCH MAKES THE the Recital disc. It's full of corny variations, each one faster than the last until the flute is playing at thousands of npm (notes per min- ute). Look out for "The French School at Rome " - it is a pair of sides entirely de- For Good Living voted to flute exercises, probably the classic And familiar ones in every flute player's early Good Giving years. Musically zero and most of them dont even sound spectacular, for they emphasize the subtler aspects of flute technique, espe- solvY cially the varieties of tone color, of rhythm and portamento, of melodic aliveness. One will go "wow000, wow000, wow000 ", for a FM -AM special melodic curve, another will be all "ta, ta taaah, ta, ta, taah ", for tonguing. All- Transistor No doubt about 1t, the priceless sound of Portable Radio the great flute age is right here. But no doubt, too, most of us will say, not for my brass ear. The recording is technically good (you can hear all the breathing -in sounds) but is miked rather amateurishly. Living room sound. Pi- ano tinny and in the background, evidently not considered in the miking, where it should he given careful treatment to back the flute itself. 7B

'F 6 ; B nuen"t 1 16 12 id 16., MATRIXING q ... IJrv,al page ._'I) 17,.,-'t 1. N1 A Ni "left" and "right" channels, rather than "mono" and "stereo" (Fig. 4). The major listening area was not in the edge -on position of either speaker, where transverse radiation predomi- nates. But the characteristics of this s type of radiator were used. Each unit was a doublet, but only the front lobe can also be used as tuner of the "figure 8" pattern was used. for your hi- fidelity system The theoretical explanation accom- Receives both FM and stand- panying the verbal presentation of the ard broadcasts with world - paper was based on relative intensity famous SONY precision and from the two units, as controlled by the clarity. Works instantly and "figure 8" patterns. But there can only with equal excellence in- be a simple intensity combination at the doors or outdoors. Can also be point where their lines of pure longi- used as tuner with your Hi -Fi tudinal radiation intersect (Fig. 5). system! And as a very spe- At this point, resultant velocity, as cial gift, it has few equals. well as pressure, is controlled by the (ill. above) SONY TFM 121 with 12 -tran- phase between the radiation sistors, self- contained telescopic dipole relation antennae. Measures 21/4"x 5'x 91/4 from the two units (Fig. 6). At other Weighs 3! lbs. Complete with batteries. points, some transverse radiation is in- evitably present too, and undoubtedly helps the intensity gradient in creating the necessary difference at the two ears. A practical limitation to such a sys- tem, using true doublet sources, is the presence of the rear lobe of the "figure 8." If the unit is placed at all near to a wall, reflection occurs and complicates the radiation pattern to the extent of invalidation. (ill. directly abcvc) SONY TR 812-3 - The Heath engineers, who developed a band 8- transistor portable. ReceivesAM, similar system (for kit builders) under Short Wave ; ' Marine broadcasts. Size license from CBS, controlled the back 10y' x 715- ., ". Telescopic antenna. or Electronic Perfection" radiation by allowing it to "escape" SONY"The Peak CORP. through slits at the sides of the unit, OF AMERICA pointing forwards (Fig. 7). This re- 614 Broadway. NewYorkl2, NewYork tains the essential method of the CBS Canada: Cen'I D.sv.; s,ttd.,T91 Notre DameAe..Winnipeg3 At fine radio & dept. stores, or write system, without the speaker placement Dept. *11 for name of nearest store. limitation. Its front radiation is somewhat more TSB directional than the simple doublet

AUDIO NOVEMBER, 1960 77

www.americanradiohistory.com (Fig. 8). It probably limits the useable left and right, work in unison. For who put their ears close to individual area in similar proportion, but not so "stereo" components (in which left and units to find out "how it works," obtain much as the CBS method would be lim- right are in phase opposition) there is the illusion that each unit (as they listen ited by misplacement of the units to re- no sound output from the front units to it) is not working appreciably : all flect the rear lobe. and the internal air behaves as a fluid the sound must be coming from some- coupler between the backs of the left and where Complex Cylindrical Radiation else. So getting much too close right units, so their combined operation does invalidate the effect. Another variation of this approach is essentially as in Lauridsen's original At greater distances, a cylindrical was developed by the writer for an inex- edge -on unit. wave (which this then approximates) re- pensive "basement" loudspeaker, called Use of four units vertically in -line for duces its longitudinal magnitude in in- the "pillar of sound" (Fig. 9). Although each group results in approximately verse proportion to the square root of this was arranged to be connected to con - cylindrical radiation. This reduces the distance, while the transverse component ventional "left" and "right" amplifier rate at which both longitudinal and reduces in inverse proportion to the one - outlets, it used acoustic matrixing. transverse waves reduce magnitude with and- one -half power of distance (Fig. For monophonic components in the distance. Due to the length of the com- 10). There will still be a variation of left and right channels, the speakers posite source, the initial rapid reduction effect with listening location. The trans- facing in all three directions, forwards, does not occur at all. Curious listeners verse velocity always reduces a unit power "faster" than the longitudinal component, because it is not accompanied The newest model of the famous by the usual pressure drop. But the fact that both follow a lower power order, and the restriction to a horizontal radiation, improves the ratio between the controlled sound waves and unwanted reflections responsible for confusion effects. Ready action of the air as a coupling fluid for stereo (phase opposition) com- ponents will occur throughout the mid- NOW RECORDS range frequencies. Above this, where the TRACK distance between the backs of the units STEREO, becomes comparable with wavelength, the three sets of units will begin to be- TOO! have more or less independently, work- 4 ing as left, right and mixed center e 4 -Track Stereo Recorder groups. Mono or Sound -on -Sound Recorder Notice that this approach uses a phi- Plays 4 -Track or 2 -Track Stereo or Half Track and Full Track Monaural losophy that is the opposite of other sys- tems that put two stereo radiators in one from *495 "box," with various means of reflecting the "left" and "right" sound outwards, r.ar- in that the design depends on close inte- _ 9g01.l9- gration in a horizontal area, whereas other systems try to "bounce" their sound out, beyond their physical Now! The amazing all -in -one professional recorder that made history bound- aries. In this approach, reflection effects with its modest price yours in ... an improved 505-4 model which are avoided, rather than utilized. also records 4 -track stereo. Compare the exciting features ... found Over the mid -range particularly, an only in the finest instruments ... the price is still $495! acoustic matrixing occurs, to produce a radiation similar to that from Laurid- FEATHER TOUCH PUSH BUTTON OPERATION 4 HEADS, INCLUDING SEPA- sen's arrangement on mono and stereo RATE 2 -TRACK AND 4 -TRACK PLAYBACK HEADS 3 MOTORS, INCLUDING sources. However, the vertical line ar- HYSTERESIS DRIVE MECHANICAL FLUTTER FILTER DYNAMICALLY BAL- rangement produces a cylindrical radia- ANCED FLYWHEEL INSTANT SOURCE /TAPE MONITORING TWO tion pattern and the acoustic matrixing avoids RECORD/PLAYBACK PREAMPLIFIERS INSTANT START /STOP AUTOMATIC any lack of integration due to vertical displacement CUT -OFF SWITCH IPS SPEEDS AUTOMATIC between the mono 33/4.71/1 TAPE LIFTERS and stereo radiators. TAPE LOCATION INDICATOR SEPARATE MICROPHONE /LINE INPUTS, A signal EACH CHANNEL originating wholly from the "left" channel will have the left and right units working in phase opposition, which is the same direction in space, and AMERICAN CONCERTONE, INC. the left ones will be in phase with the e ASTRO- SCIENCE CORPORATION front ones. So the resulting sound wave 9449 W. See the phenomenal Jefferson Blvd., Culver City, Calif. is radiated to the Art: Dept. left of the listening AUD -11 area (Fig. 11). CONCERTONE 505 -4 Please sena your illustrated brochure on new CONCERTONE Similarly sound from 505 -4 STEREO RECORDER any at your dealer. For or the 505 2TRACK RECORDER other original position will be radi- and the name of nearest dealer. ated in a resultant direction to corre- name of your nearest Name spond. dealer and descriptive Address brochure mall coupon. Effect of Program Miking City lone State Dealer Inquiries invited. This last statement is predominantly

78 AUDIO NOVEMBER, 1966

www.americanradiohistory.com true only if the program is miked either with the M -S or Stereosonic technique, or with close -in mikes using electrical mixing to achieve the desired "position" KIVIGHT® effects. But this does not mean a satis- factory effect cannot be obtained if the A PRODUCT O F ALLIED RADIO program is miked by a method that in- troduces time as well as intensity differ- ences between individual program com- ponents in the two channels (left and the fastest growing name in hi -fi right) . because people who appreciate integrity in design Experiments have shown that smaller listening rooms, of the size most often and manufacture and who appreciate value, used in homes, achieve the most natural recognize these qualities in Knight fine products stereo effect on a given program, when the loudspeakers are arranged in close proximity and utilize directivity to ob- KNIGHT High Fidelity Amplifiers tain acoustic channel separation. In the ..from $39.95 to $169.50... extreme case, where the time differential See the new KN775 75 -Watt between channels is such that instan- c=3 Stereo Amplifier with such new -611eD features as front panel headphone taneous sound in each is virtually unre- jack, Monitor control lated to the other, the matrixing method and Separation control can be regarded as projecting each chan- nel (left and right) at the extreme angle of its control area. Thus even program that used a micro- KNIGHT High Fidelity Tuners... from phone technique not best suited to re- $49.95 to $139.95...all with Cathode production in smaller listening rooms, Ray Tuning Indicators... See the new KN 150 Deluxe FM Tuner with can be projected at least as well by an unique multiplex indicator, exclusive acoustic matrixing system as by com- Dynamic Sideband Regulation and pletely separate left and right loud- 1 microvolt sensitivity speakers. Perhaps one more thing should be clarified. One of the multiplex systems proposed, that we alluded to in our open- KNIGHT High Fidelity Tape Recorders ing paragraph, has made to ...from $86.95 to $249.95... See reference the new KN4300 featuring dual the term "acoustic matrixing," but with illuminated VU meters and complete a connotation not compatible with that stereo record and playback facilities we have used. The system in question with 3 speeds and Va track and '/z track all in one unit proposed to substitute a cross -mixture, consisting of something like 2L -R for "left" and 2R -L for "right," as the trans- KNIGHT High Fidelity mitted channels. It was suggested that Speakers... from $9.95 to $124.50... See the "acoustic matrixing" would cancel the wide selection of L -R part of "left" with the R -L part of speakers with magnet "right," leaving pure L and R which the weights up to 6'/a lbs. ..Choices include ears should interpret into a stereo effect. Polyethylene Foam Quite evidently this use of the term Cones, American made no KNIGHT High Fidelity Electrostatics and has reference to the employment of Cabinetry...from $34.95 to exclusive die cast acoustic effects in the ways discussed in $129.95...Choose from the frames...All with this article, and the suggestion itself world's largest selection... verified specifications striking new Room Divider contains a serious fallacy. Assuming an Sets...beautiful American out -of -phase component (the L -R and Colonial, French Provincial and FREE R -L parts) would cancel acoustically, Danish Modern Cabinets 1961 Catalog then any differences between one chan- EASIEST TERMS: Only $5.00 down featuring (or less) on orders up to $200; up everything in nel and the other would be similarly to 24 months to pay hi -fi and electronics "averaged out." Stereo is impossible. In products of and point of fact, it is the failure of such unconditionally guaranteed by cancellation, even when the sources are in close proximity, as in the pillar sys- ALLIED RADIO tem, that makes acoustic matrixing pos- sible. So, not only is such use of the ALLIED RADIO, Dept. 1964 100 N. Western Ave., Chicago 80, 111. term incompatible -it is contradictory G Send FREE 1961 Catalog featuring the complete line of money. to the facts. saving KNIGHT products and the world's largest selection of hidi equipment. Conclusion Name It is suggested that closer attention to arrangements that employ true acoustic Address matrixing will probably yield some more City Zone State effective loudspeaker systems for home L

AUDIO NOVEMBER, 1960 79

www.americanradiohistory.com stereo listening than have been presented so far. As well as producing more con- sistent realism, of which two -channel stereo is capable, they avoid the need for two separate locations, at the mystic spacing of seven or eight feet, where separate units are usually recommended. So this approach will also make stereo much more acceptable in the average living room. Æ

SOUND SYSTEM The new Electro -Voice 644 "Sound Spot" - a revolutionary development, the 644 is the most directional microphone ever made. (from page 26) Its complex array of transducer units demands Circuit Reliability -failproof connections -so that with exacting precision it will provide trouble -free performance through the years. described here is driven by a pair of 50- watt amplifiers. An electronic crossover At Electro -Voice they make highly efficient fast-holding solder joints with Multicore 5-Core is used to divide the audio range at about Solder. The exclusive Ersin extra -active, noncorrosive resin flux in Multicore wets metals faster 500 cps. There are two reasons for the ...guarantees a continuous flux stream avoiding high dry or resistance (HR) joints...and, because choice of 500 cps as the crossover f re- of its exclusive thin -wall construction, it melts instantly and holds fast on all metals, even if quency. In the first place, the woofers they are oxidized. should not be used much above that frequency because they tend to break up. Specify the ERSIN In the second place about one half of World's Finest the total acoustical power lies on each side of that frequency and thus it is FIVE -CORE convenient to use identical power ampli- Cam" SOLDER fiers. It may surprise some readers to bwm

80 AUDIO NOVEMBER, 1960

www.americanradiohistory.com of the large area removed by the loud- speaker openings. The midrange loud- speakers are mounted on subpanels and relieved in front. The finished box is shown in Fig. 3. The back panel must have some added rigidity and this is provided by glueing a pair of 2- by 4 -in. 4 boards to it. The box which houses the tweeter array is constructed separately and screwed and glued into place last. The entire interior of the box is lined with 1 -in. Fiberglas. In addition, a cur- tain of Fiberglas is placed in the center of the box conveniently supported on 3 2- by 4 -in boards as shown in Fig. 7. The enclosure is made of fir plywood. For a more finished job the panels could be veneered. The total weight of the en- closure is about 300 lb. and therefore it should be mounted on casters. I must ad- mit that the box is rather large and that take when two of them are used as in a stereo system they tend to dominate the room. the controls- Indeed some people might go so far as see why everything a tape recorder should do... UHERthe new e Stereo Record III does best! From the moment you hear its incomparable high fidelity performance -from the instant you realize the wide range of capabilities the versatile controls put at your command -you know that the Uher Stereo Record III is an exciting new experience in stereo tape recording. Here's what the Stereo Record III does ... and why it does it best! High Fidelity Performance, Unsurpassed -Broad 40 to 20,000 cps frequency re- sponse; negligible wow and flutter 0.1% ; high -55 db signal -to-noise ratio and con- Fig. 7. Enclosure with back cover stant speed hysteresis- synchronous motor assure the highest possible performance removed. standards. to say that they are unsightly. They Versatility, Unlimited- Sound-on- sound! Play back on one track, record on the other sound very nice however and one can -simultaneously. It plays either 2 or 4 -track pre-recorded tape, 4- tracks of 1/2 mil tape, on a 7 -inch reel, played at 17s get used to having them around the ips provide more than 17 hours of play. The optional AKUSTOMAT automatically operates the tape house. transport only when voice or program material reaches the microphone. The Stereo Record III is adaptable for I would by no means consider the synchronizing automatic slide projectors. present loudspeaker system the end -all Flexibility, Unequalled -Fool-proof and jam -proof controls provide individual of systems. There are certainly improve- adjustments of each channel: volume, tone, fade -in and fade -out, channel and ments being worked on all the time. speaker selection. Fingertip control of pause, stop, rewind, fast rewind, forward, fast Perhaps a full-range electrostatic array forward, speed selections of 71/2 , 344 , or 17/s ips, and a recording safety lock. Has an will some day be available. However, accurate digital cueing meter. when better systems are built, I am sure Monitoring facilities, plus dual recording level indicators, simplify making stereo or they will be large. One simply can't es- mono recordings. High and low impedance inputs accommodate any type of program cape the need for a large piston to move source. Outputs for external speakers and for direct connection to external high the large amount of air necessary at low fidelity amplifiers are provided. Truly portable- weighs only 33 pounds. Complete with frequencies and that is that. We may 2 Dynamic High Impedance Microphones, Amplifiers, Speakers and Carrying Case. $399.50 some day reach the state of perfection with loudspeakers that we have with FAMOUS UHER UNIVERSAL - High fidelity perform - other parts of the audio system and ance-a most remarkable dictating /playback instru- ment-3 speeds from 15/16 then manufacturers will start using ips -voice activated - automatic continuous playback. With Remote Control terms other than silky, smooth, clean, Microphone, Carrying Case, Reel, Dust Cover. gooey, brilliant, etc., etc. ;299.95 plus f.e.t. Next month we will the talk about Your dealer electronics of invites you to take the controls of the exciting Uher Stereo Record III. c the system. For further details write: Dept.A- 11,WARREN J. WEISS ASSOCIATES TO BE CONTINUED Sole U. S. Agents, 346 West 44th Street, New York 36, New York

AUDIO NOVEMBER, 1960 81

www.americanradiohistory.com biggest sound HAROLD LAWRENCE

Report On The New York High Fidelity Show ou ever heard from °a bookshelf speaker It is always easy to tell when New York and an unobstructed path for the stereo is holding a High Fidelity Show. The vicin- signal -a case of "better sound through ity of Herald Square comes alive with the decor." bright colors of shopping bags sporting the Interior decoration of another sort was AUDAX CA-60 name of a components firm (1960 version: used to appeal to the serious audioman. white emblazoned with red). These har- Under the beams of pinpoint spotlights, he $59.95 9°xóiyx18" bingers of the high fidelity industry's fall could examine the insides of a preamplifier, season are indispensable to the audio show- the drive mechanism of a turntable, or a k: goers. Upon entering the Trades Show speaker system stripped of its grill cloth. Building, the latter notes the name on the bags carried by the departing visitors. Spotlight on Sound After purchasing his ticket of admission, A few exhibitors neglected lighting and he consults Directory room num- the for the decor and concentrated on providing better - ber of the thoughtful exhibitor providing than- average audition setups for their the complimentary receptacles, and heads guests. In one of the finest presentations straight there to collect his copy. Now, compact speaker systems were arranged properly equipped, he begins his tour of in- one on top of the other in a pair of col- spection. umns, with identification cards next to each To spare his eardrums, the audioman cabinet. Through a switching device, the will try to spend his time in the most effi- exhibitor could relay the same recording r cient manner possible. He has probably from one system to another in rapid suc- heard about most of the new products being cession, and pilot lights indicated which introduced at the show and marks these speakers were in operation. The recordings Among many individuals, there is exhibits as priority stops on his itinerary. music a need to minimize on the space to were selected with care; there was A glance in the doorway will suffice for for orchestra, string quartet, piano, and be devoted to a component stereo those exhibits of peripheral interest to him, system. A rash of "bookshelf" voice, illustrating how these transducers such as, say, record changers and "pack- behaved under a wide variety of program types have appeared in an attempt aged hi -fi." At the conclusion of the tour, to meet this need. In practice, how- material. Rows of chairs had been placed his feet are sore, his ears are ringing, he in front of the speakers, and no attempt ever, they seem neither fish nor is tired of in fowl,...either too large for com- squeezing and out of crowded was made to "ventilate" (as the Editor pactly spaced bookshelves or too rooms, and his shopping bag is loaded with would put it) the area at regular intervals small for use as free -standing units. high fidelity literature, but he is now au by lowering the volume level or removing courant. the seats -the visitor was welcome to stay The AUDAX CA -60 is a true The Visual Element as long as he cared. Not surprisingly, the bookshelf speaker system, measur- exhibit was jammed with people, and there by ing only 9" high by 10%" deep Like most audio show veterans, he has was an overflow crowd. 18" wide. houses a 6" woofer It come principally to see rather than hear One could hardly accuse the exhibitors in - and separate tweeter a ducted the new products, because he is aware of under- slot enclosure constructed of sa" at the New York show of sonic the futility of attempting to evaluate com- statement, but there was a perceptible de- thick wood, finished in oiled, hand - ponents on the basis of a show audition. rubbed walnut on four sides. The crease in output compared to aural levels And, at this fall's show, there was more to at previous shows. Steam locomotives were grille is shaped in an attractive see than in previous Decor, events. for ex- nearly as extinct this year as their real - parabolic contour, giving the ample, played a prominent role in many of unit a character which blends life counterparts, and this writer did not with a variety of surroundings. the exhibits. In fact, one often had the have to dodge ping -pong balls or run from impression of having wandered accidentally tropical rainstorms. The new "soft -sell" ap- A real powerhouse ... handles 20 into the furniture wing of a large depart- proach is due as much to the high fidelity watts in integrated program mate- ment store: there was the model living industry's growth as to the IHFM's meter rial! Hear it at your dealer's. room, with its shelf of 'rare' books in old monitor. There are solid indications of a bindings, the paintings on the wall, the return on the part of wayward firms to DO YOU KNOW ABOUT THE FULL LINE OF floor -to- ceiling lamp, and the ubiquitous standards that had prevailed before so AUDAX -ENGINEERED REPLACEMENT SPEAKERS piece of African aboriginal sculpture of a many record companies and components E&) AND COMPLETE SPEAKER SYSTEMS? dour old tribal chieftain holding his belly. manufacturers galloped off in all directions In transplanting the living room to the at the approach of stereo. However, there AUDAX.Division of Rek -O.Kut Co., Inc. high fidelity show, exhibitors hoped to win was the usual lag between the achievements Dept. AA-11, 38.19 108th St., Corona 68, N.Y. over the housewife by demonstrating how new the Please send full information on: represented by the products and their components can blend gracefully with manner in which they were exhibited: too Model CA -GO And Other Systems elegant home surroundings. Mindful, too, Audax Replacement Speakers few of the people who actually conducted of female sensitivity to the upper frequen- the demonstrations treated their equipment Enclosed is 250 for book of 6 plans cies, they omitted high- powered audio war- "How to Build Your Own Audax Enclosure" with the respect and consideration it de- horses from the repertoire of musical selec- served. Name tions chosen for demonstration. Ropes were Address stretched across the rooms to prevent visi- Loudspeakers tors from overrunning the exhibits; this City Zone State gave the public a clear view of the display There is, of course, no fixed method of Morhan Export Corp., 458 Broadway, N. Y.I3 placing loudspeakers in a stereo setup. The Atlas Radio Corp.,50Wingold Ave.,Toronto. 26 W. 9th St., New York 11, N. Y. distance between them depends on the size,

82 AUDIO NOVEMBER, 1960

www.americanradiohistory.com shape, and acoustical properties of the room. However, we know that certain things should not be done. For example, when speakers are placed on different levels, the Build This Superb 9i&%eì stereo effect is often eliminated. At one exhibit, the left speaker was lying on its side, and the right was in a vertical posi- tion. Ostensibly, this was to demonstrate and the decorative versatility of the enclosures. Organ From Simple Kits It didn't help the sound -with the tweeter unit in the erect cabinet (right) approxi- mately three feet higher than its reclining partner (left), the right cone tweeter natu- The Beautiful rally predominated over the left, thoroughly SAVE OVER 50 %! upsetting the musical balance. [WIC/9I Beaming was another frequently encoun- tered defect in stereo setups. A pair of CONSOLETTE large speaker systems was being demon- - the only small or- strated in a medium -sized room. The dis- gan with two full 61- tance separating them appeared to be cor- note keyboards and rect, but the speakers were angled toward 22 stops. Requires only 2' x 3'2" floor each other. When the exhibitor's attention space! Ccmmercial was drawn to the lack of spread and the value approximately channel- cancellation effect resulting from $1600 or more - yet this he went off to "remedy" the you save over 507, placement, LET US when you build this situation. But instead of arranging the SEND YOU thrilling instrument! speakers straight out, be angled them in even more It was surprising to learn once again FREE how many exhibitors were unaware that their systems were out of phase. When Ed- DETAILS ward Tatnall Canby conducted an informal HOW TO ASSEMBLE A survey earlier this year, he came up with the report that, out of approximately one hundred rooms visited, forty -two stereo sys- ELECTRONIC ORGAN tems were out of phase. Things haven't IN SPARE TIME! changed much since Mr. Canby's dispatch. Finally, one often encountered channel - blocking at the show ; that is, the spectacle of the exhibitor standing directly in front of one of the speakers in a stereo system he is supposed to be demonstrating. Program Material Although some exhibitors pre -selected Give Your Family A Lifetime of Musical Joy their musical examples, it is apparent that insufficient control was exercised by most With A Magnificent Schober ELECTRONIC Organ! manufacturers over the recordings used. A Details On Schober Organs can build the brilliant, full-range Send For Complete mediocre recording will certainly reflect ad- Now you and For Hi -Fi Demonstration Record component or system being Schober CONSOLETTE or the larger CONCERT versely on the tools. No skills The coupon will bring you a handsome 18- for ex- MODEL with simple hand demonstrated. A dull -sounding disc, to construct an instrument with page booklet in full color describing Schober give the impression of poor are necessary on ample, may one of the finest reputations organs in detail, plus articles transient response; the presence in a re- No THE G SEAT how easy and rewarding it is to among electronic organs. CONCERT MODEL cording of hum (50 -cycle hum mars certain woodworking necessary con- build your own organ and how - meets spedfications of is to learn European recordings) could sully the repu- soles come completely assem- pleasant and quick it of a perfectly acceptable turntable; finished. All you do is America n Guild to play the organ. In addition, tation bled and an exciting and inner diameter distortion could make assemble clearly marked elec- of Org anists we have prepared hi -fi LP record demonstrat- a appear to be suffering from tronic parts guided by clear il- 10" cartridge instruc- ing the full range of tones and voices avail - inadequate compliance. All of this points lustrations and detailed step -by -step -agers can assemble the able on the Schober, which you may have out that a demonstrator cannot be too care- tions. Even teen a You build from kits, as fast or as for only $2.00 (refunded when you order recordings he utilizes. Schober! ful about the slowly as you please ...at home, in spare kit ). Literature on the Schober is FREE! time - with a small table serving as your There is no obligation; no salesman will call. Level entire work shop! the universal complaint of In the past, Pay As You Build Your Organ; Mail This Coupon audio show visitors has been directed at the Start With As Little As 518.941 For FREE Literature threshold -of -pain volume chosen by exhibi- You may start building your Schober at once and Hi -Fi Record tors to show off their equipment. Compared of as little as $18.94. The with an investment Today! to previous years, this show might be de- musical instrument you assemble is as fine, scribed as almost soft -spoken. In fact, the and technically perfect, as a commercial sonic has swung over to the op- in a factory yet you save over The Schober Organ Corp., Dept. AE -4 pendulum organ built - 43 West 61st St., New York 23, N. Y. posite pole at certain major exhibits, and 5O' on top -quality electronic parts, on on usual retail store mark- ¡1 Please send me FREE fullcolor booklet and the formerly annoyed show veteran now high -priced labor, the Schober organs. up! In your own home, with your own hands other literature on found himself frustrated, for, too often, he -. Please send me the 10" hifi Schober demon- you build an organ with genuine pipe organ on would enter a room featuring large speaker stration record. I enclose $2.00 (refundable real tones in an infinite variety of tone colors receipt of my first kit order). systems and hear muted music with no into your home the full grandeur much to bring dynamic range and with about as in- of the Emperor of Instruments. You may Name strumental contrast as a late evening build the CONSOLETTE for your home, or you Muzak program. Now this may be ideally may want to build the great CONCERT Address

suited to an exhibit of cabinetry or a radio MODEL for home, church, school or theatre. ione.. . State (Continued on page 101) You save 50% and more in either case. Lcity

AUDIO NOVEMBER, 1960 83

www.americanradiohistory.com NEW PRODUCTS Economy Three -way Speaker System. ven during multiplex .h c;, h cartridge, coils, and other components s Intended to be a budget system that is low also boasts wide -band design and live lim- housed in a Mumetal case to reduce hum in cost yet high in performance, the Jen- iters to enable a capture ratio of 1.5 db. and noise. In addition, Mumetal shielding sen Model TF -3 is a four -speaker three - The AM section includes a four -position is employed throughout the entire length way system using a specially designed 10- bandwidth switch, a rotatable ferrite an- of the arm, providing a signal -to -noise in. long travel woofer for a bass response tenna, and an automatic volume control. ratio well over 100 db. Frequency range is to 25 cps. Two specially designed mid- On AM, a 5- microvolt antenna signal from 20 to 16,000 cps and is flat ± 2db from produces a 1 -volt output. Selectivity at 1 20 to 15,000 cps. Replacement of the stylus megocycle is 68 db. On FM, the signal -to- noise ratio is 68 db at 100 per cent modu- lation. Harmonic distortion Is 0.35 per cent at 100 per cent modulation. Frequency re- sponse is 20 to 20,000 cps ±?tfi db. Output voltage is 2 volts rated, 4 volts maximum. Hum is 76 db below rated output. The Model 202 -R is available In a vinyl - covered metal cabinet or a wood cabinet. Fisher Radio Corporation, 21 -21 44th Drive, Long Island City 1, New York. L -3 Automatic Automobile Record Player. There are two basic requirements for an automobile record player. The first is ob- may be accomplished without special tools range units take over from 2000 to 10,000 vious-it must be extremely simple to within a few seconds. Each arm is in- cps, and a new spherical- sector super - operate. The second is that it must be im- dividually factory balanced to track at 3 tweeter extends response to beyond audi- pervious to the various shocks due to road grams. Lafayette Radio Electronics Corp. bility. This system is housed in a tube - conditions. Operationally the Norelco 165 -08 Liberty Avenue, Jamaica 33, New loaded, vented enclosure which Is rigidly "Auto Mignon" more than satisfies the Y, irk. L -5 constructed of % -in. plywood, and is lined basic requirement. It is so simple to use with heavy layers of Fiberglas acoustic that even a child can operate it. In answer Portable Disc Recording and Playback insulation to provide acoustic damping. to the second requirement, the "Auto System. Billed as the world's only pro- Though vented, the enclosure employs the Mignon" is provided with special built -in fessional 13 % -in. portable disc recorder, "air suspension" principle, and is tightly shock absorbers which compensate for the Rek -O -Kut "Imperial II" is designed to sealed at all joints. Input inpedance is sharp turns, car sway, abrupt braking, ac- meet the needs of professional recordists, eight ohms, and power handling capability celerations, or had roads, without jarring musicians, educators, and home recording is 25 watts. The frequency range Is enthusiasts. The unit will cut master twenty -five cps to beyond audibility. records at 33 1/3 and 78 rpm, and comes Crossover frequencies are 2000 and 10,- with an idler and adapter from 45 rpm re- 000 cps. The TF -3 is furnished only in un- cording. The overhead recording lathe has finished, grained hardwood. Jensen Manu- a calibrated scale for timing, a hand crank facturing Company, 6601 South Laramie for run -in and run -off spiral grooves, and Avenue, Chicago 38, Ill. L -I provision for interchanging lead screws for standard and microgroove recording. A Improved Stereo Amplifier. Now rated safety cam automatically raises the cutter 1 at 15 watts per channel, or a total of 30 as the center of the disc is approached. watts overall (by IHFM standards), the Frequency response of the recording head H. H. Scott Model 222B is an improved is 30 to 13,000 cps. The playback arm is version of their popular Model 222 stereo equipped with a dual sapphire magnetic amplifier. Among the new features are cartridge and can be used for records up tape monitoring facilities, separate tone to 12 inches. The recording and playback controls on each channel, tape head inputs, amplifier has an output of 20 watts and a aluminum chassis, oversized 20 -watt trans- frequency range from 20 to 20,000 cps. It

the stylus or affecting the records. De- N signed to operate through the car radio, the "Auto Mignon" requires no more at- tention on the part of the driver than In operating a radio. The only additional step required is sliding the records into the slot with one hand. All operations there- after are automatic. After the record is played it automatically slides out of the slot, available for easy removal. Operating off either 6- or 12 -volt car batteries, the "Auto Mignon" has a power consumption formers and an input for electronic organ. of 50 milliwatts. Switching from phono- The frequency range of this improved am- graph to radio, or from radio to phono- plifier extends to below 25 cps. H. H. graph Is done by pressing a pushbutton Scott Inc., Dept. P, 111 Powdermill Road, switch Maynard, -2 which is located on the front panel Mass. L of the "Auto Mignon." The turntable is driven by a stabilized d.c. motor and a Highly Sensitive PM -AM Stereo Tuner. specially constructed drive mechanism. Featuring a sensitivity of 0.5 microvolts The diamond stylus is automatically for 20 db of quieting with a 72 -ohm an- cleaned between playings. A pilot light in- tenna, the Fisher 202 -R utilizes six IF dicates when the record player is on. The stages following the sensitive "Golden "Auto Mignon" plays all 45 rpm (large Casode" front end to achieve the stated center hole) records. North American sensitivity plus unusual selectivity. In- Philips Co., Inc., High Fidelity Products corporating an exclusive Fisher "Micro - Division, 230 Duffy Avenue, Hicksville, Tune AFC," AF tuning becomes relatively Long Island, New York. L-4 simple. By touching the FM tuning knob, the AFC is automatically shut off. When Integrated Stereo Tone Arm and Car- has inputs for microphone, tape, phono- the knob is released, the AFC clicks back tridge. Intended to provide optimum stereo graph, and high -level tuner, as well as on. Interstatlon noise is suppressed by performance by integrating the cartridge sufficient controls to adjust level, tone, electronic switch muting that functions into the tone arm, the Lafayette Model and volume for all functions. A panel PIC-449 is supplied complete with a .7 mil meter with a calibrated scale indicates diamond stylus. The raison d'etre of inte- the correct recording level. Rek -O -Kut grating the cartridge into the tone arm is Company, f ornna, N. Y. L -6 to provide exact positioning of the stylus in the record groove and produce a re- 35 -Watt Amplifier Kit. A high -quality lationship between tone arm and cartridge t onoph on ie amplifier with a modest which is not usually achieved in non -in- price tag, the new Heath Model AA -10 tegrated units. Arm structure, balance and provides 35 watts (IHFM standards) with compliance can be precisely engineered to an adequate amount of distortion -free re- complement the cartridge. The cartridge serve. Among the features in this easy-to- utilizes the "moving- magnet" principle, assemble kit are: F.í.34 /6CA7 output

84 AUDIO NOVEMBER, 1960

www.americanradiohistory.com

r tubes; Heath "Bass- bal." circuit for bal- ancing; two a.c accessory sockets; and a specially designed output transformer. The amplifier is 12 -in., wide, 8 -in. deep, and 6% -in. high. At 35 watts, response is within one db from 30 to 15,000 cps. IM distortion is less than two percent at full - rated output power and input sensitivity is approximately one volt for 35 watts out. Impedances are four, eight, sixteen, and thirty -two ohms. Heath Company, Ben- ton Harbor, Michigan. L -7 Premium Grade Tape Line. Produced and marketed by Orr Industries Company, a Division of the Ampex Corporation, and distributed by United Stereo Tapes, a Di- vision of Ampex Audio, the new Ampex "500" series of premium grade tapes marks $ß99y

NOW ...BUILD AN FM KIT THAT WORKS AS WELL AS FACTORY ALIGNED TUNERS

NEW! Kit -Pak Container? The new LT -10 Tuner Kit will work as well Opens to a self- contained as factory units, yet it can be aligned with- work area you can use any. out expensive equipment. You align this the first consumer tape to carry the Am- where. pex name. The new series features per- tuner using the meter on the tuner itself. sonalized "signature binding ;" a leather - All needed alignment tools are included. finished backing that can be inscribed by NEW! Part -Chart? the owner with the use of gold foil and Speeds your work. All parts This is the first kit to use H. H. Scott's attached to the back edge of the tape box are mounted Kit Wide -Band circuitry. This results in greater for quick, easy identification. The self -ad- on -Pak cover hesive backing and gold foil is contained in numerical sequence. And selectivity and sensitivity than possible in each tape package. United Stereo Tapes, every part meets H.H. Scott's with any other kit on the market. Sunnyvale, California. L -8 tough test standards. Phonograph Slides. Complete ball -bear- The exclusive H. H. Scott silver plated ing action for smooth, noiseless operation NEW! Ez -A -Lign System front end is completely pre -assembled and is combined with easy side or underneath Requires no extra equipment. installation for radios, amplifiers, phono- pre- aligned. All parts are mounted in se- graphs, etc. in the new Selby slide. Per- You align this tuner using the quence of assembly. All wires are pre -cut manently lubricated and engineered for meter on the tuner itself! All vibrationless performance, the steel slides to proper length and stripped. Parts such as have load capacities up to 60 lbs. and are needed alignment tools are tube sockets and terminal strips are already black -oxide finished. Only % -in. clearance included. riveted to the chassis. Here's a kit that's is required for either side or underneath mounting. Track lengths of the four stand- NEW! Pre -Stripped, fun to build, and that you'll be proud to own. ard sizes range from 13 to 21 inches, chan- Pre -Cut Wire Priers slightly higher trrst of Rockies. Accessory nel lengths from 10 to 18 inches, and cane extra. normal travel from 9% to 17 inches. Slides Every piece of wire is included. may be made to individual specifications. And each piece is pre -cut to Selby Furniture Hardware Co., 11 West 17th Street, New York Il, N. Y. L -9 proper length, stripped and tinned. H.H. SCOTT

LT -10 Laboratory Tuner WORLD'S LEADING COMPONENT MANUFACTURER Specifications Usable (IHFM) sensitivity 2.55v H.H. SCOTT INC., 111 Powdermill Rd., Maynard, Mass. Signal: noise ratio 60 db below 100% mod. Harmonic distor- Please send me FREE the followingti booklets: A-11 tion 0.8% Colorful new 1961 catalog and hi guide. Drift 0.02% Fre- Ci Complete technical specification sheets on your new products, quency response 30 cps -15Kc including your new 11.10 Tuner Kit. t 1 db.(IHFM measurements are made only in the range 30- 15,000 Name cps. The LT -10 actually has far wider frequency range than Address here.). shown City Zone State Export: Tetero International Corporation, 3 West 40th Street, N. Y. C.

AUDIO NOVEMBER, 1960 85

www.americanradiohistory.com Danish Oil Pictish. Fast, easy oil- finish- "Danish Oil Finish" may be used on wal- ing of component cabinets is the feature nut, birch, oak, cherry, teak, mahogany of the Watco "Danish Oil Finish" now and other similar woods. A simple applica- available for the first time to the home tion seals, primes, and finishes at the craftsman. Recommended by the American same time. Compounded of special oils and NEW LITERATURE Walnut Manufacturers Association, the additives, this finish is claimed to solidify the oil within the wood to eliminate the non -drying qualities of usual oil formu- Shure Brothers, Inc., 222 Hartr,3 Ave., las. It is available in 16 -oz. aerosols, Evanston, Illinois describe their complete pints, quarts, and gallons. Watco- Dennis line in catalog No. 60A which was Just Corporation, 1756 22nd Street, Santa Mon- issued. The 28 -page catalog covers more ica, California. L -10 than 30 microphones, plus microphone ac- cessories, high fidelity components, mag- netic recording heads, and replacement phono cartridges. Also included is the COBRBSCTION-Last month, in re- Shure line of Dynetic moving- magnet porting the details of the new Fisher stereo and monophonic cartridges, stereo SA -300B stereophonic amplifier, we and monophonic tone arms, broadcast stated that it was conservatively rated equalizer, and line preamplifier. Copies of at 35 watts per channel. This was in- the catalog are available at no charge by deed a conservative statement, since writing to the company. L -11 the SA -300B is actually rated at 45 watts per channel for an over -all am- Bek -O -Ent Company, Inc., 38 -19 108 St., plifier rating of 90 watts. Corona 68, N. Y. has just released an 8 -page brochure entitled "How to Deco- rate with Music." Illustrated in the bro- chure are five interesting room arrange- ments incorporating stereophonic music systems. The room settings -two in mod- ern decor and one each in contemporary, traditional and early American -feature in Audio, Edward Tatnall Canby says this regarding the Dual-1006: Rek- O- Kut /Audax components as sug- gested by "Living for Young Homemak- ers," a leading home decorating magazine. An artist's drawing of each room is ac- companied by an easy -to- follow floor plan showing placement of components. The placement of speakers is especially inter- esting and illustrates how today's small - sized units can be blended with any in- terior setting. "How to Decorate with Music" may be obtained free by writing to the company. L -12 North American Philips Company, Com- r mercial Sound Department, 230 Duffy Ave., Hicksville, N. Y. announces an illustrated brochure describing the Norelco line of industrial sound systems and components. Included are loudspeaker columns, ampli- fiers, preamplifiers, microphones, inter- corns, delayed sound equipment, and induc- tive paging systems. Detailed specification sheets, in addition to the brochure, are available free from the company. L -13 Motorola Semiconductor Products, Inc., 5005 East McDowell Road, Phoenix, Ari- zona has published a Power Transistor Handbook. Prepared by the Motorola Ap- plications Engineering Dept., this 200 -page handbook is devoted entirely to power transistor theory, design, and applications. Chapter headings include: Semiconductor Electronics, Transistor Characteristics, Power Amplifiers, Switching Applications, Electronic Ignition Systems, Special Tran- sistor Circuits, Power Supplies and Power Rectification, Transistor Testing, and Tran- ABOUT THE DUAL -1006 is its unique method of record -indexing . . . sistor Specifications. Important factors such as voltage and current ratings, bias using roller -feeler guides in the tonearm to find the lead -in groove for considerations, thermal stability, efficiency, each record." BUT OF PRIME SIGNIFICANCE is the fact this indexing and distortion are discussed fully. Circuits that include high fidelity amplifiers, converters concept eliminates the need for any mechanical linkages to the tone - and inverters, oscillators, time base gen- erators, and TV horizontal deflection sys- arm. When cycling, the tonearm is engaged only by a slip -clutch ; during tems among others. Copies are available play it floats completely free. This ensures professional tonearm and for $2.00 from Motorola Semiconductor Products distributors or from the Tech- turntable performance regardless of how you choose to play any of nical Information Center at the address your records ... manual single play, automatic single play, or auto- given. matic changer. (And this is the only machine that permits all three !) As American Standards Association, Dept. Electronics World says, "Make sure the dealer demonstrates this PR 185, 10 East 40th Street, New York 16. New York provides a uniform set of one for you." $79.95 at authorized dealers. criteria for the sound pressure level of Write for descriptive brochure, Dept. A -11. OÀ allowable background noise in their re- united dio cently approved publication, "Standard WIGO PRODUCTS OF DISTINCTION DUAL Criteria for Background Noise in Audiom- 1,' -14 W. 18t h St., N.Y. 11, N.Y. eter Rooms," The number of this bulle- tin is S3.1 -1960. The standard pertains to earphone listening and pure -tone audiom- etry. Its criteria enable the designer to plan appropriate acoustic treatment in a room used for audiometric tests. The cri- teria are based upon psychophysical data, but stated In physical terms, and the de- termination of them is influenced by indi- vidual differences In the ability to detect noise and in the fit of the earphones on the ears. Copies are available at $1.00 each from the Association.

86 AUDIO NOVEMBER, 1960

www.americanradiohistory.com AUDIO ETC lle!úg!eahfleAY (from page 14) The each special case. And he seldom has the Sensational Bozak circuit -he can't even open up the speaker box in many systems to find out what's in- B FULL -RANGE SPEAKER z side. It's a thing worth thinking about, -800 1 PENDING 1 since it involves a crucial macro- factor in PATENT sound reproduction. (The difference be- tween two good pickups is, as I see it, a is yours for only $45.00!* micro -factor on the same scale.) ;Eg In its correctly balanced form, then, the little Pilot PSV -3 makes good use of its An 8 -inch speaker of unique design, the B -800 provides unbelievably three rather inexpensive cone -type tweet- fine music and voice reproduction over a frequency range of 50 to ers, all of them carefully doctored for op- highs timum performance in the three ranges. 15000 cycles! Its clean bass, detailed midrange, and smooth Its sound- dividing arrangement strikes me combine to give exceptional transient response and remarkably satis- as effectively simple, too, and I really do fying tone. It works beautifully from a small, infinite -baffle bookshelf like the solid little cabinet. Nothing cheap enclosure, or can be mounted flush in an ordinary interior wall. about that, I'm not claiming that this speaker sounds as good as the "best," but You'll be proud to own the B -800! Now, at last, you can extend your Pilot probably isn't either. It does sound music system to other parts of your home - bring Bozak musical good, though, and I'll bet it sounds a whale of a lot better than most of the other sound to den, playroom, kitchen, bedrooms - at a truly moder- small speakers you'll find in your local ate cost! radio -TV store. If the price seems a bit high under the circumstances, you may ac- and, curately gauge it by figuring the full retail markup that Pilot must provide, if it is to sell at all in this market. You can com- THE BOZAK B -801 plain, but if you think something ought to be done, don't chase after Pilot. Go out SPEAKER SYSTEM and abolish the retail stores. By the time you get through there won't be any PSV -3's a B -800 Full -Range Speaker ft. anyhow. Mounted in a Handsome, KLH Model Eight Well -Built Enclosure At first thought it may seem strange to include an FM receiver of the relatively is only $89.50!* high cost and standard of quality displayed by this new unit among the "in- between" own a Bozak Speaker System! Thousands who heard items- between component hi -fi and mass - Your chance to production appliance areas -that I am dis- this instrument at the New York and other High Fidelity Shows cussing this month. But a glance at Model were delighted with its musical quality and amazed at its price! Eight will show you why. You'll agree that it's the biggest bargain ever in really fine sound! The question is not one of pricing in this case, but of typing. This integrated, two- Consistent with the Bozak principle of pro- unit small-size tuner -speaker combo opens up a wholly new area in its field- which, viding for systematic growth, your B -801 can as with the other items here mentioned, achieve a broader dispersion of highs through Graneo and Pilot -is territory not in either the addition of a Bozak B -200X Dual camp. The Model Eight is not quite a Tweeter. An opening is provided for verti- component, but not quite a "radio" either. It is in two sections, but neither one can cal or horizontal mounting of the B -200X, be used on its own; they are built for as shown in the adjacent photo of the enclo- each other. It is compact -tiny, indeed, as sure with grille cloth removed. compared to component FM tuner- ampli- fier -speaker systems in the component area. Hear this great But it is large as compared to many home FM -AM standard radios, not to mention new speaker soon at a transistor models. And its voice, not as big Bozak Franchised Dealer! as that of big component systems, is posi- tively enormous next to any home radio 'SLIGHTLY HIGHER IN SOUTH AND WEST. roughly its own physical size. Unusual, and interesting. Model Eight consists of two cabinets about the same in size, and you'll goggle at the speaker unit, less than eleven inches by six by seven. The tuner, with simplified controls, comes in a matching cabinet, the two connected (banana plug at the tuner) by a slim 30 -foot twisted cord, white cov- ered. The price of the two together is about $140-this is clearly no low- priced unit. It's a full -scale a.c. circuit (no a.c: d.c. DARIEN, CONN. here) temperature -compensated so that AFC is unnecessary (each unit is individ- ually compensated), plus a push -pull audio section that uses 14 db f fefeedback. dba k. TheT e T H E V E R Y B E S T 1 N M U S I C tuning dial is geared down fo r precise and accurate adjustment,, the three other basicac ..,w:..»..:;ta:<';wiï::Y.'z:r».:.aw.....w.,...... ',:tc!n::» .>.>.u;<:r :::;zz>:: ,,:3,,:.:m;. ....,MMEW'M'.

AUDIO NOVEMBER, 1960 87

www.americanradiohistory.com if you are about to buy a tape recorder - YOU CAN SAVE MONEY! control knobs provide on-off, volume, and KLH itself disagrees. The company, at if you own a tape recorder - a modest tone adjustment, up only slightly or at least one of its partners, feels that ENJOY BETTER PERFORMANCE! from flat but down far enough to act as "flat is flat" and a flat high end should a noise filter as well as room -sound ad- stay flat regardless of bass content. Inter- GETTING THE MOST OUT Of YOUR juster. On the rear are provisions for mul- esting point, and you are wisely given TAPE RECORDER tiplex in the future; a high -quality phono- the means to make your own choice in this by Herman Burstein tape preamp unit is coming up soon, to fit receiver -speaker. Suit yourself. unobtrusively out of the way as an attach- One minor unsolved point of disturbance Herman Burstein, noted high fidelity author- ity, provides information that is worth many ment. And if you insist, you may tap off came from the tuner, via the excellent times the price of the book to tape recorder the tuner into your own hi -fi amplifier - high -end reproduction. On louder passages owners and prospective owners. Written in though this is obviously not the idea of the the Model Eight showed a slight tendency non -technical language it provides the answer to these questions: Model Eight at all. It speaks for itself, to break up every so often, even with an and its voice is quite portentous. apparently strong signal Just what adjust- What features are necessary or desirable in The little speaker unit contains a most ment this involved, or whether it had to do a tape recorder ". ingenious tweeter -turned -woofer (a pair of with the built -in antenna and the vast What can I do to get the best performance them), none other than the basic 3 -inch quantities of competitive interference in- out of a given tape recorder ? How to select the best tape recorder for the money and your tweeter used in the Model Six speaker sys- herent in New York's FM listening, I could needs? Special questions and problems tem, here revamped for extended cone ex- not say. But with such a sensitively bal- raised by stereo, #251, $4.25 cursion and much increased bass response, anced high end, a very slight transitory FUNDAMENTALS OF HIGH FIDELITY by Herman to complement the original upper end. This distortion shows up only too quickly, in Burstein. How to select the best hi -fi equip- is the first genuine 3 -inch tweeter unit the listening. ment for the money you have to spend -how to achieve the best performance and realize I've ever seen adapted as a woofer-such I had two diabolical thoughts the instant the most pleasure from your equipment. #226, audacity! And it really qualifies as full - I saw the integrated Model Eight. Tuner $2.95 range, believe it or not. Pretty full, any- and speaker designed for each other - STEREOPHONIC SOUND by Norman H. Crow - how. I didn't try any 30 -cps sine waves natch, I had to be perverse and try them hurst. Saves you hundreds of dollars in select- through it (I couldn't, via the FM tuner) ing your stereo system, #209, separately, just to see what would happen. $2.25 but the pizzicato plucked double bass on a But an irrelevant tragedy has left this bit REPAIRING NI -FI SYSTEMS by David Fidelman. number of broadcast jazz recordings came of testing incomplete for the moment. An Save money! Deals with finding and repairing in the troubles. #205, $3.90 through virtually the original octave - old friend, my college roommate, was not merely the harmonics; nor was there seriously ill in the hospital, could not read HI -FI LOUDSPEAKERS & ENCLOSURES by Abra- ham B. Cohen. Answers all questions on loud- undue doubling, according to my ear. though he loved it, needed a boost in speakers and enclosures, design, crossover net- Amazing, and the volume is positively stu- morale. In a burst of compassion, knowing works. etc., #176 Marco cover, $4.60; #176 -H pendous for a speaker system literally the he loved music, I thought of the Model cloth bound, $5.50 size of a shoe box. Enough to drive any Eight as a perfect bedside companion for GUIDE TO AUDIO REPRODUCTION by David next door neighbor to fury at eleven o'clock him, on brief loan. But he had a semi- Fidelman. Covers design, assembly and testing of a quiet off d - --d hifi of sound reproduction systems and compo- night-"Turn that private room and, I found, was deadly nents, #148. $3.50 system!" It would fool almost anybody. afraid to play classical music on a radio at bookstores, or order direct: Dept. A -11 You really have to hold it down. for fear his neighbor would take the cue M *PRICES EJECT ro COSOS, wn5OOT NOTICE The trick in Model Eight is integration. and turn on mood music and disc jockey I have not discovered, though you may stuff on his. So I had a brilliant thought JOHN F. RIDER PUBLISHER, INC. have the - by time you read this, just where earphones. Aha 1 says I, to myself, with 116 W. 14th St., New York 11, N.Y. the ingenious rigging is done, whether via low-impedance phones, via that banana - impedance trickery or in amplifier output plug facility on the tuner, here's my chance F Circle 88A of a nonlinear sort; but Model Eight's to get an idea what one half of Model speaker isn't supposed to be plugged into Eight sounds like minus the other half. No OUTSTANDING anything but Model Eight's tuner, and IN QUALITY AND PERFORMANCE that sooner said than done, though it took me is that. A sort of baby Integrand. about five cables hooked together to pro- OUTSTANDING I was frankly fascinated by Model gress from my phones to a banana plug that FOR JUST PLAIN POPULARITY Eight's performance the first few days I would fit. I hate re- wiring. OUTSTANDING had it, and so I soon ran into a few peculi- Well, the half -Model Eight tuner- ampli- IS THE WORD FOR ROBINS arities, none of which do much to weaken fier sounded a bit odd in the phones, I'll Bulk my feeling that here is a really unusual Tope Eraser, .r- ME99, List $33.00 admit; but you could hear the music fine, and ROBINS Head Demagnetizer, item. A fine tuner, high quality and in- especially with the highs rolled down a _HD -6, List $10.00 shown below: geniously simple. I got everything in New ways. So I turned the system over to my York City, of course, with a built -in an- friend and went away feeling virtuous. tenna, nondirectional and invisible. When I retrieve it I plan to try the other Sounded terrific on speech, with the famil- half of my experiment, using the speaker iar smooth top of the Model Six tweeter in as it was never intended to be used, with a evidence. Maybe the bass is rigged-it standard amplifier. must be-but there is no boominess on One significance of this system is its voice. No bass -range peak, as in many a unity- from -diversity, in the two-piece inte- larger home -type console system. grated design. Also, I'd suggest, there's On music I ran into an interesting dif- significance in the KLH desire, here, to see ference in aesthetic philosophy between my just how far the idea of a tiny speaker ear and KLH's. First item I heard was a with a big voice can be successfully pushed. solo Koto player, Japanese- American, who But most of all, I think, Model Eight is produced no bass at all and so sounded just important in that it clearly heads into the qliffr fine. But as soon as I tuned in on some HD -6 LIST $10.00 uncharted "in- between" area, combining Both are listed by Beethoven, I found that the flat treble out - features of componentry and home -style Underwriters Laboratories, Inc. balanced the somewhat rolled off bass in simplicity. This is the radio for people who In addition, ROBINS manufactures the full orchestra sound. I rolled down the don't like components. And it's the com- a complete line of Audio Acces- top, via the tone control, and achieved sories - more than 300 items - at ponent -style tuner for people who don't the lost count. ALL ROBINS Acces- what for me was a lovely balance. Extra- like radios. It has virtues taken from both sories ore designed to help you en- ordinary. and it ought to please a lot of folks, once ¡oy and core for your topes and Minus balance -by -boom, the bass end in they get used to it. tape equipment. this tiny speaker is, relatively, somewhat less than of full strength all the way down. The treble, on the other hand, is 100 per 2. EARPHONES - ROBINS cent, equal to that from speaker systems THE BAUER CIRCUIT INDUSTRIES CORP. twenty or forty times this one's cubic vol- Send for ROBINS FREE complete ume. For my ear, given the standard musi- Readers with extra -sharp noses and keen catalog #C -15, or ask your dealer. cal repertory for orchestra, a balance be- logical minds will have noted a slight non tween bass and treble content is a necessity sequitur in my September discussion of Please send FREE complete ROBINS catalog #C -15 to: -either more bass, or less in the highs. earphone listening to stereo. (The rest will With other music, with new types of music, have missed it, as we did in the proof.) I Name Romantic -style organ (big bass but weak noted only one reservation, as far as this Address highs), and of course, music for bass -less sort of listening is concerned and then in-

City - Zone State ._... 1 combinations, the roll -off is unnecessary serted a parenthesis: "(aside from what Circle 888 and, in fact, meaningless. follows below)." It did not follow.

88 AUDIO NOVEMBER, 1960

www.americanradiohistory.com The material I had written to follow, we decided, should wait until after the AES convention in October, where it was the subject of a paper. Herewith, then, my con- tinued earphone discussion, concerning an ingenious way to make a pair of earphones produce stereo sound- pretty much as heard via speakers. The idea was worked out, as a sort of hobbyist's sideline in the midst of his more major tasks, by Ben Bauer, late of Shure (the Dynetic car- tridge) and now veep at CBS Labs. To be sure, it was demonstrated in an earlier AES convention, on the West Coast last Febru- ary. But we Easteners are entitled to our own "opening" and we got it on October 14 in New York. Now that the idea is out, both East and West, I'll merely suggest the interesting principle to you. I did try the earphone stereo circuit, however, right in Mr. Bauer's CBS office, and was immediately convinced that, for a careful listener the difference was quickly noticeable between straight earphone lis- tening to stereo and the modified sort here proposed. I suspect, moreover, that over a period of time, more than I had to listen, the difference in earstrain would mount up very rapidly in favor of the Bauer cir- "MATCHED TWIN" cuitry, attached to your earphone set -up. The principle is, as usual with such ideas, blindingly simple. How do we listen to stereo./ Via loudspeakers, each ear hear- ing both speakers (in a two -speaker set- up). Therefore (a) we must blend the two CERAMIC MIKES... signals being fed to the earphones, so that each ear hears both signals, in the proper loudness proportion. Cross -feed them in your circuit. for superior stereo recording! Now how do we get the separation and the sense of space in our loudspeaker stereo? By actual directionality, the inter- Now you can capture live stereo sound at its natural best...with action between the two signals as propa- gated from two different sources, in the Sonotone's "Matched Twin" ceramic microphones. These super- space in front of your ears. (Oh how nice it lative new matched mikes...model "CM-T10"... were designed would be if the stereo industry could get back to that simple truth- speaker sepa- to give j'ou the greatest possible clarity in your stereo recording. ration I ) Here's how. Each mike in a "Matched Twin" set has a rugged, How do we locate those sources, By phase differences, between the same sounds rubber -encased ceramic transducer that's immune to tempera- as heard in the two loudspeakers; as well as by volume differences. ture and humidity extremes; plus a lifetime damping grid. Every So (b), let us re -phase our channels "CM -T10" pair is acoustically matched at the factory to a toler- before mixing them, for each ear. One phasing mixture for the left ear and a ance of ±2 decibels. Jacked into any stereo recorder, they feed different one for the right. That will put at the apparent sound of each channel out flat 50 to 13,000 cycles signal professional quality output in space where it belongs, via the interac- level of -62 decibels. Sonotone's "Matched Twins" are easy tion of both channels in each ear. That is the way stereo does it. to handle, too. All that remains is to do what the imaginative inventor must always do, get For stereo sound at its natural best, buy "Matched Twin" mikes down to details and figure the circuitry. by Sonotone. Unequalled for performance...and for true stereo Mr. Bauer is the sort who can manage that quite nicely, and so he did. His black enjoyment. (For even greater sensitivity, buy Sonotone's matched box I gather, is quite simple and can be made by anybody who can hook up the twins- CM -T11 -with frequency range of 50 -8000 cycles and an handful of components. increased sensitivity of -55 decibels.) Both models retail at With the Bauer circuit you'll get a real approximation of true stereo sound via $36.75 per matched pair. Matching Table Stand: $4.00 each. your phones. If you're just a listener, you'll get truer stereo, and you'll avoid a lot of earstrain, over the long pull. And if you're a professional, you'll stop fooling yourself that you're getting stereo through those monitoring phones you've been using. If you're trying to judge stereo results by phones, you're barking up a very wrong onotone- tree unless your ears have been trained to ELI ELMSFORD, N. Y., DEPT. P26-110. interpret stereo in binaural terms, like RADIO CORP., LTD., TORONTO judging positive photo prints from the LEADING MAKERS OF negatives. Can be done, but it's hard on the senses. l /, P.S. I understand that the Bauer circuit III for earphones will be embodied in a com- I / mercial product via Stephen Temmer of Gotham Audio Corporation for those who BATTERIES CARTRIDGES SPEAKERS TAPE HEADS MIKES ELECTRONIC TUBES are unable to build the thing for them- J selves. Like me, for instance.

AUDIO NOVEMBER, 1960 89

www.americanradiohistory.com RECEPTION Maxim FM range reproducer 30 cps to (from page 50) well beyond audibility

Only 18" nal, This is sufficient to overload any o 24"e 4th thin amplifier, including those with low -fre- quency cutoff filters. In the new 310 -D this problem has been eliminated by having the Dynaural Interstation Noise Suppressor (DINS) a dream circuit actuate a mechanical relay. In one position of the relay, the audio output from every is fed to the output jack. In the alternate position, the signal is fed to ground. angle... The action of the relay introduces no switching transient into the audio out- put. It is also capable of remarkable speed. Referring back to Fig. 1 A, if the plane is traveling at 300 mph, fading will normally occur at a rate of up to thirty times per second. 310 -D's set for switch diversity reception can alternate THE " 440" BI- PHONIC COUPLER up to forty times per second. Most squelch circuits operate either of The first complete full range reproducer, so radically different that it is two ways : is by means classed as a musical instrument. Like a precious violin, the Si- Phonic One approach of Coupler Is hand -crafted of selected woods - with the panel structure the AGC voltage. This works quite well radiating hi- directionally (unlike the usual restricted "boxed -in" speakers) although it does lead to a partial time - reproducing the full realm of sound with acoustic depth, fundamental delay. Another method is to utilize the tonal and realism. The wafer -thin Si-Phonic Coupler beautifully purity 100 KC the de- blends into any decor arrangement. . noise output above at In mahogany, oiled or lacquer tector stage. This noise output is created ADVANCED ACOUSTICS CORPORATION walnut $134.40 by the limiting and detecting process 391 Lakeside Avenue, Orange, New Jersey Ebony base A subsidiary of Electronic Research Associates. Inc. (optional) $7.50 and does not include any broadcasting material or either the main channel or any multiples channel. The amount of The First Book of its Kind -No Other Like It! noise is directly proportional to the deg- radation of the signal. Any excess am- plification of this noise for control pur- poses, however, can create crosstalk and SOUND in the THEATRE overload problems in the tuner. by Harold Burris -Meyer and Vincent Mallory In the H. H. Scott DINS a combina- tion of both methods is employed. The Nothing like SOUND in the THEATRE rived systems and equipment specifications. AGC voltage is amplified by a two -stage has ever been published. It is the first Complete procedures are given for: Planning, d.e. amplifier which actuates the relay. book to set forth in authoritative detail what assembling, and testing sound control installa- you can do with sound by electronic control, tions- Articulating sound control with other The amplifier also serves as an a.c. am and how to do it whenever the source (singer, elements of production- Rehearsals and per- plier for the noise output of the detec- musician, speaker, etc.) and the audience are formances - Operation and maintenance - of tor, which it rectifies and applies as an present together. The book develops the re- sound control equipment. additional d.e. control signal to the d.c. quirements for electronic sound control from the necessities of the performance, the char- THE AUTHORS amplifier and relay circuit. In this way acteristics of the audience (hearing and psy- During the past thirty years, the authors have developed the advantages of both methods are uti- choacoustics), and the way sound is modified the techniques of sound control in opera, open -air amphi- lized and the disadvantages minimized by environment, hall, and scenery. Sound theatres, theatres on Broadway, theatres on -the -road and A d.e. reference bias controllable from sources are considered for their susceptibility off -Broadway, in concert halls and night clubs, in Holly- wood and in the laboratory. Some of their techniques are the front panel is the DINS threshold of control and need for it, and the many tech- used in broadcast and recording as well as in perform- control. A differential sensitivity of ap- niques for applying electronic sound control ances where an audience is present. From their laboratory are described and illustrated in thirty-two spe- have come notably successful applications of sound con - proximately 2 db is obtained. cific problems. From these problems are de- trol to psychological warfare and psychological screening. For diversity operation, the differen- tial sensitivity is reduced by using only one -half of the AGC voltage. This is ac- complished by inserting a shorting plug RADIO iii ++_ 14, in a special jack provided on each tuner. MAGAZINES, INC. SOUND ,.ht This is to allow simultaneous fading in Dept. 2 An invaluable reference an ,n !,g each tuner and still have an available Post Office Box 629 dispensable guide for anyone in the a audio output. A cable is provided to Mineola, New York working in the theatre com- plete technological thesaurus for couple the d,c. amplifiers of each tuner 11/ the engineer, architect. designer, r 1 am enclosing my remittance for $10.00 technician, student. and teacher THEATRE together. By this method, fading at one Send my copy of concerned with the reinforcement of sound and speech. receiver will lead to a differential sen- SOUND in the THEATRE postpaid. sitivity between tuners of up to 0.5 to (No C.O.D., all books sent postpaid in U.S.A.` 1.0 db in the other tuner allowing it to and possessions, Canada, and Mexico. Add 50c for Foreign orders.) supply the audio output.

Name AUDIO NOVEMBER, 1960

Address

City Zone State www.americanradiohistory.com may be necessary to Operating the Tuners for nated the output of that tuner, with the weak signal areas it quite low on one Diversity Reception other tuner continuing to perform. The set the DINS control passage of an airplane nearby could only or both tuners with dual diversity. An- With only a single tuner in use, the be detected by noting that the tuners other advantage accruing from the re- DINS is set so that only an acceptable were switching back and forth. This can markable high -speed relays in the 310 -D signal will pass. If a weaker signal with be done by watching the indication of is that even on the infrequent occasions greater noise can be tolerated, the DINS the signal- strength meters on each tuner. when both tuners drop out, it happens control can be further reduced. When- However, it was impossible to observe so rapidly that only a small portion of ever the signal fades below the prede- that this was happening by listening to the sound is lost. Frequently it goes un- termined threshold, the mechanical relay the speakers. The station continued to detected. clicks into operation and turns off the come in cleanly, with no noise, and no Certainly for the house recordist, the audio output. (This same phenomenon unpleasant transients. FM broadcasting station, or even the occurs when tuning from one station to Naturally if the Dynaural Suppres- critical music listener, space diversity another.) sors are set too high, the signal will drop techniques present an opportunity to When setting up for diversity opera- out in both tuners. With triple diversity obtain usable (or better) results in re- tion, the following procedure is sug- (three tuners in use) the possibility of gions where this had not been previously Æ gested : is less. Therefore, in possible. Connect an antenna to each tuner (the minimum desirable distance between antennas is 35 feet as was pointed out above). Only one tuner is connected to the amplifier. A shorting plug is inserted in the input marked J -1. of each tuner. i The tuning dial is turned off station to A MOST UNUSUAL OFFER a point where the meter indicates a minimum. The DINS control is turned to 0 (point of maximum sensitivity). The typical interstation noise is now from Tandberg heard. If it is not, then the Diversity Threshold control accessible on the top THE WORLD'S MOST RESPECTED NAMES IN HIGH FIDELITY TAPE RECORDERS. of the chassis should be turned with a ONE OF screwdriver until the noise appears. It should not disappear until the front ASK YOUR DEALER TO DEMONSTRATE ANY TANDBERG MODEL panel DINS control is rotated at least See and hear for yourself the 20 per cent. This is to make allowance magnificent clarity that can -Y 0.11111... for different d.c. levels when the shorting í r Pegg Series 5 plug is inserted. be yours with a Tandberg This same procedure is repeated in the recorder /playback ... the first other tuner(s). Then they are all set to self-contained, fully portable « the desired station with the DINS set stereo -monaural 3 speed, 4 track system. for an acceptable signal -to -noise ratio Or, listen to the incomparable response from on each tuner. The actual setting may the Tandberg 6 Stereo Tape Deck with 3 separate vary between tuners because of the ad- heads, push button control, plus portable relay sensitiv- justment of the pot, the or built-in versatility. Then, investigate the Tandberg Model 5 voltage avail- ity, the amount of AGC Series 2, 3 or 4 ... those excellent general purpose from $419 retail of noise level from able, and the amount recorders that have no peer in value or economy. system. future each antenna units feature i s IPS ... "The professional's speed of the Set the level controls for identical All Tandberg outputs using a meter if available. audio If you decide to buy any new Tandberg unit between Sept. 1, 1960 If not, then adjustment by ear will be as your own, any of these valuable gifts ... satisfactory. Connect the Channel A or and Nov. 30, 1960 you may select, B "high" output jacks of each tuner to- gether. Connect a lead from one of the SPEAKER TAPES MICROPHONE tuner's "low output" to the amplifier (as An 8" Tandberg hi-fi compo- 3 large 1200 ft., fine quality A new Tandberg design, described in the instruction booklet). nent for added versatility. 7" Ip plastic tapes with met- mounted in shock insulated And finally, connect a shielded cable be- Dual cone type. allized leader. cover; with desk stand attach- tween the J -2 jack (on top of the chas- Model #165-BK Model #1251 ment. #CM6 sis) of each tuner. This will ensure rapid Model switching.

Actual Performance With the system in operation, employ- ing dual diversity (two tuners) it was obvious that the problem of fading has been virtually eliminated. When a satis- SEE YOUR AUTHORIZED TANDBERG DEALER OR factory signal was present at both an- WRITE FOR THE NAME OF THE FIRM NEAREST YOU. tennas, both tuners operated with their audio outputs in parallel. As soon as a wtl [1 iÍ b L 0 of America, Inc. 8 Third Ave., Pelham, N. Y. poor signal appeared on one tuner, the suppressor went into action and elimi- 91 AUDIO NOVEMBER, 1960

www.americanradiohistory.com RECORDS SOUND BEST LEVEL -TEST with TAPES AID PROGRAM REPRODUCTION Bó (from page 30) D d uô STEREO DYN ES gested copy for this flyer might be as In each case and regardless of the follows. program material the tone level test satis- Choose either the Stereodyne II factorily performed the task of estab- (mounts in all standard arms) or WARNING WARNING WARNING the slim, trim TA -12 arm -cartridge TO AID STATION ENGINEERS lishing a positive known playing level. combination for the most natural IN ESTABLISHING LEVEL OF Satisfied that this revised system could sound from both stereo and mono THE PROGRAM MATERIAL be depended upon a second series of recordings. CONTAINED IN THIS RECORD- broadcasts were released with the tone ING, A 15 SECOND LEVEL -TEST test system. A call from the first station RECORDING IMMEDIATELY confirmed that this system could be de- PRECEDES THE ACTUAL pended upon and further the steady tone BROADCAST MATERIAL. THIS signal permitted an even faster setting RECORDING REPRESENTS of controls. THE LOUDEST PASSAGE Where the operator is not planning THAT WILL BE ENCOUN- duplication of the program, he should record TERED DURING THE BROAD- a test tone signal at zero db on CAST AND A LEVEL THAT the machine used to make the original WILL NOT BE EXCEEDED. recording and attach it ahead of the pro- gram. PROGRAM INFORMATION AND TIMING CAN BE FOUND If a recording has been made where ON inadvertently THE SECOND TIMING LEADER the level creeps into the WHICH FOLLOWS THE red zone or, say plus 2 db in level, then TEST the TAPE. THANK YOU. operator must select this point in preparing his test tape and not zero db. On those recording machines that do If overlooked or a regular zero db tape not employ db level $29.95 net meters but favor is attached then overload can certainly other devices to indicate peak recording be expected. As with the musical level levels, the same means that have been test tapes, operators should make a defi- Ai fir outlined can be employed. For "magic nite point of indicating the presence of eyes," the eye would just approach over- such material on tapes released +'`! -- for rec- . lap, or for neon lamp the overload lamp ord or air -time use. would just flicker. When a large number of duplications The principal fault with the original are being prepared, sufficient tape can procedure was the time- consuming fac- be recorded as zero -level test tape to tor of finding and reproducing a dupli- supply the current production, DESIGNED TO THE HIGHEST providing cation from the loudest musical passage. the test tape is recorded at the DYNACO same STANDARDS Further the operator had to find a pas- time to preserve the original intent of sage * unequalled performance where the sound was sustained long this system -to present a true picture of * outstanding engineering enough to give the operator time to set recording factors at the time the produc- his equipment. * unsurpassed value tion was undertaken. Returning to the original idea em- The procedures outlined in this ar- Rigorous laboratory testing of ployed by wire-photo transmission where ticle represent a start in what is hoped every unit assures that your a single note is used to set level it was will be an aid to those engaged in the decided to experiment with the cartridge will exceed possibil- recording field. Experience undoubtedly every ity of employing a generated tone signal specification. will show the system can be modified or that could be set to zero db level. simplified and still achieve the same re- In Smoothest response: ±2 db from 30 cps practice the tone system for pre- sults. For example, tape manufacturers to 15 KC. With standard Westres IA test disc. paring level -test tapes has proved quite might come out with a line of colored simple and is a procedure that does not timing strips which could be de- True stereo: More than 22 db channel used to separation effectively maintained through- necessarily have to be performed on the note or identify test recordings to the out the audio spectrum, with accurate spot or in the field. balance and proper phase relationship. industry. Possibly a 15 second test may First a series of duplications were be felt to be too long. Indeed a host Superior tracking: highest compliance, of low mass, plus exclusive symmetrical made and on completion and with the other suggestions may be forthcoming. push -pull design for minimum record wear controls and lowest distortion. still at the same level, input Meanwhile, however, the challenge is connections were transferred to an given to recordists to recognize the Complete freedom from hum. audio generator. The note selected for plight their work has brought to the Hear and compare it at your this test was 400 cycles and the genera- broadcasting and record fields and what, favorite dealer's showroom. tor output control adjusted until the re- if willing, they can do to overcome the Write for complete specifications cording meter reached the 100 per cent problem. Local experience with this sys- or zero db level. 10 to 15 seconds of tone tem has conclusively proved that in giv- DYNACO, INC. was then recorded for each program. ing engineers a break in their daily work These 3912 Powelton Ave. Phila. 4, Pa. test tone tapes were then affixed they have more than reciprocated in pre- CABLE ADDRESS: DYNACO, PHILA. to the program tapes as previously out- senting the program material so offered. lined.

92 AUDIO NOVEMBER, 1960

www.americanradiohistory.com BE PROFESSIONAL -RACK MOUNT page 44) DYNACO tapes are used black %crinkle, anti Lauouertone gray. console, since recorded MAKER OF THE WORLD'S FINEST Sound is For hard -type markings, any of the three as the main source of music. HIGH FIDELITY COMPONENTS are satisfactory, but if decals are to be fed into a wide variety of speakers in- applied, the smooth finish panel will yield terspersed throughout the building, baffle units the best results. ranging from S -in. ceiling A2141"44 th/gededeed For illustration purposes, photographs to radial trumpets. The monitor speaker of two rack mounted installations are at the top of the rack, is a low -cost unit de all ,mou. shown. One, a commercial installation by of the type used in rear -deck auto in- Allied Radio Corporation using com- stallations. The rack has a hinged front mercially available components, and the door with lock, and the entire unit is dynatuner other, a home constructed unit by the set on casters for easier servicing. author. If it is necessary to page a person, Allied's new sound distribution system, pressing the switch that covers this Fig. 4, is a rack -mounted unit installed section "mutes" the music for the area in the telephone switchboard room, being paged. Sound level of each of the functioning as both a plant -wide pag- areas served by the system is inde- "Aft ed:41."" ing system and a music distribution pendently adjustable. For areas where system. The rack is a standard model, the noise level is high the level of sound is raised -for quiet areas sound level is lowered. DYNAKITS Music is turned on or off at preset times by a program timer switch, lo- cated in the tape console, and easily accessible for setting. The system is in- operative during the night. A "silent sensing" device on the tape console, al- lows a musical selection to run to com- pletion even if the time switch is set to shut off the program in the middle of the selection. The unit of the author, Fig. 5, is a two- channel record, three -channel play- $79.95 Kit back machine that functions as part of $119.95 Wired Fig. 6. Top of record /playback amplifier. a stereo playback system, doubles as a and polished steel panels (optional ac- piece of test equipment (component cessories sold with the amplifiers), are substitution) and triples as a small used to "dress up" the installation. studio recorder. Looking from top to bottom of the Looking from top to bottom of the EASIEST TO ASSEMBLE rack (see photo), it employs these com- rack are the following : American Elec- Dyna's traditional stream- ponents : a monitor speaker, the Knight tronics Concertone tape deck, blank lined circuits and etched Model KN -110 FM -AM Tuner, two panel, record and playback amplifier, circuit boards enable com- Knight Model KN -3035 35 -watt public six- position stereo mixer for both high plete construction and address amplifiers, blank panel, phono and low impedance mikes, blank panel, alignment in 6 hours. drawer, and two Knight Model KN- two d.c. heater supplies for all tubes in 3061 60 -watt booster amplifiers. amplifiers and mixers, and regulated SIMPLEST TO ALIGN Immediately alon,^-ide of the rack, is high -voltage supply. You achieve minimum dis- placed the Ampex Model 450 -D tape Switching is accomplished by a corn- tortion and maximum sens- itivity- yourself - without any instruments.

UNPARALLELED PERFORMANCE Highest effective sensitivity plus lowest distortion plus superior quieting plus pre- cise. drift -free tuning.

Hear and compare it at your favorite dealer's showroom. Write for complete specifications DYNACO, INC. 3912 Powelfon Ave. Phila. 4. Pa. CABLE ADDRESS: DYNACO, PHILA.

Fig. 7. Bottom of Record 'playback amplifier showing component layout.

Allnln NCWFMBER 1960 93

www.americanradiohistory.com bination switch -jack operation. With all toriug incoming and recorded signals by Get the best in jacks switched off, the unit functions as meters, headset, and speaker systems an integral unit, receiving all signals -all from separate cathode follower from a main stereo console for record- outputs so as not to have the audio sig- Electronics ing, and plays back through the main nal loaded or affected by switching tran- For today's enjoyment console, external amplifiers, and speaker sients. Provisions for monitoring and systems. For Christmas Switching the jacks on, di- adjusting B+ voltage and current, d.c. giving vorces that part, or parts, from the heater voltage to each unit, and bias For year 'round pleasure main system, and complete flexibility is current are included on the front panels. obtainable by various combinations of These examples are, of course, just Send for Radio Shack's jacking arrangements. Live recording is two approaches to rack mounting, but accomplished by simply jacking from illustrate that complete flexibility is pos- the mixer to record inputs after switch- sible while retaining a professional ap- ing main inputs off the line thereby pearance. Whatever your specific needs, making the jack positions hot. rack mounting offers a custom solution. The recorder has provisions for moni- Be professional -rack mount. Electronics CATALOGS

LIGHT LISTENING

(from page 1, lion by the New York City Center Light Opera lineup within the reeds and brasses of a con- Company. ventional band. The most obvious stereo advantage shows up in some of the more farfetched E. Y. Harburg lyrics. when Howard Morriss reveals Og's Robert Merrill and Vivienne leprechaun reaction della Chiesa to mortal girls in the tune Sing Porter and Youmans Something Sort of Orandish, the twist of each syllable can be easily unscrambled. The high- Everest SDBR 8001 light of the album is the performance of Jean- nie Carson in The appearance of opera singers on records the starring female role of devoted to show tunes Finian's daughter. The best -known songs such is hardly a novelty. One as of the great American opera stars, Eileen Far- Sow Are Things in Glocca Mor-a?, Old rell has recently Devil Moon and If this Isn't Love fall within gone a step further in a her Columbia album called "I've Got A Right To responsibilities. She carries the show over Sing The the boundary line that demarcates secondary Blues." This release, however, boasts attractions. one unusual twist. Vivienne della Chiesa. in the course of the past three years spent sing- ing popular songs in night clubs, has developed Cha:Ies K. L. Davis: Adventures in Para- a voice of remarkably low pitch. I barely rec- dise ognized her on this record despite the fact Mail coupon for latest free 192 -page that Everest SDBR 1106 I used to hear her voice almost daily back In Radio Shack catalog plus every new the days when she was a fixture on transcrip- issue for full year. Songs with a South Sea Island locale are the tions available only to radio stations. So low special province of the Hawaiian lyric tenor, is her current register that, when heard for Charles Davis. (The initials are handier than the first time, more than one listener may some people suspect K momentarily See world's largest line of electronics -the standing for Keo- blame the speed regulation of his naonalaulani and the L for Llewellyn.) This turntable. Both Miss della Chiesa and Mr. items: Hi -Fi, Ham Radio, Stereo, like release is the latest in a series of Everest Merrill are more convincing in the Cole Porter values shown below. stereo discs by Davis that occupies a special and Vincent Youmans tunes that can be taken niche in the relaxation corner of the catalog. at a slow tempo. Individually and in duet, The Pacific islands have produced their share Everest has attained exceptional results in the of native singers who have made a name for stereo recording of voice. Robert Merrill's B uy voice on Easy Budget terms, up to 2 themselves here on the mainland but Davis has has never before been processed with the crisp- years to pay. Money -back guarantee the advantage of remarkable vocal resources ness and range audible on this disc. In fact, on every item always. and the comprehensive background of a any listener who considers a baritone voice to schooled musician. If you've already heard his be one of the better indicators of true response TYPICAL VALUES IN work in more ambitious fare, you know that in a sound system is hereby advised to take Davis is thoroughly at home in operatic and along this item when he attempts to evaluate RADIO SHACK CATALOGS light concert items but he really comes into his one or more unfamiliar components in the own in the lush "island" favorites programmed course of a shopping tour. here. The sheen of his distinctively bright voice can now be heard to full advantage in a col- lection that includes Lionel Newman's theme Tutti Camarata: I Want To Be Happy song for the television series Adventures in Everest T 41062 Paradise. In the rest of the disc the Pagan O All Transistor Love Song and Now Is The Hour really blos- They've figured out a way to touch all bases Pocket Rodio . $8.88 som when this guy applies his Hawaiian brand with this tape. Starting with the great show of sunshine to the lyrics. tunes of Vincent Youmans, Everest has lined up Camarata's orchestra to supply the pliable Tak Shindo: Accent on Bamboo and easy rhythmic beat preferred by today's dancing crowd. Gene Capitol ST Lowell's eight -voice 1433 group furnishes the wordless vocal coloring Now that percussion in every form has taken that seems to be mandatory these days. Just - 3.98 d 4.98 Stereo the center of the stage, the- right -distance milting Records ....Each Capitol has assigned a in a rigorously up $1.00 second album to Tak Shindo. In his initial re- to date studio and a bump -free recording lease, arranger-conductor Shindo introduced curve deliver a tape that's worthy of play- RADIO SHACK CORPORATION the concept of ancient oriental instruments back on an "ultra- linear" system. used within the framework -band Listening 730 Commonwealth Ave., of big dance to the gibberish these choral Boston 17, Mass. arrangements. Apparently the first project did groups have to use these days instead of not exhaust his supply of exotic drums because words, I occasionally find myself wondering one of the items featured in his original "Fes- how long this current vogue is going to last. tival in Swingtime" Radio Shack Corp. Dept. 601.12 is a Gagaku drum which It was a great idea when it first appeared - 730 Commonwealth Ave., Boston 17, Mass. rests suspended within a large circular frame. voices used as instruments to give new colors Send latest Electronics The unusual rhythmic pattern of this swing to the sound patterns of jazz and popular Catalog plus tune stems from Japanese As every new issue for music of the eight- favorites. employed by Duke Ellington one year, FREE. eenth century. The other Shindo original is a decades ago, it was a startlnig device. It still Japanese-motif blues based on a six -tone scale. has its uses in the pop field where the music Nome The arrangements of Cherokee, For You, and naturally lends itself to a high degree of color- Address It's So Peaceful in the Country include back- ing. Ray Conniff's arrangements of light clas- Postoffice ground use of a female voice. The thirteen - sics on the Columbia label are a case in point. it City Zone State J string Koto and a Japanese xylophone called The end of this reel found me convinced that L .= - the mokkin round out a highly nonstandard the music of Vincent Youmans, despite the

94 AUDIO NOVEMBER, 1960

www.americanradiohistory.com best efforts of the Gene Lowell Choir, is not the best choice for wordless voicing. The world's new stereo standard Ray Anthony: Dancing Alone Together Capitol ST 1420 I ...loaded with new advantages: The Ray Anthony trumpet is surrounded by smooth and subdued strings in this back- ground release. The album may remind some listeners of the famous Jackie Gleason Capitol recordings that made the trumpet a new star PERFECT BALANCE -EASILY in the take -it -easy department. In place of the usual rank of brasses, arranger Don Simpson uses viola. violin and a group of cellos in this collection of standard torch ballads. Following a swing through the night club circuit with a ALL ARM FRICTION small combo, Ray Anthony has returned to the REDUCED TO THE format of the full -size band. A logical move in VANISHING POINT the opinion of this listener. 2E

TAPE GUIDE (from page 38)

give the saute reading does not neces- sarily signify that the same level is being recorded on each channel of the tape. HEIGHT OF ARM AND REST EXACT STYLUS OVERHANG For the same signal input, there may be ADJUSTABLE FOR ALL -ADJUSTABLE INSTANTLY. differences in recording level due to STANDARD TURNTABLES variations between the sections of the stereo record head. Or, for the same sig- ALUMINUM PLUG -IN SHELL nal input, the recording level indicators STYLUS FORCE NUMBERED ITS A STANDARD, may each give a slightly different read- ing. To check for equal recording level and the relative indications by the record level indicators, the following procedure and many more, yet only s FOR LISTENING AT ITS BEST can be used. at your dealer's. Electro -Sonic Assume that the position of the play- 3495 Laboratories, Inc. back gain controls for equal signal out- FIRST IN BEAUTY...FIRST IN PERFORMANCE Dept. A 35 -5436th St Long Island City e, NY put has already been determined. Feed the same signal, say from a mono phono- graph disc, into each recording input. Adjust the input gain controls for equal STATEMENT REQUIRED BY THE ACT OF AUGUST 24, 1912, AS indications on the record -level indica- AMENDED BY THE ACTS OF MARCH 3, 1933, JULY 2, 1946 tors. Play back and compare the signal AND JUNE 11, 1960 (74 STAT. 208) SHOWING THE outputs with a VTVM, or by ear. If OWNERSHIP, MANAGEMENT, AND CIRCULATION OF these signal outputs differ substantially, AUDIO, published Monthly at Lancaster, Pa., for October 1, 1960 repeat the process, but after reducing the recording gain control setting for the 1. The names and addresses of the publisher, editor, managing editor, and busi- ness managers are: Publisher: Charles G. McProud, 204 Front St., Mineola, N. Y.; channel with the louder signal. Continue Editor: Charles G. McProud, 204 Front St., Mineola, N. Y.; Managing editor: David this procedure until the playback signals Saslaw, 204 Front St., Mineola, N. Y.; Business manager: Henry A. Schober, 204 on the two channels appear equal. Now Front St., Mineola, N. Y. on the re- note the relative indications 2. The owner is: Radio Magazines, Inc., 204 Front St., Mineola, N. Y.; Henry A. cord -level indicators, and be guided ac- Schober, 204 Front St., Mineola, N. Y.; Charles G. McProud, 204 Front St., cordingly in the future. Mineola, N. Y. 4. Matched Frequency Response. A 3. The known bondholders, mortgagees, and other security holders owning or hold- check for reasonably similar frequency ing 1 per cent or more of total amount of bonds, mortgages, or other securities are: response on each channel can be made none. quite easily. Record a high quality mono 4. Paragraphs 2 and 3 include, in cases where the stockholder or security holder disc on both channels; the disc should appears upon the books of the company as trustee or in any other fiduciary relation, be one that substantially covers the audio the name of the person or corporation for whom such trustee is acting; also the range. Then in playback compare one statements in the two paragraphs show the affiant's full knowledge and belief as to channel with the other by switching be- the circumstances and conditions under which stockholders and security holders who trustees, hold stock and securities in right sig- do not appear upon the books of the company as tween the left signal and the a capacity other than that of a bona fide owner. nal, as most stereo amplifiers enable one 5. The average number of copies of each issue of this publication sold or distrib- to do. If there is a significant difference uted, through the mails or otherwise, to paid subscribers during the 12 months in frequency response between channels, preceding the date shown above was: (This information is required by the act of of frequency of issue). this can be due to such factors as dif- June 11, 1960 to be included in all statements regardless 26,210 ferences in equalization, in bias current, in playback head gap width, and in azi- (Signed) HENRY A. SCHOBER, Business Manager. muth alignment. The last three factors Sworn to and subscribed before me this 20th day of September, 1960. named will primarily affect treble re- (Seal) Donald F. Mattone, Notary Public. sponse. State of New York. No. 30- 7766600. Qualified in Nassau County. Term expires March 30, 1962. 5. Common Bias Frequency. It is im-

AUDIO NOVEMBER, 1960 95

www.americanradiohistory.com $2.50 each SAVE YOUR SYNCHRONIZING COPIES OF CAPACITOR

.005 Nf AUDIO OSCILLATOR IN LEFT OSCILLATOR IN RIGHT CHANNEL Each file holds a CHANNEL RECORD Attractive and AMPLIFIER RECORD AMPLIFIER full year's copies. practical for your Jesse Jones Vol- home or office ume Files for every publication. 3 for $7.00 6 for $13.00 Covered in durable ORDER NOW-send leather like Kivar, check or money order Fig. 8. Synchronizing the frequencies of two bias oscillators. title embossed in 16 Kt gold. MAGAZINE FILE CO. 520 FIFTH AVENUE portant that the bias frequency be the frequencies, so that crosstalk due to the Satisfaction guaranteed NEW YORK 36, N. Y same on each channel. Bias current pass- head characteristically has a tinny DESCRIPTIVE ing through one section of an in -line sound. F R E E FD head tends to leak through to some de- Conversion for Stereo CGrcle 96A gree to the other section. Hence there are two bias currents through each sec- Converting a tape machine for stereo tion, although of different magnitude. purposes may mean either (1) convert- IF YOU ARE MOVING If the frequencies of these two currents ing from mono to stereo or (2) con- Please notify our Circulation Department are different, there will be resultant verting from two- to four -track stereo. at least 5 weeks in advance. The Post Office does not forward magazines sent to wrong beat frequencies that are recorded on In the latter case, the conversion is destinations unless you pay additional post- age, and we can NOT duplicate copies sent the tape. If the stereo tape recorder usually quite simple, involving the re- to you once. To save yourself, us, and the employs separate record amplifiers for placement of the two -track head by a Post Office a headache, won't you please cooperate? When notifying us, please give each channel, each with its own bias four -track one in the same mounting your old address and your new address. current supply, it becomes necessary to fixture, and possibly the addition of an Circulation Department synchronize these two frequencies so electronic component or two. Figure 9 RADIO MAGAZINES, INC. P. 0. Box 629, Mineola, N. Y. they are the same. This is a simple mat- shows a conversion kit put out by Am- ter, at least for the audio technician. As pex that enables owners of its two - shown in Fig. 8, a small capacitor can track stereo machines to convert a four - be connected from the plate of one bias track stereo for playback. oscillator to the plate of the other for Most tape recorder manufacturers of- synchronization. This assumes that the fer a conversion kit. If they do not, it two bias frequencies were originally is possible to purchase a stereo head fairly close together, say within about from one of several prominent manufac- 10,000 cps of each other. turers of tape heads, such as Brush, 6. Crosstalk. Coordination between Nortronies, Shure, and Viking. Some- channels in this case means keeping the times the head is available in a variety Dramatic Events Recorded First left signal in the left channel and the of mounting styles so as to fit the Time From Short Wave Radio! right signal in the right channel. Cross- President's voice from outer space talk can occur because of improper ... police capture of a gunman ... vertical positioning of the head or be- radio contact with record altitude cause of construction of the head. In flight! Many other fascinating, his- modern high quality heads, crosstalk toric events -ships, planes, foreign stations -all transcribed on a lim- within the head has been reduced to ited- edition recording, "The Amaz- negligible proportions by shielding be- ing World of Short Wave Listening," tween sections and by other design fac- narrated by world-famous news- tors. Such crosstalk as does occur caster Alex Dreier. If you're alert, con- adventuresome, send for this re- sists prinsnrily of the Mailer audio markable recording today! As heard on Hallicrafters precision receivers, $59.95 to $395.00. 1:;.01° till J L rs r - -'I - -, I ®halliirafters .a gaeç 2: 'Enclosed is 15e. Please rush' The. Aaz- ing World of Short Wave Listenimng.' NAME I ADDRESS STATE LCITY :II Fig. 10. Various head mounting method Circle 968 Fig. 9. Four -track conversion kit. for four -track stereo conversion.

96 AUDIO NOVEMBER, 1960

www.americanradiohistory.com endowed with uncanny intelligence ...

Fig. 11. Mounting the head "outboard ".

mounting fixture in a particular ma- chine. For example, as shown in Fig. 10, Nortronics makes three mounting styles, which among them will fit the majority of tape machines on the market. For all other machines, Nortronics has a fourth mounting style, with an accompanying mounting bracket, as shown in Fig. 11. In the last instance it is necessary to attach the mounting bracket to the tape deck with self- tapping screws. The bracket has slotted mounting holes to permit proper vertical positioning of the head relative to the tape. Azimuth adjustment is performed by bending the records gently with care bracket. It is usually desirable when Handles your all the *GENTLY AUTOMATIC* you would want them receive. per- using an "outboard" head installation of to Superb formance of stereo monophonic records. this kind to also install a tape guide and only record with `turntable post, such as that in Fig. 12, to insure GLASER * STEERS World's changer $59.50 At proper passage of the tape across the pause.' (less cartridge and base). head. your hi -fi dealer or write for brochure. DEPT. All If the tape machine is a mono device, GS *77 Glaser- Steers Corp., 155 Oraton Street, Newark 4, N. J. then it is necessary to install not only A Subsidiary of American Machine and Metals Inc. stereo heads (including a stereo erase head), but also additional electronics DON'T SPEND ANOTHER for the second channel. If the tape ma- chie is intended for playback only, at CENT ON STEREO . . . least for stereo, it is likely to be un- necessary to purchase a second playback amplifier because most stereo amplifiers UNTIL YOU READ THIS provide an input for accommodating the signal directly from a tape head. BOOK! On the other hand, if it is desired to record as well as play stereo tapes, then a second tape record amplifier, which incorporates the required amplification and equalization for the second channel, must be acquired. Such tape amplifiers are available from several manufac- turers. As discussed previously, when Why play hit-or -miss with your stereo answers all your questions about the - It will give separate record amplifiers are used for system? The fact filled, illustrated theory of stereophonic sound. STEREO HIGH FIDELITY HANDBOOK you a new understanding of the whole each channel, it is necessary to syn- will be worth many times its price in world of high fidelity. Illustated with chronize their bias oscillators to avoid savings to you on home sound systems. hundreds of helpful photographs. Order heat notes. JK Its accurate, easy -to- follow instructions your copy of Norman H. Crowhurst's tell and show you STEREO HIGH FIDELITY HANDBOOK today. $5.95 how to buy, build, place and connect your stereo equipment r MAGAZINES, INC. how to convert your present mono set to RADIO stereo l'.O. Box 629, Mineola, N. Y. u e STEREO HIGH FIDEL- how keep your stereo in Send Crowhurst's to system top ITY HANDBOOK for 10 days' examination shape without incurring expensive repair on approval. In 10 days I will remit $5.95 bills few cents for delivery costs, or return ookbplus postpaid. (We pay delivery costs if you how to choose among the latest com- remit with this coupon; same return ponents and how to rate the newest privilege.) developments Name ...... Written by a leading electronics engi- neer, this trouble -shooting handbook Address Fig. 12. Guidepost used in conjunction guides you step step by . i illustrated City ...... Zone . State with "outboard" head mounting. through every stereo problem, and L

AUDIO NOVEMBER, 1960 97

www.americanradiohistory.com F

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NEW! "the best of AUDIO" No. 124 No. 120 A new compendium of AUDIO knowledge. THE 4th AUDIO ANTHOLOGY Here is a collection of the best of AUDIO -The AUDIOclinic $2.95 Postpaid by Joseph Giovanelli...noted audio engineer and the original high fidelity answer -man- EQUIPMENT PROFILES edited by This is the biggest Audio Anthology ever! C. G. McProud ... Editor of AUDIO. Here is a wealth of hi-fi Contains a wealth of essential high fidelity and audio information. Answers to the most important issues know -how in 144 pages of complete arti- in high fidelity and a valuable reference on the performance of cles by world- famous authors. leading makes of high fidelity components. Volume 1 $2.00

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CITY ZONE STATE

www.americanradiohistory.com TELEX PARALLEL SPEAKER ARRAY SERIES- SUPERIORITY IN SOUND (from page 56) STOP THIS! we have in this array, the better the re- our purpose. These hard -coned tweeters do sound very good by themselves. sponse curve becomes. Each unit, because not Ivp of manufacturing tolerances, is just a Because of the small magnets and other little different than the next one. So the considerations a single four -inch tweeter chances of having say twenty speakers leaves much to be desired. Just as a sin- with identical characteristics would gle six-inch speaker sounds terrible when seem to be improbable. played on today's wide -range equipment The reason that we must connect the at high volume levels. But if we use speaker array in a series -parallel, rather about six of these small tweeters instead WITH than simple parallel arrangement, is pri- of one, we again take advantage of the marily because we would like to keep the "response levelling" characteristic and THIS! overall impedance of the array at a value we end up with a velvety- smooth high that will permit connection to conven- end that is free from peaks and distor- tional amplifiers with impedance taps of tion. 4, 8, or 16 ohms. I will now describe a loudspeaker sys- The response of the array at the low tem which incorporates all the principles frequencies depends entirely on the num- of the series -parallel array. There are ber of loudspeakers used. The greater 22 six-inch speakers arranged as shown new dynes -twin Why shock around the clock? Love , thy neighbor by doing your late rw evening hi -fi stereo listening -fully relaxed and in private -with the all -new TELEX Dyna -Twin. With TELEX Dyna -Twin private

STEREO COVERAGE FROM TWO SYS- listening you can experience the full STEREO COVERAGE FROM TWO SYS- TEMS USING UNCONVENTIONAL sound of true third dimensional bal- USE OF SIDE SPEAKERS PER- TEMS. PLACEMENT. STEREO COVERAGE. anced stereo without arousing the MITS INCREASED wrath of neighbors. Other sound reasons for speci- Fig. 4. Stereo coverage of a pair of series -parallel systems in various room positions. fying TELEX Dyna -Twin: Matched receivers give perfect of working in unison, in Fig. 3. In addition, there are six four - stereo balance Frequency re- the number units 15,000 cps. Sensi- low fre- inch tweeters arranged along the top sponse: 30 to the greater the efficiency at the 80 db above .000204 dynes to use a row. You will note the speakers on the tivity: quencies. The author prefers per sq. cm. for 1 milliwatt input large number of six-inch speakers. These angled side. This arrangement gives an Comfort for hours, weighs only speakers can be very inexpensive units. excellent polar response pattern on the 9 oz. Perfect weight distribution Magnet weight of over one ounce is un- higher frequencies. Figure 4 shows how with seven -way headband adjust- necessary. Voice coil size and cone mate- two of these systems arranged for stereo ment Single, non -tangle cord Sturdy Tenite and stainless steel rial are not critical. About 20 six-inch present the ideal stereo dispersion all the rust speakers will guarantee that you can way across the front of the listening construction Moisture and never overload or cause the cone move- area. proof $2310 There four loudspeakers facing ment to become nonlinear for average are CHOICE OF PHONE PLUGS! home listening conditions. This number directly at the floor. This gives a sur- TELEX can provide terminals com- will also give you superb low frequency prising sock to low frequency transmis- patible with your existing equip- response down to 20 cps. These small sion along the floor plane. ment. lightweight cones and Because of the wide high -frequency speakers with their ITEM MODEL No. high rigidity give a transient response pattern there is no "focusing" of high - Dynes -Twin Headset, which is fantastic. The whole array is frequency energy in a narrow beam in cord stripped and tinned HDP-1 front of the system. This is an annoying Dyna -Twin Headset, highly damped. standard phone plug- monaural . . . . HDP -2 The high -frequency response suffers problem with conventional speaker sys- Dyna -Twin Headset, . . . HDP -23 beginning at about 8500 to 9000 cps. The tems. 2 standard phone plugs -stereo Dyna -Twin Headset, quality is excellent but the overall out- The low, narrow cabinet takes little 3- circuit plug-stereo HDP -53 put is down in db. This is due simply to floor space. It does not have to be in a for For more information and a demonstra- the fact that these inexpensive speakers corner or any special place satisfac- tion, see your TELEX dealer. Or write do not have the voice coil design required tory reproduction. My previous array' directly to us. to put out much above these frequencies. using 32 six -inch speakers was extremely In order to resolve this problem we long and heavy. However, by reducing should use a tweeter system to bring the the number of speakers to 22 and ar- TELEX on the high end. response up I Charles F. Mahler, Jr., "Hi -Fi perform- Communications Accessories Division The small four -inch hard -cone tweeters ance from small speakers," Arnim, Decem- Telex Park, St. Paul 1, Minnesota, CA -709 19, Ontario which sell for $2 or $3 are excellent for ber 1959, p. 22. In Canada : Atlas Radio Corporation, Ltd., Toronto

AUDIO NOVEMBER, 1960 99

www.americanradiohistory.com ranging them closer together, we have a smaller cabinet without any serious sacrifice in sound quality. The completed CLASSIFIED system Rates: 10e per word per Insertion for noncommercial weighs about 65 pounds. In my advertisements: 25e per word for commercial mire, previous article, I had stated that it was tlsemcnts. Ratas are net, and no discounts will be allowed. Copy must be accompanied by remittance in essential to rigidly brace the cabinet be- full, and most reach the New York office by the cause of the great low frequency output. best of the month preceding the date of issue. I am afraid that I was led astray by the volumes of information printed on the HIGH FIDELITY SPEAKERS REPAIRED Amprite Speaker Service subject. Some writers have suggested 168 W. 23rd St., New York 11, N. Y. CH 3-4812 brick or concrete enclosures for their ENJOY PLEASANT SURPRISES? Then write speakers. The reason for all this fuss was us before you purchase any hl-ft. You'll be the tremendous amount of cone excur- glad you Electron- ics, 0 Libertyuty St., NewYorky 6, 1 N. Y. sions on these other "sophisticated" CLoverdale 84288, . speakers which caused the whole cabinet WRITE for confidential money-saving prices structure to shake and rattle. Large cone on your HI- Fidelity amplifiers, tuners, speak- ers, tape recorders. Individual quotations only ; excursions are necessary when a single no catalogs. Classified HI -Fi Exchange, AR, loudspeaker tries to reproduce 20- and 2375 East 65th St., Brooklyn 34, N. Y. 30 -cycle tones. So, cabinets had be SALE : 78 rpm recordings. 1900-1950. Free to lists. Collections bought. P. O. Box 155 rigid and strong. In our series -parallel (AC), Verona, N. J. array we are moving a large wall of air LOW QUOTES on everything. Hi Ft and with no cabinet vibration. There are Stereo tapes. Bargain list. HIFI, Roslyn 4, no Pa. violent cone excursions. Instead we move small COMPONENTS, recorders, free wholesale amounts of air which combine with catalogue. Carston, 125 -N East 88th Street, other small amounts that result in a large New York 28, N. Y. wall of air which was generated with AMPEX, Concertone, Crown, Magnecord, Norelco, Presto, Bogen, Tandberg, Sherwood, practically no effort all ! N% at So our main Rek-O -Cut, Scott, Shure, Dynakit, others. concern with cabinetry is to keep the Trades. Boynton Studio, Dept. AM, 10 Penn- MANUFACTURER cabinet from exerting some resonance of sylvania Ave. Tuckahoe, N. Y. its own into the RENT STEREO TAPES -over 1500 differ- FUKUYO SOUND system. This can be ent -all major labels-free catalog. Stereo- avoided by packing sheets of Fiberglas Parti, 811 -H Centinela Ave., Inglewood 3, 2.25. une, Kita ku, e Tokyo in the rear of the cabinet. This damps California. Cable: CORALFUKUYO any standing waves and cabinet INCREASE CLARITY PRESENCE, reso- DEPTH with the new DUO-PHONIC IN- Circle 100A nances. DUCTOR on Stereo or Mono. Send for FREE FACTS or order now $29.90. MONEY BACK In conclusion, I would like to list some GUARANTEE. The Audionics Co., 8 West of the advantages and disadvantages of Walnut St., Metuchen, N. J. save on the series- parallel loudspeaker array. RENT-A- TAPE /stereo or monaural. No de- posits-no minimums. Free catalog. Colum- bia, 9651 Fosbury Way, Rivera, California. Advantages stereo VAN EPS disc recorder, Fairchild 541 cut- 1. Excellent low-frequency response. ter, $125. Pickup only. C. Zak, 139 Grand St., hi -fi 2. Excellent transient response. Jersey City 2, N. J. 3. Very low distortion. PRESTO 75 -A, 16" recording table in port- 4. No frequency doubling. able case, 112 and 224 lines, 1 -D cutter, G. E. 5. Simple cabinet design. turn -around playback, $100.00 FOB Omaha, send for the 1961 New RCA MI -9449 15" woofer $50.00 FOB 6. High efficiency. Omaha, G. E. Al -501 16" transcription arm 7. High power -handling ability. with 4 slides $10.00, G. E. Al -901 compen- 4111E0 8. Low cost. sator $10.00, G. E. Al -903 rumble Biter $5.00. Gray 602 equalizer $25.00, McProud "Minia- CATALOG turized Pre-Amp with Presence," with tubes $25.00. Stephens Tm -Sonic C2S -0D5 con - Disadvantages densor microphone system with case $95.00. Charles F. Craig, 5813 Blondo St., Omaha 4, 1. High labor time necessary to cut holes Nebr. and mount and wire 28 speakers. SEVERAL efficient 4" deep -cone tweeters. JE each SAVE MOST! Here's your enniplete 16 ohm; 2000- 15,000 response. $5.35 money- saving guide to Hi -Fi, including postpaid. G. Cain. 15 Manet Circle, Chestnut products available only from ALLIED. See Hill, Mass. how you save on our recommended com- plete Stereo systems. Choose from the FACTORY SELL OUT. Germany's finer 12" world's largest stocks of famous -name coaxial speakers, full range, formerly $49.50. amplifiers, tuners, changers, speakers, Send $18.50 each, 2 for $35. No COD. Chesh- enclosures, period -style equipment cabi- AUDIOCLINIC ire Co., Parent; Str. 10, Mainz, Germany. nets, tape recorders. accessories; save most with KNIGHT° deluxe components. MAGGIE : 521 E. 162 St., New York 51, Build your own -save even more with (from page 4) N. Y. WE SAID TRANSIENTS, NOT our exclusive Hi -Fi KNIGHT- Ktre'. For TRAMPS. COME HOME M. S. 1. everything in Hi -Fi and Elec- tronics, get the FREE 444 - the coil. This must be done how- only $5 down page 1961 ALLIED Catalog! carefully, on orders ever, or the wedge will cut through the in- INTERNATIONAL RECORD COMPANY up to $200 ALLIED RADIO sulating paper and possibly break or short - circuit some of the turns. This will ruin the Musical and Technical Coordinator transformer. available spring 1961 seeks re- rALLIED RADIO Dept. 146 -L 1 As a general rule it will do no good to 100 N. Western Ave., Chicago 80, sponsible position utilizing full III. pour resinous material into the lamina- qualifications. details of posi- O Send FREE 1961 ALLIED Catalog. tions, for this is usually done in a vacuum State which enables deeper penetration. It is oc- tion available in first reply. Box No. Name casionally possible, but it is very messy, CE -1. Address and it is often impossible to separate the core from the laminations without com- I City Zone L State J pletely dismantling the core. The dipping Circle 100B would then serve no purpose. l£ Give The UNITED Way

100 AUDIO NOVEMBER, 1960

www.americanradiohistory.com FM/Q 9ftcilrudbhv /Votes ... FREE AMPEX APPOINTS HARVEY. Harvey ANTENNAE Radio was appointed exclusive distributor THE FINEST OF ITS KIND of Ampex Professional and Instrumenta- stereo Get more FM stations with the world's most tion Tape and Ampex Videotape in the powerful FM Yogi Antenna systems. Metropolitan New York, Lower Connecti- cut, Northern New Jersey area. A totally informed, new sales force, headed by Thomas B. To be fully Aldrich, has been set up to handle this balance kit send 30,; for book new line. Mr. Aldrich was formerly In- "Theme And Varia dustrial Sales Manager of Presto Record- bons" by L. F B. Carmi ing' Corp. and a well known figure in the and containing FM electronics industry for more than 20 ask your years. According to Harvey Sampson, Sr. Station Directory. this move will strengthen Harvey Radio in the industrial field. APPARATUS DEVELOPMENT CO. dealer WETHERSFIELD 9, CONN HARMAN- KARDON MOVES PLANT. With all the pleasure of a pretty lady in Chele 101B a new dress, Harman-lCardon announces the completion of their move to a new 1P- plant. Located in Plainview, Long Island, N. Y., the new and improved surroundings audio empire ELECTROSTATIC TWEETER are expected to permit increased produc- tion. Good luck -wear it well! THRILLING =:l HI FREQUENCY AUDIO DYNAMICS CORP.-NEW RESPONSE COMPONENT MANUFACTURER. Housed ... y,il#;` in an air conditioned plant in Ridgewood, ONLY $19.95 N. Y., the newly formed Audio Dynamics is BY Corp. headed by Peter E. Pritchard, ORDER formerly an engineer with G. E., Shure MAIL Bros., and the English firm of Kelvin, Hughes, Ltd. Bert Gedzelman, long known 1015 in the audio field as a manufacturer's rep- resentative, will be responsible for sales. S. FIGUEROA Included in the plant are a machine shop, LOS ANGELES a test laboratory, and automatic assembly CALIFORNIA equipment. Their first product is a stereo cartridge. äuäiörlempire George Alexandrovioh has been appointed Circle 101C 1075 STEWART AVE., GARDEN CITY, N. Y. as Chief Engineer of professional and con- EXPORT: EMEC. PLAINVIEW. N. Y. sumer product lines by Fairchild Record- CANADA: ACTIVE RADIO TV LTD.. TORONTO 2. ONT. i CANADA ing Equipment Corp. Mr. Atexandrovich High Fidelity Equipment has been with Fairchild for many years. Circle 101A His latest developments include the new Complete Lines Complete Service Model 440 turntable and Model 500 arm Hi -Ft Records - Components and cartridge,. Congratulations! and Accessories Rene Snepvengers has been elected Vice President of Electro -Sonic Laboratories, HELP &LQECTRO-UO10E Inc. Long identified with the audio field, Mr. Snepvengers was formerly Director SOUND SYSTEMS of Engineering of Fairchild Recording 126 DUNDAS ST. WEST. Equipment Corp. and before that served with CBS and RCA. The election of Mr. Circle 101D Snepvengers is in keeping with the ex- SCIENCE pansion of the ESL high fidelity and in- dustrial lines. PACKAGE HI FI Prank C. Eumb has been named by or SINGLE COMPONENTS American Concertone, Inc., a Division of the Astro- Science Corp., as Vice President FIGHT TB You'll find our prices low for Engineering. Prior to Joining Concer- and service fast. tone, Mr. Bumb was Chief Engineer, Space ANSWER YOUR CHRISTMAS Write for our quotation Science Department, of Consolidated Elec- LETTER TODAY Center Industrial Electronics, Inc. trodynamics. Mr. Bumb is past President SEAL 74 -A Cortlandt St. New York 7, N. Y. and Chairman of the Board of Cal -Tech al _ Alumni Association. Circle 101E

HEADS YOU WIN! ABOUT MUSIC You'll be a winner by say- (from p,,;. ing "heap plenty" on your Hi -Fi needs. Write today! station devoted to background music, but Ask too for discount cata- log A -12. it is totally inappropriate to an exhibit in a KEY ELECTRONICS CO. which loudspeaker or a stereo cartridge 120 Liberty St., N.Y. 6, N.Y. is the center of attention.

Circle 101F Traffic Clogged corridors seem to be an integral part of New York audio shows, and prob- A NOTE TO THE HI -FI BUYER ably of other shows throughout the land. AIR MAIL us your requirements for an IMMEDIATE WHOLESALE QUOTATION The French, however, have developed a so- Components, Tapes and Recorders lution for this problem. At the Paris Hi -Fi SHIPPED PROMPTLY AT LOWEST PRICES Show of 1959, one -way traffic was strictly WRITE TODAY FOR FREE CATALOG enforced, with notable success. The Palais 714 -A Lexington Ave. audio d'Orsay Hotel is shaped rather differently unlimited Now York 22, N. Y. f, than the Trades Show Building, of course, Circle 1010 but the idea is worth consideration. Æ

AUDIO NOVEMBER, 1960 101

www.americanradiohistory.com a áyette Superior Quality Hi -Fi Kits ADVERTISING OUTSTANDING DESIGN - INCOMPARABLE PERFORMANCE INDEX NEWS KT -250A 50 WATT INTE-

Acoustic Research, Inc. f,1 GRATED STEREO AMPLIFIER Advanced Acoustics Corp. 90 AIWA Co., Ltd. 12 A completely new stereo high fidelity amplifier Allied Radio Corp. 73, 79, 100 with a high quality of reproduction, versatility of Altec Lansing Corporation 46, 47, 55, 72 operation, and distinctive styling. American Electronics, Inc., American A full range of controls enables you to enjoy the Concertone Division 78 utmost in listening pleasure in any situation. De- Ampex Audio Company 39 luxe features include: unique "Blend" control Ampex Professional Products for continuously variable channel separation - Company 33, 34, 35 from full monaural to full stereo, 4- position Apparatus Development Corporation .. 101 Selector, Mode, Loudness and Phase witches. Audio Bookshelf 98 Also provided are outputs for 4, 8 and s 16 ohm Audio Devices, Inc. 29 speakers. Hum -free operation is by the Audio Empire 101 use of DC on all prsomp and tone nuredcontrol tubes. Audio Fidelity Records 65 Harmonic distortion, less than 0.25 %. IM distor- Audio Unlimited 101 50 WATTS MONAURALLY - 25 WATTS tion, less thon .5%. Hum and noise, 74 db below EACH STEREO CHANNEL RESPONSE 15- full output. Designed with the kit builder in Belden 13 40,000 CPS --:.5 DB (at normal listening mind, assembly is imple -no special skills or Bell Telephone Laboratories 18 tools required. Complete with deluxe cabinet and Bogen- Presto level) UNIQUE "BLEND" CONTROL Company 49 legs, all parts, tubes and detailed instruction Bozak 15, 87 PREMIUM EL86 OUTPUT TUBES SEPA- manual. Shpg. Wt., 26 lbs. British Industries Corporation 3, 80 RATE BASS AND TREBLE CONTROLS KT -250A Stereo Amplifier Kit 5.00 Down Net CLUTCH- OPERATED VOLUME 74.50 Center Industrial Electronics Corporation 101 CONTROL 1A -250A Stereo Amplifier, wired 5.00 Down Classified 100 3rd CHANNEL OUT Net 99.50 Dynaco, Inc. 92, 93

KT -500 FM -AM EICO 11 Electro -Sonic Laboratories, Inc. 95 Electro- Voice, Inc. 59 STEREO TUNER KIT Electro -Voice Sound Systems, Inc. 101

F idel itone 6 More than a year of research, planning and en- Fisher Radio Corp. 9 gineering went into the making of the Lafayette Fukuin Electric (Pioneer) Tuner. FM 27 Stereo specifications intrude grounded - Fukuyo Sound Co., Ltd. (Coral) 100 grid triode low noise front end with triode mixer, double -tuned dual limiters with Foster- Seeley dis- General Electric 68 criminator, less than 1% harmonic distortion, full Glaser- Steers Corp. 97 200 k< bandwidth sensitivity 2 and of microvolts Gotham Audio Corporation Coy. KT ' LT -50 for 30 db quieting with at mi- III -500 full limiting one Grado Laboratories, Inc. 74 I COMPLETELY WIRED crovolt. The AM FM and sections hove separate 3 -gong Hallicrafters 96 tuning condenser, separate flywheel tuning and Harman Kardon 124.50 separate volume ontrol. Automatic frequency 40, 41 control "locks i ' c FM signal permanently. Two Jensen Manufacturing Company 43 Output New Stereo FM separate printed n circuit boards make construction Multiplex for and wiring simple. Complete kit includes all parts Key 11 Tubes (including 4 dual -purpose) and metal cover, a step -by -step instruction man - Electronics 101 Tuning Eye Selenium rectifier Provide 17 vol, schematic and pictorial diagrams. Sire is Kierulff Sound Corporation 101 13'6" W x 10%" D x KLH Research & Development Tube Performance Pre -aligned IF's 4'h" H. Shpg. wt., 22 lbs. KT -500 .... _. 5.00 Down . Nat 74.50 Corporation 69 Tuned Cascode FM Dual Cathode LT -SO. Same as above, completely factory wired Follower Output and tested 5.00 Down Net 124.50 Lafayette Radio 102 Lansing, James B., Sound Inc. 61

Magazine File Co. 96 KT -600 PROFESSIONAL McIntosh Laboratories 45

STEREO CONTROL CENTER Neat Onkyo Denki Co., Ltd. 2 North American Philips Co., Inc. 4 Solves Every Stereo, Monaural Control Problem! Paco Electronics Co., Inc. 67 Pickering & Company 17 Provides such u uol features o a Bridge Con- Pilot Radio Corporation 57 trol, for variable s cross -channel signal feed fax elimination a of "ping -pong" (exaggerated separa- Radio Corporation of America Cov. II tion) effects. Also hos full input mixing of mono. Radio Frequency Laboratories, Inc .. 75 tat program sources, special `null" stereo bal. Radio Shack Corporation 94 KT -600 ancing and calibrating system. Also has 24 equal. Reeves Soundcraft Corp. 5 ration positions, all-concentric controls, rumble Rek -O -Kut Company 63, 82 KIT FORM 1 COMPLETELY WIRED IN and scratch filters, loudness switch. Clutch type Rider, John F., Publisher, Inc. 88 volume controls for balancing or as 1 Master Robins Industries Corp. 88 79.50 i 134.50 Volume Control. Has channel reverse, electronic phasing, input level controls. Sensitivity 2.2 mil- Sansui Electric Co., Ltd. 80 livolts for 1 volt out. Dual lawimpedance out- A REVOLUTIONARY DEVELOPMENT puts (plate followers(, Sargent -Rayment Co. 76 1500 ohms. Response 5- Schober IN STEREO HIGH FIDELITY 40,000 cps -!- I db. less than Organ Corp. 83 .03% IM distor- H., tion. Uses 7 new 7025 low -noise Scott, H. Inc. 85 UNIQUE STEREO & MONAURAL CONTROL dual triodes. Sherwood Size 14" x 41/2" x 10% ". Shin. wt., 16 lbs. Electronics Laboratories I FEATURES AMAZING NEW BRIDGE CIR- Complete with circuit board, Shure Brothers, Inc. 71 printed cage, pro- Sonotone CUITRY FOR VARIABLE 3d CHANNEL OUTPUT fusely illustrated instructions, all necessary parts. Corp. 89 LAFAYETTE KT- 600 -Stereo Preamplifier Sony Corp. of America 77 CROSS-CHANNEL FEED IG PRECISE kit - "NULL" 5.00 Down Net 79.50 Stromberg- Carlson, A Division of BALANCING SYSTEM RESPONSE 5- 40,000 LAFAYETTE LA- 600 -$torso Preamplifier, Wired General Dynamics 52, 53 Superscope, Inc. 37 CPS ± 1 DB - 5.00 Down Net 134.50

Tandberg of America 91

13, I 1 JAMAICA NEW YORK NEW YORK 13, N.Y. I BRONX 50, N. Y. I BOSTON 10. MASS.I Tannoy 76 GTAFAYETTE Telex Inc.. 2. N 1. I Communications - R A D I O NEWARK PLAINFIELD, N. 1. 1 PARAMUS, N.J. 1 I Accessories Division 99 1 Thorens I Lafayette Radio, Dept. AK-6, 66 E /The NEW 1961 Transistronics, Inc. Coy. IV I P.O. Box 190 Jamaica 31, N. Y. Lafayette Electronics Uher 81 1 324 -Page Ultraudio Products 7 I Name United Audio 86 United Stereo Tapes 25 Address Catalog ------. No. 610 Weiss, Warren, Associates 81 I City ._._ _.._..Zone State _

102 AUDIO NOVEMBER 19Hí1

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BEYER DT -48 Dynamic Peak - BEYER M -100 Moving Coil Performance Headphones Dynamic Microphone

The M -100 represents the latest achieve- ment in the field of quality dynamic studio microphones. Its miniature size follows the present day trend toward more compact, unobtrusive trans- ducers. It is impervious to tem- perature and humidity.

Wind screen avail- able to completely eliminate "pops" and "wind rushing" noises when used for close talking or outdoor pickup. M-100-;170.00

A hand -built, high -fidelity transducer used in critical evalu- Overall response: ation of recorded and transmitted sound, yet in a reasonable Directional 20- 20,000 cps price class. Frequency range: 30- 15,000 cycles, down no more characteristic: Omnidirectional Impedance: 50 /200 ohms than 7 db at 15 kc, and perfectly flat at 30 cycles. Comfortable Frequency response: exchangeable foam rubber pads and separate cords for each ear Sensitivity: 50- 16,000 cps 2.5 db for stereo application. Impedance: 5 ohms each side; input volt- 0.100 my /microbar age required: 0.1 volt; peak power demand: 0.4 watt; weight: Dimensions: 43/4" x '/e" 121/2 ozs. 1 Weight: 4.5 ozs. BEYER M -160 Dynamic Ribbon BEYER M -61 b Ultra- directional Microphone ( Ultra-directional) Dynamic Microphone

An ultra -directional characteristic has now become The ideal microphone for theater and possible in a ribbon microphone. The warm night club sound systems, recording, transparent classical ribbon quality -in a mini- and remote broadcasting, as well aturized form, with response approaching as conference and musical re- near theoretical limits through miniaturi- cording for the advanced audio- zation of the vibrating system. Close phile. Its ultra -directional tolerances in manufacture assure characteristic discrimi- uniformity of characteristic be- nates against random, tween microphones, permitting M-160-$195.00 unwanted sound and paired use for Stereo. M-611)-46720 permits higher non - feedback output levels Directional characteristic: from public address Ultra- directional systems. Rejection ratio: 20 db Frequency response: 50- 16,000 cps - 2.5 db Sensitivity: Directional characteristic: Impedance: 50/200 ohms Overall response: 0.060 my /microbar Ultra- directional (high impedance on 20- 20,000 cps Dimensions: 11/2" x 6" Rejection ratio: 17 db special order) Impedance: 50/200 ohms Weight: 6 ozs. Frequency response: Sensitivity: 50-15,000 cps 0.200 my /microbar M -100 and M -160 microphones are plug -in and are supplied with mating receptacle and swivel microphone stand adapter coupling Dimensions: 13/4" x 43/4" for 5/8-27 thread. Velvet -lined jeweler's cases protect the units Weight: 6.5 ozs. when not in use. GOTHAM AUDIO CORPORATION

2 WEST 46 STREET. NEW YORK 36. N. Y. . . . COLUMBUS 5 -4111

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