...lie o ~free aóarei4 /%14- ./ FROM THE LINE MOST WIDELY USED BY PROFESSIONALS... I TO High- Fideli urntables for Home Installations PRESTO 7 -2 A crowning achievement in engineering design -the T -2 For over 20 years, Presto transcription turntables have two speed model offers superb high -fidelity- performance at been the choice of broadcast- station and sound- studio en- modest cost. Its heavy, balanced aluminum turntable and gineers. Today, more are in professional use than any rugged drive system eliminate wow. flutter and rumble. The make. interchangeable idler wheels disengage in the "off" position other to prevent flats. Heavy- duty. 4 -pole motor insures accurate Now, Presto offers the audiophile three precision turn- speeds. Shift mechanism permits quick change from 33's incorporating many of to 45 r.p.m. while table is spinning. Comes equipped with tables for high -fidelity installations, built -in strobe disc. 45 r.p.m. adapter. and rubber record the design features that have made our transcription turn- mat. Only $59.50 tables famous. See them at your local high- fidelity shop-or PRESTO T -18AH for full details and specifications, write for catalog to Undoubtedly the finest high -fidelity turntable for home use Dept. G12, Presto Recording Corp., Paramus, N. J. that money can buy-. Three speeds; precision -made through- out: wow, flutter and rumble are virtually non -existent. Employs 12 ", cast -aluminum turntable and constant -speed hysteresis motor. Speed selector has five positions: 45 oiT 33',4- off - 78. Only $1.77.nn PRESTO T-18A Has all the features of the T -18A11 (above) except that it 1 /P/n/ssr( TURNTABLES TAPE RECORDERS DISC RECORDERS is equipped with a heavy- duty. 4 -pole induction motor. Only $75.00 DISCS STYLI AND HIGH FIDELITY CABINETRY A SUBSIDIARY OF THE EIEDLER CORPORATION THE BRITISH INDUSTRIES MODEL 301 7 e P,rojeslCa «af" TRANSCRIPTION TURNTABLE 114,*!: q WORLD'S FINEST! A simple explanation of the thinking behind this great turntable! N any transcription turntable, there are two potential sources of c noise which produce the effect commonly termed "rumble'. These are the motor ... and the spindle on which the turntable itself re- volves. Since any turntable and motor rotate on bearings which create heat and noise, the problem is to reduce the noise to a point of in- o audibility, first by minimizing the source and then by isolating it. The motor used in the Garrard Model 301 is a precision -engineered, dynamically -balanced 4 -pole unit, encased in a heavy die -cast frame. o Designed by Garrard, it is also built in Garrard's own plant. This guarantees its quality. However, in any motor, some vibration may be evident. Therefore, the 301 motor is completely isolated from the I unit plate, suspended by three tension and three compression springs, so that it is actually isolated in a 360° sphere. This method of sus - I pension is unique, and it is one major reason why the Garrard 301 is I so remarkably free of vibration. In addition, the one lever which connects the motor to the unit plate (the speed control lever) is also ingeniously suspended within three springs, rather than by using a conventional bushing or pivot. The Garrard 301 is the only unit wherein the motor is entirely suspended by springs from ever) lever and even from the unit frame itself! (OVER The ìui turntable weighs a full 61/2 lbs. and it is made of precision - machined cast aluminum. Being heavy and dynamically balanced as well, it imparts flywheel action, which tends to override a variation in speed. The all- important turntable spindle is polished to mirror finish. This minimizes any turning noise. Then, by setting the spindle in a die - cast housing which is completely filled with a special lubricant under pressure, even that minimum of noise which remains is isolated and prevented from reaching the turntable or unit plate. This, in turn. also prevents vibration from reaching the pickup. In order to insure that the spindle is at all times under the influence of strong damping pressure, a reservoir for the lubricant is built into the housing. By simply turning a knurled knob, a new supply of WIMP'grease is forced into the housing whenever required. Another 301 feature is the method of setting the precise speed. After the major speed selection has been made, a control knob on the top of the unit can provide an addi- tional 21/2% variation, plus or minus. This magnetic speed control operates as an eddy current brake. Two permanent magnets are set on either side of a rotating disc, which is attached to the motor arma- ture. By increasing or decreasing the distance of the magnets from the center of the discs, the field strength of the magnets is varied and reflects in the speed of the motor. The eddy current method of control is instantaneous, precise, permanent and fool -proof. The wow, flutter and rumble specifications of the 301 are well below those required by the NARTB. The 301 was developed in conjunction with the highly critical British Broadcasting Corporation, and it is used in their broadcasting work. This great product meets all the qualifications which are desirable in a turntable. It is quiet, precise, rugged and proven through count- ,1.,u less hours of use under the most ^ » ^ r "'" arduous conditions. The performance of every Garrard t - r- 301 unit is checked exhaustively _.. by the factory and appears on an 1 individual test card supplied to the purchaser. For literature write Dept. 6X17S. GARRARD SALES CORPORATION PORT WASHINGTON, N. V. DECEMBER, 1957 VOL. 41, \.,. Successor to RADIO, Est. 1917. for Ultimate Fidelity AU D Io 1.Nr :INF.F.RINC. MUSIC SOUND REPRODUCTIO, C. G. McProud, Editor and Publish.. Henry A. Schober, Business Manager Barrie K. Richardson, Associate Editor Marie Caspe. tssistant Editor outatandin9 hon- M. Durgin, Production ora bestowed, un Janet Manager soil:ited, by most recconixed testing Edgar E. Newman, Circulation Director or lenirations. Sanford L. Cahn, Advertising Director Special Representative - H. Thorpe Covington, 814 Lincoln St., Evanston, Ill., DAvis 8-8874 .01 Mid West Representative - Sanford R. Cowan, 300 W. 43rd St., INC' New York 36, N. Y. West Coast Representative - James C. Galloway 6535 Wilshire Boulevard, Los Angeles 48, Cali!. CONTENTS No matter what your source of music Atuliocliitie-Joseph Giornaclli -FM, your own discs, or tape -you Letters _ 6 will enjoy it at its best coming from Sherwood's complete home About lnsir -I! troi/ Low re rnee 12 music center ... most honored of them a l!Sherwood Coming Events 14 tuners for example .. Editor', Review . 16 The Stereo Recorder -.\ Recitation and an Education-Joseph E. /'re,I,, 14 First to achieve under one microvolt Ilote To Platt Your Ili -1'i System -C. R. T'ie,i,no 2-1 sensitivity for 20 db FM quieting in- creases station range to over 100 miles. Lnpcdanee und Feedback iii . \tulio Circuits -I1, rfun li,u.4ei :nid Mens'', C. /'allok 26 Other important features include the new "Feather -Ray" tuning eye, auto- The Sad of a \Watt Resistor lase Ilall'- - Walther Birbl, r :Ili matic frequency control, flywheel tun- Loudness, Its Definition, Measurement and Calculation, l'art II- 11arref ing output level control aid cathode - Fletcher and W. .1. Manson tll follower output. 1:lfaipuunt Review -//W,u ¡,real /, mol llrn,dI ;it III, (,.nerd' /sleelrie CR-I/. and traa..eriptirn, 511 Fairchild I,,rut,,hlr arm. the Garrard line Model S -2000 FM -AM Tuner S139.50 net 1(ee ird Revue -Edward Tatwall ('ant l 56 Model S-3000 FM (only) Tuner S99.S0 net Audio ETC- Kelward Tat null Canby 112 New Literature 69 For complete specifications, write De. t. Jazz and All That- ('hdrl,:. .1. Bob, it ,on 711 New Products 7, SHERWOOD Industry Notes and Peuple 93 ELECTRONIC LABORATORIES. INC. Annual Indes 94 2802 West Cullom Avenue, Chicago 18, Illinois Advertising Indes 96 COVER I'!I()'l'O Prout "Down Muter colors this attlaeticc nrrallnlcut ereate,l The "complete high fidelity home music center." by : \. E. II i -don '.1 IIavili n \ 'Wright. Ltd., Radio & . \udiu I :ngincers, of I \ "ietoria Slrel t \Weir, . \nckl:nul, N. Z. The equipment consists of a Philips . \I tuner, 1'\c :naiIliicr. I ;:nrard changer with 'l'anuov cartridge, a Tauuuv lai' dual 1L9 ('oneeutrie speaker ton opposite wall) and a Philips tarp. recorder- removable for pmtable use. 'Plie taule trame at the lover right. ventilates the rupin amplifier. AUDIO trifle registered It. S. Pat. 00.1 Is published monthly by Radio Magazines. Inc., henry A. Schober, President: 11 C. G. Merroltd, Secretary. Executive and Editorial Offices. 204 Front St., Mineola, N. Y. Suhsrription rate -U. S. Possessions, Canada and Mexico. $4.00 for one year. $7.00 for two years, all other countries. $5.00 per year. Single copies 50C. Printed in U. S. A. at Lancaster. Pa. All rights reserved. Entire contents copyright 1957 by Radio Magazines, In Ne.,, York hear "Accent on Sound" with Sklp Weshner, WBAI -FM, week nights, P.M. In inc. Entered as Seeond Class Matter February 9, 1950 at the Post Office. Lancaster. Pa. under the Act of March 3. 1879, 9 Loa Angeles. NRHMFM, 10 P. M. RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y. AUDIO DECEMBER. 1957 1 AUDIOCLINIC ?? JOSEPH GIOVANELLI Note: One of the results of the al Ono. :oplitiers as ti. scribed, be sure that the recent high fidelity shows is that we have amplifiers are identical. Should one have gained numerous new subscribers. For one more stage than the other, the output James Melton their benefit, let me state that it is the signals would be 180 deg.