By LARRY KLEIN, Technical Editor
Belts, Wheels, Idlers, and Pucks
Q. Do you have any idea where I could buy a replacement drive belt for my old Gray turntable?
PETER GRAF
St. Louis, Mo.
Anyone seeking a replacement belt, idler, or drive wheel for an old record player or tape recorder will probably find it listed in the very comprehensive twenty-page reference catalog published by Projector Recorder Belt Corp. (Dept SR, 147 White water St., Box 176, Whitewater, Wisc. 53190.) The catalog costs $1, which is refunded with the first order.
For olde-tyme audiophiles like myself, the catalog is a tour down memory lane. I found listings for Fairchild, Gray, Rek-O-Kut, Sherwood, and Stromberg-Carlson turntables, and for Pentron and Magnecord tape recorders, among many others. And even if your cherished audio heirloom doesn't show up among the twenty pages of fine-print listings, all is not lost. The PRB Corporation offers to ex amine your old belt-if sent along with brand, model, and function information-and either supply a replacement from stock or make one up. Prices range from a low of $3 to a high of $11 (for the Stromberg-Carlson belt).
Showroom Speaker Evaluation
Q. It seems to me that in your August article on speaker myths you left out one important factor. Isn't it true that if you are auditioning speakers in the showroom you should make an effort to have the salesman play them with equipment that is comparable to that which you are going to use at home? Otherwise you will have no Way of knowing how they really are going to sound.
CHARLES BROCKWAY
New York City, N.Y.
A. I agree. There are two precautions to be observed: the most obvious one has to do with the amount of power the speakers will require to play as loud as you like in your own living room. Suppose, for example, you are impressed by the showroom sound of a pair of moderately inefficient speakers being driven by a 150-watt-per-channel power amplifier.
When you get the speakers home and connect them to your 40-watt-per-channel receiver, you are not likely to achieve the same quality of performance. The sound will probably not be quite as "clear," "crisp." or "open." and there will be some compression of the dynamic range. The differences won't be gross, but they will be apparent. In addition. if your room is substantially larger than the hi-fi showroom. you're going to need more power to achieve a given loudness.
Therefore, have speaker demonstrations done with the sort of musical material that you listen to most and have it played through equipment whose power ratings are similar to yours: then make mental allowances-if you can-for the difference in the size and acoustics of the showroom as compared to your listening room. As I said in the August issue. showroom listening, for more treasons than I've given above, is a chancy proposition at best. Don't make things more difficult for yourself than they have to be.
Tone-Controlled Taping
Isn't there another--and simpler--answer to the question about feeding a tone-controlled audio signal to a tape recorder printed in your June 1975 issue? In order to obtain tone control of the input to my cassette deck, I feed the front-channel head phone output of my receiver directly into the "aux" input of the cassette deck-as suggested to me by a radio technician. I can hear no difference between the cassette recordings I obtain by this method (other than the desired adjustment of highs and lows by the tone controls of the set) and those I obtain when using the normal tape output of the receiver.
I have also heard this set-up referred to as "the poor man's Do/by," inasmuch as one can turn up the treble control during taping from records or radio and roll it off a corresponding amount during playback. Seems to work, too, although I prefer the effect of the Dolby circuits built into my machine.
EDMUND W. OVERSTREET
San Diego, Calif.
A.
The technician's suggestion will work well-- sometimes. One potential difficulty comes about because the normal hum and noise that occur in amplifier circuits after the volume control is unaffected by the volume-control setting. Also. the relatively high input impedance of your cassette deck would eliminate any signal-attenuation effect of the headphone-jack resistors. Therefore, for lowest hum and noise, it is necessary to adjust the volume control of the receiver and the record-level control of the cassette deck simultaneously (one is turned up as the other is turned down) until you find the best relative position for each. Of course, the usual precautions regarding signal level as shown by the recorder's meters should be observed.
In regard to the "poor-man's Dolby" technique, this idea may have unfortunate consequences. Tape recorders, particularly cassette machines, tend to overload with strong high frequency signals. Therefore, boosting the highs before recording and cutting them back in playback may help the signal-to-noise ratio, but only at the risk of distortion and/or loss of highs through tape saturation. (The Dolby circuit avoids this problem by boosting only the "soft" rather than the loud high-frequency signals.)
Record-Jacket Mutilation Revisited
Over the years, it has become obvious that when I give a wrong or inadequate A. to someone's Q., my friends out there in readerland are going to tell me so-usually in large numbers. So, aware that I'm being closely monitored by experts in many different fields, I write this column in much the same way that porcupines are said to make love-that is, very carefully! Nevertheless, my reference sources sometimes stick me with a wrong answer which I innocently pass on-or they neglect to correct an error or mis-apprehension I originate. To avoid giving the impression that I'm a veritable font of misinformation, it is probably necessary to point out that, at worst, I give birth to an error no more often than every nine months or so.
Last June I innocently informed a Mr. Cardoni that the reason some record jackets have holes punched or corners cropped is to mark them as copies sent to reviewers. My answer wasn't really wrong, just myopic. Since most of the review albums that come to me have punched holes and cropped corners, I com mitted the error in logic of assuming that all punched and cropped jackets were therefore reviewer's copies. (My music-department associates here at the magazine, when I checked with them, did not quarrel with this conclusion.) The complete story, as about twenty or so interested readers hastened to inform me, is this: most of those mutilated tapes and discs are either "cutouts" or "over runs." A cutout is an item deleted from the catalog; an overrun is a disc the manufacturer overproduced-probably in anticipation of enormous sales that never materialized.
These discs are sold in bulk to retail outlets by wholesalers specializing in such merchandise at prices ranging from 50c to $1 or so. They are given identifying "mutilations" because, in general, the dealer cannot return them even if they are defective, and no one involved with the disc is supposed to either pay the normal price or make the normal profit. The same general story seems to be true of those tapes that have holes melted or punched through their boxes.
Incidentally, none of this has anything to do with those records which come with holes punched in their very centers. I suspect there's an entirely different reason for this, and I'm still checking. (See, I've learned not to jump to conclusions in these matters!) Because the number of questions we receive each month is greater than we can reply to individually, only those letters selected for use in this column can be answered.
Sorry!
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