TAPE GUIDE (Sept. 1990)

Parts and Repairs for Old Decks

I've recently received two queries from readers who have old tape decks in need of parts or repair, so perhaps it is time to repeat some recommendations I've given in the past: For drive belts and pinch rollers, try Projector-Recorder Belt Corp., Box 176, Route 3, Highway 59, Whitewater, Wisc. 53190. For decks or other old equipment requiring other parts or service, help may be available from Acoustatronic Laboratories, which specializes in renovating and modifying old, high-quality audio components. Their address is 140-11A Cherry Ave., Flushing, N.Y. 11355.

Playing Old Tapes

Q. I have a considerable number of recorded cassettes that have not been touched for years and am wondering about their condition. Would the tape layers bond together? Would the oxide chip off? Can you recommend any steps for preservation of my collection?

- Tyler Roberge; Prince Edward Island, Canada

A. If your long-stored cassettes have not been subjected to extremes of heat or cold or humidity, chances are that they will perform satisfactorily.

It is unlikely that the tape layers have bonded or that the oxide has flaked.

However, the tapes may have acquired a physical set as well as developed print-through. Therefore, it is advisable that prior to using them again you put them through fast-wind and rewind or, better yet, operate them in both directions at normal operating speed. For proper protection of a collection, cassettes should be stored on end, kept away from extremes of temperature and humidity, and wound and rewound at least once a year.

Double Trouble

Q. In the past five years, I have experienced the same problem with two cassette decks made by different manufacturers. When recording, all appears normal. During playback, there is static, and the deck's meter display is erratic; sometimes, one channel drops out completely and then pops in again. In the case of one of the decks, pressing hard on some of the buttons causes the static to start and to disappear; probably pressure on the buttons is causing the circuit board to flex. The tapes sound fine when played on other decks. I haven't taken either of my cassette decks to a repair shop because the problem is intermittent and because I have had a few bad experiences with the repair shops in my town.

-Chris Pillar; Anchorage, Alaska

A. Apparently, the long arm of coincidence has reached you. My best guess is that there is poor soldering somewhere in the playback circuit or a hairline break in a circuit-board connection. If you are up to this kind of thing, you might visually check the playback circuit board for poor solder joints, which are usually dull and grayish instead of bright and shiny, and resolder them. If you see nothing, you might carefully go over all the solder connections in the hope that they are causing the problem. A magnifying glass might help you find hairline breaks.

Binaural Miking

Q. In the March 1986 issue of Audio, an article on the history of binaural recording suggests putting two omni mikes on stands 7 inches apart with a quarter-inch-thick, 4 x 6-inch board between them. Wouldn't you get just mono sound with the mikes so close together? As one mike disappears behind the board when the sound source moves left or right, wouldn't the board chop some frequencies more than others?

-Ken Thorberg; Duluth, Minn.

A. The spacing between the two mikes and the board between them are intended to simulate a human head and ears. This will not result in mono sound; it will result in binaural sound, intended to be heard through earphones, with (approximately and hopefully) the same perception of width, depth, and location of sound as human hearing provides. Yes, the board will "chop" some frequencies as the sound comes well from the left or right. But this is the same effect as caused by the human head.

(Source: Audio magazine, Sept. 1990, HERMAN BURSTEIN)

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