TAPE GUIDE (Apr. 1992)

Dolby NR Wobble

Q. I seem to have a problem with the Dolby circuit of my cassette deck.

Whenever I make a tape of a mono record with Dolby NR on and listen to playback through 'phones, the sound wobbles slightly from side to side. This happens with both Dolby B and C NR. However, when I make such a recording without NR, the sound does not wobble. I have taken my deck to two repair shops, and both told me there was nothing wrong with it. Would this problem be solved if I upgraded to a better deck? Or is this simply a phenomenon that occurs in all decks?

-Mark Bean; Montgomery, Ala.

A. I can say for sure that the phenomenon you describe does not occur in all decks. Feeding a mono source into my deck and listening through headphones, I could not duplicate the wobble you experience with either Dolby B or C NR. Voices and instruments remained centered. If your problem occurs only with Dolby NR on, the cause has to be in the Dolby circuit, quite likely due to mistracking.

If your deck works well in all other respects, I suggest that you live with it until another problem comes up. Then evaluate whether to put the cost of repair toward a better deck. In the meantime, if your system has a mono/ stereo switch, set the switch to mono mode.

The Squeak from Nowhere

Q. I was recently recording a CD onto tape. Suddenly, out of nowhere, a rather loud squeaking noise came from the cassette deck. At first I thought it might have been the tape itself, but I was wrong. I stopped the tape, replayed it, and heard the same squeaking noise. After waiting a while, I resumed recording. It went fine for about 10 minutes, and then the squeaking resumed. What's wrong?

-George Lin; Cincinnati, Ohio

A. If a squeak occurs at the same portion of the tape, the culprit has to be the tape. If the squeak occurs only with one particular cassette or one brand of cassette, the fault also lies with the tape. The cause might be insufficient lubricant in the tape coating.

Sometimes the cause of squeak is either the material of the cassette's pressure pad or the amount of pressure it applies. Excessive tension of the supply reel and/or take-up reel can also be responsible; as a deck warms up, things like reel tension tend to change somewhat. Or the cassette may not operate properly as it warms up. Hence a deck and cassette may initially operate satisfactorily but may manifest a problem after a while. Try to find brands and/or types of tape that work well. If none does, your deck apparently requires service.

(Source: Audio magazine, Apr. 1992, HERMAN BURSTEIN)

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