AUDIOCLINIC (Apr. 1992)

Fuzzy LP Sound: Distortion or Dirt?

Regarding your answer to the question about distortion on LPs in the September 1991 issue, I would like to add that I use Last liquid on really bad spots. Many a second-hand LP can be an important addition to your collection if it is washed properly. The stylus itself must be kept free of deposits, too, so it is very important to keep the records as clean as possible.

-R. D. Streeter; San Francisco, Cal.

Quartz-Locked Motor Problem

Q. My cassette deck has a quartz locked motor. When the equipment is first turned on, I have to press "Play" or "Play/Record" several times before the motor starts. The quartz-lock display fades in and out during this process.

Once the motor starts, I can listen or record a tape without interruption.

What is wrong? Why should the problem disappear after a time? Another factor I neglected to mention is that, even after the motor is warmed up and running, the quartz lock display is dimmer than it is when the drive mechanism is stopped. Fast forward and rewind work fine. I want to fix the problem myself, if possible. Otherwise, if my situation is hopeless, I will throw the machine out.

-Paul Dixon; Milwaukee, Wisc.

A. Whether we are talking about a cassette recorder or a phonograph, the problems are the same. There could be many reasons why your motor does not start to turn immediately.

Perhaps the motor needs some lubrication, or there may be drag from some other cause. Either problem can keep the motor from turning until a little heat builds up. A motor that is prevented from running will draw excessive current, which could lower the voltage.

This reduced voltage could affect the brightness of the display.

It may be that the motor is mechanically okay, but the voltage applied to it is low. After a warm-up, the motor can turn just a bit easier, and so it begins to run. Once up to speed, the lower voltage will be sufficient to keep it running at proper speed.

Maybe the crystal that controls the oscillator frequency is "lazy." It may take a few presses of the play button to set it oscillating.

Perhaps the IC which includes the oscillator is defective. If it draws too much current, it could produce a low voltage and prevent the motor from running as it should. This also will affect the brightness of the display. When the motor is stopped, the voltage returns to normal, and the display brightens. When it runs, the display dims.

Power-supply problems can also be a factor. These could include anything from a bad regulator or pass transistor to defective resistors.

(Source: Audio magazine, JOSEPH GIOVANELLI, Apr. 1992)

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