CHICAGO SUN-TIMES, Sunday, October 11, 1987                                         Page 37

The HOME Advisor

Re-equalizer quiets

scratchy old records

By Al Fasoldt

Newhouse News Service

Playing music on disc or tape could hardly be easier these days. All you need to do is pop a cassette or Compact Disc into a player and turn up the volume. The result is fuss-free hi-fi.

But those who love to listen to old recordings have a hard time of it. First, most old phonograph records are fragile and easily scratched or marred. Second, their sound quality is often marginal.

But the biggest problem in playing old discs is the guesswork involved. Old records-especially early ?8s-usually don't sound right unless a lot of fiddling is done with the bass and treble controls. Even then, the result is sometimes unsatisfactory.

This comes about because discs that were recorded before the mid-1950s used a variety of different standards for sound equalization. Some sort of EQ, as it is called, is needed for all phonograph records because of the difficulty in getting both low frequencies and high frequencies into the same groove.

Basically, the lows have to be tamed in recording so they don't literally wiggle right out of the groove, and the highs have to be boosted so they can be distinguished from the scratchy groove noise. In playback, the opposite treatment is necessary, with the lows boosted and the highs cut back-a simple matter as long as the same kind of circuit is used in playback as in the recording.

That's just the problem- in playing old discs-the circuits and EQ settings used in those days were usually entirely different from what we use today. One recording company might have boosted the high frequencies by a large degree, and another might have done it only to a small extent. Still another might have cut back the low frequencies greatly, while a competitor might have left them mostly alone.

To collectors of old records, the answer to this dilemma has generally been to play with the tone controls on the amplifier and take a guess at what sounds best. But the hit-or miss approach is no longer necessary, thanks to a device from a small company called Esoteric Sound (4813 Wallbank Ave., Downers Grove 60515). (NOTE OLD ADDRESS!)

The firm's little miracle is called the Re-equalizer. It looks like a simple tone equalizer, with only two knobs and a "bypass" switch, used for canceling the knob settings.

The Re-equalizer provides a choice of preset equalization curves for nearly all old records. These pre-sets can be used in a guess-what-sounds-best fashion, but they are best used if you look up the record you are playing in a chart supplied with the owner's manual.

The chart lists the recommended knob positions for recordings in each of 140 different categories, even listing different settings for discs from the same company issued only a year apart. Because each knob has six possible positions, there are 36 different equalization settings-enough for nearly every situation.

On the test bench, I checked the Re-equalizer's circuitry and found that it met modern hi-fi standards in both inherent noise level and over-all frequency response. I also checked the various EQ settings, which

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