TAPE GUIDE (Feb. 1987)

Tape for "Oldies"

Q. I plan to record the "oldie" re cords which I have been collecting for about 25 years. What type of tape should I use? Some people say I should use metal-particle, and some say I shouldn't. At present, I use a good-quality Type II tape.

-Matthew Franco; West Hartford, Conn.

A. I suggest that you stay with Type II. You might even try a high-quality Type I (ferric-oxide) tape. The advantage of metal-particle tape, Type IV, lies principally in its ability to record extremely high frequencies, especially those of high amplitude, without loss or distortion when recording at a high level. This advantage is most apparent when recording live material or from such sources as Compact Discs.

On the other hand, the proof of the pudding is in the eating. You might invest in one Type IV cassette and judge for yourself whether the extra cost is warranted. Possibly your ears will detect a worthwhile difference, al though the odds are against this.

An Attack on the Tape

Q. Recently my cassette deck has developed a problem. On a number of tapes recorded at home, the audio quality had degraded significantly. On close inspection of the tapes, I found the tape surface covered with wrinkles and creases. The deck exhibits no operating difficulties such as jamming or stalling, yet the tape looks as if the pinch roller has attacked it. The deck is less than a year old, and tape-path components are kept very clean. What might be the problem?

-Zachary B. Freeman; Athens, Ill.

A. The cause of your problem could be the pressure roller or something else in the transport system, such as improper tape tension exerted by the hubs that drive the supply and take-up reels. The problem you describe might also be caused by a faulty pressure pad, but since that is part of the cassette and you are having trouble with many of your tapes, it wouldn't appear to be the cause here. A trip to a repair shop is indicated. Look for an authorized shop for your brand of deck.

Expansion or Compression?

Q. I plan to purchase a dbx noise-reduction unit and a dbx dynamic-range expander for use with my cassette deck. The dbx NR system claims to preserve the dynamic range of the source material. I can see the advantage of using dbx NR when making a tape from a good Compact Disc, be cause such a CD usually has a wider dynamic range than a conventional LP.

However, when I dub an LP onto a tape and use dbx NR, I can see that I would end up with the original narrow dynamic range of the record. The tuner/deck that I have in my car is equipped with dbx NR, but I cannot use a dynamic-range expander in the car. Thus, when I make tapes for play back in the car, I need to expand the dynamic range of the signal before it is fed into the dbx decoder. When re cording on my home deck, I plan to feed the signal from the turntable to the preamp, then to the expander, then to the dbx NR unit (for encoding), and then to the cassette deck.

Would this way of connecting the units work? Would the overall S/N ratio deteriorate? How much expansion should I apply to the source material?

-Kunio Mitsuma, State College, Pa.

A. I believe the arrangement you describe will work. However, to be on the safe side, you should have your audio dealer demonstrate this hookup.

I doubt that the overall S/N ratio would decline significantly, if at all. The desirable amount of range expansion will vary with the source material and your own listening preferences. However, I wonder whether dynamic-range expansion--which lowers the low-level sounds as well as raising the high-level sounds-is desirable in a car, at least with the motor going. The engine and road noise are apt to obscure the low level passages of the music unless you play at very high volume, which raises the problem of road safety. The latest (and the earliest) expander units made by dbx can also be set to compress dynamic range. This should be far more desirable when making tapes for the car, for it would limit the loss of low level information when playing at sensible volume while you drive.

(Source: Audio magazine, Feb. 1987, HERMAN BURSTEIN)

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