Tape Guide (Sept. 1982)

Head Demagnetization

Q. In demagnetizing tape heads, I wonder how important the speed of withdrawal is. If one withdraws the demagnetizer in only a few seconds rather than extremely slowly, will the heads still be demagnetized? How important is it to demagnetize the capstan? Does the deck need to be demagnetized after eight hours of operation or eight hours of recording? Do tape players (car or home) need to be demagnetized?

-Randy Webb; Pullman, Wash.

A. The advice typically given about withdrawing a demagnetizer slowly from the heads implies that this is done in a few seconds, say three to five. I doubt there would be any difference in the results if one took, say, 30 seconds.

Typically, one is advised to demagnetize all metal objects encountered by the tape, which includes heads, guides, mechanical filters, tension arms, the capstan, etc. If demagnetization is required, it should be done after about every eight hours of use, whether recording or playback. Tape players are not exempt.

Longer May Not Be Better

Q. I am presently using 90-minute tapes with my cassette deck, which can operate at 1 7/8 or 3 3/4 ips. Many retailers are discounting the 120-minute tapes because of warnings that these cassettes may cause a loss of fidelity and may strain the deck's motor. If I buy the C-120 cassettes, I would gain about 15 minutes of recording time when operating at 3 3/4 ips. Would I have the same problems with C-120 cassettes at 3 3/4 ips as at 1 7/8 ips?

-Donald McHugh; Brooklyn, N.Y.

A. Use of a C-120 cassette would be just as disadvantageous at 3 3/4 ips as at 1 7/8 ips. The disadvantages consist not only of possible motor strain but also of more dropouts and poorer signal-to-noise ratio due to the very thin oxide, greater distortion, and greater wow and flutter owing to susceptibility of the tape to stretching.

Obiter dicta: In view of the remarkable performance possible today at 1 7/8 ips with cassette, and the continuous improvements at that speed, I find myself in opposition to those who are promoting the use of cassettes at 3 3/4 ips.

As a result, persons like you find that recording time is cut in half and seek to compensate by using extra-thin tape, namely C-120. The net result tends to be that worse performance is obtained at 3 3/4 ips than at 1 7/8 ips. Not all change is progress.

The chief advantage of 3 3/4 ips over 1 7/8 ips is greater headroom in the treble range-that is, less tendency to saturate the tape when recording high-level treble frequencies. But this headroom can be substantially restored by such expedients as metal-particle tape, the Dolby HX system, and other noise-reduction systems (which signify that one can record at a lower level and avoid saturation, yet without deterioration in signal-to-noise ratio). Finally, let me point out that at least one manufacturer, Nakamichi, has gone in the opposite direction by bringing out a cassette deck which records at 15/16 ips in addition to the standard 1 7/8 ips.

Second-Hand Deck

Q. I plan to buy a cassette deck and am trying to make up my mind between two units. One is a new deck that sells for $258. The other is a used deck whose original price is substantially higher, but that is offered to me for $150. Which do you think is a better buy?

-Dan Scanlon; Detroit, Mich.

A. On general principle. I advise against buying a mechanical component on a second-hand basis because there is so much that may soon need replacement or repair--heads, belts, etc. New heads alone could cost in the vicinity of $150.

A Clunker?

Q. I have cassette tapes recorded off radio with a Panasonic deck. I want to transfer them to open-reel tapes using an Akai 1722. But no matter how I do it, there is always a "clunk" as I release the pause button on the Akai to start recording. Suggestions to eliminate this sound would be appreciated.

-Farrel Sveslosky; Long Beach, Cal.

A. Regretfully I cannot give you specific instructions for eliminating the "clunk" sound. This is a problem whose best solution tends to vary from one deck to another. Often the solution requires only an inexpensive capacitor, and perhaps a resistor too, wired into an appropriate part of the deck, usually across the pause switch. However, your wisest course is to contact the deck's manufacturer for the solution he thinks best. Or you can contact an authorized service shop for your deck. If the shop charges fair prices, the modification should not be expensive, but it is a good idea to ask for an estimate.

Metal Tapes for Open Reel?

Q. I would like to know if and when metal tape will become generally available for open-reel decks, and whether there will be a new generation of open reel decks that can meet the bias and other requirements of metal tape.

-Jim Boros; Euclid, Ohio.

A. As yet I have heard no reports that metal tape and metal-capable decks are to be available for the open reel format.

The benefits of metal tape tend to be more audible at the low tape speeds than at the high ones. Thus, metal tape finds a greater welcome in the cassette format with its 1 7/8 ips speed than in the open-reel format, where the speed is customarily 3 3/4 ips and upward. Inasmuch as metal tape costs substantially more than the other types (so far), few recordists would be willing to pay a premium price for a minimal improvement in recording quality. Furthermore, there have been improvements in ferric oxide and cobalt-modified (EE) tapes which have narrowed the performance gap between them and metal tape. So there is still less call for metal tape in the open-reel format.

On the other hand, some open-reel decks do provide a 1 7/8 ips speed and they could benefit somewhat from metal tape. If there are a substantial number of such decks, if the price of metal tape relative to other tapes continues to descend, and if makers of open-reel decks with the 1 7/8 ips speed are willing to make their machines metal ready, we might find metal tape available on open reel.

(adapted from Audio magazine, Sept. 1982; HERMAN BURSTEIN)

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