Tape Guide (Q and A) (Apr. 1970)

by HERMAN BURSTEIN

Cross-Field Heads

Q. I have been told that the cross field head has more distortion than the conventional type. Is this true? If so, do the advantages of the cross-field head outweigh its bad points?

-Richard Cleary, APO San Francisco, California.

A. To my knowledge, the cross-field head does not cause more distortion than does the conventional type of recording head. However, if this head uses insufficient bias in order to achieve extended treble response, then extra distortion would result.

Double Recording

Q. Would you be good enough to suggest a method whereby I could use two tape decks and an audio preamp so that I could record and play back from a common source. If this is not possible, is there a unit or circuit or perhaps a switching arrangement that could be used. Perhaps recording and playback from deck to deck could also be incorporated.

-J. Metz, Chicago, Illinois.

A. I assume that you want to be able to record into your two tape machines simultaneously; and that you want to be able to switch between either machine in playback. So far as recording goes, you might try a Y-connector between the tape recorder output jack of your audio pre amp and the inputs of your two tape machines. Such a connector is available for a relatively few cents from mail order houses. Inasmuch as the preamp's output impedance is usually low, while the input impedances of the tape recorders are usually quite high, there is a good chance that the two tape recorders will not interact so as to affect each other adversely.

Similarly, you might try a Y-connector between the outputs of the two tape machines and the tape input jack of the audio preamp. You would have to perform your switching between the two machines by means of each one's individual controls.

If the Y-connector does not work satisfactorily in playback, then you can go to a simple switching arrangement whereby you alternately connect the hot lead of each machine's output cable to the hot terminal of the pre amp's tape input jack. Alternatively, you could use one of the mixers on the market, feeding the output of the tape machines into the mixer, and the mixer output into the preamp's tape input jack.

Tape Storage

Q. What is the best way to store tapes? My tape machine has the automatic reverse function, which nine times out of ten means my tapes will be returned to their containers tightly wound. My tape machine has a tension selector that provides a setting for use with 1/2-mil tape. Would you advise my using the 1/2-mil setting?

-DuLaurence A. Miller; APO San Francisco, Calif.

A. The preferred way of storing is after operation in the normal operating mode (such as 7.5 or 3.75 ips) and tail out (last part of the recording at the outside of the hub). Accordingly, when you come around to playing the tape, you are obliged to rewind the tape, thereby relieving stresses that may have accumulated during storage. It is undesirable to store tape after fast wind or rewind, because of the stresses that build up during such winding. I would suggest following whatever instructions are supplied by the manufacturer with respect to tension setting, storage, and so on. He generally knows best, and the more reputable the manufacturer and his product, the most wisdom there is in following his instructions.

Using Earphones

Q. I have a ---- tape deck. When I record I find that I'm unable to monitor the tape with earphones.

As soon as I place the earphones in the tape deck, my VU meter stops registering. It seems as though the power is drawn to the earphones because I can't hear anything from my speakers. What might be the reason and what can I do?

-Martha Flack; APO, San Francisco, California.

A. It seems that the earphones are shorting out the playback signal. Apparently the source impedance of the tape recorder is a good deal higher than the loud impedance presented by the earphones. Have you tried using high-impedance earphones? Does your audio system amplifier provide a place for monitoring by earphones?

If I am correct that your earphones are of much too low impedance to be used satisfactorily with your tape recorder, and if you don't wish to buy new ones, you might be able to obtain an impedance-converting transformer to be used between the tape deck and the earphones. Consult electronic supply houses for an appropriate transformer. However, this might not be cheaper than buying new, high impedance earphones.

15 ips?

Q. I am considering the purchase of a tape deck for dubbing purposes. Would it be to my advantage to purchase a deck with 15-ips speed? I would use this deck only to record at lower speeds, probably 3.75 ips. Are 15-ips prerecorded tapes readily available?

-Robert B. Kellogg; APO 96312

A. I can't see any point in purchasing a 15-ips deck if you will not be using this speed, unless such a deck offers a quality of performance at lower speeds that you cannot find in other decks. I don't know of prerecorded tapes at 15 ips that are readily available. Prerecorded tapes are usually offered at 7.5 and 3.75 ips.

(Audio magazine, Apr. 1970; Herman Burstein)

= = = =