TAPE GUIDE (June 1989)

Suitable Tapes for Hi-Fi VCRs

Q. I recently purchased a Hi-Fi VCR which will be used for audio as well as TV recording. Is it necessary to use tapes designated "Hi-Fi" for high-fidelity audio recording?

-Bill Dormer, Brooklyn, N.Y.

A. It is not necessary to buy VCR tapes labeled "Hi-Fi" for the purpose of high-fidelity audio recording. However, you should buy tapes of good to excellent quality in order to minimize dropouts and the consequent deleterious effect on the audio signal. Stay with the name brands for this reason and to avoid possible malfunctions.

Pause Mode

Q. Is there any harm in leaving a cassette deck in pause mode for a long period, such as one-half or even one hour? What is happening in the pause mode? Are any parts moving? Is the tape in contact with any moving parts? Is anything, including the tape, wearing out?

-Edward J. Gardyan, Melville, N.Y.

A. Leaving a tape deck in pause mode for about one-half to one hour is unlikely to do any harm. Usually, the capstan keeps turning in this mode, but the pressure roller and heads are moved away from the tape. On the other hand, it is probably inadvisable to leave a deck in pause mode for extremely prolonged periods of time because this contributes to the aging and eventual failure of electronic and mechanical components that remain switched on unnecessarily.

Mysterious Erasure

Q. In 1987, I purchased a new cassette deck and made about 150 recordings from phono discs, using high-quality tape. They sounded beautiful. Being aware of magnetism as an enemy of tapes, I stored them in a wooden wall rack--safely away, I thought, from metal, speakers, etc. But over the next couple of months, the tapes were all ruined because most of the sound was erased. I looked in the attic to see if anything of a magnetic nature was behind the wall. There was nothing of the sort. While a light switch is about 3 1/2 feet away, there are no electrical conduits behind the wall rack. A hot-water heater is behind the wall, several feet to one side of the rack. Could this, or a water pipe several feet away, affect the tapes? What about a hair dryer used in the next room and 4 to 5 feet away? What about the air-conditioning unit 10 feet away? A motorized wheel chair is never closer than 5 feet. What do you think could have erased my tapes? How far from a speaker, a TV, or a receiver should tapes be kept?

-Wally Dutko, Rolling Meadows, Ill.

A. From my own experience and from everything I have learned from authorities on the subject, about 3 inches is sufficient to protect tapes from all but the very most powerful magnetic fields, such as those produced by industrial lifting magnets. A distance of 1 foot provides ample margin of safety. Therefore, I am very puzzled by your experience. If you had a magnetometer (such as Model 20/B5, made by R. B. Annis Co., 1101 North Delaware St. Indianapolis, Ind. 46202), you could check for the presence of an unsuspected strong magnetic field where you store your tapes.

Does anyone besides yourself have access to your tapes? Has anyone been cleaning in close proximity with a hand-held vacuum? I don't seem to be able to come up with other possible explanations. Perhaps some Audio readers can suggest something.

Head Demise

Q. How can I tell when the heads in my tape deck are shot?

-Gary Salituri; Plattsburgh, N.Y.

A. Head failure is usually a matter of gradual deterioration, rather than sudden demise, and sound quality is the most common telltale for head wear. It is also likely that, if your deck has separate record and playback heads, the playback head will be the first to go.

The sign is a drop in treble response caused by widening of the gaps. However, poor treble in playback may be due to factors other than a wide gap.

The head may just need cleaning and/ or demagnetization, or it may only require azimuth adjustment. If heads appear substantially grooved by the tape, this may suggest the need for replacement, but performance is the true test.

If you can see the gaps of the playback or record/playback head with the naked eye, replacement time is here.

The sure way to check is with instruments that allow you to measure frequency response and distortion, provided the heads have first been cleaned, demagnetized, and azimuth aligned. In general, if your deck still appears capable of as faithful reproduction as ever, head replacement is not indicated.

Tape Deck Durability

Q. I am trying to choose among several tape decks-in good part, on the basis of which one will give me lasting good performance.

- Walter Tchuk, New York, N.Y.

A. One clue to durability is price; another is reputation. Perhaps the best clue may be obtained from service shops. They know which decks, relative to the number sold, come in most frequently for repair. Possibly you can contact an audio service technician and ask him to "open up."

Too Much Treble

Q. When comparing recorded material with the original, I notice a slight emphasis of the high frequencies, which leads me to believe that the bias is not correctly adjusted for the Type II tape I am using. The schematic diagram in the owner's manual shows a variable resistor in the bias circuit. Can this resistor be adjusted to obtain proper bias for my tape? Are any other changes necessary?

-Peter Smith, New Hope, Minn.

A. Yes, insufficient bias could be responsible for your excessive treble, and if you have correctly located the bias resistor, you can turn it slightly in the direction that increases bias. If the manual doesn't clearly indicate the proper direction, you will have to use trial and error. Carefully note the original setting of the resistor before adjusting it, so you can always get back to where you started, if necessary.

Factors other than bias could be responsible for your problem, though, including improper equalization in recording and/or playback. You may have chosen a tape which requires more bias than other Type II tapes.

(adapted from Audio magazine, June 1989; HERMAN BURSTEIN)

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