TAPE GUIDE (Apr. 1988)

Wow Woes

Q. I do a lot of taping of phono records using a moderate-price cassette deck and moderate-price cassettes. At times I have encountered wow. Sometimes it disappears after I put the tape through fast wind and rewind; at other times the cassette mechanism will begin to click, and occasionally the auto-stop mechanism will bring the tape to a halt. What's the problem?

-Stephen A. Leslie; Philadelphia, Pa.

A. For all its seeming simplicity, a cassette is a very sophisticated mechanism, requiring excellent design, top-quality internal components (such as high-grade slip sheets to permit smooth travel of the tape), and very accurate alignment (such as that of the guide pins, which must be almost perfectly vertical) in order to achieve high quality performance. And the tape itself, of course, must have all of the appropriate physical as well as magnetic properties.

Perhaps by running the cassette at fast speed you are loosening up the tape and the moving parts in the shell, thus improving performance with respect to wow; there may be similar improvement in the deck itself. I suggest that you try several well-known cassette brands whose reputations are excellent in order to determine which ones give better physical performance. If this doesn't help, the problem lies in your deck, and you will need to visit a competent service shop.

Print-Through Protection

Q. If I record a cassette tape in just one direction, in order to avoid print through, is it still necessary to leave the tape in the "tail out" position when storing it? If so, why?

-Monte Kim; Reedley, Cal.

A. Print-through occurs between adjacent layers of tape on a reel, not between adjacent tracks. Therefore, recording a cassette in only one direction will not prevent print-through.

Leaving a tape in the tail-out position-that is, not rewound after recording-tends to produce post-echo, which is a faint repetition of the original sound. Leaving the tape "head out," in ready-to-play position, tends to produce pre-echo, which is a faint forerunner of the original signal. Post-echo tends to be less annoying than pre echo. Therefore, in the case of a tape recorded in one direction, it is usually advisable to store the tape tail out.

Moreover, when it comes time to play the tape, the act of rewinding prior to playback tends to reduce the print through somewhat.

Give It a Smack

Q. Over the past year, I have been experiencing intermittent problems with left-channel dropout. Sometimes the left channel will be as much as 10 to 20 dB below the right channel; at other times it will drop out altogether.

My temporary, although occasionally long-lasting, solution is to forcefully strike the right side of the deck with my hand. This lowers my frustration level and raises the left channel's level. What is the cause?

-Stuart Zimmerman; Solana Beach, Cal.

A. There is probably a poor connection, perhaps due to improper soldering, in the left-channel circuitry. There may also be a defective part, such as a resistor, or perhaps there is dirt in the wiper of a level control. You need the help of a qualified service technician.

Recording Music at 3 3/4 ips

Q. I have a problem with my open reel deck, although it is only two years old. At the 3 3/4-ips speed, it is totally unsuitable for music reproduction. At 7 1/2 rips, music reproduction is fine, but this offers practically no advantage in recording time over cassette when using 1-mil tape on 7-inch reels.

-Saverio Giordano; Hoffman Estates, Ill.

A. A good modern open-reel tape deck should be able to provide very good reproduction at 3 3/4 ips, with frequency response about as good as that of a cassette deck and with somewhat better performance in such respects as distortion, headroom (freedom from tape saturation), modulation noise, etc. It appears that your deck isn't performing up to specifications and should be brought to a service shop. It may have such problems as incorrect bias, improper azimuth alignment, a widened gap in the playback head, or faulty equalization.

At 7 1/2 ips, recording quality should be far superior to that of a cassette tape. You are right, however, in saying there's no advantage in recording time at that speed. At ips, a-inch reel of 1 1/2-mil tape will play for 32 minutes per side, versus 30 minutes per side for a C-60 cassette; a reel of 1-mil tape will play for 48 minutes per side as opposed to the 45 minutes per side of a C-90. In practice, a few seconds' worth of tape will be used as leader, making the reel's recording-time advantage over cassette even smaller. At 3 3/4 ips, of course, recording times would be doubled.

Connections

Q. I want to connect my FM/long/ medium/shortwave receiver, which includes output jacks for a tape deck, to my tape recorder, which has microphone input jacks. How can I connect these to record from radio?

-Jonathan Taylor; Tulsa, Okla.

A. Chances are that if you connect the tape output of your receiver directly to the mike input of your tape deck, the deck will be overloaded, resulting in severe distortion and possibly in serious aberrations in frequency response. The solution is to interpose in line attenuators between your receiver outputs and tape deck inputs. Check with your local audio shop as to what they have in the way of such an item.

Radio Shack has what it calls a "signal reducer," selling for just a few dollars each, that might solve your problem. It is Model 274-300. Of course, you will need two, one for each channel. This item provides about 40 dB of signal attenuation, which might be too much.

If so, you'll have to look for devices with less attenuation.

Distortion S.O.S.

Q. I am getting a lot of distortion when taping. Please advise.

-W. H. Martina; Emmastad, Curacao.

A. There are a number of possible causes: Insufficient bias current fed to the record head, excessively high record level, faulty heads, defective parts in the record or playback amplifier of the deck, or a fault in the component to which the deck is connected.

You will need the help of a service technician to root out the cause.

(Source: Audio magazine, Apr. 1988, HERMAN BURSTEIN)

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