TAPE GUIDE (Jan. 1985)

Trading Up

Q. I own a three-head, direct-drive cassette deck, about three years old, which is loaded with features. Its frequency response is specified as 25 Hz to 21 kHz with metal tape. The meters go to +8 dB. Signal-to-noise ratio is 67 dB with Dolby B NR. The deck makes fairly good tapes, but the solenoids are noisy, as they have been ever since the deck was new.

I have been looking at a deck made by another manufacturer. Its frequency response is specified as 20 Hz to 24 kHz with any tape. It has three heads, Dolby C NR, HX Pro, dual-capstan drive, twin flywheels, fader control, meters that go to + 10 dB, a switch to prevent overloading the tape, and silent solenoids. Should I trade up to the new deck? Will it make better tapes and sound better? I play mostly rock music at about +3 dB.

-John De Rosa; Mattapan, Mass.

A. Apart from the fact that you failed to give the signal-to-noise specification for the new deck you are contemplating, it appears that both decks provide very good performance. With Dolby C NR, the new deck probably has S/N in the mid-70s or so, and, with HX Pro, it is more immune to tape saturation and consequent treble loss. In sum, the new deck probably measures better than the old one.

On the other hand, this doesn't necessarily mean that its audible performance will be superior. For example, if you listen to rock music, which ordinarily has rather limited dynamic range, the superiority in S/N may not be audible. You really have to base your decision on listening to both decks. If the new one is clearly better to your ears, it becomes a candidate for purchase.

Awkward Starts

Q. On playing one of my cassettes I heard the kind of intermittent and distorted sound that is usually made by a very defective phono cartridge. I'm sure the culprit is the cassette. I found that some of the coating was missing, enough so that one could see through the edge of the tape for the first 20 feet, after which all seemed normal; that is, the tape then looked and behaved fine.

I checked a number of other cassettes and found that most of them played back with some distortion at the start--for about the first minute--and then settled down to proper behavior. What is causing this? Is the tape stale? Is the deck's take-up tension too great? Is the tape stretched at the end of rewind?

-Leo D. Dulberger; Staten Island, N.Y.

A. Of course, if parts of the magnetic coating on the tape are worn thin or worn completely, this would cause intermittent and distorted sound. Good tape, however, should be able to go through several hundred passes before reaching this condition. In many cassettes, the way the tape is attached to the hub leaves a slight bump in the tape pack at each end. This may cause problems in the first moments of use. In most cassette decks, the tape is held against the head by the pressure pad built into the cassette; in a few decks, the pressure is exerted by tape tension. I have no way of knowing whether pressure is excessive in your case. Rewind and fast forward are usually slow and gentle enough not to cause stretching of the cassette tape.

If you experience problems with cassette tapes of high quality, it would be advisable to have your deck checked by a qualified service shop.

Snap, Crackle, and Pop

Q. I recently purchased a high-quality cassette deck in order to tape my records, but I have a common problem--"snap, crackle, and pop" when playing the discs. I've had the experience of playing side one of a disc without cleaning anything but the stylus, and having the disc sound fine.

Then, when I played side two, this produced the familiar "SC&P." My records are 5 to 10 years old but have been played only once or twice. I use a recommended record cleaner, which I apply before playing a record. I have also washed the records with water and have tried using compressed air, but to no effect. How can I get rid of this problem?

-Julius I. Levin; Glencoe, Ill.

A. The snap, crackle, and pop may be recorded in the grooves, in which case you can do nothing with the record itself. However, you can buy a click and pop filter, such as that made by SAE. Or, the SC&P may be due to foreign material in the grooves, possibly there because of static attraction.

Several devices deal with static, such as the anti-static mats and anti-static sleeves made by various companies, the Zerostat instrument sold by Disc washer, and those Shure phono cartridges which come with a special brush that both reduces low-frequency resonance and combats static. See what your local audio dealers have.

(Editor's Note: If Mr. Levin has this problem far more often on side two than side one of a record, the problem might be dirt in his turntable mat, against which side two presses while side one is playing. -I.B.)

Slow Tape Speed

Q. I am dissatisfied with my tape deck because the speed is slow. Do you have any information or advice on what I should do?

-Anthony J. Lauria; Copiague, N.Y.

A. Seldom is a tape deck exactly accurate in speed. Good decks usually are within about 0.5% of correct speed, and very few human ears can detect such an error. Keep in mind that a semi-tone represents about 6% deviation in pitch; this may help you appreciate what a small deviation is represented by only 0.5% departure from correct speed.

If your deck is substantially more than 0.5% off speed, you are probably entitled to have something done about it. The first step is to make sure of your grounds by having the speed checked by your audio dealer or an authorized service shop. (Your dealer or the manufacturer can provide the names of the nearest authorized shops, which can make such repairs as are warranted.) On the other hand, how do you know your deck is slow? If its speed varies, there is definitely something wrong with it. But any tape's speed will sound correct if it is played back on the same deck it was recorded on. If tapes made on another deck sound slow, the problem may be that the deck which made the recording was too fast. If tapes made on several other decks sound slow, then it's usually safe to assume the problem is in your deck.

Choice of Tape Type

Q. I recently purchased my first cassette deck and am having trouble deciding which tape to use. I found a Type I that was particularly great and compared it with a well-known Type II tape, which sounded dull in comparison. However, another Type II sounded real close to the Type I. Thus, my question is about the quality of Type I (ferric oxide) versus Type II (chromium dioxide or ferricobalt). To my ears, the Type I and Type II tapes that I tried appeared to have equally low noise levels. In the long run, would I be better off with Type II even though the Type I that I tried has an audible edge over the others?

-David E. Fincher; Knoxville, Tenn.

A. Although at one time it appeared that Type I tapes would be significantly outdistanced by the other types, the Type I tapes have nevertheless kept improving so that the margin between them and Type II tapes remains scanty. In fact, it appears that Type I often has an advantage over Type II with respect to low distortion.

Tape decks with fixed bias and equalization settings for the several tape types can offer only an approximation of correct bias and equalization, which differ somewhat from one tape brand to another. Therefore, the usual advice is to try several brands and types of tape and settle for the one that works best with one's deck. In your case, it appears that a particular brand of Type I tape works best, and I can see no good reason not to stay with it. (Of course, decks which automatically match the tape's bias, equalization, and sensitivity requirements tend to give their best performance with a wider range of tapes.)

Bells, Whistles and Cassettes

Q. With all due respect to the vast improvements in cassette technology, I'm not holding my breath waiting for the ultimate cassette deck. The supposed advantages over open-reel usually turn out to be a battle of the bells and a war of the whistles, while more basic functions and necessities have been neglected.

Why can't a C-60 cassette be fast wound from end to end in 60 S or less? Sometimes, I'd rather be flipping a scratchy record.

Why must we suffer the lack of fidelity inherent in the dismally slow 1 1/4-ips speed? Hanging on to this instead of 3 3/4 makes distortion the rule rather than the exception, technology moving three steps backward. Philips imposed stringent cassette mandates and ruled out the fast speed, while the promising Elcaset was promptly removed from the market.

As far as I'm concerned, Dolby NR colors the sound. No tape subjected to Dolby or any other NR system sounds as true as a straight recorded tape.

And HX Pro causes high-end distortion in metal tapes, which were intended to minimize such distortion.

In my opinion, the only true advances in cassette decks have been solenoid, feather-touch controls, asymmetrically diffused capstans, and perhaps introduction of three heads instead of two. Everything else is pure gimmickry, and mostly junk.

-Paul C. Macaluso; Phoenix, Ariz.

A. While I do not totally disagree with you, for the most part I do not agree. I think you may have a point in deploring the emphasis on bells and whistles instead of good performance-wide and flat frequency response, low noise, low distortion, and steady and accurate speed.

On the other hand, I feel that the top-quality cassette decks have achieved something very close to true high-fidelity performance. I do not know what decks you have been listening to, but there are several which have elicited very favorable reviews in terms of basic performance.

Fast wind and rewind speeds are deliberately kept moderate in order to obtain smooth wind and avoid undue tape stress. I believe that some decks do take less than 60 S for a C-60. The 3 3/4-ips cassette deck disappeared for at least two reasons other than pressure from Philips. First, it provided too little recording time, except on C-120 tape, which is extremely thin and makes good results difficult to achieve. Second, steady improvements in the state of the art with respect to tapes and decks have made it possible to deliver performance at 1 7/8 ips which previously could be had only at 33 ips. The Elcaset also disappeared for that reason and because there was too little market for it.

I have had extremely few complaints from readers--perhaps two in the last five years--about coloration or other audible effects due to noise-reduction systems. I have no trouble with them, and colleagues with greater hearing and musical sensitivity than mine on the whole seem satisfied. This is not to deny that side effects are caused by NR systems, but such side effects appear to have been tamed to the extent that very few listeners can detect them and find them objectionable.

Quality Complaint

Q. The quality of prerecorded cassettes is bad because of poor quality shells, poor quality tape, slow speed in playback, high duplicating speed, and azimuth and zenith mismatch. Will the same problems occur with open-reel decks? I have a source of prerecorded open-reel tapes, and I would like to know the score before buying an open reel deck.

-Robert B. Mugrdechian, Ridgefield Park, N.J.

A. In every respect-frequency response, noise, distortion, wow and flutter, etc.--performance tends to improve as tape speed increases. Therefore, if you intend going from 1 7/8 ips cassette to 7 1/2 ips open-reel, this should bring a definite improvement.

For example, consider the results of azimuth misalignment. A 12-minute error, which produces a loss of nearly 8 dB at 15 kHz at 1 7/8 ips, causes a loss of only slightly over 1 dB at 7 1/2 ips.

On the other hand, I can't promise that prerecorded open-reel tapes will be good enough to suit you. They, too, have their duplicating problems for reasons the same as, or similar to, those you have listed. I suggest that you borrow or buy a prerecorded open-reel tape and listen to it on open reel decks at an audio store in your area--then make your decision.

Not all prerecorded cassettes are as bad as you describe. Some of their purveyors are trying to do a conscientious job, and the number of these appears to be on the increase. Watch the reviews in audio periodicals to see which one might be worth buying. Be prepared to pay more for tapes of better quality, particularly those duplicated on a real-time basis, that is, duplicated at 1 7/8 ips instead of a speed much, much faster.

(Source: Audio magazine, Jan. 1985, HERMAN BURSTEIN)

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