Box 392: Letters to the Editor (Vol.2, No.2: 1979)

Letters from manufacturers in response to our reviews or to other comments about their equipment are usually published unabridged and unedited in this column. So is the correspondence of audio professionals on specific technical, musical or philosophical subjects. Letters of general interest from readers may or may not be excerpted, at the discretion of the Editor. Ellipsis (...) indicates omission. Address all editorial correspondence to The Editor, The Audio Critic, Box 392, Bronxville, New York 10708.

Again, we open with the letters on what appears to have become the trademark topic of The Audio Critic, phono pickup tracking geometry.

The Audio Critic:

I was amused to read your derogatory reply to my letter in your Winter/Spring 1979 issue. You are quite correct when you state that tracking error at the outer groove is irrelevant, and it is | agree within limits of little importance.

However, | have to advise you that the amount of overhang adjustment available in our headshell means that a cartridge can be aligned for zero error at various distances from the turntable spindle, including your quoted one. We specify 63.500 mm in our setting up instructions, as it happens to be the correct distance for minimum distortion due to lateral tracking error optimized for 12°" discs. Our figure can be found in articles by J.K. Stevenson, Wireless World, May and June 1966. To the best of our knowledge Stevenson's work is the definitive one on tonearm geometry, and the articles also refer to Baerwald's much earlier 1941 JSMPE work. The difference between your figure and ours is of little importance and is due purely to the variations of the discs. You have chosen to specify the 'representative' inner design value whilst our 'minimum' design value obtained from measurements by Stevenson on a batch of records of different makes and different types of music covers all extreme distances in exceptional cases as well, therefore we suggest that our figure is to be preferred.

Finally out offset angle is within the correct range specified by Stevenson.

Sincerely, Gerald Bearman Director Mayware Ltd.

(Formula 4) England

1. Our reply was not derogatory by any standard; it was a simple recitation of facts which you apparently found un comfortable.

2. What we called irrelevant was not tracking error at the outer groove but your question about it. Tracking error is highly relevant at all points across the record and is predetermined by the laws of geometry.

3. There is no discrepancy among the serious writers on the subject of lateral tracking error (Lofgren, Baerwald, Bauer, Seagrave, Stevenson or anyone else) as to the basic geometrical problem and its proper solution. Thus there is no definitive work on the subject in the sense that one is more correct than any of the others, although Baerwald's paper almost completely pre empts the available analyses.

4. As long as the correct mathematical understanding is applied, the only differences that can arise are due, as you your self suggest, to the chosen maximum and minimum radii of the record between which lateral tracking is to be optimized. What you conveniently forget to mention, however, is that in modern recording practice these two radii are defined by the IEC Standard for 12-inch LP records. The alignment tables published by The Audio Critic show the correct figures obtained when this standard is adhered to-as it is by all professional record makers today-whereas your figures are then incorrect.

5. As we've pointed out once before, messing with the alignment values to obtain a compromise for a broader range of records than just the standard LP' s will result in considerably increased distortion on the latter, which after all represent the bulk of any serious audiophile's collection.

-Ed.

The Audio Critic:

Thank you for printing my further letter about the careful use of language in your Winter/Spring 1979 issue. I was rather touched to see you donning Columbo's clothes in order to place a charge of 'first degree intellectual weaseling', but if that delightful bumbling detective had indeed attempted to arrest me on the suspicion that I had not really studied Baerwald, Bauer, Woodward and Cooper, I would have referred him to the Library of Congress-where | trust they keep back copies of Hi-Fi News.

In the course of a series of six articles entitled 'Pickup Problems', spanning December 1962 to May 1963, I had occasion to quote the Baerwald, Bauer and Madsen formulae in a footnote to Part 2 ('Tracking Error') and included Fox and Woodward's two January 1963 JAES articles in the sub stantial bibliography appended to Part 6 ('Towards the Perfect Pickup'). Of course this doesn't mean that I actually understood what they were on about (being a mere engineer-turned-technical-author), but I hope that Columbo would at least hesitate and mumble a bit before making up his mind.

Yours faithfully, John Crabbe Editor Hi-Fi News & Record Review Croydon, England Columbo would not hesitate. He would at this point immediately say ‘You know, Mr. Crabbe, I admire you- you've got class.' As this column amply testifies, not many audio practitioners are able to respond to technical criticism with this kind of Britannic aplomb.

We would just like to be sure, as we shake hands and part as friends, that the central fact of pickup tracking geometry has not been obscured by the fun and games in these letters: namely that tracking error, either lateral or vertical, creates time dispersive distortions, which are more irritating than simple harmonic or IM distortion.

-Ed.

Next, miscellaneous other subjects as seen by the trade.

The Audio Critic:

"The truth, the whole truth and no thing but the truth' is the slogan of The Audio Critic.

Unfortunately, in your efforts to bring to the reader's attention new and exciting developments in the field. you also do them and their dealers an occasional disservice by failing to disclose the whole truth: product availability.

If John Doe develops a new concept and technology in the production of a speaker or amplifier, a JD-1, it is your responsibility to bring this to our attention. Your review tells the audiophile that something better has been made and pushes the other manufacturers to work harder.

But all too often, while the new technology may have just arrived, production is still "*around the corner.'' John Doe cannot make more than two or three JD-1's a month, be it for lack of capital, or an inability to get 'mass production'' of some unique, previously hand-crafted component.

By your recommendation, the audiophile seeks the best; that is-the JD-1. From all over the world consumers and dealers, relying on your ' 'whole truth," send in de posits, often never to hear from the manufacturer again. Furthermore, dealers, both domestic and foreign, lose business as their customers try to buy the unproduced JD-1.

The audiophile is not purchasing what is available and already paid for by the dealer (and probably recommended by you last month).

After all, hi-end audio is as much a business as mid-fi. Both the dealers who have made an investment in the products you praise and the manufacturers who are actually producing these products must be given the opportunity to sell them to the audiophile without competing against products which may never make their way to the market place. We all need sales to stay in business so old products can be produced for your readers to buy and new ones for you to review.

The credibility of the whole hi-end audio industry is at stake; this includes manufacturers, dealers and reviewers alike. If John Doe can make a fantastic new piece of equipment, you do have an obligation to review it. But it must be kept in the proper perspective: product availability as well as product superiority.

Sincerely yours, Michael T. Berns

President; M. Berns Industries, Inc.

New York, NY Right on. But ''proper perspective' should also include the realization that The Audio Critic is merely a journal of opinion-enlightened opinion, we hope- not a guardian angel protecting members of the audio community against their own hasty business judgment.

As you know, we do issue occasional warnings about product availability (see for example Vol. 2, No. 1, p. 66, re the Cotter System 2), but our insights in this area are obviously limited, since the management practices and production schedules of a company are unlikely to be revealed by our examination of a product sample. Like everyone else, we must take the manufacturer's availability promises at face value.

Somehow you appear to suggest that we ought to possess more accurate intelligence about the inner workings of manufacturing companies than do dealers, reps, distributors, export-import agents, etc. Sometimes we actually do, since we talk to a lot of insiders who tell us a lot of things, but that isn't really our line of work.

It would be generally wise to assume that a new high-end audio product under a new brand name constitutes a calculated investment risk, both for the trade and for the consumer, no matter how well the initial samples perform in the laboratory and the listening room. Audio has never been a sure-thing business like funeral parlors, but you wouldn't be in it-would you, Mike-if the fun and the potential profits didn't out weigh the risks.

-Ed.

The Audio Critic:

We read your comments about our FM 600A power amplifier in your Vol. 1, No. 6 issue and would like to give you the following information: Our products were imported and distributed by Dayton Wright Associates Ltd.

(today we do have a few selected dealers in the U.S.A.) until mid-1978. One shipment in September 1977 included the FM-600A, No. 133. All these amplifiers were tested and tuned to the same accuracy as today (see enclosed description) and left Switzerland in perfect condition. In the meantime we found that some of the amplifiers they imported did in fact ring (although we did not hear of one that was ringing 125%). This ringing is not a feedback problem as you assume, but was due to the fact that on a few amplifiers they changed the compensation of one of the amplifier stages. This could be a reason for the indicated hardness in the upper registers.

Please note that our amplifiers do have a certain overshoot when loading with different impedances and this is deliberately done so (e.g. as with some old Marantz amplifiers). [cannot move into theories here as this would need much more time and space. However on our amplifiers there should be only very little ringing. Therefore we expect that you received one of the slightly "modified" amplifiers. This might be interesting for some of your readers, although until today we have only received two comments on this.

I thank you for being able to bring the above to your attention and remain,

Yours sincerely, Manuel Huber FM Acoustics Ltd.

Zollikon, Switzerland

A recheck of our laboratory measurement data on the FM-600A reveals a simple error in computation-the overshoot was in reality exactly one half of the 125% re ported. Sorry about that, but the sound of the unit was still what we heard. Incidentally, all overshoot figures reported in that particular issue of The Audio Critic (but not other issues) should be halved. This is of relatively small practical importance, since the duration and decay pattern of ringing have more to do with listening quality than the amplitude of the first overshoot. In any event, we genuinely regret having reviewed a corrupted version of your product and hope to make amends in the near future.

-Ed.

The following letter constitutes some thing of an editorial embarrassment. We really shouldn't publish it, since malice without the saving grace of wit makes poor reading, especially when coming from someone who doesn't even have his basic facts straight. We have no choice, however; it happens to be our policy to allow reviewees to respond to our reviews in this space. So, palatable or not, here goes.

The Audio Critic:

Thank you for the kind review of the FET-5 Mark V in the most recent issues of The Audio Critic. Unfortunately, your testing procedure is quite flawed.

A competent engineering evaluation of the Mark V would show the following results:

1. The phono section slew clips on 10,000 Hz square waves of any amplitude from amplitude clipping of the phono section down to 5 mV peak input.

2. The ratio of the low-frequency small-signal cutoff vs. power supply stiff ness after regulation produces rising harmonic distortion with lowering input frequency on any amplitude of 20 Hz square wave input signal. (Sic.)

3. The buffer stage overshoots more than 50% on 10,000 Hz square waves in excess of 0.5 volt peak input level.

4. The buffer stage also exhibits problem #2.

5. The output IC stage slew clips on any amplitude of 10,000 Hz square waves.

Inasmuch as the problems described above produce harmonic distortion and IM distortion in the audio range, and inasmuch as we consider any distortion measureable at all to be undesirable (I hope you don't consider distortion to be desirable), the measured results predict the following sonic problems:

(1) Excess harmonic distortion in the audio range, worst at low frequencies but audible at least into the midrange. This would relate somewhat with your vague subjective description of ''hooded mid range'', and since I expect you have never heard audio electronics with undistorted low-frequency output, it doesn't surprise me that you failed to describe subjectively the bass problems, because until you hear undistorted electronics, I suspect you are not aware of the distortions you are always hearing.

(2) Loss of resolution at higher frequencies due to slew clipping with excess IM products throughout the audio range, which would relate to your vague subjective description of ''obvious colorations.' More unfortunately, your publishing schedule is also quite flawed. The Mark V was discontinued and off the market before the review was published. Perhaps The Audio Critic should be considered to be more of a history book rather than a buying guide.

You did make one accurate statement in the review. There is a Mark VI, the FET-6 modification of the PAT-5, which since we have learned how to accurately measure and analyze the distortions we can hear, we have been able to eliminate all of the problems mentioned above. The FET-6 has zero slew induced distortion under any condition of input, operates always within linear trans conductance, has low-frequency time constants that are valid and will put out perfect square waves under any condition of input up to clipping. No phono cartridge can over load it. Of course in accordance with Jung, the slew rate and power bandwidth cannot be specified.

Since we know of no other pre amplifier that will pass our engineering evaluations (except for four of our other new designs), we would predict that the FET-6 will probably be subjectively superior to all other preamp designs in existence. We would of course also predict that any pre amp that does pass our test series would be at least as musical as the FET-6.

We would be happy to prove this to you and would normally offer to update the Mark V to our new standards for you at no charge. However, we understand that you sold the preamp in question which we had previously modified at no charge. That makes it more profitable to review expensive equipment if that is your policy, doesn't it? Thus, we suggest you use the profits from the sale to acquire another PAT-5. We will modify it for our standard price of $200, including return shipping. If you are not interested, that is your problem, not ours.

By the way, your phono equalization test procedure is also flawed. Since an RIAA equalized preamp in essence drops forever at 6 dB per octave, and since you cannot build a reverse RIAA equalization circuit that rises forever, the input to test for RIAA equalization is flawed. In addition, the reverse RIAA network must act as a low-pass filter (sic), which will mask most phono preamp problems by eliminating high-frequency components the preamp will see in the real world.

The implications of this letter are quite obvious. Referring to the cartoon on page 6 of this issue of The Audio Critic, it appears to us that your efforts are mostly in the same league as the bearded gentleman. You can not continue to claim superior technology in review procedures when your procedures are inadequate. You cannot expect to mea sure equipment under narrow-band conditions and predict results under wide-band real-world use conditions unless you live in an RF shielded room. You cannot make nonscientific statements such as in the Hafler DH-200 review, "we measured 30% overshoot on square waves..." when you fail to specify the frequency or amplitude of the square wave. A statement like that would get you laughed out of any really scientific journal. In the seminar published in this issue, only Matti Otala's comments were consistently within the realms of objective rationality. I suggest you take a few lessons in scientific methods from him.

Understand that we don't claim to be perfect, we are not. Our argument with you is that it appears that you do claim to be perfect, and you are not. We view such claims with suspicion.

Sincerely, Frank Van Alstine; Jensens Stereo Shop; Burnsville, MNPLS, MN.

We will update any PAT-5 we have previously modified for no more than $100.00.

We refuse to dignify the above out pouring of undisciplined techno-rant and sheer personal bitchiness by responding to it item by item. Even if one or two of the engineering points made by Frank Van Alstine bear some distant relationship to the facts of electronics (after all, it's very difficult to be 100% wrong all the time), his newly discovered priorities in preamp de sign, his perception of our test procedures and his understanding of certain basic principles of physics are, to use his phrase, quite flawed. In fact, his letter is a perfect illustration of what we' re talking about when we warn our readers against the semi educated gurus operating in the twilight zones of audio.

Just one quick example--and no more!--that even the less technically minded might be able to appreciate: When reproducing the leading edge of a square wave, an amplifier doesn't know how long it will take for the trailing edge to arrive, i.e., how long the ramp will be. The amplifier has no prescience; it overshoots and rings or it doesn't, depending on the rise time of the leading edge and the various characteristics of the circuit. Thus, you don't have to specify the frequency of a square wave that makes an amplifier overshoot and ring, not withstanding sophomoric debate phrases like this-will-get-you-laughed-out-of what ever.

More disturbing than this howler and several others like it in Frank Van Alstine's letter is the utter predictability with which he will replace the world's greatest circuit with something even greater every few months. We defy any publication to keep up with it. The Mark IV, immediate predecessor of the Mark V we reviewed, came to us with a note saying, 'You're not going to believe it!!' And now even the Mark V is the butt of high-minded self-ridicule, like Cyrano's nose, because the Mark VI makes it totally obsolete. Were all these laws of nature still undiscovered when the Mark IV and Mark V were designed? Will the in evitable Mark VII make all of them look like a joke? We deeply regret that we took any of this nonsense seriously to begin with.

The only other thing we wish to comment on is the swinish insinuation that it was somehow greedy or financially unethical of us to sell our PAT-5, which was our un questioned, fully paid-for property, simply because it had been diddled with and bless ed by Frank Van Alstine. The truth is that we took a huge loss on it because nobody wanted it, but that's irrelevant to the case.

What's relevant is that a man capable of a low-down slur like that, no matter how angry or frustrated he may be, must be deemed obviously unfit for consumption by civilized people with a sense of right and wrong. Good-bye, Mr. Van Alstine.

-Ed.

The Audio Critic:

The recording of Cantate Domino was not-repeat, was not-made with B & K instrument mikes but with a mike called Pearl, made in Denmark.

This isn't just to nitpick at you but to let you know-because, in fact, this Pearl mike is the second best mike I have ever heard.

The B & K's are by far the finest mikes I have ever heard. They are gorgeous sounding things . . .

Proprius started out with the Pearl mike and switched over to B & K's-and you are correct, most of their recordings are made with B & K's but not Cantate Domino. 1 telexed Proprius, and they said two Pearl TC-4's, I believe . . .

I have been working with the two-mike technique-and only that!-for some time, and this setup is easily the finest and cleanest. I think you have heard some of these tapes made with B & K's, so you know.

Your magazine is doing a very fine service by having Max Wilcox write his superb articles bringing back really the only true recording technique which captures sound as it really exists.

Sincerely, Jonathan L. Horwich; Clearwater, FL

We stand corrected on Cantate Domino. Actually, the Pearl condenser mike is an old familiar face to us; we owned a pair back in the mid-1960's, when hardly any body knew about them. (An earlier model, of course.) They sounded fantastic. But they were made-and we believe still are-not in Denmark, but in the part of Sweden nearest Denmark, in the vicinity of Helsingborg.

That's just across the strait from Hamlet's castle, so you weren't far off.

-Ed.

Finally, some psychoacoustic observations by astute listeners.

The Audio Critic:

I am convinced after reading many opinions that most of the differences between high-quality components are often in the listener's head or explained by certain electronic phenomena.

For instance, 1 feel that depth and stereo stage width as applied to how a cartridge reproduces often is due to phase problems in the cartridge. In other words anomalies are being extolled as desirable effects in high-quality gear.

Also a great deal is made of stereo imaging and placement of instruments. A concert in a large hall just does not give this unless you are sitting very close. Without visual clues one cannot pick out one instrument and place it perfectly, so this is some thing that really isn't true to life yet is used as a criterion for superior speakers and other equipment . . .

Sincerely, Will J. Price, M.D.

Hyannis, MA

What your cartridge, amplification chain and speakers must reproduce accurately is not your own memories of the con cert hall but, perforce, what the record producer captured with his microphones.

Ideally that should be a concert hall sound you can relate to, but seldom is. Usually what the producer records is the sound you would hear in the concert hall if your ears were extended on fifty-foot antennae and aimed at the musicians from a few feet above their heads.

We, too, have often sat in the concert hall with closed eyes and observed that there was little or no imaging in the hi-fi sense. Therefore pinpoint localization is unquestionably an electronic artifact, but in our opinion more often due to the recording process than to the peculiarities of the re producing equipment.

It also happens to be true, however, that speakers with extremely small angles of coherent radiation can give you that snap into-focus effect as you move your listening position or even just your head. That, too, is an artifact, though much prized by some audio cultists. The ideal is a naturally re corded sonic perspective combined with proper radiation launch by the speaker.

-Ed.

The Audio Critic:

I have your first Reference B system except for the disc playback components. I have to admit that it's far superior to any other 'popular brand' component stereo.

However, I have a problem which is not unique, from what I hear from other audiophiles. My concentration is often drawn from the music to the sound of the music. The better the system, the more I listen to the system. I have found my most enjoyment out of music itself on my car radio. Still, I would rather listen to my stereo over my car radio. What am I doing wrong?

Russ McBride Woodridge, IL

P.S. Please don't bring up your Reference A system unless it can drive me to work.

A man we know had a similar predicament. Although of moderate means, he married one of Hollywood's great sex symbols, a glamorous love goddess who happened to be really turned on by him and made him the envy of all men. Unfortunately, whenever he made love to her, he was unable to concentrate on his pleasure because all he could think of was his incredible good fortune and his number one rank on the erotic status scale. He ended up having an affair with one of the checkout girls at the local super market, who was not particularly good looking but conventional hot stuff. Our suggestion is that you get one of those kiddie steering wheels and hold it while you listen to your Reference B system. Maybe if you can fantasize that you are listening to your car radio . . .

-Ed.

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[adapted from TAC]

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Also see:

Reference System Revisions and Updates: Assorted Editorial Ramblings, Rumblings and Grumblings

Why We're So Mean, Vindictive, Arrogant, Negative--and Truthful

Various audio and high-fidelity magazines