Audio, ETC (Audio magazine, Jan. 1968)

by Edward T. Canby

1. Chromed cassettes

Believe me, if you can possibly make it, go to the next AES convention West Coast, East or wherever. If you are even slightly knowledgeable, you'll be fascinated, both by the audible "papers" (as they are so coyly entitled) and by the associated exhibits. If the annual Hi-Fi Shows give you a bird'seye view of audio as it is, and will be for the next months, the AES meetings let you in on the future. At the New York meetings last fall I got enough ideas for a couple of years' worth of this department. One day, the talk didn't stop (except to listen) from 9:30 in the morning to 10:30 at night.

And if there's too much of a muchness, you can pick up "pre-prints" of just about everything and sometimes even more. (Most papers are too long and get cut in midstream when the warning gong goes off.) All of which is merely prelude to things that will hopefully come later on in this department. I found that the most exciting characteristic of the AES subject matter is exactly its lack of fait accompli-for these are developments not so much completed as under way, inconclusive--if often loaded with audio high explosive. Frequently, indeed, one must read between the lines (and view between the exhibits) ; for our wary engineers quite rightly do not like to commit themselves about `commercial" prospects until those prospects are actually launched and under way.

Thus there were all sorts of interesting things persuasively set forth and demonstrated at AES which were invariably "purely experimental" no particular future exploration contemplated. It's all, of course, just for the fun of it, we are supposed to understand. Well, maybe, maybe not.

Granted that many developments as presented in this preliminary stage do, in fact, veer off in other directions, never arriving on the commercial scene at all in the form we at AES see them.

But, to use an old phrase, where there's smoke there's fire. And the wonderful fun at AES is to try to smoke out the fire, if you wish, by sheer gamesmanship.

Thus, just to name one item, we were introduced to what may be the biggest thing in tape for the future, a new kind of tape coating. No-it isn't even being contemplated for audio and con sumer use-yet. It is in development for the much more important (yes, alas ...) computer market, branching out from business into Defense and Space and all the rest. But there the tape was. And there was the Gauss Company, which makes fancy tape duplication systems for the trade, showing off a couple of cassettes full of the stuff, plus the results of their testing, comparisons of various parameters with the best standard (that is, ferrous or iron oxide) tape.

Available in cassettes? Oh, no-no.

Gauss got a sample of the new tape in a computer formulation and size. Just for the fun of it (oh yeah?), they sliced it up into the 1/7-inch cassette width--by razor blade, mind you. Then they hand-wound the stuff into an empty cassette. Big apologies were made for finger prints, grossly enlarged in the photomicrographs we laughed. Also for some edge distortion where the 4 track stereo ran into some of those hand razor-blade edges! The producing company for this new tape was silent as the grave. (I was told they had representatives on hand, to listen.) They are not officially interested in consumer audio. Really, truly.

Too busy elsewhere. They probably wished that we all would please look the other way and just concentrate upon the fabulously good ferrous tapes now being produced. Let well enough alone.

But they aren't going to have it that way, I suspect. Because right now we are in fact in a crisis and a bind, if I read all the signs right, precisely in this area-as the tiny slow-speed cassette takes over in miniature four-track stereo. Our tape isn't really quite up to it. Touch and go. Even the very best.

The commercial tape people are singing out bravely and, in the end, their sing will be right. Stereo in cassettes, two-track each way, four tracks, and competitive as all get out. But the quality corner-again if I guess right hasn't yet quite been turned. We desperately need a breakthrough, and a big one.

What just might do it would be a really different tape, one that could give that chrome-trimmed sound in stereo even at 1% ips. Not just a further refinement, but something new.

This tape is new, if unrefined as yet.

I need say no more, at this point, than this: it isn't ferrous, it's chrome-was it chromium dioxide? (They didn't pass out any literature or even a pre-print--the demonstration was thrown in at the last minute.) And, other things hopefully being equal, at 1 7/8 ips in a cassette configuration this new tape added up its major performance parameters to match standard tape traveling twice as fast. Does that mean something, or doesn't it? We most certainly will be finding out.

Not much question about those micro-slides we saw. Finger prints aside, the oxide surface was astonishingly smoother and finer than any ferrous tape. That would do it.

Some snide Doubting Thomas whispered in my ear that chrome oxide was well known as an excellent abrasive.

Could be. But I suspect our engineer brothers will figure out a way to take care of that, if they really have to. So watch duPont, and chrome oxide tape. Maybe in a couple of years or so...

2. Pine needles

These days, audio seems to be everywhere in my thoughts. Even on weekends, and in the most unlikely situations. Like, say, raking up pine needles off my lawn.

Raking leaves takes a bit of planning--you advance across the lawn in a sort of ragged frontal progress, moving forward a few feet at a time, curving your "front" here and there so you won't get trapped in corners and behind trees, gracefully converging all your leafy lines until you break them up into piles and burn them or cart them away-assuming a windless state of the atmosphere, of course. Only fools try to rake leaves in a cross wind.

(Haven't you?) Pine needles are something else again. I have several gorgeous old white pines above my house and-in case you didn't know-they shed their old needles profusely each fall, right along with the leaves on the other trees.

But unlike leaves, pine needles have no cross-section. They are two-dimensional. Now here comes the audio.

When these ornery needles start moving earthward they tend to spiral down fast, and they arrive, often with quite some momentum points first.

They penetrate, into the grass, into corners, crevices, cracks, and there they consolidate. They interlock neatly in compact bunches, orientated in the easiest direction.

My first thought, as I tackled the pine needles last fall was: magnetic domains. Yeah, yeah (rake, rake) .. . that's it! Random interlocked formations.

Now what happens when you start to rake pine needles? They so to speak become magnetized. Remember, they are two-dimensional, with a North and a South. So of course, as you rake, they line up in parallel. Because they come in clumps (five to a clump in white pine), the North ends neatly point all one way. And the darn things just stay right where they are. All you've managed to do is to "magnetize" your lawn. The needles are still there, but all of them pointing one way.

Well, the next time I went out to rake (no sooner do you clean up the needles, somehow or other, than a new batch comes spiraling down), I found myself shifting analogies. That was because I had at last found how best to cope with the ornery, sticky, un-budgeable things. And the physical action reminded me forcefully of another aspect of audio. The stereo groove.

My first solution to this problem was precisely that which was first used in stereo disc to get two signals into one groove. I combined vertical and lateral motions.

First I raked one way all over the lawn. Lined 'em all up. Then I came upon the lawn sidewise, and raked at a 90 degree angle. That caught the needles with their magnetic domains orientated crosswise-and they had to give in. Once I had got them up and out of the grass, the corners, crevices and cracks, the rest would be easy, more or less.

But I wasn't finished yet. You'll remember that the original lateral-vertical system for stereo disc, though it worked, offered a number of doubtful features, principally the lack of uniformity between the two systems, lateral-cut and vertical-cut. When one stereo channel was assigned wholly to each, the requisite uniformity of sound was lacking. In a word or two, lateral music just didn't sound the same as vertical; nor did various other parameters come out the same either.

I found that the lateral-vertical pine needle system just wasn't working. So, taking a leaf, or rather a needle, from the stereo disc book, I tried what the stereo people tried. 45-45! It worked like a charm.

Now, if you follow me, I rake my needles with a channel-A, channel-B sort of stroke; one stroke of the rake out to my right at an angle of 45 degrees, the next out to my left. The two sets of strokes are identical, but always 90 degrees apart, plus or minus a small tolerance (too small for the pine needles to notice). And no matter which way I retreat (one rakes backwards, of course, the way one rows a boat), the 45-45 relationship remains fixed. The needles are neatly caught in the cross-raking, and I can move along in flexible fashion, following the curves and irrationalities of the terrain just as I wish. Wonderful! It only takes twice as long as raking leaves.

3. Transposition

Sometimes I look at what I have written here--months afterwards, of course--and marvel at the unintelligibility of it all. Sometimes, anyway.

A splendid example, I thought, was that second installment of my study of Lawrence Lessing's "Man of High Fidelity," all about Major Howard Armstrong, the radio pioneer and inventor of FM. Digging out the carbon of my MS, I feel better about it. It's a simple case of transposition.

If you will quietly remove the top three lines of Column 2, p. 8 of July issue, you will find out what I was talking about--the closing down of Armstrong's pioneer FM radio station at Alpine, N. J. And if you will carefully transport those three lines in a Northeasterly direction, placing them delicately on top of Column 3, you will clear up another area of Total Canby Incomprehensibility. What I tried to say there was--"The trend towards 'rehabilitation,' both of Armstrong's own importance and toward recognition of his work and of his inventions themselves, has gone onwards as projected in the final pages of his written life. The rest of the story, up to date, has now been added by Lessing ..." Make sense? Good. And I now can add a footnote: Man of High Fidelity, with the extra updating included, is now on the way to paper book publication at a very easy price. Look for it.

(Audio magazine, Jan. 1968)

Also see:

AUDIO EQUIPMENT PROFILES (Jan. 1968)

Letters

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