David Manley: Tubes, Logic, & Audiophile Sound Page 2

We were talking earlier about analog and digital. I played some tapes at an AES meeting several years ago and they couldn't wait to say "Listen to all that hiss and horrible analog garbage. It's outclassed necrophiliac stuff here. It's not relevant anymore." And as you well know better than anybody in the magazine industry, the bulk of the stuff today is being mixed to 30ips half-inch analog. It's the medium of choice, even when budget constraints aren't an issue. So what does that tell you?

I think the AES does an outstanding job. I really believe that. I just think they're a bit over the moon on newness and a bit "anti" on older stuff. I think all history is important. History and experience are vital. How can you build something better if you don't remember how good the thing you're trying to supersede was? It's funny—if it was built yesterday, it's got to be scrapped in favor of what was built this morning. I suppose that comes out of just trying to propagate electronics as an ever-growing industry.

Going back to your question about some of the equipment in the recording chain not being so hot, I put this down in large part to the fact that the AES are not concerned about what 1% percent of the public who are audiophiles think, they're concerned what 99% of the public think. They think that the sound on television and car radios is just dandy.

I wrote in this little book of mine [The Vacuum Tube Logic Book] that when I was heavily in the recording industry, English recording company executives and A&R men would have Leak amplifiers driving Tannoy speakers in their offices or their reference playback system, and in America they had McIntosh driving JBL or Altec Lansing speakers. That's all changed. Now they have boom boxes and little Auratones—a car radio is now the standard. If you make a pop record and it sounds softer on a car radio than the Colgate commercial preceding it, you're finished as a mastering engineer. That's your last job. They're going to want to know why their stuff sounded sub-loud, sub-clear, sub-punchy to the Colgate toothpaste commercial. The quality criteria have shifted to where "good enough" is the order of the day. That's sad.

Harley: Why do you think tubes aren't more widely used in recording and playback?

Manley: Because ears aren't more widely used in recording and playback. Whenever I expose people in the professional sector who have little tube knowledge to tubes, they immediately latch onto them. Immediately! We never have to talk about them; we just play them an amplifier or a preamplifier and that does the trick. It's so evident. And you well know the ridiculous values of some of the older classic microphones. Because of the tubes.

Some of the reasons why tubes are easily able to surpass transistors are very clearly evident: the ability to handle large swings of program input voltage elegantly with no clip, and an elegant clip when they do; the higher working voltage rail; the more comfortable impedances at which to couple, where you don't have to use 100µF or 200µF [electrolytic capacitors] because of the 10 or 20 ohm source [impedance].

And when you say "widely used," again, you know that in the guitar industry the tube amplifier has never lost an inch of ground. The solid-state amplifiers are laughingly poor copies of tube amplifiers. My wife EveAnna's father, Al Dauray, was President of Ampeg, manufacturers of the guitar and bass amplifiers which are so hotly wanted. I made this point at a Stereophile Show designer's panel: people are still buying and selling Dynaco tube amplifiers, of which there were some 200-and-odd-thousand built, which I think is wonderful. The solid-state amplifiers that are of the equivalent age, you can't even get rid of at a garage sale. You pay a guy to take 'em away.

So certainly, in microphones tubes are widely used. That would be a fair statement. And the guitar industry, they're very widely used. We think we can bring them back in the recording industry. The original Pultechs [a classic tube equalizer—RH] are like the Neumann and AKG capacitor microphones of yore: they have a sky's-the-limit value. Which is why we build Pultechs that are better. People are finding out about those now.

I think tubes are getting more and more widely used where reliability and absolute performance are critical. Tubes are reliable. Hyper-reliable.

Harley: What's the prospect for continued tube production?

Manley: Excellent. That was a brief question and I have a feeling I'm going to be too wordy here, but anyhow...

America always made some of the best tubes in the world. The last American factory is the General Electric MPD factory, which plans to cease production of "receiving" tubes, as they are generally classified, about a year from now. (The entire factory's not closing down—just closing down its divisions of audio tubes. They'll go on making planar triodes and radar tubes for the military and so on.) The Philips ECG plant closed about a year and half ago, and there have been no more American tubes made of the types that interest you and me and all audiophiles and recording people. But three other countries are very hot into tubes: Russia, China, and Yugoslavia. We have been using a lot of Russian tubes and we are very close to the Yugoslavian people now. I spent the whole of January in Yugoslavia with my then fiancée EveAnna, who works closely with me. She's mostly at VTL, but she's been doing a degree which just comes final now. We were able to design a whole new tube with their cooperation, because they opened their doors and were willing to have me help them.

Harley: Was that a result of the barriers to Eastern Europe breaking down?

Manley: Well, the funny thing is that Yugoslavia is not very much barriered because it's been a freely enterable country for 20 years or more, even though it's pretty antiquated in its socialist ways—people's wages and lack of private enterprise. I'm referring here to a government factory, obviously. But it's an outstanding tube factory.

The Chinese can make some outstanding tubes. The technology was put in there by Russia, who make extremely outstanding tubes (footnote 4). Russia uses an awful lot of tubes today in all kinds of very exotic places, including the computer onboard a fighter aircraft—a tubed computer. They're capable of, and do build, a tube with 100 elements [used as logic gates—RH]. (That, by the way, is supposed to be a classified secret, but it isn't really.) The barriers are breaking down with Russia, particularly, where there already have been barriers. But anything that's remotely military is classified. They classify a 1" stainless steel bolt—if it was only used by the military—as a top-secret thing.

So those three countries—Hungary stopped a little while ago—are making fine tubes in great quantities and quality. The Chinese make one of the best 12AX7As that's ever been seen in the history of the world. They do some lesser-quality tubes too, but that's only because they're targeted at a lower price point, for musical instruments and so on. It doesn't mean it's the best they can make. We get astonishingly good 807s from China, which proves that they know how to make them. There is nothing they don't know how to do about tubes. Same with Yugoslavia. So there's not a problem for tube manufacturers that I can foresee.

The British Mullard factory, which was Philips-owned by that stage of the game, closed its doors in June of '86. We were a couple of miles away from them. They were having to make a lot of different types and were not doing sufficient volume in any one type. Making a tube is obviously a highly labor-intensive endeavor, akin to watchmaking. It's not cost-effective to make tubes with expensive labor.

We were very worried prior to my visits to Yugoslavia in January because we have a special version of the GE 6550A built for us at the moment. With that coming on to the demise list along with analog LPs, the funeral notices were posted and they were asking us to buy huge quantities of tubes. It's horrible to try to predict your needs and stock them for years in advance. The 6550 was a very important tube to us, but we showed the Yugoslavs how to use existing size and tubing they had for another tube, which is similar in power rating.

We worked out a way of using a lot of existing former sizes and jigs to originate an entirely new tube particularly for us, which we will supply to others if anybody's interested. We called it the KT90 because it was designed in 1990, and KT stands for "kinkless tetrode." It exceeds the KT88 in performance. The Chinese build a KT88 but it's more correctly an 8850 because they use the same interior for a KT88 and a 6550, but they're different tubes—one's a tetrode, one's a pentode. Then again, they don't build them rugged enough. Not because they can't, but because they want to build them to a price point, to sell lots of adequate ones rather than a smaller number of really excellent ones.

But we've got an excellent tube here. The KT90 will be our staple tube. We also use a Russian KT66, which is not identical to a KT66 but it's very close. It's a very robust and well-made tube. We're really excited about this KT90. We've had them on test for nearly three months, and at cruel voltages—50% higher than we normally use. We've tried to break them and we can't. That's going to be an astonishing tube. We're not worried about the demise of tubes. We've got plenty and are getting plenty from wonderful sources. Sadly, though, they're not American sources.

Harley: As someone who has spent a lifetime in analog and tubes, how do you feel about digital?

Manley: You know, that's a long conversation to which I could reply over 10 or 12 pages. I think it's healthier that I try to keep an open mind about it. I mean, I love the sound of analog. If I were given a straight preference, I'd choose analog. Master tape, that is.

I've read letters from guys in the magazines about how the cat goes into a state of neurosis with digital, and one guy wrote that he goes into nervous tremors and rigor mortis sets in and all this. I don't dispute that the guy feels this way. I fully empathize, sympathize, etc. But as I read, I think one of the factors is just sheer damn listener fatigue. That's one of VTL's major marketing strategies—we don't have a lot of marketing strategies—but one of our major marketing points to studio owners and audiophile listeners is that tubes are much less prone to listener fatigue. Especially digital sound through what I find fatiguing anyway—solid-state amplifiers. Sorry and all, but that's how I find them. And the less good they are, when combined with digital, makes the whole thing a damned fatiguing project.

Just a couple of weeks ago I listened to digital at a friend's house from 4pm until midnight on what I call a "mid-fi" system. High mid-fi, but not royal electronics. And I can tell you I felt like I'd been through a threshing machine. But that was just common listener fatigue. I've had huge experience and seen other guys experience huge listener fatigue with crummy monitor amplifiers that are mainly used in studios on hard-sounding monitors. And sure, digital exacerbates the listener-fatigue factor.

I don't believe that the low-level detail has to be as bad as some of that I've heard. I think it can be gotten better and I think our project [the VTL D/A converter, reviewed in Vol.13 No.12] will get it better. I think Mike Moffat's approach is excellent, and I've enjoyed your reviews. In fact, I couldn't wait to get the latest issue of Stereophile [August 1990]. Three relevant machines [Wadia X-32, Theta DSPro Basic, Stax DAC-X1t] reviewed all by the same man in the same publication.

It's got to get better. It's no good lamenting that analog discs are on the way out, or they are out, because that's the way we find ourselves. And it's also no good lamenting about the 44.1kHz sampling rate because that's what we're stuck with. At least on the credit side of the balance sheet it's a stable format. It's not as though they had CD, super CD, VHS CD, Beta CD, etc. So the public at least are not being conned and re-conned into buying newer and self-liquidating or self-outphasing systems. Digital has hyper-convenience, is easy to maintain, etc., and has other good things going for it. And there are bad things going for analog discs, even in the best stage.

One of the ones that used to drive me mad is the LP's diminishing peripheral speed. Figuratively, you start out with about 18ips and you wind up with about 6ips if it goes very near the label, to use a tape analogy. Well, your ear compensates as it drifts on through the record. But meanwhile, most classical music—my favorite is classical—builds up to a climax, and that's when you're wanting to finish big, as it were, and that's when the dynamic range is shrinking. Which is why they had inside-out records as an optional cutting method way back.

I try to be completely liberal about the digital and analog controversy. You can see the music I play and the source it's from: master tapes that I use as a reference tool. This is my collection I've been building up over years and years and years. Quite a lot of it's got my work in it.

But digital is where it's at! It's pointless in my position as a designer, as an important audiophile company, to just turn my back on it and say it sounds awful or that I'm only going to contribute a minute's time to it. I'm trying to consistently get it better and better. We long had a tube-modified, after-market modified tube CD player. In fact we had them ready and available in England before one was ever in America. Very few people know that. We never put it under any kind of marketing mode because the models were changing almost by the month.

Incidentally, I can tell you with absolute certainty that I was probably one of the earliest audiophile types ever to hear a CD in the flesh. This was long before they were in the market because I used to do consulting to the advertising agency that was given the project by Philips of Holland to get the promotional story ready. They called me in early on because they knew my background and interests. For the record, when I first heard CD it sounded terrible. But it was being played with some typical, incredibly terrible advertising agency-type low-fi system. I took that machine home that very day, which was one of the prototypes of the Philips 100 with the pop-top, and I played it right through tubes. And I said, "wait, this thing isn't nearly as bad as it sounded at lunchtime in the advertising agency."

Of course, I have to be honest and say I do like the high signal/noise ratio. I do like the wide dynamic range. I do like the channel separation. I'm in fact surprised that they haven't made more of that: the complete left and right separation you can get which is akin to a master tape. Which of course the LP can never do. It's a miracle that the LP gives any channel-to-channel separation with a common stylus and a common groove. And I do mean miracle.

Harley: Tell me about the recording studio you're building.

Manley: Well, we're building a recording studio now for about five key reasons. One of them is to be able to demonstrate our recording equipment to visiting prospective purchasers. Another is to have a truly neutral playback and recording acoustic—and I believe they should be so. The history of studios where you have a hyper-dead studio and then people listening in their hyper-dead playback rooms, to me that's not how it should be. I know you feel the same way. Another one of the key reasons for the studio is that we will make recordings here for release either by ourselves or offered to some marketing organization. And we'll offer the studio to people who want to make worthwhile recordings—free of charge. We won't charge them a dime for the use of the studio, to help do what you're doing—to help propagate and promulgate good recording.

Good recording is not a lost art. It doesn't have to be. It was getting pretty lost out there. There should be absolutely no difficulty—I demonstrate this daily—in being able to record to that standard [the old classic recordings] with high-quality microphones and a clean, simple audio chain that's not fiddled with. One of the key routes is tubes. All that stuff was recorded on tubes. Tube microphones, tube microphone preamps, Ampex 300 series tube tape recorders. There you have the sound, and provided you don't use a diabolical acoustic, it's really hard to miss.

Footnote 4: The Chinese also bought the tube production equipment from England's M-O Valve Company, who manufactured the "KT" line of output tubes.—John Atkinson