A Near-Death Experience for High Fidelity
In the latter part of the Sixties, the High Fidelity industry continued to grow, but the pace of innovation slowed down after the conversion to stereo sound. More ominously, the transistor revolution proved the undoing of the domestic Hi-Fi industry. (This is why the Hi-Fi line in the Markets chart breaks off around 1968 ... sadly, the dreams of many Americans came unraveled in those bitter years, with the triple assassination of both Kennedys and Martin Luther King.)
To return to the story of audio, the early transistor amplifiers used the notorious quasi-complementary output scheme, since matched complementary output transistors were not then available. In addition, the dangers of exceeding the Safe Operating Area were very poorly understood, so the first generation of transistor amps weren't even remotely "solid-state reliable." Instead, they failed at the drop of a hat, and were so aggressive and harsh with Class AB crossover distortion and Transient Intermodulation Distortion (TIM) that an entire generation of "East Coast Sound" speakers became duller and duller to compensate.
The return rates eventually became so bad that Scott, Fisher, Sherwood, and many other well-known names were driven out of business, while the hallowed Marantz name was sold to the Tushinsky brothers (who owned the US distribution rights for Sony). I've talked to folks who owned hi-fi shops during this time, and some US-made transistor amps had a failure rate of more than 50% out of the box! Customers aren't exactly impressed with a sales demo that include sparks and a puff of smoke from a brand-new amplifier. (Don't think this is a problem of the bad old days. It wasn't that long ago I was sitting with the editor of a national audio magazine and his $15,000 transistor amplifier expired in a puff of smoke and took his $22,000 speakers along for the ride. I actually saw the tiny flash of light as the woofer voice-coil vaporized from 30 amps of DC offset. True story, folks.)
This was the market opening for Pioneer, Kenwood (Trio in the rest of the world), and Sansui. The Japanese had extensive experience with transistors in cost-sensitive consumer products (the US experience was limited to the military and instrumentation sectors), and they made products that were reliable-enough, looked expensive, had good reviews in the mass-market magazines (a little cash under the table ...), and best of all, had 40 to 50% profit margins for the retailer! The Japanese understood the workings of the US market better than the US manufacturers - after all, as outsiders, they had no preconceptions of how the market should or shouldn't work - they just accepted it as it was, not as it should be.
The well-financed and business-minded Japanese, unlike the American manufacturers, were quite willing to pay substantial advertising costs in expensive glossy magazines like Playboy, wining and dining magazine editors and staff, and paying generous Special Promotional Incentive Fund (SPIF) payments to thousands of salesmen at the end of the day. Back when I worked in retail, SPIF payments that came right out of the cash register of $50 to $100 at the end of the day wasn't at all unusual - and this was back in the early Seventies. For American magazines, product reps, and the local hi-fi store, it was, as they say in the Syndicate, an offer you cannot refuse.
As the traditional American manufacturers sank under the tidal wave of Japanese imports, slow progress was made in the development of output transistors, allowing the use of a matched PNP/NPN complementary (or push-pull) output stage with direct-coupling. This removed the worst of the bias reliability problems of the quasi-complementary output stage, but problems with high-frequency instability and thermal runaway still plagued transistor amplifiers, keeping the long-stated goal of "solid-state reliability" as empty as the digital promise of "perfect sound forever."
Things weren't much better in the movie theaters. By now, widespread color television ownership had cut deeply into the movie-going audience, and most theater owners were not interested in maintaining costly 70mm projection systems with large curved screens. The theaters had been divested from the movie studios by Supreme Court order, and the new independent owners wanted to maximize profits as quickly as possible. That meant bigger popcorn concessions, faster audience turnaround (no more double features where you stay all day if you wanted), smaller screens, a much smaller (and non-union) theatre staff, and a serious technological regression to 35mm film and 1930's-vintage mono optical sound.
We now know the Eastmancolor filmstock of the late Sixties and Seventies was inferior, color-shifting and washing out in less than 20 years. The films that were not transferred to separate frame-registered black-and-white negatives for archiving are now essentially beyond recovery - but frankly, technically, they were crap to begin with, with a reduced 35mm aperture to provide the illusion of widescreen, and low-fi mono optical sound. When you see a really terrible-looking movie or TV show from the Seventies, that's why.
It took more than a decade for high-fidelity stereo sound to return to the new, smaller, multiplex theatres, thanks to the runaway success of the Star Wars movies. (Without Star Wars, it's quite likely the theatre owners would have ignored Dolby Labs and stuck to antique optical-sound mono.) When word finally got out about the poor stability of Eastmancolor, the industry put pressure on Kodak to improve the filmstock, and archivists and historical societies put pressure on the industry to improve storage conditions. Although very few theaters can now exhibit 70mm, a few big-budget pictures are shot in that format, mostly so special effects can be more effective and realistic.
The tape-recorder market was in a state of flux. The introduction of small-signal transistors was a more positive development than in power amplifiers, since high power is not an issue in tape-decks, and the circuit complexity is high ... a situation tailor-made for transistors. Japanese tape recorders, some of high quality (TEAC and Sony), and some not, steadily drove the US-made machines like Ampex, Magnecord, and Viking off the consumer market.
In an unlikely alliance, Nakamichi, Dolby Labs, and Advent co-operated in transforming the Philips Compact Cassette, originally designed as a no-fi portable dictation format, into a near-hifi tape format (similar to MP3s today). In less than 4 years, the new cassette format drove the unreliable 4 and 8-track endless loop systems off the market. The non-technical public had an easy-to-use, hard-to-break stereo tape recorder for the first time. For better or worse, the Compact Cassette is by far the dominant medium for world sales of pre-recorded music, being dirt-cheap, plenty good enough for the mass market, and trivially easy to mass-copy and pirate. The latter is a major advantage for Third World nations that have no intention of paying royalties to obscenely rich Western entertainment corporations - cassettes are still the dominant medium in the Third World, although mass-duplicated CDs and almost-free CD, VCD, and DVD recorders and players are quickly closing the gap.
The Rise from the Ashes
As the Sixties fizzled out into the spreading gray twilight of Asian mass-fi, a tiny ray of light emerged from an unlikely corner of the industry: J. Gordon Holt's typewritten zine, the Stereophile. This was a very different magazine than the glossy 4-color product you see on every newsstand today. Every pint-sized issue had a grainy black-and-white picture on the cover, and J. Gordon's zany sense of humor was evident in the writing, the goofy cartoons, and the downright funky photos.
This tiny little magazine, with never a single advertisement, was just about the only place where you'd see serious discussion of the sonic merits of the JansZen 130 electrostatic tweeter, the Paoli Mark III, the KLH Nines, the Fulton FMI-80, and a brand-new vacuum-tube preamp from a small company in Minneapolis called Audio Research. This was something else ... a different set of values was in place here. If you looked hard, you might even find a funky little hole-in-the-wall dealer that actually carried this hard-to-find stuff. In the formative years of high-end, image, style, and fashion counted for nothing, zilch, nada.
The designer-jean, style-over-substance, marketing-uber-alles zeitgeist had to await the ascendency of Ronald Reagan, still some ten years in the future. Remember, these were the dark and war-torn Nixon/Ford years, a different kettle of fish altogether. The counterculture was ferociously alive and well in the early Seventies - this was the time of the Kent State mass murders, antiwar rallies that drew millions to every major city, the release of the Pentagon Papers uncovering a decade of high-level government deception about the Vietnam War, revelations of FBI spying and black ops, and the Watergate dam bursting with the President exposed as the Criminal-In-Chief.
During this unsettled time, J. Gordon Holt played a pivotal role in unearthing the interesting things when the American Hi-Fi business had to all appearances entered a state of terminal collapse. Sure enough, here and there, in little workshops all around the land, folks were building strange new products ... vacuum-tube electronics, electrostatic speakers, making direct-to-disc recordings, all kinds of zany items. They made their way to the door of the early Stereophile, and the market kept on growing. Slightly less funky dealers started picking them up. More companies appeared. In a few years, a new industry, risen from the ashes of the old, had a name: the High End. (No, Harry Pearson did not invent the name High-End. Long before his magazine appeared at the end of the decade, everybody in the industry was already calling it that, so let's put that self-serving little fable to rest.)
No more cut-n-try approximations, no hypercomplex theoretical math filled with mistaken assumptions, just straightforward Butterworth and Chebychev filter functions ... and none of this outdated "M-derived filter" stuff, either. Theile's paper also gives precise methods of measuring fundamental properties of the driver such as Fs (resonance frequency), Qt (damping), and Vas (compliance). With a scope, an oscillator, a voltmeter, a frequency counter, a test box, and a basic hand calculator, you could accurately design a closed or vented box system and get results within a fraction of a dB of the prediction ... a genuine breakthrough in low-frequency design that removed all of the hopeless cut-n-try guesswork of the last 40 years.
What's a little sad is that Theile's paper was ignored for nearly a decade simply because it was published in a little-known Australian journal. It took Robert Ashley of the Audio Engineering Society to pick up Theile's work and also that of Richard Small, who published a very comprehensive summation and extension of Theile's work in his doctoral thesis (as well as the modern near-field method of measuring loudspeakers). All of this material appeared in the AES Journal in 1973-74, and it took the speaker-designing world by storm. Within a matter of months, Theile-Small became the accepted method of designing, prototyping, and measuring closed-box, vented-box, and passive-radiator speakers all over the world.
Small simplified the system so powerfully that all it took was one of the new scientific calculators (the slide rule was beginning to fade away) and a set of nomograms to design accurate bass response. After personal computers were introduced in the early 1980's, the T/S equations became an integral part of every commercially available software package for designing loudspeakers.
Over at KEF in England, Laurie Fincham was extending the analytic techniques pioneered by Theile and Small on the more difficult problem of crossover design. Using the best available HP minicomputer of the day, he was able to acoustically measure the driver using FFT techniques, measure its impedance characteristics using the new T/S techniques, set up a prototype "target function" for the desired crossover filter, and let the computer optimize all of the possible values of crossover elements. In effect, the computer goes through thousands of potential crossover variations and picks the closest approximation to the desired response curve.
Although nearly everyone adopted Theile-Small techniques for bass design (except the transmission-line holdouts), it took ten years longer for computer-based crossover optimization to be widely adopted, due to the high cost of computers and programming. KEF paid more than $100,000 (in 1975 dollars!) for the two-rack-wide PDP-8 DEC system they had; this on top of the custom-built anechoic chamber required by early FFT techniques. The FFT programming was entirely custom-written in FORTRAN for KEF by full-time computer engineers on loan from a local technical college. As you might imagine, this was far beyond what a little company like Audionics could do, and the high-profile American companies of the Seventies, then as now, invested their profits in marketing, not engineering. Serious advances in loudspeaker design was the province of the British in the Seventies. (The Canadians would have their day in the late Eighties and onward, thanks to the government-funded NRDC of Canada.)
KEF, Celestion, and Bowers & Wilkins were pretty much alone in using the target-filter-function technique until the advent of low-cost, powerful PC's with off-the-shelf speaker-design software. Today, the speaker designer mouse-clicks the "optimize crossover" function after measuring the electrical and acoustical response of the driver, choosing the desired crossover topology, and selecting a set of starting values. After the PC models the crossover and graphs the response, you can build the physical crossover, measure the speaker system, and sure enough, it'll be within a small fraction of a dB of the software model. You still have to know what you're doing and how to measure the speaker; the computer won't think for you. But what it has done is level the playing field between the biggest and littlest speaker companies. We all use the same software, and the PC's used by JBL are no different than the one you're using right now - in fact, the computer you're reading this Web page with is far more powerful than KEF's PDP-8 I saw in the mid-Seventies.
The systems-modeling approach perfected in the early Seventies extended to driver design, an even more intractable realm. The BBC was seeking a cone material that would provide exact pair-matching as well as permitting the design of a highly consistent and repeatable monitor speaker. Bextrene, an acetate plastic derived from wood products, first saw use in the KEF B110 driver, which had a starring role in the legendary BBC-designed LS3/5a compact monitor.
In the late Seventies, the BBC perfected polypropylene cones, which had the significant advantage of not requiring a treatment with doping material, as well as higher efficiency and much flatter response. By a process I still don't understand, the BBC patents were circumvented in less than 3 years, and everybody and their brother started making polypropylene-cone drivers. Even mass-fi rack stereos use polypropylene drivers these days, which tells me that they must be even cheaper than paper to make. However, the BBC was very much on the mark in not using poly drivers any larger than 8 inches; the latest BBC monitor (the successor to the LS3/5a) uses a Dynaudio 5.5" driver with a poly cone, which I feel is the just about the right size for getting the best sound from polypropylene.
Moving on to electronics, the power amps of the late Sixties and early Seventies blew up a lot and sounded pretty nasty. We're not talking classics here, we're talking about junk that should never have been put on the market. The engineers of the early Seventies were still wrestling with problems like maintaining adequate phase margin with real loudspeaker loads, Nyquist feedback stability criteria, staying within the Safe Operating Area for the driver and output stage, and little things like that. Audionics' first amp, the PZ-3, fit right into the picture: loads of feedback, and very low THD distortion measurements. (0.03%, get it?) It measured just fine, but it wasn't too reliable in the real world, with an alarming fondness for shorting out driver transistors, smoking bias resistors, and shooting flames out of the cooling vents (in anticipation of the much larger solid-state melt-down at Three Mile Island).
In the mid-Seventies, along came Matti Otala and the discovery of TIM (slewing) distortion. Our Number One engineer (the conservative old-timer who designed the PZ-3) was utterly horrified by Otala's first Audio Engineering Society paper and said it was unscientific bunk (well, his language was stronger than that). Our young Number Two engineer took Matti seriously, let "traditional values" go by the board, and tried a different approach.
Bob Sickler let the distortion rise up to the 0.1% level, by making very large decreases in feedback (feedback dropped from 40-50 dB to 20 dB) and using the most linear complementary-symmetry topology possible. The slew rate and power bandwidth improved by a factor of 10 to 50 times. Best of all, you couldn't break it, even with a speaker simulator load hooked up.
In 1976, Audionics introduced the CC-2, which was the first low-TIM amplifier sold in the US. Sure enough, it sounded much better than the PZ-3, and the failure rate in the field was well under 1%. The reason for both was probably the 200 kHz power bandwidth and an excess phase margin of 60 degrees, both quite unusual at the time. Although I rarely listen to my CC-2 these days, it's still not a bad transistor amp; by now, though, nearly all transistor amps use the same design principles as the CC-2. Matti's paper had such a profound impact on the solid-state design community that nearly all high-end engineers got on board ... besides, it's hard to argue with better reliability, which a high slew rate and adequate phase margin certainly provide. Everyone loves reliability (well, I have to make an exception for software companies, but I digress).
As the high end market expanded in the mid-Seventies, Harry Pearson's "The Abso!ute Sound" magazine made its first appearance. HP's approach was more subjective than Holt's, and he was attracted to more unusual products than Holt. I wasn't a big reader or follower of HP, since he was attracted to things that left me cold, like the Dahlquist DQ-10, the big big Infinity panels, and the ever-updated galaxy of Magneplanar and Audio Research products. Still, despite my personal feelings, I must credit HP with playing an absolutely crucial role in blowing the whistle on the truly appalling sound of the first CD's, and in kindling the flames of the tube revival. Also, HP provided a continuity that could easily have been lost when J. Gordon Holt sold Stereophile to its new owners. (The "Establishment" Stereophile you see today bears no resemblance in style or content to the sassy, funny, and contrarian earlier magazine.)
I still remember the massive PR blitz (similar to the Windows95 onslaught) pushing the first CD's and their players. I didn't take the claim of "Perfect Sound Forever" too seriously, but I really did expect that digital sound would be a significant advance for the entire industry. (In extenuation, I was an AES member at the time.) After all, LP's have serious problems with end-of-side distortion, noise buildup, guessing the correct VTA adjustment, etc., and tape has its own set of troubles with scrape flutter, IM distortion, setting bias and EQ for the exact tape formulation, Dolby mistracking, etc. etc. Digital sidesteps all these problems, and has noise and distortion approaching that of an op-amp ... hundreds of times better than any LP or tape medium. In principle at least, it should sound as transparent as a good amplifier. Little did I know.
As it turned out, the designer of the CC-2, Bob Sickler, went out and bought one of the very first players, the Sony CDP-101. His roommate was a professional musician for the Portland Symphony, so when they both sang the praises of the new medium, I was expecting my first experience with digital-in-the-home to be something like hearing a well-done mastertape, or even a live mike-feed straight from the console. After all, both them had good taste in music, and I knew that the digital process was almost distortionless compared to any other medium. It had to be good, right?
My friends put on a all-digital DGG classical disc and all I heard from the big TAD studio monitors was screech, screech, screech. The massed violins were far worse than any Columbia LP I'd ever heard ... they actually sounded like carbide saws cutting into two by fours, and I heard tearing and ripping sounds in the loud passages. Gross over-the-top clipping distortion on a so-called "audiophile" recording. Unbelievable. The quiet passages were dead silent ... actually, like a switch turned off ... but any sensation of space, of stereophonic dimension, and of acoustic presence was totally absent. The start-stop reverberation sounded as flat as a paper moon and just as fake. I was speechless ... this was the most repellent sound I had heard in many years, and I knew it wasn't the fault of their hi-fi system, which was pretty good.
My friends were grinning the whole time and saying, "Isn't it so clear! There's no noise and clicks at all!" I was silently thinking "Is this the future of audio!?" So I simultaneously experienced both bitter disappointment and astonishment that my friends were having such a radically different sonic experience. And my CD-loving friends weren't headbanging yahoos; heck, one played violin in the Portland Symphony and the other had designed a first-rate amplifier, the best of its day. But they loved those first DGG discs and I was nothing less than appalled.
That whole experience really opened my eyes - and ears. I realized that people really do hear things in quite different ways ... my friends thought the Sony CDP-101 and the shiny little coasters were just terrific, and I thought they sounded awful! After that, I started taking the reviews in any magazine a whole lot less seriously. After all, how was I to know the reviewer was hearing same things that I did?
This experience gave me an unpleasant premonition about the future of the high-end industry. The exhibitors could only play LP's for so long at the CES before they gave into the tide of weirdly artificial CD's. What would that mean for product design in speakers and amplifiers? For one thing, forget about super-performance tweeters that went beyond 20kHz; that was dead forever with the ferocious brickwall filter that had to descend 96dB (the entire dynamic range of the CD) in the tiny frequency range of 20 to 22 kHz. And the sonics themselves? How would even the most clever engineers get around that?
Of course, little did I suspect that "tweaking" would become the relentless obsession of many audiophiles and reviewers including myself, and develop into an entire sub-industry of its own ... the first funny-looking Fulton speaker cable has only been on the market for a few months. I was still in the Seventies mind-set that you built audio equipment to sound good, and then you listened to it until it was time to build something new, and hopefully better.
No more big frog in a little pond, but the time spent with the Spectrum Analyzer business unit was an education not available in any sector of the audio business. MIL-SPEC and consumer-grade are two very different ways to build products. I peeked in on the audio world from time to time. I remember a brief flurry of interest created by the Quad 405 quasi-feedforward amp, with different exotic mixed feedback schemes appearing in every other issue of the Audio Engineering Society Journal. For a while there, it looked like the old-time high-feedback engineers and the new boys on the block could have it all: zero distortion, very wide power bandwidth, ultra-high slew rates, a simple output stage that didn't require any bias tweaks, and the complete elimination of crossover distortion!
Unfortunately, once you hooked these miracle amps up to real loudspeakers, the balance equations evaporated. (Isn't that just like speakers ... they're always screwing up the latest "wonder amp") As a result, none of this intense theoretical activity resulted in any lasting sonic breakthroughs, except to once again point the finger at loudspeakers.
The Fashion-Magazine Gatekeepers Take Over
From the perspective of an outsider, the Eighties were not the best decade for audio. As CD's wiped out LP's, many high-end consumers gradually forgot what good sound was like, and looked for guidance from the Big Two audio magazines. As these publications grew in circulation and advertising revenue, they tightened their grip on the industry, becoming gatekeepers that told faithful readers and chains of audio-boutiques which brands were "in" and which was "out", following the model of the fashion industry.
After Gordon Holt sold Stereophile magazine at the end of the Seventies, the policy did a swift 180-degree turn from "No Advertising" to only reviewing products that were advertised in the magazine - and had a minimum of six dealers, making for a slick little Catch-22 for new manufacturers trying to break into the market. You either had deep (corporate) pockets and entered the market with a big splash, or could forget about any reviews in the magazine that now saw itself as the industry's gateekeeper. Gotta keep the riffraff out, doncha know.
In a few years, things reached the point where high-end audio was no longer about sound, but perceived status, with high-profile reviewers passing out awards to the "inner circle" of manufacturers. Dealers had little choice but go along and get along; customers came in to the store clutching a dog-eared copy of the magazine, and by golly, they wanted that "Component of the Year" right now. At a discount. Especially if the review said it was much better than last month's favorite.
At a time when the Japanese magazine "MJ" was seriously writing about the sonics of Western Electric 300B's, Osram PX25's, RCA 845's, and GEC KT66's, the Big Two American magazines were rhapsodizing about this month's favorite $7000 DAC and $3000 speaker cables ... all supported by 4-color ads costing the manufacturer several thousand dollars per issue. The cheapskates were amused and entertained by the "tweaks" section and the letters column while the High Rollers got the color picture on the cover, the lead article, and most of the reviews. It was the Age of Reagan, after all. The stock market was rising by the day, hostile takeovers were reshuffling the map of corporate America, and Greed Was Good.
One reason audio magazines of the Eighties never compared Western Electric and Golden Age tube equipment to modern high-end was a simple result of the business ethic of the times:
Nobody ever paid Advertising Money for something that was 40 years old ... so it was off the radar screen entirely. Didn't exist. Hey, it's old, how could it be any good? Since Americans were taught by the magazines that old-timey stuff was junk anyway, guess where it ended up? The Akihabara district in Tokyo, to be sold to wealthy Japanese who sold Japanese mass-market electronics - to gullible Americans who believed every word in the trendy US audio-fashion magazines.
Big-name equipment reviewers came up with their own wacko vocabulary for aspects of sound ... words having nothing to do with sound or music, "bleached," "chocolate," "white," and others became part of audiophile jargon. This trained the audiophile to zero in on abstract sound elements, instead of the simple pleasure of listening to music. The magazines eventually came out with their own CD's complete with listening instructions for each track ... truly "Hi-Fi for Dummies," marking the degeneration of High Fidelity into a fashion-lifestyle statement.
The reader might think this is a pretty harsh assessment of an entire decade, but seriously, what has endured? Are there any classics from this time? Would you want a 1986 "state of the art" cable? A "statement" 1988 CD player? A 200-lb transistor amplifier chock-full of silicon goodness?
I didn't think so. Nothing goes stale faster than yesterday's hype. Nothing exemplifies that better than the magazines themselves; it's a thrill to read Fifties enthusiast magazines, J. Gordon Holt's Stereophile of the early Seventies, or practically any issue of Audio Amateur. But seriously, who wants to read a 1985 issue of Stereophile or Absolute Sound? C'mon, anyone?
Two good things came out of the Eighties: slow but steady improvement in speaker-driver technology and Walt Jung's important article about capacitor sonics in Audio Amateur. This article put "passive" components under the microscope for the first time, and surprise, they turned out to be a major source of subjective coloration.
Capacitors have easily measured differences in Dielectric Absorption (DA) and Dissipation Factor (DF). Teflon, polypropylene, and polycarbonate are best, and electrolytic, ceramics, and solid tantalums are the worst. And dielectrics (insulators) are everywhere, in circuit board substrates, wire insulation, anywhere two conductors must be electrically isolated. As with Matti Otala's TIM article 5 years before, there was a lot of resistance from the old-timers, but Walt Jung's DA and DF measurements were easily made and correlated well with what you could hear. In addition, people were finding out with digital sound that measurements right at the limit of detection were just as important as traditional THD and noise measurements.
This opened the door to examining discovering subtle weaknesses not seen before: caps are microphonic, and can self-excite and "sing" at resonant frequencies. Metallized-foil caps sound different than solid foil caps. Even solid-state electronics can be affected by vibration thanks to circuit board flexing and low-level microphonics in the polarized and charged electrolytic power-supply caps. Resistors can have voltage coefficients, and low-level point-contact rectification where the dissimilar metals meet. Insulation on wires in transformers and inductors can have poor DA and DF characteristics, and the process of winding the wire induces stress cracks where oxygen enters the wire. Low-level, hard to measure, but plainly audible on a good system.
For speaker and electronics designers, this adds another layer of fine-tuning ... but also another degree of freedom. I was surprised when I designed the Ariel that changing the tweeter caps to a different brand was subjectively equal to about 0.5 to 1.0 dB of equalization. Back in the Seventies, I used junkbox Mylar-films, along with everyone else, and equalized the speaker around them. These days, it's a choice between solid-foil Polypropylene, exotic Silver/Oil, or new-production Teflon caps if you want the best sound. Yes, they may cost as much as the tweeter itself, and it'll be worth it - and a lot more cost-effective than messing with cables.
The biggest difference between pre- and post-Eighties design is the awareness that "passive" parts may actually have more coloration than active circuitry. A pre-Eighties circuit will toss "nonpolar" electrolytics all through the design ... take a good look at a Revox A77 or Dynaco PAT-4 schematic if you want to see a lot of coupling caps in the signal path. It wasn't until the mid Eighties the idea arose that every single part in the signal path had to be examined for sonic degradation, not just transistors and tubes. The "Progressive Optimization Of Generic Electronics" (POOGE) concept goes back to Audio Amateur's series of articles about improving mid-fi amplifiers and CD players by replacing bad parts with good ones; it can be applied with even more success to a new design, and became standard practice in the industry.
The Thermionic Revival Meeting
or, Back to the Future
Thousands of engineers, designers, and hi-fi fans were ready for a return to good sound after a decade of more and more "accurate" speakers, power amps, and CD players. The crusade for magazine-defined "accuracy" had reached the point where reproduced sound was spectacular but also becoming bizarre and unreal.
In 1989, Ed Dell, publisher of Audio Amateur, took a chance on a new magazine devoted strictly to vacuum tube amplifiers. "Glass Audio" had three strikes against it: vacuum tube manufacturers were disappearing, most hi-fi retailers refused to carry tube equipment, and the magazine catered to the hobbyist market, which was also fading away. Yet a year later the magazine grew to twice its original size, and the readership kept growing with each new issue. What was going on here?
A little anecdote might illustrate what was happening on a larger scale. At the time I glanced at the first promotional issue of Glass Audio, I was also working on an advanced 200 watt MOSFET amplifier with two friends from Tektronix. This amp represented the pinnacle of the high-end art: fully differential, all-cascode, all-Class-A, zero-TIM, 200V/microsecond, fully regulated, and 120 watts/channel. The same month, I went to the second Oregon Triode Society meeting, and one of the members brought a rusty old Dynaco Stereo 70 that first saw the light of day when Dwight D. Eisenhower was President. The sum total of his "tweaks" was to convert the EL34's to triode (cut and tape two wires), and replace two coupling caps. About 2 hours with a soldering iron. We're not talking aerospace engineering here.
The OTS guy turned it on, and we compared the Stereo 70 to everything in the dealer's showroom. It was plainly superior not only to any transistor amp in there, it wiped out the latest $3000 Audio Research all-tube confection that had received a glowing review in the latest Stereophile. Say hello to humble, and good-bye to price, power, and prestige. (That dealer did not invite the OTS back - gee, wonder why? Buncha troublemakers if you ask me.)
If you stay in audio long enough, that kind of experience can make you do some deep thinking about cherished assumptions. I set aside the transistor project, stopped laughing at the "tube nuts" and subscribed to Glass Audio (Vol. 1, Issue 0). Two years later, I reviewed the Herb Reichert Silver 300B and the Audio Note Ongaku for Positive Feedback (on the newly-designed Ariels).
felt I knew my speakers inside and out. Or so I thought. The Ariels were transformed from a pleasant speaker to near-electrostatic realism and "you-are-there" quality. All from changing an amplifier! David Robinson later called this my "Road to Damascus" experience. That ended any idea that amps were pretty much all the same, or if they weren't, mainstream high-end gear was pretty close to perfect. I was surprised to discover that speakers were better than I thought, and that amps had a long long way to go.
As articles from Japanese and French magazines appeared in Sound Practices, Glass Audio, and Vacuum Tube Valley, the notion of craft, or "artisan" audio began to emerge. People started to design and build exotic amplifiers that cost thousands of dollars in parts alone, and then told others about their experiences in new magazines, the Internet, and regional vacuum-tube audio fairs. The subversive notion grew that quality was something you built, not something you bought.
As people built more, it became apparent that mainstream prices were grossly inflated relative to parts cost ... the transistors in a $15,000 high-end amp cost less than a hundred dollars, while fancy metalwork, 4-color ads, and a dealer network add zero to the sound. On the other hand, hand-made power triodes, point-to-point chassis wiring, and custom-wound transformers are obviously expensive and labor-intensive ... and the difference from mainstream high-end to triode are obvious to the most casual listener. Oddly enough, many audiophiles are relatively deaf to the experience, but non-audiophiles can hear it right away.
I've had audiophile friends play "Planet Drum", "Jazz at the Pawnshop" or the latest Stereophile test CD on a superlative amplifier like the Ongaku and just not "get it." I would play ravishingly beautiful music that would take me close to tears and my guests would just look bored, or start talking over the music. That's when I realized there really is a difference between listening for certain audiophile sound effects and getting swept up in the music. Obviously, musical tastes differ, but there's listening to music and listening for sound effects.
The home-theater boom of the Nineties underlines this. These gadgets don't play music at all; they measure well and all that, but music? It's like there's a hidden MP3 processor in there, stripping away 90% of the content, leaving behind a music-like shell with nothing in it. I have no clue how the home-theater people do it, but music has a real struggle getting through these things. Dialog, sound effects, car crashes, phaser blasts, you bet. Music? Nope. Can we interest you in a personal MP3 player?
Like ancient Gaul, the audio market has split into three parts: home-theater (the life-support system for just about every dealer), high-end (for few remaining true believers in the review magazines), and last but certainly least in terms of market share, equipment optimized for music playback.
But thank goodness it's there, otherwise we wouldn't have any High Fidelity at all. And somebody must be paying attention, since we finally have the gift of digital done the way it should have been in the first place, the competing Sony DSD and DVD-A systems. How the same companies that designed the mid-fi 44.1/16 PCM Red Book standard came up with not one, but two genuinely high quality digital systems is a mystery I don't understand (although the expiration of the original Sony/Philips patents might have a lot to do with it).
What's interesting about DSD and DVD-A is that it exposes the "accuracy" claim of 44.1/16 digital as the fraud it was all along. The new mediums sound very close to top-quality analog mastertape or direct-disc sources, while the exact same material on a top-flight CD player sounds flat, artificial, canned, the exact words that were used to describe it 20 years ago.
Play some music from SACD, DVD-A, LP, or open-reel tape on a vacuum-tube system to an audiophile used to solid-state, and they are usually startled by just how "Stereo" and three-dimensional everything sounds. Well, why do you think "Stereophonic Sound" made such a big impact in the Fifties? It was all-analog, all-tube sound, and the difference between "Stereophonic" and mono was astonishing. We are very lucky to have to have both triodes and SACD/DVD-A make their joint appearance at the turn of the century. Rather than a bunch of old-timers grousing about how great things sounded in the Golden Age, all you have to do is build a simple triode system, get some efficient speakers, and show friends what Stereophonic High Fidelity is all about. If you don't want to build, well-restored Golden Age equipment is satisfying and a heck of a good deal.
Don't know where to look? For building, try the Tube DIY site at Audio Asylum. Want to own an American classic? Try Vacuum Tube Valley for starters (avoid eBay!).
The New Millenium
Looking back, it's interesting how the 1930's, the 50's, the 70's, and the 90's were periods of rapid innovation and change, while the "out" decades have been times of backsliding, mass-fi, and technical regression. Where next? The fizz and argumentation of the first wave of triode mania has come and gone, taking many of the early magazines with it.
Home theater continues to make inroads on the remnants of the mainstream High End business. Transferring the prestige game from 2 channels to 5 ... or 6 ... or 7 channels is pretty simple, especially if you can persuade the client to build a "media room" to show off all the fancy, soon-to-be-obsoleted gear. What's funny are the short time horizons of the home theater crowd; it was only a few years ago they started buying expensive system controllers that were all digital. All digital at 44.1 or 48 kHz, of course.
What about higher-fidelity mediums like DVD-A 192/24 or DSD? Ooopsie! Thanks to the paranoia of Hollywood executives, a standard for transmitting DVD-A or DSD from player to receiver or DAC has been a long time in coming - many CD and DVD players still downsample to the legacy Red Book 44.1 or Dolby Digital 48 standard before they transmit a digital signal to the outside world. (Pioneer is a welcome exception here.)
The business model for vacuum tube audio is still being developed. The Japanese market is a pale shadow of the glory days in the early Nineties, so sales must go into the ever-cautious American market and the Chinese portions of the Asian market. The Internet is making a difference; although individual newsgroups, bulletin boards and forums are regularly disrupted and eventually destroyed by anonymous trolls, quieter and more civilized groups promptly appear to replace them. The Internet is a big place, after all. The biggest opportunity are people who love music, then discover that home theater or mainstream high-end are not for them.
This is where well publicized regional hifi shows can make a real difference. Another idea would be adult-education classes through local community colleges, similar to existing classes in Wine Appreciation or Gourmet Cooking. There's no reason that music-appreciation classes in Quality Audio couldn't be offered in the same way, with advanced classes offering hands-on instruction in kit-building. All you have to do is connect music lovers with genuine high fidelity, show them it doesn't have to cost absurd prices or turn the home into an engineering lab, and they'll figure out the rest.
The “High End"
After the destruction of the US consumer electronics industry, a small domestic cottage industry arose. In other parts of the world, this sharp break didn’t occur, due to the survival of the traditional high-fidelity manufacturers. In the US, though, an entirely new market with new magazines, new dealers, and new manufacturers arose, creating a separate market called “high end.”
Over time, the market grew larger and larger, and the two little magazines that were originally considered the “underground press” became more and more powerful over the decades, eventually exercising life-and-death power over the smaller companies. Why? Very few dealers dare question the wisdom of the slick magazines; if a new product doesn’t get a glowing review, most customers don’t even want to listen. Of course, new products from the “big ten” go to the head of the review list; newcomers get to wait, sometimes for many years, and with no assurance of a favorable review. In essence, there is an inner circle (who always get favorable reviews), and there’s everybody else (who take their chances).
Not to toot our horn too much, but Positive Feedback and Sound Practices have begun to crack this monolith by reviewing and discussing products far off the beaten path of “approved” audio. The whole idea of diversity co-existing with quality is slowly changing the manufacturers, the magazines, the dealers, the consumers, and most importantly, the enthusiasts.
The increasing conservatism and cash-flow problems of many American hi-fi dealers is leading them to the easy and profitable solution of selling pre-packaged home theatre systems that bear the magic logo. The marketing logic is rock-simple; if it's good enough for world-famous Hollywood movies, it’s good enough for a consumer like you! The saturation of the traditional high-end market in the US is leading many dealers to take the path of least resistance and get out of specialist audio entirely, carrying only equipment blessed by the logo and designated as “home theatre.”
The home theatre-only dealers may get an unpleasant surprise when they find themselves competing with discount warehouses and mail-order. If all the consumer wants is a shiny little sticker that says “Windows,” “Intel Inside,” “Dolby,” or “THX,” why not buy the commodity from the cheapest source possible, since it’s all the same anyway?
Shucks, why not cut out the middleman and just sell the stickers by themselves? That way folks can stick ‘em on their K-Mart VCR’s, TV sets, and microwave ovens, and show off their new “home theatre” system to the neighbors!
This isn’t a name I like, but the triode amp/high efficiency speaker phenomenon hasn't yet received a good name yet. It taps into an enthusiasm that has been carried forward by dedicated Japanese, Italian, and French experimenters for 4 decades, and is now beginning to change the character of the US market. Although some may think all the noise is about archaic technology, it’s actually about re-thinking the entire esthetic of the high-end. These folks are turning away from the sound-effects orientation of the high-end (audiophile literally means “sound-lover” after all) and turning towards the emotional quality of the music and how it influences the listener. The retro technology is only a means to an end; modern ingredients can get you there as well.
Distortion Over The Decades
This chart marks the path that amplifier THD has taken over the decades, with dots indicating the presence of a “landmark” designs that others followed, like the Williamson or the fully-complementary transistor amplifier. It shows that for a few designers, the THD figure has lost the powerful grip it once held on the industry, while for others, they continue to do all they can to drive it lower and lower.
The problem with using THD as a yardstick of quality is the order of the distortion term has a far more audible effect than its absolute magnitude. When you have 3 or more fundamental tones, the number of IM sum-and-difference terms are much worse when you have to contend with a large number of harmonics past the third. This was first discussed by Norman Crowhurst and D.E.L. Shorter of the BBC in the mid-Fifties, so it’s hardly a new or radical concept.
Regrettably, the single-tone additive THD and the SMPTE or CCIF IM tests in common use today do not take this into account, thus ignoring the far more deleterious effects of the upper harmonics with real musical sources, which invariably have more than 3 fundamental tones. With real music, the large number of sum-and-difference terms modulate the noise floor of the musical program, covering up the low-level room reflections the listener uses to analyze the spatial qualities of the performing space.
The market-driven pursuit of the ever-lower THD number is why the audio industry progressively abandoned of linear amplifying devices in favor of less linear devices with more gain, and turned to circuits that used greater and greater amounts of feedback. With each step the THD figure moved downward, while the harmonic structure became less predictable and more chaotic. Back when all audio equipment produced several per cent distortion, the THD figure told you something about how it might sound. Today, with low-fi car stereos producing less than 0.01% distortion, the specification no longer has any meaning.
This long-term trend was a direct result of Norman Crowhurst and D.E.L. Shorter losing the distortion-weighting debate of the 1950’s. Back in the days of the slip-stick, who wanted to calculate all of those terms out to 9th or higher? Worse, their proposals cast question on the wisdom of choosing high-feedback pentode circuits over low-feedback triode circuits. When the 2A3-powered Brook went out of production, the triumph of the Williamson was complete. No triode amps were made anywhere. The debate was over.
With nobody minding the store, the industry was to free to take the next big step downward: transistor sound, in an ugly quasi-complementary debut. It took 10 to 15 years of very challenging work to get transistor amps to approach the quality of the pentode amps they obsoleted. By the time transistor amps had reached a rough sonic parity with their direct predecessors, the much older triode technology, along with the weighted-harmonic debate, had been forgotten.
Now that amplifiers had been perfected (in the thinking of the AES mainstream), it was time to extend the same philosophy to recording media – digital sound replacing analog tape and records. And once again it has took another 10 to 15 years of difficult work to approach a rough sonic parity with the systems it obsoleted.
This is why listening to a 30ips mastertape (the speed used by Ampex in 1948) or a good LP (also introduced in 1948) on a 2A3 or 300B amplifier is a profoundly disturbing experience for an audiophile with a sense of history.
What do we have to show for a half-century of two-steps-forward, one-step-back? What direction would audio have taken if distortion-weighting had been taken seriously when it was first proposed?
The Yuppies Invent Boutique Audio
After the flurry of advanced theory faded out in the mid-Eighties, the leading manufacturers turned instead to a heavy-metal approach, led by the cost-no-object full-time Class A transistor amps made by Krell, Threshold, and Mark Levinson. By general agreement, the heavy-bucks, heavy-weight, ultra-high-current amps were considered “state of the art,” to use the hip phrase of the day. Actually, we could have built these monsters at Audionics in the mid-Seventies, but we just couldn’t bring ourselves to cross the psychological barrier of building a hundred-pound amplifier with a steady-state power dissipation of more than 400 watts. Maybe it was because we all worried about energy shortages in the 1970’s ... remember when people turned thermostats down to 68 degrees and the White House turned off the Christmas lights to save energy? Oh well, you didn’t miss much.
As the decade moved on, Stereophile and The Absolute Sound magazines tightened their grip on the industry, with dealers and customers becoming slaves to the fashion magazines. With each new issue, the ads got slicker, prices went further and further into the stratosphere, and the sound became more spectacular, more impressive, and less enjoyable. Conspicuous consumption as-a-fashion-statement had finally arrived. Listening Pleasure? Satisfaction? What’s that?
By the end of the 1980’s, there wasn’t much room left for breakthroughs in solid-state amps and preamps. No new MOSFETs (which have major problems with nonlinear gate capacitance, still unsolved after 20 years), and very few new bipolar power devices. Motorola, the pre-eminent supplier of military-grade semiconductors, has made it clear to the remaining builders of high-quality transistor amps that the company intends to gradually withdraw from analog semiconductors and concentrate on more profitable digital gizmos like cellular telephones. There are plenty of analog semiconductor vendors in Asia, but nearly all of their output is concentrated on mass-fi components designed for use in car stereos and TV sets. There’s just no way you can modify a modular “brick” intended for the dashboard of a Toyota pickup into a high-fidelity component.
The arc-welder approach to building transistor amps came to the end of the road, with the high-prestige amps becoming absurdly large and expensive, and sonic gains reaching the point of diminishing returns. The late 1980’s high-end market settled down into a steady state. Entry-level now meant designed-to-a-price Class AB transistor amps, and compact little speakers on expensive stands. The “true” high-end was populated with 200 to 500 watt amps (tube and Class A transistor), and large, complex, and inefficient planar, hybrid, and dynamic speakers.
Many reviewers, audiophiles, and dealers still believe in this trinity of price, power, and prestige. But not all. At the end of the decade, a new esthetic began to change the industry once more.
"It is the mark of an educated mind to be able to entertain a thought without accepting it."