Behind The Scenes (Apr. 1979)

After trying to cope with too many "winters of their discontent," in the arctic clime of Chicago, the powers that be in the Consumer Electronic Show decided to hold their annual winter pow-wow in Las Vegas. I missed the inaugural event in 1978, but with the year 1979 still in its swaddling clothes, I spent January 6th through 9th at the Winter Consumer Electronics Show in Las Vegas.

Ah, Las Vegas! A tacky tinsel town, full of tawdry temples of titillation and temptation, with an infinite capacity for rapacity and rip-off. (How's that for alliteration!) Getting around the town is an onerous task ... taxi fares are outrageously high and there are interminable delays in getting one at every hotel. This factor alone was responsible for our inability to cover many events and keep up with a very tight schedule. In Las Vegas there are two kinds of deserts ... one is the sandy 12 wastes surrounding the town ... the other is the gastronomic desert that is Las Vegas itself. You can get two kinds of food in Las Vegas ... cheap awful food and expensive awful food. Well, why go on ... if you are a gambler, the town is paradise ... if you are not, it can be a purgatory. Considering amenities, attitudes, and prices between Las Vegas and Chicago, one almost longs again for the latter's stinging sleet and frozen feet! In spite of the vicissitudes of Vegas, it must be admitted that at the convention hall, the WCES was both well organized and well laid out. If you wanted to concentrate on audio and avoid the watches and games, these areas were better isolated from each other than previously. So it was with the other areas of interest. As usual, the sound demo rooms suffered from sound transmission through their walls, but better that than trying to demo on the open floor of the convention hall. There were isolated exhibits in many of the hotels around town, but the bulk of the so-called "esoteric" audio demonstrations were concentrated at the Jockey Club, an expensive cab ride from the convention hall.

With the economic situation in this country, 1978 was considered a "soft year " for the audio industry. Thus, manufacturers and dealers came to this WCES with a certain amount of trepidation, looking for hopeful signs that the bottom wasn't going to drop out of their business in 1979. Well, this WCES certainly wasn't the up-beat, ebullient, optimistic gathering of some past years. However, attendance was very good, said to be the best ever, and there was enough new technology introduced and generally aggressive marketing plans unveiled to buoy confidence in the industry, which was reflected in a respectable amount of buying.

As noted, this WCES was a tough show to cover. There were many things I just didn't get the opportunity to see. Needless to say, I've had to give priority to those items which are currently in the prime areas of interest.

Metal Particle Tape

Whether metal-particle tape and cassette decks capable of recording this new tape would have reached their present state of development without the stimulus of the audio sales slowdown in 1978 is debatable. In any case, metal-particle tape is on the market in the form of the 3M "Metafine," and a commitment to manufacture this type of tape was announced by TDK, Maxell, Fuji, and BASF. There is little reason to doubt that Memorex and Ampex will climb onto this bandwagon as well. Some manufacturers had some actual samples of metal-particle tape at the show, and there were even a couple of demonstrations, with that of JVC making a notable impression, showing the difference in dynamic range and headroom between a high-bias ferric tape and the metal-particle tape in the recording of a small jazz combo. As for cassette decks equipped with the special erase and record heads and bias and equalization circuitry to record metal tape, the pioneering deck of Tandberg has been joined by models from JVC, Nakamichi, Aiwa, Teac, Sanyo, and BIC/Avnet. In fact, 131C stole a march on some of its rivals by unveiling their model C-1, the first car stereo cassette to handle metal-particle tape.

Both the C-1 and the BIC T-4 metal compatible deck are of the two-speed variety recently introduced by BIC. The combination of metal tape and a cassette speed of 3 3/4 ips should really satisfy those looking for widest possible frequency response. Technics was showing its Model M-95 cassette deck, which at $1300 was the highest priced metal compatible unit at the show.

Lux was showing two metal-particle tape compatible decks, interesting in that both units employ d.c. amplifiers in the record and playback circuits and have user adjustable azimuth control for the record head. Most unusual is that the entire head housing assembly is easily removable and could accept heads in a new configuration, should such items appear in the future ... i.e. "half-track" cassette heads. The Eumig company showed its model FL1000 metal-particle tape compatible deck, and they also announced that the first Eumig cassette deck, their CCD model, can be updated with new erase and record head and bias and equalization circuitry to handle metal tape at a cost to the consumer of $200. In addition to the aforementioned metal compatible cassette decks, models of the same kind will be forthcoming from Hitachi, Fisher, Yamaha, Toshiba, Sony, Onkyo, Marantz, Sansui, Pioneer, and Sharp.

With such overwhelming industry response to metal-particle tape, we are unquestionably entering a new era of high-quality cassette recording, which should come into full flower at the CES in Chicago, and have a most salutory effect on the market.

Before we leave cassette decks, it should be noted that other technological advances were in evidence besides metal-tape capability. Hitachi and Aiwa had decks in which tape formulation bias, equalization, and sensitivity were set via a microprocessor. The JVC KD-A8 deck is another of this breed, but gilds the lily by its ability to record metal-particle tapes as well.

Nor should we forget that open-reel decks still furnish the very highest quality in tape recording, along with their special capabilities of editing, overdubbing, etc. A number of new 10 1/2-in. open-reel models appeared from such old pros as Teac and Technics, along with Akai, and relative newcomer, Philips. Many new performance and convenience features are on these new decks, including quartz-lock capstan drive.

Digital recording at the WCES is still on the back burner in contrast to the red-hot professional arena. Still, there were the PCM units from Sony, JVC, Mitsubishi, and Technics. At the Technics exhibit they were playing their VISC digital disc, using the Stravinsky L'Histoire du Soldat I had recorded for them on their PCM/VCR system last summer. It is worth noting that Dave Monoson, one of the most astute and knowledgeable PR men in the audio business, who handles Yamaha and Maxell and imports the interesting new Nagatronics ribbon phono cartridge (and a man with his ear close to the ground in Japan), feels that such tremendous advances are being made in LSI (large scale integrated) chip technology that PCM capabilities will be built into future VCR machines within 18 months to two years. The price range envisioned for these units would be around $2000, and of course this would make pre-recorded digital music cassettes a distinct possibility.

One final note on the tape scene ... don't forget that while metal-particle tape is causing a minor revolution in the world of cassette decks, the very same kind of metal tape has equal applicability to open-reel decks, to video cassette recorders, and even digital recorders. The super high packing density of the metal-particle tape will have an equally profound effect on the performance of these formats.

Audio Mainstay

It goes without saying that at the WCES, receivers were still the mainstay of the audio business. Models continue to proliferate, with every imaginable gizmo and technological advance being applied to them to gain some competitive advantage with each other and have greater appeal to the audio consumer. The horsepower race seems to have reached a plateau, with the 330-watt-per-channel Technics unit still the leader.

However, fast gaining ground on the receiver market is that of integrated amplifiers with associated tuners.

Some of the integrated amplifiers are invading the "ultra-fi" quality once the exclusive province of high-end amplifiers and preamps. For example, Kenwood's KA-907 integrated amplifier is rated at 150 watts per channel, with a rise time of 0.8 microseconds and a slew rate of 230 volts per microsecond! This, along with many amenities in the preamp section, including an input for moving coil cartridges.

Sansui has its 160-watt-per-channel AU-X1 integrated amplifier with rise time of only 0.5 microseconds and a 260 volts per microsecond. Let's face it, friends, those kinds of specs are better than many of the highly regarded "audiophile" of the separate amplifiers! Technics has a new waveform input/output distortion analysis system, which uses complex music signals for testing rather than the usual sine and square wave signals, and they state the use of music signals is a more accurate representation of an amplifier's true transient response and TIM distortion capabilities. One of the first fruits of this new analysis system is the Technics SU8099 integrated d.c. amplifier which puts out 115 watts per channel with THD claimed to be no more than 0.0007 percent. Yamaha and JVC, just to name two that come to mind, have equally sophisticated integrated amplifiers. The separate tuners, made to be companion pieces to these integrated amplifiers, are very advanced units. Perhaps the most sophisticated of the tuners was the Kenwood KT 917, which utilizes what is termed a "pulse count FM detector" that converts each cycle of an FM signal into a digital pulse. The detector's output is proportional to the count of density and is said to be theoretically and practically perfectly linear. The system is claimed to reduce FM distortion by a half, while improving signal-to-noise ratio 6 to 12 dB.

Quadraphonic Comeback?

As mentioned earlier, the Jockey Club in Las Vegas was the exclusive headquarters for the so-called "esoteric" audio manufacturers. With all those exotic audio goodies all in one place, needless to say, the audio press corps spent a lot of time there auditioning them. However, before we take on the Jockey Club, a slight diversion to the MGM-Grand hotel, to listen to some quadraphonic sound.

HUH! You heard me correctly, friends.

Regular readers of this column will know that for several years now I have been dealing with Mr. Wesley Ruggles, a charming fellow whose uncle is that fabulous comedian, Charley Ruggles.

Wesley had acquired the rights to the Tate Directional Enhancement System, an ultra-sophisticated SQ four-channel decoder, featuring separation of 35 dB between channels. Wesley was trying to get this circuit reduced to integrated chips by the National Semiconductor Co. First results were promising, and I was supposed to receive one of the first SQ decoders built around the chips. Well, problems developed, promises were made, things got worse, quadraphonic sound became moribund . . . in any case, I never got the decoder and forgot about the whole thing. Well, I saw Wesley Ruggles in the convention hall, and he directed me to the suite of the Fosgate Company at the MGM-Grand hotel. Fosgate has heretofore been involved with high-quality auto-stereo components, but it seems the three chips of the Tate system finally had all the bugs ironed out, and Mr. Jim Fosgate had acquired a license to use them. His company has developed what he calls the Tetra One, a four channel decoder, amplifier, and equalizer for cars, and the Tetra Two, a straight SQ decoder for home use. At the present time, only the car unit is in production, and this is what I heard through a very elaborate high-power four-channel system. In the SQ mode, playing various SQ recordings, the unit was as good as I had heard in the prototype some years ago. Separation was outstanding, with none of the annoying pumping that was the bane of some of the gain/adjust-logic decoders. However, it is in synthesizing four channel effects from normal stereo records where the Tate system really shines. Depending upon the micro phoning techniques used in the original recording, some extraordinary effects are produced. It is interesting to note that the Audionics Company of Oregon also has a license for the Tate chips and will be producing a decoder.

And, of all things, Dr. Ray Dolby has acquired a Tate license for the four channel decoding of his movie sound tracks! Does all this mean a return to four-channel sound? The FCC decisions are still pending, but the Fosgate people are quite enthusiastic about the prospects for the Tate system.

There are a lot of old SQ recordings around, and it is true that all EMI classical recordings and some of those of German Electrola are recorded in SQ. We will watch this development very closely.

Let me preface my report on things at the Jockey Club by stating quite candidly that at that hotel, the bastion of the "high end," I heard a lot of appallingly bad sound . . . a good deal of indifferent sound, and , I'm afraid, a bare modicum of really good sound. I went into many rooms loaded with expensive equipment, and the poor balances, screechy distortion, boomy distortion, annoying buzzes, rattles, hums, undamped resonances, and crummy source material was beyond belief. The worst part of it was that there were people there smiling and saying, "Isn't that great?" In several instances, I tried to point out the distortions I was perceiving, but they just wouldn't acknowledge the fact. I assure them and you, dear reader, that I wasn't trying to be a "wise guy" or a "big deal." I was genuinely trying to be helpful. Most of the problems were in the phono playback setups, with a lot of mistracking, etc.

Superb Speaker Sound

In the area of exotic technology, the Plasmatronics loudspeaker is a tour de force. This was my third encounter with this system, and with an entirely revamped midrange and bass speaker, the sound was superb. Of course the major area of interest is in the "plasma" driver which operates from 700 Hz to beyond 20 kHz. Helium gas is bled into an "ionization" chamber and the output of a Class-A tube amplifier into the chamber ionizes the helium creating a "plasma" and subsequently modulates what is, in essence, a "massless diaphragm." As you might expect, the sound from 700 Hz up is seamless and silken smooth, with utterly astonishing transient response.

Percussive sounds happen instantaneously with not the slightest smidgen of overshoot. It is big, expensive ($6500.00), complicated in its set-up, and with the helium costs about 25 cents an hour to play. And good though the new midrange and bass is, you wish that the plasma technology was also operative in this end of the frequency spectrum. It certainly isn't for everyone, but it is also incontestably one of the finest transducers extant.

Another sound that would be easy to live with was found in the Acoustat room. Their new electrostatic Monitor has been further refined and is now in full production. Though large, the styling is sleek, modern, and elegant. Here too, the sound is exceptional for its smoothness, especially on strings and voices, and transients are sharp and clean. Stereo imaging is exceptional, with good depth perspective and image stability.

Magnetic-Field Amp

Bob Carver brought some of the first products from his new Carver Corporation, which along with the metal particle tape, represented some of the newest technology at the Show, and aroused great interest. As I'm sure you know, Bob founded Phase Linear some years ago, and his line of high-power amplifiers and an innovative preamp were the basis for a very successful company. Bob sold his interest in Phase Linear (which has subsequently been sold to U.S. Pioneer) and formed his present Carver Corp. His first products are a 250-watt-per-channel and a 350-watt-per-channel amplifier in what he terms "conventional" design.

Decidedly unconventional is his innovative M-400 "Magnetic-Field Amplifier." The amplifier is a brushed-gold, 63A-in. cube, which weighs in at only 12 pounds. There is a moving LED display with VU ballistics covering a 50 dB dynamic range. This tiny unit has an output of 200 watts per channel at 8 ohms from 1 Hz to beyond 20 kHz! Frequency response is listed as from 1 Hz to 250 kHz. THD is rated at 0.05 percent and TIM distortion is said to be unmeasurable. Hum and noise is rated below-100 dB at full output.

Slew rate is said to be better than 80 volts per microsecond. Ok ... very interesting, but what is a magnetic field amplifier? Patents are still pending, but I was able to determine that one of the different things about the unit is that it has neither transformer nor big electrolytic storage capacitors.

Voltage is stepped down, and energy stored in a small field coil. The amplifier has neither heat sinks nor cooling fans, as the efficiency of the amplifier is said to approach 94 percent! Consequently, the amplifier rarely gets warmer than room temperature. The M-400 employs fast-acting FETs, except for special silicon transistors in the output stage. An interesting point is that the M-400 maintains a constant output impedance so a number of speakers can be played in parallel without damage to the amplifier. The amplifier cannot be conventionally bridged, but merely using one output channel the unit gives a 400 watt output! The projected price of the M-400 is $349.95. In other words, a pair of these miniscule lightweight units will give you a 400 watts per channel for $700.00. I can see a lot of applications for such a unit. If the amplifier proves to be reliable, rock music road shows could really cut down on the weight of the huge amplifiers they now drag around, and their ability to accept multiple speakers without impedance changes would be equally useful. In consumer situations, a pair of them would furnish a 200-watt-per-channel bi-amp set up.

I listened to my latest London Philharmonic direct-disc recording of Morton Gould's Spirituals for Orchestra, with the M-400 amplifier driving a pair of KEF 105 speakers. These are not the most efficient speakers in general and, by coincidence, happen to be the monitor speakers I used on the London recording sessions. There are some very violent and heavy bass passages in this recording, and we played it back at a good high level. The sound was excellent ... highly detailed, with good solid bass, and crisp clean transients. String sound was very smooth.

After playing through the disc, the M400 was slightly warm to the touch.

Quite an amazing demonstration considering the size of the unit. Bob Carver has always had a special expertise in signal processing. Next month we will report on some of the unique new circuits in his new C-4000 preamp, along with many more audio goodies from the WCES.

(Source: Audio magazine, Apr. 1979; Bert Whyte)

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