At the conclusion of the first part of my report on the Winter CES, I described
the new Carver "magnetic field amplifier" and now I continue the
report with Bob Carver's other innovative product, a preamplifier he calls
the "Model C-4000 Sonic Hologram Generator." Now there is a mouthful
for you! I am sure most readers are familiar with visual holograms produced
by a laser beam, which in their three-dimensional projection creates such a
vivid image it appears to be real. In the somewhat ambiguous press release
put out by Carver's PR firm, the C-4000 preamplifier is said to produce the
sonic equivalent of a hologram, with the spatial positioning of musical instruments
as "precisely defined" as in the original sound field. Making allowances
for catchy adjectives and PR enthusiasm, there is no denying Bob Carver's expertise
in signal processing, and his new preamplifier does do some interesting things
that do indeed contribute to a heightened sense of musical realism. Bob wouldn't
reveal any details of the circuitry involved, but apparently it is a very clever
variation on phase switching and manipulation. Using conventional stereo recordings,
when the "hologram" switch on the front panel of the C 4000 is activated,
the sound is no longer confined to a direct output of the loudspeakers, but
becomes somewhat analogous to a sound "stage," A broad panorama of
sound is heard stretching to the left of the left speaker and to the right
of the right speaker, as well as the space between the speakers. This is accompanied
by an apparent in crease of front-to-back depth perspective. There have been
such devices used before, but the difference is that this "sonic panorama" is
created with out some of the anomalies that previously accompanied similar
devices. For example, there is no change in the amplitude of the music signals.
There is neither "bloating" nor "truncation" of the apparent
size of musical instruments. There is no image "wandering," and instruments
are in proper spatial perspective. In essence, the "hologram" facility
enables music to be reproduced from loudspeakers with out the characteristic "boxiness," which
plagues most speakers, even those with wide-dispersion tweeter and midrange
drivers. It must be noted that while the "hologram" device affords
a "sonic panorama" with most types of loudspeakers, it is most effective
with speakers which produce good stereo imaging. The KEF 105 speakers, with
which Carver was demonstrating his equipment, are particularly good in this
respect. As far as I could determine, the "hologram" circuitry appears
to work without any degradation of normal sonic qualities.
To gild his lily, Carver had added a built-in delay system to his new preamp. Utilizing the Reticon chip of the "charge-coupled device" variety of time delay, the unit affords initial delays of 50 and 85 milliseconds, which are user adjustable. There is also a 20-watt-per-channel amplifier built into the C-4000 to drive a pair of delay speakers. Bob had placed a pair of in expensive speakers at the wall/ceiling junction slightly to the rear of the listening position. Judicious use of the time-delay control in combination with the "hologram" feature can remarkably enhance the illusion of reality. Simultaneously defeat the "hologram" and time-delay switches, and the panoramic sound "stage" you have created collapses rather dramatically.
As you might expect, the C-4000 has many other facilities, such as a third-generation auto-correlator noise reduction and peak unlimiter system, low-noise RIAA phono stage, etc., but the foregoing outlined the highlights of this unusual new preamplifier.
Heavyweight Turntables
The emergence of so-called "audiophile" discs . . . direct-to-disc, digital/analog hybrid, super carefully processed analog recordings . . . has once again focused attention on disc playback equipment, and at the Jockey Club in Las Vegas there were quite a number of new items, some of them as "far-out" esoteric as you can imagine. For example, the indefatigable Bob Fulton was showing a new turn table, apparently designed for Texas oil barons! The turntable platter was machined from a solid billet of copper and weighs a mere 65 pounds! This massive platter is mounted on equally massive machined-steel tripod sup ports, with slots in each leg of the tri pod so that a phono arm can be mounted on each leg, in the manner of the Micro-Seiki unit. A huge synchronous motor is completely free standing in its own housing and drives the copper turntable via a special silk belt, which is said to have compliance factors to afford a filtering effect on motor vibrations. Belt tension is adjusted by moving the entire motor / housing assembly. If Bob is serious about this unit, it can be yours for (gasp!) $6800.00! Obviously, review samples will be on the scarce side.
At the Win Laboratories exhibit, the urbane Sao Win was proudly displaying what has to be the most beautiful turntable I have ever seen, his new model SDC-10. While constructed entirely in this country, it uses crystal clear, 3/4-inch thick, special German Lucite (or Plexiglas if you like) for the base and dust cover. The base rests on satin-finished stainless-steel tripod supports which incorporate leveling devices and a proprietary suspension system in each leg. The turntable platter itself was lathe turned from a solid billet of aluminum and hence has no balance holes drilled into it.
The turntable spindle is made of surgical stainless steel, so hard it must be ground and honed. The SDS-10 is a belt-drive unit, using a special low-speed motor, and is not sold with an arm, the user selecting the arm he prefers. It comes with appropriate mounting plates to avoid drilling the Lucite. Mr. Win was playing a record with an arm of his own design and casually picked up a Discwasher record cleaning brush, which you probably know has a substantial, solid walnut handle. I'm sure Dr. Bruce Maier wouldn't approve of how Mr. Win used his beautiful cleaning brush, but in any case, all of a sudden Mr. Win struck the base of his turntable several hard, resounding blows with the walnut handle of the brush, and, amazingly, there was no effect on the sound of the music nor did the turn table or arm even quiver. A few more lusty whacks of brush on the base, just to prove it was not a "fluke," made a pretty convincing demonstration of the efficacy of the suspension system of this unique turntable. The Win SDS-10 turntable is expected to be produced in fairly limited quantities, with an anticipated price of $2000.00.
No specs available yet, but in two respects, immunity to both external vibration and acoustic feedback, this turntable is the solution (albeit an expensive one) to these problems.
Also contributing to the refinement of turntable mounting and reduction of feedback was the ever-versatile Mitch Cotter. In his exhibit Mitch was showing a special turntable base and suspension system. The heavy mounting board is a laminate of differing materials, combining very high strength with especially inert acoustical properties. Mitch recommends using the top-of-the-line Denon turn table or the Technics SP-10 Mark Two with his base. To accomplish this, the turntables are completely demounted from their usual bases and installed in the special mount in the Cotter base.
Details of the suspension system were not revealed, but the mounting board and turntable appeared to be "semi-floating" on the support plinth. Mitch had mounted the new Fidelity Research "long length" arm on his turn table, with an FR Mark Three moving-coil cartridge playing through his Verion transformer. He had his prototype preamplifier on display, but no details or specs as yet. The conversion of the Denon or Technics turntables to his special base is supposed to be strictly a function of dealers handling his line. In other words, it is not envisioned as a consumer "do-it-yourself" project.
Speaking of Fidelity Research, their "long length" arm mentioned above is what they consider their "transcription" arm, but instead of the tradition al 16-inch length, it is actually a hair over 15 inches. Needless to say, not every turntable can accept this length, and it would be wise to check this point if you have a yen for this arm.
Among features of this arm is a maximum tracking error of +1 degrees and an effective mass of 38 grams. As original equipment with this arm is the B 60 tonearm stabilizer. This is a heavy weight which fastens to the arm pillar post beneath the mounting board.
Once a rough setting of the arm post is made and tightened with set screws, this stabilizer has a knurled knob which can be used to adjust stylus tracking angle under dynamic conditions. With the proper test record and measuring equipment (or "golden ears"), it is possible to adjust the stylus tracking angle to complement the angle used for the cutting stylus. If you want to indulge in some further "lily-gilding," FR now has available phono cables made of pure silver! Also new from FR is their FR-7 moving-coil cartridge. This uses a pure silver coil with no iron in the core. Looking somewhat like the EMT moving-coil cartridge, the FR-7 has a claimed stereo separation of 28 dB at 20 kHz, which is quite remark able. Finally, for the "man who has everything," how about the companion step-up transformer for the FR-7, the FRT-5. This unit has toroidal windings of pure silver for ultra-low distortion and is a great Texas stocking stuffer for $1850.00!
Phono Cartridges
Of phono cartridges in general there were many new models in evidence from the likes of Empire, Stanton, and Audio-Technica in the moving-magnet and moving-iron camp, and the interest in moving-coil cartridges continues with new models from Supex (lower-priced than their 900 Super E +) Satin, Audio-Technica's new $100 AT30E, plus their top-end Signet model. Bob Fulton has a $350 moving-coil cartridge with a conical stylus, and he offers an interesting paper on why he thinks this type of stylus is better than elliptical or Shibata type. Ortofon has introduced its MC30 moving-coil cartridge, a hand-made model in very low production (so scarce, in fact, that none were available at the show). In combination with Audio Standards Corp. Mx10A pre-preamp, it makes for some outstanding phono reproduction with exceptional definition and transient response. Ortofon was also showing their new, very tiny VMS models. Their "Concorde" does in deed resemble the famous "droop snoot" needle nose of the supersonic jet and weighs in at a mere 1.5 grams! Before we leave phono cartridges, I should mention the very exotic Electro-Kinetic pickup system, which works on yet another variant of the strain gauge principle and is sold only with its own preamplifier. The brain child of John Iverson of Electro Re search amplifier fame, the system is expected to sell "under $1000." The more sophisticated a stereo sys tem becomes, the more it benefits from subtle refinements, especially in the area of phono playback. For example, if you strike most turntable platters, they will exhibit ringing modes. Damping these resonances is a good idea and can be accomplished by such special turntable pads, such as the "Platter Pad," and I have had good success with the very high-density turntable pad from Osawa. With one of these on my Technics SP-10 Mk2, flicking the turntable platter with your fingernail produces a satisfying non-resonant "thunk." A new accessory now becoming available from a number of sources . . . Keith Monks and Audio-Technica to name two . . . is what are termed "record weights." As you are probably only too unhappily aware, the majority of records exhibit "dish warp" and exasperatingly won't lie flat on the turntable. A record weight, at approximately a pound and a half, fits over the turntable spindle and roughly covers the area of the record label. The Audio-Technica model is rubber covered; others add a handy phono strobe marker. Fitting one of these weights on the spindle does help to control the dish warp, but far more important and not generally known, is that the stylus/groove play back dynamics produces a resonant "ringing" in the vinyl which is effectively damped by these record weights.
Finally, on the subject of phono playback, our British cousins had a joint display by a number of English audio concerns, and among them was Metrosound Audio Products. Now, quite frankly, I have always cast a jaundiced eye towards such record cleaning products as adhesive rollers and the like; always figured that they would leave an "icky" residue on the record after use. Well, when I encountered several ultra "audio purists" using the Metrosound rotary cleaner and waxing enthusiastic about its effectiveness, I took another look. The Metro-sound roller is made of a new super soft polymer, a material purportedly used by the police in lifting finger prints. Used properly, which means with light, even pressure, the unit does indeed get down into the grooves and picks up the most minute particles, while leaving no residue. Records treated with this unit are audibly quieter and virtually "tickless." Equalizers of all types continue to proliferate, and there were many in evidence at the WCES. There now appears to be a trend towards the more sophisticated parametric types, and versatile new models were shown by Phase Linear and SAE. These can be valuable additions to a stereo system, when used intelligently and with restraint. There is the rub ... unfortunately, the interaction of the physiology of the hearing phenomenon and psychoacoustics, with maximum sensitivity in the midrange frequencies invariably seduces the auditor into striving for more "presence" in that part of the spectrum. The resultant "over boosting" makes for some grotesque balances.
As noted in the first part of this report, the power race in receivers has apparently reached a plateau, and now the emphasis appears to one of refinements or innovations. For example, the Bose people, heretofore most famous for their direct/reflecting equalized loudspeakers have introduced what they call their "Spatial Control" receiver. An FM/AM unit, it has four amplifiers, which in bridged mode provide 100 watts per channel. Why four amplifiers? Is it back to quad? No, friends. The Bose receiver must be used with their 901 speakers to achieve the "Spatial Control" effects. As you probably know, the Bose 901 speakers have four drive units on each side of their V-shaped rear panels which reflect off a wall. In the "Spatial" mode, each amplifier drives a corresponding rear panel. A special control on the receiver controls the reflected sound image by directing high frequencies to either the inside or outside rear panels, producing either a wider or narrower sound image. The use and choice is naturally dependent on the nature of the music being played and its interaction with room acoustics. As the Bose 901 speakers normally need an equalizer, a bit of money can be saved by prospective purchasers of the system, since the new receiver incorporates a built-in equalizer.
Well, friends, I could go on and on, as I've said about these Shows time and again. In the midst of all this disheartening news about our economy, the supposed imminence of a "recession" and other alarms, it is nice to realize, that though the audio industry is in a "soft" period, the avalanche of new products at every audio show is proof positive of the viability and resilience of this industry.
(Source: Audio magazine, May 1979; Bert Whyte)
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