by Ralph Hodges
An "Equalizer" SOME years ago it was my privilege, or misfortune, to serve as an informal listening consultant to a phono-preamplifier design project-which is to say that on weekends I got to listen to the circuit cards the designer had concocted during the week. It was not an amateurish or condescending project in any sense. The premise was that room for improvement could and would be found in phono preamplifiers, and short of running the supply rails at ± 200 volts and wiring the whole thing with Monster Cable, virtually everything that characterizes today's hot-ticket phono preamplifiers was tried in one form or other.
Although the project led to a highly esteemed product, for some of us the experience proved a disappointment. It showed us that once the obvious problems of noise and distortion, including slew-rate factors, had been handled, the only things that appeared to distinguish the circuits we liked best from the discards were minor differences in frequency response! Well, the hope that new distortion discoveries would explain all audio disagree-abilities and point the way to audio perfection died hard for me. In the ensuing years it was easy to forget this hard-won lesson in the primacy of frequency response and to lapse back into speculation on eldritch distortion mechanisms that, although plainly audible, somehow managed to elude the scrutiny of test instruments. Naturally, therefore, I was doomed to learn the lesson all over again.
My re-education occurred during a recent visit to Cello, a new company in Hamden, Connecticut, that has been put together by Mark Levinson-yes, the Mark Levinson, although he is no longer involved with the company bearing his name.
We have become accustomed to astonishing price tags from this gentleman, and Cello's first product, the $8,750 Audio Palette, is not disappointing in that regard.
On the face of it, the Audio Palette is little more than a six-band stereo equalizer, with unremarkable Bessel-function filter characteristics and no parametric features what ever. Yet a case can be made, and Levinson makes it persuasively, that in concept and function the device is more than it appears to be.
The six center frequencies are 15, 120, 500, 2,000, 5,000, and 25,000 Hz, and the click-stop adjustment increments for each band, dialed in by rotary switches, are 1, 0.5, 0.25, 0.25, 0.5, and 1 dB, respectively.
The total adjustment range is typically ± 15 dB. Each switch, custom-designed and exquisitely crafted in every respect, contains more than a hundred precision resistors.
The total parts count for the Audio Palette and its external power supply is more than 6,000, much of it devoted to fifty discrete Class A amplifiers that, with controls centered, seem to be truly inaudible when switched in. The high-current design consumes 100 watts and drives loads as low as 90 ohms, and the external supply can handle the Palette, a modular preamplifier that Cello is just putting into production, and a pair of optional 25-watt power-amp cards, giving the ensemble complete-system potential.
It is a killer equalizer, to be sure.
But what is it actually good for besides conspicuous consumption of greenbacks and house power? One thing Levinson finds it uniquely good for is the refurbishment of antique recordings: jazz classics, the artistry of Artur Schnabel, and the like. As a rule, the control settings have to be pretty extreme for the best results, particularly at the ends of the band, but a little courage here certainly brings its rewards. It's particularly interesting, when one goes dredging deep for information above 8,000 Hz, to find how little of it is objectionable distortion and how much is worth while signal or benign noise.
For my part, I found the Palette scoring its strongest points in the refurbishment of modern recordings. We managed to find a couple of thoroughly obnoxious CD's (still no trick even today), replete with unbearably aggressive strings, seemingly oozing with distortion and bearing all the familiar murky artifacts of inept multi-miking. They were the sort of catastrophes one gives up as a total loss on first hearing. But what a difference a half-decibel or so can make! At first tentatively, and then with assurance, I found I could tame the raucousness of overbalanced violins while retaining the appropriate edge for brass and the sparkle of percussive effects. The transformation was flabbergasting. Mind you, nothing at all could be done for drums picked up by two dozen micro phones spaced anywhere from five to thirty feet away; such a wall of mud does not succumb to equalization. But, if I focused on the treble voices of the orchestra and ignored the foundation as perhaps the result of a synthesizer having a really bad day, there was some genuinely satisfying music to be heard.
Levinson has a philosophy for this product: "People are spending fortunes on exotic equipment, only to wind up listening to the records the system likes to play, rather than the music they want to hear. The most revealing equipment, instead of affording you more freedom to explore music, imposes more restrictions." I'll leave the philosophy to Levin son and merely add that if we critical listeners don't regularly familiarize ourselves with the effects of very subtle but very precise frequency-
response adjustments, introduced in just the right places at just the right times, it does appear we're going to miss many of the pleasures of music, if not the music itself.
Also see: Japan Audio Fair -- special report from Tokyo (Jan. 1986)