The Carver Challenge

Is it possible to make a $700 "mainstream-audio" power amplifier sound exactly like a high-priced perfectionist amplifier? Bob Carver, of Carver Corporation, seemed to think he could, so we challenged him to prove it.

The question posed above seems laughable. If it were possible to make an average, modestly priced amplifier sound just like state-of-the-art, wouldn't it already have been done? Of course it would. State-of-the-art sound would thereby become much more affordable, and high priced power amplifiers would become as extinct as Diplodocus (footnote 1). That is the conventional wisdom. Bob Carver, founder and personification of Carver Corporation, has never been noted for his conventionality.

Ever since he introduced the first high-powered solid-state amplifier in 1971, Carver has been laying waste to conventional wisdom with one brilliant design innovation after another—the "magnetic amplifier," the "peak unlimiter," the "sonic hologram generator," the "auto-correlator," the "asymmetrical charge-coupled FM Detector," and the "digital time lens" (footnote 2).

But everyone has his limits of capability, and pride goeth before a fall; when Bob claimed, some time ago, in conversation with Stereophile Publisher Larry Archibald, that he could make his $700 Model 1.0 amplifier sound "indistinguishable from" any amplifier of our choice, we were confident that he was finally out of his depth. Carver Corporation is, after all, a "mainstream" manufacturer, not a "high-ender". Bob's designs are unabashedly aimed at the mass market, notorious for its lack of aural perspicacity. What, then, could he possibly know about the design subtleties that make a Stasis 500 sound different from an Eagle 7A? Bob's claim was something we just couldn't pass up unchallenged.

Our first task was to come up with a "reference" amplifier that would represent a genuine challenge—one as different from, and as superior to, his solid-state Model 1.0 amp as possible. One obvious contender was a large tubed amplifier we had on hand, but we soon realized that our choice would not be all that simple. There were, it seemed, some peripheral considerations.

We knew that Carver couldn't possibly pull this off, at least not to the point where none of us would be able to distinguish between his modified 1.0 and our reference amp. After all, some of the most highly trained audio ears in the world would be listening for the differences. What worried us was the possibility that Carver might come so close to matching the sound of our reference amp that its designer/manufacturer would be embarrassed, chagrined, and outraged. And, while not normally concerned about offending a manufacturer in a product, we are concerned about fairness.

In order to select a reference amp for this experiment, we sould be obliged to "single out" one model of one manufacturer's line. If Carver then managed to even approximate the sound of that amplifier, its manufacturer would quite naturally ask "Why us? Why did you single us out for ridicule?" And we would be hard put to answer withoug appearing unfair.

So, we decided to make an exception to our usual policy of forthrightness. We decided not to reveal the "reference" amp's identity, saying only that the reference unit is a high-powered, very expensive stereo unit with a strong and unique sonic "personality," and a penchant for being very finicky about the loudspeakers it works with (footnote 3). It was, we were gleefully confident, likely to be very dissimilar in sound from Carver's own designs, and probably much more unpredictable in terms of its behavior with a given loudspeaker.

We then turned to the matter of loudspeakers. Again, we wished (with no implied malevolence) to make things as difficult as possible for Carver, and were fortunate this time in that two speakers which seemed to meet that criterion were among the six then in-house for routine testing. We're not going to identify them, either. Suffice it to say that both are exceedingly revealing of subtle details in the sound, are in different ways "difficult" loads for an amplifier, and between them, excel in every aspect of loudspeaker reproduction (footnote 4). We were confident that we had effectively stacked the deck against Carver's success.

Getting Started
Although both Larry Archibald and J. Gordon Holt had met Bob Carver several times before, this was to be our first one-on-one association. We didn't know what to expect. It turned out that Carver, too, had misgivings about us, based on past experiences with the "underground press and a normal anxiety about whether his success at meeting our challenge (about which he had no doubt) would be fairly reported.

We found Bob to be a friendly and personable gentleman, powerfully built, outgoing in manner, and just as serious about the reproduction of sound as are we. It took only an hour or so of relaxed banter before he confessed that he, too, was pleasantly surprised—to find that we didn't have horns or cloven hooves.

Before Bob started work in earnest, it was necessary for us to all agree on certain ground rules, so that we could ultimately agree as to whether or not he had succeeded in accomplishing his goal. After some amicable discussion, we agreed on the following:

• The objective was to make the two amplifiers sound absolutely identical, or at least similar enough in sound that none of us could tell one from the other with better than 50% (pure chance) consistency.

Footnote 1: Diplodocus was a dinosaur who hasn't been around for about 80 million years.—J. Gordon Holt

Footnote 2: Brilliant innovations some of them may be, but their names are notable more for catchiness in the marketplace than for descriptiveness of engineering innovation.—Larry Archibald

Footnote 3: I believe it appropriate nearly a quarter-century later to identify the reference amplifier as a Conrad-Johnson Premier Four.—John Atkinson

Footnote 4: One of the pairs of loudspeakers was the Infinity RS-1B, but with the Conrad-Johnson or Carver amplifiers driving the midrange/treble panels only.—John Atkinson