The Carver Challenge Page 4

But, as we relaxed with a Sheffield jazz record, we thought we picked up a difference between the reference and the 1.0. With the reference, the low range of the guitar was a bit ill-defined; with the 1.0, you could "count the cycles." Granted, in this respect the 1.0 was better than the reference, but that was beside the point! We were looking for duplication.

Bob reached into his bag of tricks and dropped the output of the 1.0 from 500 watts below 30Hz, to a mere 65–100W. Believe it or not, even though we were listening at subdued levels, that did the trick: the 1.0 was now a bit muddy and ill-defined through its lower range, just like the reference.

More interesting, though, and disturbing, was that the soundstaging had now changed, and the two amps were no longer the same. It turned out that Bob had to go back and diddle some more, exhausting his 48-hour limit.

The Final Achievement
After this last bit of tweaking, where Bob was able to reinstate his 70dB null while driving a very difficult load, we now had what sounded like two absolutely identical amplifiers. No matter what speakers we used, every "difference" we thought we had isolated turned out to be there, in equal quantity, when we swapped amplifiers.

This time, the listening went on through the whole afternoon and much of the evening, until all of us were listened out. More leisurely listening, refreshed by a good night's sleep, failed to turn up anything. As far as we could determine, through careful comparisons and nit-picking criticisms, the two amplifiers were, in fact, sonically identical. It is a gross understatement to say that we were flabbergasted!

The next morning, I told Dick Olsher over the phone what we had found. "Bull- shit!" was his reasoned response. "That just can't be." But it was, it was then that we started to realize that, in reporting the outcome of this Challenge, we were going to have more to contend with than outrage and wonderment. We were going to have to contend with incredulity.

On the face of it, what Bob Carver pulled off should be impossible. You can't make a silk purse from a sow's ear. What about the audible differences between transistors, capacitors, internal wiring—all the things that we know contribute to the superiority of no-holds barred amplifiers? What about all the things that amplifier designers have learned during the past 20 years, which enable them to build better amplifiers (at whatever price) than have ever been built before? How could all of these things have been factored into the relatively quick and painless transformation of an average amplifier into a world-beater? But, of course, the "factoring-in" was the key to all this.

You see, Bob didn't have to concern himself about quality capacitors, minimal internal wiring, gold connectors, or any of those things; all he needed to do was duplicate, at the output of his amplifier, the sum of their effects at the output of the reference amp. Once he had obtained the necessarily deep null between those amplifiers, it was his belief that ears were not going to pick up on what was left. To do this, he needed only (!!) to know how to change practically any parameter of his amplifier's performance—a knowledge which we must now acknowledge is his.

After the second day of listening to his final design, we threw in the towel and conceded Bob the bout. He packed up his equipment and limped triumphantly back to his Lynnwood, WA home base. (He had single-handedly hoisted the hefty reference amp onto a table at one point during the proceedings and injured his back.) The question remains whether or not we might have eventually picked up some miniscule but repeatedly audible difference between the amplifiers, had we been able to listen longer?

Somehow I doubt it. We had thrown some of the most revealing tests that we know of at both amps, and they came through identically. Even on the subliminal level—the level at which you gradually get the feeling that one amplifier is more "comfortable" than another—we failed to sense a difference between the two amps.

It is true that there were no "controls" here—no double-blind precautions against prejudices of various kinds. But the lack of these controls should have, if anything, influenced the outcome in the other direction. We wanted Bob to fail. We wanted to hear a difference. Among other things, it would have reassured us that our ears really are among the best in the business, despite "70dB nulls."

There were times when we were sure that we had heard such a difference. But, I repeat, each time we'd put the other amplifier in, listen to the same musical passage again, and hear exactly the same thing. According to the rules of the game, Bob had won.

Disquieting Implications
The implications of all this are disquieting, to say the least. If, after only four days of work, it is possible for someone—design genius or not—to make a $700 amplifier sound exactly like a state-of-the-art amplifier costing many times as much, what does that say for the cost-effectiveness of the latter?

Carver claims that the original, unmodified M1.0 amplifier had been designed to sound "the way he wanted it to." If, in fact, he could make it sound any way he wished, as seemed to be proven with his success in this experiment, why then did he elect to go with a typical mid-fi "solid-state sound" instead of emulating the sound of one of the best-sounding solid-state or tubed amplifiers on the market? There were, it turns out, some good reasons.

Bob admits that he is not sure himself about the audible effects of some of the parameters he juggled to match the transfer functions of his amp to that of our reference. Had he been using this trimming technique to produce a certain desired combination of sonic qualities, using only his ears to evaluate what was going on, the task would have been quite a bit more difficult and time-consuming, the results far less predictable. This, in fact, is what he did with the 1.0 amplifier, which in his opinion still sounds excellent on the loudspeakers with which it will most likely be used (if not on the loudspeakers we used).

Secondly, Bob had never before had a chance to listen critically to a "world-class" amplifier like the one we chose as our reference, and ended up admitting that there were things about its sound that he preferred to his own amp. He might, he averred, "do some things differently in future designs."

Does that mean that Carver Corporation might consider producing, commercially the modified 1.0 whose "sound" Bob had, quite literally, pirated from that state-of-the- art amplifier? Maybe yes, maybe no.

Is It Theft?
The possibility of Carver's manufacturing his modified amplifier raises some very knotty questions concerning morality and legality. Does an amplifier manufacturer who designs something from scratch, coming up with a sound unique to that product, have the exclusive right to that sound? In other words, is it dishonest or even illegal for someone to use a technique such as Carver's transfer function analysis to duplicate that "unique" sound, without having done all the usual homework involved in designing an amplifier from scratch?

There has never been a legal decision about this, but an analogy from computer software may shed some light. Some years ago, a firm called Micro Pro started marketing the first automated spreadsheet for microcomputers. Called Visicalc, this program allowed a vast number of rows and columns of figures to be set up, by the user, to perform in mere seconds spreadsheet calculations that would have taken an accountant hundreds of hours to do with pencil and paper.

When Visicalc came out, there was nothing else like it. Within months, however, it was followed by the first of what soon became a flood of imitations, each capable of the same functions as Visicalc, but each using somewhat different ways of accomplishing the same end. Those "copycat" programs are still around, because the law deemed the functions which could be performed by Visicalc to be not copyrightable; only the specific program for accomplishing that function could be copyrighted. Thus, it is likely that Carver, or anyone else with his technical smarts, would be legally free to duplicate the sound of any amplifier, as long as different circuitry was used to do it.

But whatever Bob, and others who can match his technical virtuosity, choose to do with the results of this project, I think that the field of high-end audio amplifier manufacture will never be quite the same again. High price and high status will continue to be handmaidens in audio, but the knowledge that high performance and high price need no longer be inseparable cannot help but impair the glamor of cost-no-object power amps.

We're still a little bewildered around here about how all this turned out. Not the way we expected. But that's the way it was.