Krell Full Power Balanced 600 power amplifier Page 6

And compared with the FPB 300? All too often, larger amplifiers concede quality for quantity—the treble roughens, and the more powerful amplifier may sound less well integrated, even lacking in clarity. Of course, a big amp can also sound more gracious and bighearted, if at the same time slower, less agile, and perceptibly weaker in terms of rhythmic drive.

Not so the FPB 600. It conceded absolutely nothing to its smaller sibling. I noted a more open, more naturally explosive and better-balanced sound, particularly in the upper mids and treble. Looking back at my notes for the '300, I wondered how this could be possible—yet it really was the case!

Would such an improvement in transient speed be reflected in a loss of purity and tonal balance through the midrange? Not a bit of it. Indeed, the '600 built on the '300's strengths, significantly improving on its mid character and sounding yet more positive, still more naturally "sweet."

At first the '600 sounded a little less "concentrated" in the bass than the '300—until I realized that the '600's bass breathed more easily, reached deeper, and had a "sweetness" which was, in its way, equivalent to that same quality in the mids that is usually expressed as a lack of "hardness" or "glare."

Too many superlatives?
Regular readers know that I am not prone to effusive language. A traceable continuity of opinion matters to me; I don't want to reread a review in six months or a year, only to regret that I'd overplayed my hand.

Nonetheless, I am driven to say that the Krell FPB 600 power amplifier, when properly installed and optimally matched and connected, sounds simply stunning. From a wholly musical point of view, this amplifier reigns supreme in its power to better convey the impact, meaning, emotion, and involvement of great music. So vestigial are its faults, and so great the sum of its better parts, that it's almost impossible to put the former into any valid perspective.

When I evaluated the Wilson Audio X-1/Grand SLAMM (Stereophile, December 1994, Vol.17 No.12, p.115), I felt that, as an industry, we were some distance away from realizing that loudspeaker's full potential; that it would continue to sound better with better systems. Krell's new amplifier is proof of this: The big Wilson went substantially further with the FPB 600. Conversely, the X-1 helped to confirm the very high performance achieved by the FPB 600. What a magnificent combination. Here, a closer approach to truly realistic rock-concert levels was possible in the home. (I can write this with confidence; as this section is penned—literally, with a gold-nibbed fountain pen—I can vividly recall Sting in concert last night at London's Royal Albert Hall. Sporting a Bruce Willis hairdo, he was in good form.)

Conversely, with lesser speakers the FPB 600's quality remained at the forefront; for example, it shoved the smaller WITT significantly up the performance band. You don't need a pair of Grand SLAMMs to hear what the FPB 600 can do for you. Even a pair of Epos ES12s showed what it could do.

I suspect that even the Krell team was surprised when the Full Power Balanced 600 began to take shape. On paper, it was simply a power-doubled FPB 300 delivered at a moderate and appropriate hike in price. In practice, the FPB 600 has gone much further. Great as the '300 undoubtedly is, the '600 holds all the aces, with a potential to severely embarrass a wide sampling of top-brand power-amplifier references. I'm quite certain that it redefines the art. It will certainly dictate a vigorous shakeup of the current stack of Class A power amplifiers in Stereophile's "Recommended Components." Since a Class A rating means "the best we know," I feel that, in the light of this design achievement, the rest will have to be re-classed (footnote 2).

The FPB 600 advances substantially on the FPB 300 in particular, and on the art of the power amp in general. In fact, I suspect that the Krell designers are now acutely embarrassed at the audible shortfall in matching preamplifier performance. With no disrespect intended to the KRC-HR (Stereophile, October 1996, Vol.19 No.10), just use one in conjunction with the KPS-20i/l and the FPB 600. Then bypass the KRC-HR by simply linking the existing balanced cables input to output, with no other changes whatsoever—and hear the system take off. Such is the '600's transparency that care in system alignment, choice of cable, and quality of connectors all offer substantial payoffs.

The FPB 600's sound quality was at the leading edge. The Wilson X-1 Grand SLAMM proved as nearly perfect a match as one could wish for. The overall quality and dynamic range available from this combination was both stunning and breathtaking.

Add into the equation its huge, uncompromised peak loudness, the incomparable power delivery confirmed in its excellent laboratory results, and the Krell FPB 600 is something quite special among power amplifiers. And, lest I forget: at the price, and taking everything into account, this big Krell is actually good value for money.

I confidently dub the Full Power Balanced 600 the "Grand Slam" of power amplifiers.

Footnote 2: Given Martin's enthusiasm for the big Krell amplifier, it looks as though Stereophile will indeed have to reexamine the solid-state rankings in Class A of the magazine's "Recommended Components" listing. Accordingly, Wes Phillips will be comparing the FPB 600 with other leading amplifiers in the next few issues of the magazine.—John Atkinson
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