Tube Power Amp Reviews

The Power 3 didn't sound perfectly neutral, however. Its overall character was slightly cool, dry, and distant—exactly the opposite of the VTL's slightly warm, liquid, immediate personality. On the vinyl version of the Ray Brown Trio's Soular Energy (Concord Jazz LELP 111, Bellaphon 180gm half-speed-mastered version), Brown's bass sounded a little more prominent with the VTL, but more consistent across its range with the Power 3. Similarly, the VTL had a bit more midrange and upper-midrange bloom than the SF, so Emily Remler's guitar and Red Holloway's sax were tonally richer and more vivid. Recent visits to concert halls and jazz clubs suggest that reality—and true neutrality—fall somewhere between the two.

Another immediately obvious component of the Power 3's sound, and one that contributed strongly to its character, was a reduction in the size of dynamic gradients. Compared to the Levinson, VAC, or VTL, the Power 3's deltas—the differences between loud and soft—simply weren't as big. The transients were clean and fast, and the dynamic swings were very well controlled, but just not as big. Rim shots had a crisp, clean initial impact. The character was correct, the sound was detailed, and the leading and trailing edges were sharp—but they just didn't have the snap-your-head-around sort of impact that the other amps did, and that makes the sound seem a bit more alive.

I wrestled with this a bit, playing with different preamp gain settings, carefully matching levels, and wondering if what I was really hearing was the Power 3's superior control of the speaker. That may be part of it, but I'm convinced that it's not the whole story. At any volume level and with any speaker I threw at it, the Sonic Frontiers' dynamics were genuinely smaller across the board, from micro- to macrodynamics. The second movement of La Mer runs the gamut from delicate woodwind passages with barely perceptible microdynamic shadings to all-out crescendos. With the Power 3, the crescendos didn't have as much power as with the VTL. At the bottom end, a lot of the subtle microdynamic information was noticeably reduced, and in some cases gone altogether.

Backing up a step, however, there is no doubt that the Power 3s did do an excellent job of controlling the speakers. I've mentioned the speed and precision of the dynamic transients. Images were tightly focused as well, with excellent edge definition and a very clear sense of the space between them. The soundstage was very wide, extending well out beyond the Maggies' outer edges, and the space between the images gave it an open, airy feel.

The Power 3s' soundstage didn't have quite the depth of the other amps', but the depth it did have was more consistent from side to side. The other amps' soundstages were deeper, but their shapes were slightly trapezoidal, perhaps even concave on the rear edge, with more depth in the center than at the edges. With the Power 3s, the rear corners were pushed farther back and a bit better illuminated. There was a better sense of the orchestra's back row—the percussion on La Mer, for example—and of the stage walls behind and beside them.

The Power 3s' image specificity was excellent, as was their reproduction of recorded hall boundaries. Instruments transitioned naturally into the surrounding space, maintaining distinct edges but flowing continuously into the background ambience. That ambience itself was clearly reproduced, but not as lushly as by the VTLs or Levinsons. Similarly, the Power 3s' images themselves were a little less dense than with the other amps. On La Mer and Soular Energy, the SFs sounded a bit bleached in comparison—not as rich, and with a slightly pale, less complex harmonic structure. In contrast, Diana Krall's luscious When I Look In Your Eyes (Impulse!/Verve IMPD-304) was better served by the Power 3s; this disc sounded a bit syrupy on the VTLs and Levinsons.

Images throught he Power 3s were smaller than they should have been. With some source material—say, the Ray Brown album—there isn't a real reference point, so "small" means "smaller than I've heard with other equipment." With orchestral recordings, on the other hand, the spatial relationships between instruments, sections, hall boundaries, and listener form a reference into which the apparent image size needs to fit. The Sonic Frontiers'image sizes suggested a listener-to-orchestra distance inconsistent with other cues.

Images were also less dimensional with the SFs than with the other amplifiers. And although the Power 3 did a great job of resolving low-level detail—the background whispers and noises on Dave Bailey's One Foot in the Gutter (Epic/Classic BA 17008) is a great example—they seemed to have slightly less inner detail than with the VTL, VAC, or Levinson amps, as with Emily Remler's guitar on Soular Energy. Intellectually speaking, the subtle interplay of vibrations that occurs as the string sound transitions to the body resonance were there with the Power 3, but were more obvious with the other amps. Emotionally, it's simpler: With the other amps, the guitar was a bit more vivacious and had more texture—it was a bit more alive.

Free your mind, and your heart will show you truth
Taking the rational, calculating approach, the Power 3's sonic attributes added up to a pretty solid scorecard. It got all the big things right: It was essentially neutral, sounding flat and very low in coloration, and imposing very little character of its own on the music. Bass, midrange, top end—all excellent, and all obviously cut from the same sonic cloth. Transients were fast, clean, and precise, and the amps' reproduction of images and soundstage were first-rate.

In comparison, the Power 3's shortcomings—reduced dynamic gradients, smallish images, slight lack of inner detail and dimensionality, and a tonal balance a bit on the light, dry side of neutral—seemed pretty minor when viewed analytically. But when I would switch out of reviewer mode and let my heart take over—when I would just sit back and listen to music—my overall experience just wasn't as engaging as with the VAC, VTL, or Levinson amps.

Some of my dissatisfaction with the Power 3 was mine and mine alone, and may not apply to another listener. Two of the areas in which it fell short—dimensionality and inner detail—contribute heavily to how engaging I find any given component. Similarly, the Power 3's tonal balance erred slightly on the light, dry, analytical side of neutral, whereas I'm more tolerant of errors to the warm, liquid side—where the VTLs and Levinsons reside.

The biggest drawback was the Power 3's smaller-scaled dynamic gradients. Intellectually, this is only one factor on the checklist, and was a relatively minor deficiency. On the emotional side, however, the effect was more significant. Although dynamic gradients can be extracted and analyzed, they're woven inextricably into the fabric of the music, and contribute subtly to a whole host of factors that bring it to life. In fact, the "Holiday Inn Effect"—knowing, from hearing it from your room at the end of the hall, that the music from the hotel bar is a live band—is all about dynamic gradients.

On "Authority Song," from John Mellencamp's Uh-Huh (Riva RVL 7504), there's a wonderful guitar line with a rich, complex mix of textures and dynamic shadings that makes it seem as if you can hear deep into and around the guitar's strings. With the VTLs, it bounces and careens around the instrument's lower strings, positively screaming "Let's party!"—a grin-inducing, toe-tapping, suck-you-in air-guitar riff if ever there was one.

With the Power 3, the riff was still there: absolutely, positively there, each detail and aspect of the instrument's character cleanly reproduced—from the analytical point of view. But a few of those parameters—dimensionality, harmonic complexity and richness, dynamic gradients—were slightly diminished. So, from the emotional, musical-connection point of view, something tangible had been lost. I put down my air guitar and stopped bouncing in my seat. Words like "measured" and "controlled" popped into my head, but Bonnie put it more succinctly as she got up to leave: "These amps don't rock."

Conclusion
The Sonic Frontiers Power 3 is an ambitious assault on the state of the art, and in most ways succeeds spectacularly, reflecting a sound, intelligent approach that combines well thought-out design and superb execution. It's incredibly well built, lavishly appointed, and reflects an attention to detail that's at the absolute top of the audio—or any other—craft.

It succeeds in many sonic criteria as well. Things like speed, precision, and clarity are excellent, and the Power 3 will effortlessly control virtually any speaker. Its low coloration, flat tonal balance, and superb performance at the frequency extremes are at the top of its class. In some respects, the Power 3 is among the best tube amps I've heard, and one of the best amps I've heard of any type.

For some listeners, the Power 3 may be just the ticket; I suggest that anyone shopping for a high-performance amplifier give it a listen. As successful as it is, however, and as much respect as I have for its design, execution, and performance, it wouldn't be my choice. I can analyze the Power 3's performance and explain my reactions in terms of its specific shortcomings and my listening preferences, but the simpler, truer explanation is that, as much as my head liked the Power 3, my heart just wouldn't sign up.—Brian Damkroger