Solid State Power Amp Reviews

In jazz, the chief protagonist of the berimbau is, or was, Brazilian avant-garde composer Naná Vasconcelos, an especially inventive virtuoso who played with Gato Barbieri, Don Cherry, and the Pat Metheny Group. His 1979 album Saudades (16/44.1 FLAC ECM/ Qobuz) is a tsunami of percussive reverb and a good reviewing tool. Vasconcelos died in 2016.

Compared to Bel Canto
Switching from the Maggies to the Harbeth M30.2 monitors and using the Denafrips Terminator DAC, I began my comparisons of the LKV Veros PWR+ to the Bel Canto REF600M mono amplifiers—also class-D—using Saudades's first track, "O Berimbau." This piece seemed perfect for comparing how the LKV and Bel Canto mono amplifiers handle the berimbau's extreme transients and high-energy bursts of harmonic expansion.

The Veros PWR+ passed this test with an A+ by delivering a succinct, vibrant space wherein the berimbau "spoke" with musically effective acoustic power. Think strong, minutely detailed, and surprisingly wet. Almost tubelike. There was a radiance to the sound that I'd never experienced with class-D.

In comparison, with the Harbeths driven by the Bel Cantos, Vasconcelos's berimbau seemed flatter and drier. With the REF600Ms, it was playing in a smaller space, with less atmosphere.

The REF600Ms have long been my reference for properly implemented—fundamentally musical—class-D. But today, for the first time, in comparison to the Veros PWR+, their limitations were exposed. With the Bel Cantos powering the revealing M30.2s, this Vasconcelos recording sounded clean, quick, and detailed but also austere. In contrast, the LKV rendered berimbau notes with a more complex palette of overtones and showed infinite variation in string attack. With the LKV, soundstage depth was dramatically deep. With the LKV, the marginally annoying ECM compression seemed less noisy and more tolerable. What the LKV was doing seemed inexplicable.

Alternating wires
Every recording I played via the LKV Veros PWR+ was sounding richer and wetter (atmospherically) than class-D is supposed to. It occurred to me that perhaps the LKV's un–class-D atmospherics were, in some small way, being enhanced by the Cardas Clear Cygnus loudspeaker cables, which, in most systems I've heard them in, I would characterize as slightly warm, microscopically detailed, and exceptionally effective at preserving reverberant atmospheric data—all traits I was ascribing to the LKV.

As an experiment, I swapped in a pair of AudioQuest GO-4 speaker cables, which use solid-core conductors. In my experience, solid-core wire tends to make instruments and voices sound distinct and solidly outlined while sacrificing atmosphere. Generally, the GO-4's presentation is sharper, more toned, but less atmospheric than the Cardas's.

With the GO-4s, the LKV's sound became drier and more distinctly drawn. And because it was more distinctly drawn, the sound became more 3D. The soundstage was better mapped, especially with the Denafrips Terminator DAC set to oversampling.

With the GO-4s, the aforementioned berimbau became more tangible as a one-meter-high stick-and-wire sound-generator in front of a microphone. The AudioQuest cables better defined the room boundaries where the berimbau was recorded. The change to AudioQuest cables directed my attention to dynamic contrasts—jump-factor moments—and to the reverb specifically added to "locate" the berimbau in space. With the GO-4s, the LKV Veros PWR+ now sounded more normal class-D than it did with the Cardas Clear Cygnus.

The reverb tails appeared longer when I switched back to the Clear Cygnus. The room boundaries I noticed with the GO-4 became softer. The front edge of notes became less distinct. But the music sounded fuller and more engaging.

In for a penny, in for a pound: I tried Triode Wire Labs' American Series loudspeaker cables, which struck a neutral, extremely transparent balance between the Apollonian AudioQuest GO-4 and the Dionysian Cardas Clear Cygnus. The Cardas made the LKV amp sound liquid and atmospheric, but I was afraid it was adding something to the Veros PWR+'s sound. The AudioQuest provided definition and excitement but dried up the sound too much. The Triode Wire Labs cable seemed to add or subtract the least from what I believe to be the Veros PWR+'s natural character.

Driving the Falcon Acoustics LS3/5a
The LKV Veros PWR+ amplifier did a spectacular job of powering my current-hungry, 4 ohm Magnepan .7s and my resolving, 6 ohm Harbeth M30.2s. So naturally I wondered how it would do with my BFF, 15 ohm Falcon LS3/5a, which previously had not played well with class-D amplifiers.

After a long day playing King Tubby's dub (to ease my blues and loosen up the Falcons' voice coil assemblies), I played The Beauty That Still Remains and spied into the vast, intricate soundstage of the Norwegian Girls Choir and Anne Karin Sundal-Ask performing compositions based on the diary of Anne Frank (24/44.1 FLAC 2L/Qobuz). It kept me up late with its sympathy for, and faith in, humankind.

The Falcon LS3/5a's specialize in natural tone and high-definition soundstages. They have an uncanny facility for drawing focused pictures in the space around them. They take detail down to dust-particle size and separate individual voices in choirs. With the high-powered LKV amp driving the high-impedance Falcons, The Beauty That Still Remains seemed unusually 3D with a room-filling soundstage that reached the ceiling and penetrated the walls.

The LKV-Falcon pairing produced nuanced vocal dynamics with good transparency. The next day, though, I realized that the sound on some recordings was a little off: occasionally vague and low on boogie factor. Ultimately, the LKV Veros PWR+ and the Falcon LS3/5a loudspeakers were not a great match.

Compared to Rogue Audio ST-100
Next, I played The Beauty That Still Remains and Eriks Ešenvalds's Translations through the Rogue RP-7 preamp driving Rogue's $3495 push-pull, KT120-tubed Stereo 100 amplifier (footnote 2) powering my reference Harbeth M30.2 speakers. In only a few weeks, I had forgotten how open and fully described the ST-100's high frequencies sound. Now there was real space and genuine air. The midrange and bass became less dense than they were with the Veros PWR+. On every recording, the ST-100 delivered a lighter, brighter, sunnier—but less solid—presentation than the LKV.

Switching to sublime female vocals, Norwegian opera singer Kirsten Flagstad sounded serene and enchanted with the Rogue's tubes (Kirsten Flagstad Edition: The Decca Recitals, 16/44.1 FLAC Decca/Qobuz). Flagstad's singing was goose-bump magic with the Rogue amplifier but less magic with the LKV, which made her voice sound thicker and darker than the Rogue's tubes did. Each amplifier presents its own interpretation of transparency. The LKV colors its transparency with a kind of golden-honey quality. The Rogue's transparency was brighter and fresher and more natural—more transparent?

The ST-100 driving the Harbeth M30.2s is my primary reference setup. The 30.2s remind me of Quad 57s: electrostatic-quick and neutral of tone. Nevertheless, the LKV Veros PWR+ amplifier showed me how much weight and instrumental body the Rogue-Harbeth combo was losing through the bottom octaves. I wondered if I needed a "beefier" reference amp.

Conclusion
Sound quality and music enjoyment–wise, the LKV Research Veros PWR+ amplifier sits on a higher mountain than any other class-D amp I've encountered. It seems like Bill Hutchins made a slew of listening-inspired design decisions which, in concert, led to this extraordinarily natural-sounding power amp. I will be surprised if it measures super-low THD-wise, but, rest assured, I smiled contentedly every minute it was playing music in my room.

My thatched-roof stick-hut sencha-tea mind says $10,000 is a lot of money for three transformers and a few circuit boards in a not-fancy box. But is it?

With this LKV Research amplifier, you are getting something extra of unusually high value: Bill Hutchins. I have talked to him at length, and I can vouch for his character. He is humble and patient. He is a small, well-established audio manufacturer who builds phono stages, line amps, and big-system amplifiers in his shop with his own hands. I admire Mr. Hutchins because I once did what he is doing. Therefore, I know: $10,000 is underpriced for an amplifier built entirely in New Hampshire with the love and determination of one person. Long nights under fluorescent lights.

Today, most commercial loudspeakers feature reactive, low-impedance loads. Why? Because watts are cheap? Unfortunately, cheap watts often sound like crap watts. Fortunately, Bill's watts sound like limitless, sensual, tactile, luxury class-A watts. On the speakers I used, the Veros PWR+ put minnows, crappies, and my favorites, bass and catfish, into the once-empty class-D pond. Gleefully recommended.

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Footnote 2: I used the 8 ohm taps and Ultralinear mode.