Audio Research VT-150 monoblock power amplifier Page 2

The VT-150s presented an astonishingly believable and natural rendering of timbre. Instead of hearing a hi-fi representation of the music, I felt I was hearing the music itself. The result was a complete sense of involvement, relaxation, intimacy, ease, and ability to forget the playback system. The listening fatigue I so often experience with lesser amplifiers was replaced by the ability—no, compulsion—to play music for extended periods.

I don't want to give the impression that the VT-150s sounded soft, rolled-off, overly lush, or "tubey"—they didn't. The midrange and treble magic I've described was not the result of a coloration that smoothed the treble at the expense of musical detail, immediacy, or a sense of life. Instead, I believe it was the result of a total lack of solid-state grain and etch. It may be no coincidence that the VT-150s are the first amplifiers I've heard with a tubed regulation stage.

The VT-150s resolved a wealth of detail, but in a way more subtle, more intimate than other amplifiers. I consistently felt drawn in to the music to a degree I haven't experienced before. The level of fine inner detail resolved by the VT-150s was absolutely stunning. These amplifiers revealed newfound musical information and nuance in music I'd heard hundreds of time before.

The VT-150s were particularly adept at conveying fine nuances that bring the music to life. For example, I heard vocal inflections for the first time in familiar music, inflections that greatly added to the communication of the musical message. Another example of the VT-150s' extraordinarily high resolving power was their ability to convey the inner detail of instrumental timbres. This wealth of inner detail infused instruments and voices with a stunning palpability. The VT-150s provided a greater sense of instruments actually existing in the listening room than any other amplifiers I've heard—and by a wide margin.

But these qualities—smoothness, liquidity, truth of timbre, and resolution of detail—were only the beginning of the VT-150s' magic. The VT-150s also set new standards in soundstage transparency, air, and depth. I heard new spatial information in recordings I'm intimately familiar with. Again, I'm not talking about a tubey coloration in which images swim in a featureless, washed-out morass, but a presentation highly resolving of real spatial cues.

This special quality of the VT-150s struck me as I listened to Chick Corea's Light as a Feather (Polydor 827 148-2), one of my favorite records. On the title track, Joe Farrell's sax comes in for a solo at the left of the soundstage, set back a little. The apparent distance between the listener and the sax is a dead giveaway of a product's ability to resolve depth. Through the VT-150s (fed by the LS5), I was taken aback at just how much air there was between the front of the soundstage and Farrell's sax. I also heard a delicious bloom around the instrument, along with the previously described timbral liquidity. I felt a greater joy with this music than I'd previously experienced with other electronics. This wasn't from hearing the specific attributes cited, but from the ability of these products to get out of the music's way and to take me one step closer to the musicians' expression. I had many of these transcendental moments with the LS5 and VT-150s.

The VT-150's bass reproduction was exceptional for a tubed amplifier, but still no match for those of the best solid-state units. The Krell KSA-300S, which has the best bass performance of any amplifier I've heard, has vastly deeper extension, tautness, control, and dynamics than the VT-150. The tubed amplifier lacked the bottom-end punch on kickdrum so important to some music. The VT-150, however, gave a more palpable impression of an acoustic bass existing in the listening room, and a greater sense of openness, bloom, and space in the lower registers. On most music, I gladly traded the Krell's bass for the VT-150's magic. On other music, I missed the big Krell's driving power and unlimited dynamics (footnote 3).

The VT-150 is, without question, the best power amplifier I've heard. After reading over my description of their "sound," I feel that I haven't conveyed the sheer musicality of these extraordinary products. The VT-150s went far beyond any descriptions of sonic qualities. Instead, they were truly transcendental, bringing me so much closer to my favorite music than I thought could be achieved by changing power amplifiers.

The LS5 and VT-150 combination provided the kind of musical experience that gets your heart thumping, you palms sweaty, and your whole body involved in the experience of music-making. I consistently felt that these electronics let me in on the musical event, allowing me to hear more closely what the musicians were doing. I felt somehow privy to what went on at the recording sessions, as though more of the musicians' intent was communicated by the electronics. The involvement provided by the LS5 and VT-150s wasn't the result of some spectacular sonics, but of their ability to take me several steps closer to the musical message. I left each listening session exhilarated (footnote 4).

While other superb preamps are competitive with the LS5, the VT-150s were without peer. This amplifier was nothing short of revelatory in its complete lack of grain, etch, hardness, stridency, and, most important, listening fatigue. The VT-150 is as far removed from "hi-fi" as I can imagine, and closer to the live musical experience than I've heard from any amplifier.

What's so remarkable about the VT-150s is that they achieve this smoothness and liquidity without sacrificing musical detail or sounding overly romantic.

The bottom line is that I've enjoyed music more through the LS5 and VT-150s than with any other electronics I've had in my system. In fact, nothing else has even come close. The VT-150s provided the kind of experience that must be experienced firsthand to be believed. But I warn you: after a taste of this amplifier's magic, you may find yourself unable to live without it.

Footnote 3: I'm about to take delivery of the $20,000 Genesis II.5, which includes a solid-state power amplifier for the bass. You can bet I'll drive the midrange and tweeter panels with the VT-150s. I'll include a Follow-Up in my review of the Genesis II.5.

Footnote 4: In Harvey Rosenberg's thought-provoking new book, The Search for Musical Ecstasy & the Archaic Aural Revival, he presents a strong case that audio reviewers dwell on the equipment and specific attributes of the sound, rather than expressing the musical ecstasy the equipment provides. I'll have more to say on this subject—and others presented in the book—in another forum.

Audio Research Corporation
6655 Wedgwood Road N., Suite 115
Maple Grove, MN 55311
(763) 577-9700

Ortofan's picture

... 40dB below the fundamental, one has to wonder whether you're listening to the music or to the distortion?
Is it those relatively high levels of both harmonic and inter-modulation distortion that contribute to the allegedly "magic" sound quality?

Did RH ever compare the VT-150 with the Threshold S/550e?

Bogolu Haranath's picture

These ARC VT-150 mesurements are somewhat similar to recently reviewed ARC Ref.160M and ARC Ref.160S (reviewed in Feb. 2020 issue) :-) ........

Bogolu Haranath's picture

BTW .... A rose by any other name still sounds (smells) the same :-) .........

Bogolu Haranath's picture

Sound to die for (S2D4) :-) ........

JRT's picture

Not sure how that VT-150 SE differs from the VT-150, but it's interesting regardless.

More commonly the output transformer of an "ultralinear" configured amplifier (eg Dynaco MkIV) simply includes taps on the primary to connect to the screen grids, so those taps share the same B+ power supply voltage with the anodes, which requires suboptimal voltage on the anodes to prevent too much at the screen grids, and that compromise often results in lower than optimal voltage at the anode and higher than optimal voltage at the screen grids with shortened life and degraded performance. This amplifier (at least the SE edition of this amplifier) takes the better approach of providing a separate center tapped winding for the screen grids, allowing those to be operated at reduced power supply voltage than the anodes, which significantly reduces nonlinear distortion and lengthens usable life of the output tubes. Also there are four separate cathode feedback tapes, one for each output tube. For an unchanged level of global feedback, utilizing cathode feedback tapes further reduces nonlinear distortion and reduces output impedance by including the transformer in a local degenerative feedback loop with the output tubes' cathodes.

Lorton's picture

I had this amp, worked well on my watt puppies, wounder how it would sound today and if it will hold against current ARC.