Audio Research’s $3995 model 300.2 power amplifier is a 300Wpc design based on Tripath Class D (or as Tripath would have it, “Class T”) amplification technology. At its best, the 300.2 is one of the most musically satisfying amps I’ve ever had in my system. But that said, let me express the concern that the 300.2 often might not be heard at its best, owing to its unusual warm-up requirements. Specifically, I found that this amplifier needed to be powered up for 24-to-48 hours or more before its sound fully gelled (and even then, improvements continued to accrue). To hear the 300.2 be all that it can be, keep it powered up 24/7.
When I reflect on the sound of the ARC 300.2, I think first about the amplifier’s dynamics and overall expressiveness. Because more than many amplifiers I’ve tried, the 300.2 consistently sounded vibrant and alive. In part, the 300.2’s dynamic strengths stem from the fact that, by any standard, it is a very powerful amplifier. The ARC’s high output and ability to drive difficult loads are a big help when it comes to handling the explosive demands of rock or large-scale orchestral material. But there’s more to this story than raw power, because the 300.2 also does a great job of reproducing the leading edges of transients and the complex envelopes of individual notes.
Straight from the carton, the 300.2 tends to overcook the leading edges of transients and to make mids and highs sound transparent, yet disjointed. But after a day or two of warm-up the ARC’s sound is transformed, so that problems with overwrought transients mostly melt away, even as midrange fundamentals and high-frequency overtones come into alignment. Once those issues are resolved, new channels of musical communication are opened. Valerie Joyce’s rendition of the Hendrix song “Little Wing,” from New York Blue [Chesky], nicely showcases the 300.2’s strengths. First, the ARC shows that much of the action in Joyce’s voice centers in upper-register inflections so subtle that many amplifiers have trouble revealing them. But the 300.2 makes Joyce’s vocal inflections easy to follow, so that you feel you can almost read the artist’s mind. Next, the amplifier lets you hear and feel acoustic bassist Jon Hebert stretching to reach the soulful high notes that Hendrix originally played on his Stratocaster. Finally, the ARC shows the reverberant recording space itself, allowing listeners to visualize the performers’ positions in the room, and to hear their movements as they play.
While all these good things become possible because the 300.2 is highly transparent, transparency is not really this amplifier’s defining characteristic. Good though the ARC is, the comparably-priced NuForce Reference 9 Special Edition monoblocks are even better at resolving low-level details, but that observation misses the central point. The point is that the 300.2 offers dynamic expressiveness that just won’t quit—a quality that makes it easy to hear variations in the attack, sustain, and decay of notes, and so to understand more clearly what musicians have to say. Though the 300.2 certainly sounds pure, its greater strength is its ability to show where and how musicians emphasize particular notes or phrases to adding meaning to performances.
I should add that the 300.2 offers bass that is tight and punchy, and whose razor-sharp transients that can make the sounds of electric bass guitars or kick drums fairly jump off your speakers. I tried bassist extraordinaire Victor Wooten’s Soul Circus [Vanguard] through the 300.2 and heard a slap-bass sound so compelling it made me want to get up and boogie. While the 300.2 does not offer quite the low bass weight or “traction” that the NuForce Special Edition monoblocks do, its mid and upper bass are easily competitive with the best I’ve heard in terms of textural refinement and transient speed (granted, the very expensive MBL 9011s probably offer even better bass, but those mega-amplifiers are a special case audio reality unto themselves).
Because the ARC sounds so expressive and full of life, it is more engaging on an emotional level than most other amplifiers. Instead of presenting “good sound” in a vacuum, the 300.2 gives listeners the sense of participating in musical conversations. In that context, the ARC’s ability to convey emotional content makes all the difference.
Jonathan Valin comments on the ARC 300.2
To my ear, one of the things that some of the lesser Class D/T amps, like this model from ARC, miss is—for lack of a better word—“substance.” The 300.2 just doesn’t sound quite as solid, rooted, and dimensional as a (good) conventional Class AB amplifier, tube or solid-state—or as instruments and vocalists do in life.
To put this differently, if you were to think of an amplifier as a light source illuminating what’s on the soundstage, then something like the ARC 300.2 doesn’t have all the “modeling” of, say, the Class AB ARC Reference 210 (which, at $20k, is admittedly much more expensive) or even the $6.8k Kharma MP150. The 300.2’s illumination is too soft and full-on, like a feathered light shining straight ahead rather than like a series of spots hung above the stage. It doesn’t cast the highlights and shadows that bring out the shape, texture, and depth of instrumental images; neither does it fully light up the space between and among images, nor illuminate the sharp dynamic contrasts and brilliant harmonics in a series of notes to the same extent as something like Audio Research’s own Ref 210. For instance, in the opening movement of the Prokofiev Third Piano Concerto [Speakers Corner/Mercury], Byron Janis’ Steinway sounds just the slightest bit muted top-to-bottom through the 300.2. As a result some of the brilliance and daring of his Horowitz-like playing is scanted. Horowitz himself once said: “If you want me to play only the notes without any specific dynamics, I will never make one mistake.” The 300.2’s slight flattening of dynamic contrasts and slight washing out of timbre makes Janis sound a bit like he’s trying to avoid making a mistake. Consequently some of the drama of his great performance is squelched.
As is the case with the Rowland 201 (for which, see below), there is also something definitely askew in the 300.2’s top octave, which (like the Rowland’s) sounds unnaturally airless and curtailed to me. As a result, instruments like the bells in the first movement of The Pines of Rome [Classic/Everest] sound more like rattled chains than bells; as was the case with the Rowland (and perhaps with Class D/T amps in general), it’s as if some treble harmonics and dynamics and air are just plain missing (or way down in level or mixed with noise). There may be a little band of roughness in the ARC’s upper mids, as well, that hypes upper-midrange transients without adding dynamic range elsewhere or real extension on top.