Is Class D the Future of High-End Amplification?

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.

Conclusion

On the plus side, the 300.2 is very clear, clean, bright, and forward in a curiously ARC-like way. (ARC amps typically sound as if they are weighted, just the slightest bit, to the presence range.) Its bass, though not as deep and full and powerful as that of Class AB amp (or of live music), has decent sock and extension.
On the whole the 300.2 sounds like ARC, but ARC Lite.