Audio Research Classic 60 power amplifier John Atkinson compares
The final set of comparisons was with the Audio Research Classic 60. Now it's true that the significantly lower-powered and less expensive tubed amplifier doesn't necessarily compete with the No.23.5 in the market, a more relevant comparison perhaps being between the solid-state amplifier and a pair of ARC Classic 120 monoblocks. But I'm very familiar with the Classic 60, and felt that as long as I didn't fall into the trap of describing differences that are purely due to the tube amplifier's more limited power capability, the comparison would be illuminating.
The loudspeaker used was the Wilson WATT 3/Puppy 2. Despite the WATT's rather cruel impedance, which drops to 1.75 ohms in the low treble, the Audio Research drove the speakers to reasonably high levels from its 4 ohm taps. There was no doubt in my mind, however, that even at levels well below its clipping point, the Audio Research could not reproduce the music's dynamic contrasts as well as the Levinson. However, although the 60's low frequencies lacked the slam of the Levinson's, the leading edge of a kick drum's sound and the body of its tone was more in proportion via the tube amp, the "pat" and the "purr" being optimally balanced.
In general, as described earlier, the Classic 60 offered a significantly deeper soundstage via the Wilson speakers, and individual instrumental images within that stage—the violin and piano in the Wilson Audio Beethoven Sonata recording (W-8315), for example—were more palpable, more "modeled" in the visual sense, as though the instruments were illuminated by a light placed more to the side than to the front. Tonally, however, the Mark Levinson had a little more midrange body with the Wilson speakers, which made the overall sound less lean/more neutral.—John Atkinson