Pass Labs Aleph 3 power amplifier Sonic Frontiers Power-1 comparison
For an ambitious single-ended/balanced comparison I hooked up the Pass Aleph 3 SE MOSFET power amplifier, which I reviewed in the April 1997 Stereophile (Vol.20 No.4, p.196). The first CD up was one that I noticed had been served particularly well by the Sonic Frontiers Power-1 in a previous listening session: Kathleen Battle's French Opera Arias, with the Orchestra of the Bastille Opera (Deutsche Grammophon 447 114-2).
The top octave was a little silkier with the Pass amp, the soundstage was larger, and the orchestra had more in-room presence. However, the middle of the midrange sounded a bit recessed through the Aleph 3. The frequency balance was more realistic on the Sonic Frontiers, the Pass sounding a little too thin. I preferred Battle's timbre with the SF amp, but preferred her timing and dynamics with the Pass. Her vibrato was easier to hear with the Pass.
I unveiled the big guns. The first one was the HDCD-mastered Epiphany: The Best of Chaka Khan (Reprise 45865-2). Again, the sound was a bit threadbare through the Aleph 3, while the Power-1 provided a more satisfying weight to instruments. The Aleph 3 did have "Ain't Nobody" bumpin' and groovin' until my poor head had to bob back and forth in celebration of its royal funkiness. That was gooooood. This SE MOSFET amp facilitated an almost tactile connection to the performer that the Power-1 couldn't quite match.
The next CD up was the HDCD-mastered version of Stephen Stills' first solo album, Stephen Stills (Atlantic 82809-2). I'm quickly growing horribly fond of this album, which I'd never heard until a month ago. There's a stereo-effect steel drum on "Love the One You're With" that was more recognizable through the Pass amp. The bass was less satisfying with the Pass, though—nice and quick, but less meaty. By comparison, the Power-1's bass was HUGE.
Playing in an identical system with identical recordings, the Power-1 could not dethrone the overachieving, "Class A Recommended" Aleph 3.—Muse Kastanovich