Y'know Sean, I actually had not yet thoroughly read Chip Stern's review of the AH! player when I responded above. But upon reading it carefully, not just skimming, it seems that quite a few of his comments on this unit's sound are not the kind of impressions I had implied I would have expected based on the measured results. To me, this supports one of my main contentions, which is that there's not necessarily a lot that can be directly inferred about the sound of electronic gear from the way it measures, within limits anyway.
Also, rereading the Pass review and tests, I have come to realize that really the only things about this amp that should raise eyebrows, outside of aesthetic and economic factors, are these: 1) the current capability shortfall vs. the claimed spec, and 2) the fact that apparently no caution against pairing it with a low-impedance, low-efficiency speaker - particularly in large rooms or for high volume levels - seems to have been mentioned by Pass. The shortfall in rated output (claimed 160W vs. measured 118W at 1% THD, I believe) is trivial in practical terms (at least for the specified 8 ohm load). And I was wrong above to suggest that the amp might show any linearity problems when operated within its margins. So it's only the 'grunt' question and matters of system-matching that are open to question in my mind (again, size and price notwithstanding, since these are issues that are matters of personal taste and wherewithal, unrelated to sound or engineering quality). Looked at that way, it doesn't sound crazy to me, for the right applications, that an amp featuring only two gain stages, no global feedback, just one pair of output devices, and pure class-A operation should yield only modest power for its size and weight (along with a high-than-normal output impedance). Given an appropriate load (impedance that is relatively high, flat, and non-reactive, coupled with above-average efficiency), such an amp might well sound better in some ways than more conventional designs. (Too bad JA no longer seems to be including the data graphs he once made using the Paul Miller system which showed THD vs. output power at varying loads driven by a more 'music-like' test signal. I wonder where this amp would really begin to hard-clip into 8 ohms - possibly much higher than the 1% point, considering Fremer's audition results which indicated no audible strain). None of the foregoing is meant to excuse Pass' overrating of the peak current capability (a claimed 12A vs. a measured 3.8A), or his coyness about power delivery into 4 ohm loads (not spec'ed, but which he seems to imply - incorrectly - is the same as with 8 ohms), but tubed amps with similar 'limitations' (I'm thinking especially of OTL designs) and similar (or higher) pricing are successfully matched with appropriate speakers. Maybe Pass himself will bring to market a speaker ideally mated to his new amp...
Also, rereading the Pass review and tests, I have come to realize that really the only things about this amp that should raise eyebrows, outside of aesthetic and economic factors, are these: 1) the current capability shortfall vs. the claimed spec, and 2) the fact that apparently no caution against pairing it with a low-impedance, low-efficiency speaker - particularly in large rooms or for high volume levels - seems to have been mentioned by Pass. The shortfall in rated output (claimed 160W vs. measured 118W at 1% THD, I believe) is trivial in practical terms (at least for the specified 8 ohm load). And I was wrong above to suggest that the amp might show any linearity problems when operated within its margins. So it's only the 'grunt' question and matters of system-matching that are open to question in my mind (again, size and price notwithstanding, since these are issues that are matters of personal taste and wherewithal, unrelated to sound or engineering quality). Looked at that way, it doesn't sound crazy to me, for the right applications, that an amp featuring only two gain stages, no global feedback, just one pair of output devices, and pure class-A operation should yield only modest power for its size and weight (along with a high-than-normal output impedance). Given an appropriate load (impedance that is relatively high, flat, and non-reactive, coupled with above-average efficiency), such an amp might well sound better in some ways than more conventional designs. (Too bad JA no longer seems to be including the data graphs he once made using the Paul Miller system which showed THD vs. output power at varying loads driven by a more 'music-like' test signal. I wonder where this amp would really begin to hard-clip into 8 ohms - possibly much higher than the 1% point, considering Fremer's audition results which indicated no audible strain). None of the foregoing is meant to excuse Pass' overrating of the peak current capability (a claimed 12A vs. a measured 3.8A), or his coyness about power delivery into 4 ohm loads (not spec'ed, but which he seems to imply - incorrectly - is the same as with 8 ohms), but tubed amps with similar 'limitations' (I'm thinking especially of OTL designs) and similar (or higher) pricing are successfully matched with appropriate speakers. Maybe Pass himself will bring to market a speaker ideally mated to his new amp...
