Better to listen to each for extended periods (weeks even), then decide which one you prefer to live with. You miss a lot of the little stuff doing quick A/B listening.
How does one weigh the virtues an older amp vs. a younger one?
When does new tech beat old, even at a lower original price point? For example, I’m looking at a Pass INT_150 (about 2010, at MSVP $7150) and a Simaudio Moon 340i (mid 2010s and $4950). Leave aside the age factor of the amplifier itself for the time being, and assume an A/B listening comparison is not practical. Excuse me if I’m being crass about this. My apologies to Pass and Simaudio!