In the “everything matters” way of thinking, the only valid test setup is to use identical conditions for both DUTs, and to introduce nothing extra into the apparatus that isn’t required for critical listening…that means no ABX switches, disconnecting and reassembling hookups, etc., which takes time. Critically matching playback level is known to be a necessity in assessing quality. How many of us can recall the sound well enough to judge in light of these factors? I am in agreement with Jasonbourne on this one…I also believe the preamp is more instrumental in establishing soundstage than the power amp is in my experience.
Why do some amplifiers throw a bigger soundstage than others?
Was watching a YouTube video comparing two Excellent class A amplifiers . the reviewer preferred, the one which threw a wider soundstage with the same set of speakers. Specified channel separation in db iis about the same in all quality amplifiers., so why does this happen?