Are your amp comparison’s level adjusted?


I was shown that my comparison’s of amplifiers had to be matched to precise levels (>.01 volts) or my conclusions where often erroneous! I tried it. I suddenly heard differences I hadn’t heard before and notibly the mid ranges became very similar (on most modern amps). I found a review of the AVA ABX Comparator by Doug Schroeder on Dagogo.com which lead him to similar conclusions. My comparisons were all sighted, no DBT. Has anyone tried this?
tomfoolery
Absolutely and positively 100% the only correct way to compare anything in my system.

Kenny.
I personally wouldn't find this device worth the cost. It seems better to  compare components over a span of time. Quick comparisons reveal differences, but don't tell the whole story. YMMV.
Listening levels being relatively matched is very important for the mentioned reasons. What the origins of the method and reasoning are, is a long drawn out explanation.

eg, when testing cables the listening levels should never allowed to change. Switch to different input or mute whens swapping cables...but never change levels.

Other methods like long term are part of the equation (and fundamental-critical!), but direct comparisons - level match. Then try both again at another listening level. And so on.