I am a new member, you are an old member - why emphasize this? It is not nice of you to segregate people. Just like attacking a person who has listened to several amplifiers and can draw his own personal conclusion and express it on the forum? I expressed my opinion, I have nothing more to add. All the best and peace. Be tolerant.
Here's the problem: you haven't actually listened to amplifiers.
You have watched amplifier casings, manufacturer names, carried amplifiers from your car to your 5th floor apartment when the elevator was out of order... And god damn it, that 30 kilo amp MUST sound good because you can feel a slight pinch of a nerve just below your left scapula and the person who loaned the amp to you said he paid $12345€.
Also, some amps have VU-meters, which means they're f-ing awesome. Only the BEST stuff has VU-meters.
Here are two only possible scenarios of actually hearing differences between amplifiers on normal listening levels:
1) One is a tube amp, the other isn't
2) One is broken, the other isn't
There's a third scenario outside of the above scope that involves potential hearing loss, and that's when one amp doesn't deliver enough power for loudspeakers to produce painful SPL levels, and one does.
There's no fourth scenario.