Just to give a solid ground to the "identifying" amp sound challenge:
Famous Richard Clark will award anyone
$10.000 (since year 1990), if he can positively identify beyond doubt (by statistical measures) in a double blind testing environment any two amps of the owners choice in comparison. No one, i repeat "
No one" of thousands of contestants, who tried the test
here by the stated rules has been able to win the "prey".
Those "golden ears" who speak up here may try by themselves if they are any better than those several thousands who already tried without success.

PS.: I think, he will not go through the effort of doing this without charging some amount of money for it anymore, because he spent so much time and effort for the test setups (groups and individuals) in the past (for free) without any "positive" results (winner).