Nut, a comment on your reply discussing the Stereo Review double-blind amplifier listening tests. There was an open listening session before the blind tests and it's amusing to read some of the rather extravagant language describing the differences they claimed to hear when they knew the identity of the units they were listening to, so this increased the interest of the tests. Of course, the identities were concealed during the blind tests and the sound differences disappeared when the name plates and price tags did.
These tests still stand unchallenged(unchallenged by solid evidence to the contrary, that is, not simply by stubborn disagreement).
