I think what Mrtennis was saying is that an experienced listener can tell the difference between a cd playing music and one playing white noise!
I would also love to know more about being able to tell a difference in how equipment was broken in...
My personal opinion is that any change from break-in on the vast majority of equipment is more about getting used to a change in the way something sounds than it getting better with time. When I got my tube amplifier, some music was immediately superior and others didn't sound right because I was so used to hearing it a certain way previously and simply sounding different was enough to get a negative response. Now I am enjoying pretty much everything.
I would also love to know more about being able to tell a difference in how equipment was broken in...
My personal opinion is that any change from break-in on the vast majority of equipment is more about getting used to a change in the way something sounds than it getting better with time. When I got my tube amplifier, some music was immediately superior and others didn't sound right because I was so used to hearing it a certain way previously and simply sounding different was enough to get a negative response. Now I am enjoying pretty much everything.