There was a thread awhile back about caps, it was suggested 200hrs and they'd be broken in. So I recapped a set of speakers. They immediately sounded different. However, since then they sound the same to me as they did after the recap. Is it possible the change is so subtle in that 1st 200hrs that it's impossible for the "unlearned ear" to hear it? I don't think my ears are sensitive enough or my memory strong enough to remember the sound differences.
It is quite possible. I learned this when I re-capped my M-500. I re-capped it, took it home, and turned it on. It sounded like shit in my opinion. The next morning, I put a playlist on, and left. I came home and it sounded a little better. For the next couple days, I did the same thing to burn it in, and it was a very big, clear difference. If you continuously listen throughout the burn-in, you probably won't hear it as well as if you only take a listen every once in a while. By the time the caps were burnt in, I was hearing harmonies that I had never heard before in songs that I've heard a thousand times.
Reading through his comments again. That he thinks all caps sound the same, that cables don't burn in and his comments about bypass caps gives me pause. Bypassing electrolytic caps does help, but bypassing film/foil caps results in annoying artifacts. However, in either case it is clearly audible, so for him to say he can't hear it leads me to wonder if his hearing isn't completely shot.
I was thinking the same thing. If he's not hearing it, then there's definitely something up with his hearing.