So what's in there that can "click?" At first I was thinking it was expansion of something - chassis, whatever - due to the heat as the amp warmed up but it seems to happen even after the amp has been operating for a while and has pretty much gotten as warm as it's going to.
I'm out of town so I can't check anything at the moment but thought I'd ask if anyone has had this happen/know what it could be. Again, it's totally a mechanical sound with absolutely nothing being transmitted through the electronics. The amp has run for many hours at a time and functions perfectly so I guess I don't mind if it feels like clicking on occasion but I would like to know what causes it.