The SS 60 seems to be famous for popping during channel switching, for hiss/noise in the reverb circuit, and for hiss when biased cold.

From what I've read Fender ships the amps with extremely cold bias and some of the hiss problem goes away when you bias the amp normally. I also understand that fender issued a TSB regarding a fix for the reverb noise, as well as a fix for the channel switching pop. Reading on the forums it sounds like the channel pop fix involved a relay swap, but I can't find anything about fixing the reverb noise problem.

If anyone can post a copy of the TSB I'd like to read it.