Newbie here, but long time audio enthusiast. I have a C-70 I bought when stationed in europe in the 80s ( I loaded up on lots of low priced high fi !! ) and its one of my favs. In the 90s it developed a channel issue that a local worthless repair shop fixed with a install of a new balance pot ( knob ? ) it did not fix the problem so into non use it went for all these yrs. Now I would like to fix it up to pass on to my son so off to the best local repair shop I can find. First shop was no better than the one I used in the 90s, so back to searching, so find success in my search for a shop and drop it off for a overhaul ( recap and so forth ) I quickly find the relays...HB2E-DC24V ..are hard to find but managed to get my hands on some. So everything under the hood is spanking new and I pick it up only to later find I STILL have my drop out issue, to be honest I just casually mention this issue and hope the overhaul does the trick. My repair guy is the best local to me ( he is great with tube macintosh's FWIW ) but he is having a hard time fixing this problem, anything I can tell him to point him in the right direction or should I just send it to someone anybody can recommend who has experience in these pre amps ?