I have a SUNN Beta Lead 212 that I purchased in 81. I have never had any trouble with it other than some noise from the pots. I bought some QD Contact cleaner and sprayed all the pots. Now when I play the sound cuts in and out repeatedly. I am pretty sure there is still some dirt in there. Several attempts at respraying did not change the problem. The pots that seem to affect it most are the master, level, and drive. I can't pin it down to just one. I was thinking of replacing all pots (shotgun approach) Any thought or help would be greatly appreciated.
