09-03-2012, 07:02 PM
I wouldn't mess with the mica capacitors unless there is a problem that replacing the paper capacitors, resistors, tubes, and a alignment can't cure. The only time that I would replace one of those coffin shaped micas on spec would be if the mica was split and falling apart. Distortion in the audio has nothing to do with these, it could be the speaker (dirt in the pole piece or a warped cone) or it could be drifted bias resistors, or bad capacitors, or bad tubes.
Regards
Arran
Regards
Arran