My Pro Reverb is I believe a 1978 model - 40 or 45 watt w/ tube rectifier - I've had since 'bout 1980.
When ever it's needed servicing, I've taken it in, but became wiser last week when simply switching the tubes between V4 (1/2 Vib channel gain, 1/2 reverb) and V5 (Vibrato) completely cured a bad noise floor...
So after having the amp dang near forever, I'm getting to know her a little better.
Snagged a pair of test-good Sylvania green lettering 7025, and a pair of NOS Sylvania JAN 5751 to play around with.
*I'm assuming only the output 6L6 need to be biased, correct? So away I go with looking for a cleaner sweeter sound.
Last time in the tech put a few new GT 12AX7 in, as well as JJ outputs (she ran dirty for my taste). Research for a gigging amp tends to say running vintage tubes in the output doesn't gain much sound quality compared to keeping vintage tubes in the preamp section.
Anyway, I'm rambling.
So my question: I generally play clean, enjoy the light "texture" this amp has when happy; but do, on occasion, turn the preamp volume to 10, and pop the master for a full distortion.
? Is popping the master out simply sending the preamp tube in V2 to the cleaners? Or is it nailing V4? Should I be careful putting nice NOS tubes through that torture?
Thanks, Joe (new kid on the block).