pstamler
Well-known member
Well, my old reliable blackfront Deluxe is finally showing its age. Tonight at the gig I was running the acoustic through it and all of a sudden the volume dropped way back. "Hell's Bells", says I, "The damn acoustic's battery has done crapped out again." So I switched to the ASAT (neo-Tele), and it was intermittent; if I put my foot on top of the amp it would get loud and clean, then a few seconds later drop back down.
That was on channel one; channel two (tremolo) doesn't work at all. I found that the tube shield was missing on the input tube. When I got home I tested the tubes and all but the 12AT7 were fine; I replaced the 12AT7, replaced the tube shield, fired it up...and it was the same. So I guess tomorrow I need to take it apart. Sigh.
Is this a common failure mode? Any off-the-cuff guesses? I'm thinking maybe bad connection to a coupling cap someplace. Or a leaky coupling cap...but none of them, I think, are the originals. I think they're all one or another kind of film. [EDIT: Exercising the pots made no difference at all.]
Peace,
Paul
That was on channel one; channel two (tremolo) doesn't work at all. I found that the tube shield was missing on the input tube. When I got home I tested the tubes and all but the 12AT7 were fine; I replaced the 12AT7, replaced the tube shield, fired it up...and it was the same. So I guess tomorrow I need to take it apart. Sigh.
Is this a common failure mode? Any off-the-cuff guesses? I'm thinking maybe bad connection to a coupling cap someplace. Or a leaky coupling cap...but none of them, I think, are the originals. I think they're all one or another kind of film. [EDIT: Exercising the pots made no difference at all.]
Peace,
Paul