94 Blues deluxe clean channel problem

[tbrogit]

94 Blues deluxe. In clean channel mode master volume is wide open (Always on 10). Thought it might be the pot itself except it works on the drive channel. Power and stage tubes are pretty old. Also when in clean mode sometimes just fizzles out to no sound but can bring back to full sound by resetting drive channel and back again to clean. Im am not an amp tech but I am a Guitar tech and can use a mutli meter and solder gun. I do not want to kill myself though and have never drain filter caps before. Anyway appreciate any help. I really just want to have an idea before I bring it in to some one else more experienced. If anyone know a good repairman in N. Virginia shout out.
Thanks.

[Don Moose]

This is probably the +/-16V supply that runs the channel switching and reverb op-amps - a common problem on this family of amps.

The supplies are resistor-zener setups, but the resistors (R85 and R86 on the schematic I have) tend to unsolder themselves.

Search the forums for threads on Blues Deluxe, Hotrod Deville and ... there's another common one but I can't think of it just now. Look especially for Enzo's advice on bulletproofing these.

This model amp has bleeder resistors built in - no need to connect a drain. Just unplug it and count to 30 or so. Then measure across the series stack of C34/C35 to make sure you're under 12V or so.

Schematics are available here and there - try blueguitar.org first.

Hope this helps!

[Don Moose]

Here's the thread I had in mind.

[tbrogit]

Thanks Don. I appreciate the help.

[wizard333]

IIRC, The master volume only affects the gain channel on those amps. Its there to tame the volume of that channel back down so the gain channel can reasonably match the clean channel. Same on the Hot Rod Series I think.

[tbrogit]

Sorry for the confusion. Its the Vol pot next to the input jacks.

[tbrogit]

What would be a good source for the resistors. Fender? I hope not.