Peavy Bandit Buzz. Help me Troubleshoot

[Commodore 64***]

Just replaced the input jacks on my Peavey Bandit 112 (Black Box version). When I play into the amp, if I crank the volume a little and strum the Low E string, I get a massive BUZZZZZZZZZZZZZZZZZZZZZZZZZZ. Sounds like an electric chair.

If the amp is set at like 2 on the volume, the BUZZZZZZZZZZ will be like the equivalent of 7 on the volume. It's really loud and scared the shit out of me the first time it happened.

My first thought is the speaker, since the low E would cause the woofer to flap more? But I'm learning by tinkering, so I expect there's other possibilities too. Does this sound like anything anyone else has experienced?

[jim p]

Do you have a schematic? I think you can just call or e-mail Peavey for one.

[Commodore 64***]

I do have a schematic and yes, I had to contact Peavey to get it (fax worked better than e-mail). However, this morning, shortly after my post, I fired up the Peavey after switching this switch on the back. It says "ground", apparently you can change the ground polarity with it. Anyways, I switched it, and played around a bit and was not able to duplicate the issue.

Perhaps it was a grounding issue of some sort?

BTW, I would attach the schematic (for others who stumble into this thread), but it's 1MB, and is too big for theFret's attachment thingy. If anyone wants, it drop me a PM.

edit: I hosted it here: http://www.lucky-cricket.com/files/S...0schematic.pdf

[jim p]

I am having a hard time finding the tube being a transtube amp? Thanks for posting the schematic I had not thought of using a Darlington transistor pair for a high impedance input I have been going with jfets I will have to try it out.

[Commodore 64***]

Yeah, there's no tube in a Transtube. It's just Peavey's trade name for their transistor set-up that creates tube-like sag and resposnse (so I'm told).