Ampeg J12T Tremolo Noise- Any Suggestions? What's Causing It? And, Attenuator Okay?

[stevieb]

Just recently got a nice little Ampeg J12T guitar amp. Two EL84's and two 12AX7's. It was filthy, so I removed the chassis, speaker and reverb tank, washed the cab, let it dry. Also took the circuit boards out of the chassis, and used almost a whole can of auto-shop contact cleaner (not De-Ox-It, but the stuff I used is plastic safe, etc.) on the scratchy pots and the tube sockets. Then I blasted the circuit boards, top and bottom, with the same cleaner- they seemed to have a slight film (nicotine?) on them. Put the amp back together, and the pots are much quieter, but the tremolo still makes a static-y sound that gets more pronounced the more I turn up the tremolo intensity. I thought it might be a tube, but I read that the tremolo and reverb on this amp are solid state. I don't have a schematic for this amp, and even if I did, I would not know what to test or replace to address this problem.

 

Anybody have this problem licked? What did you do to fix it? I'd love to have the on-board tremolo working right- everything else is okay, including the reverb, and it's a sweet, portable little amp. I have a tremolo pedal, but it seems silly to cart around a pedal for something the amp has and does well (except for the noise.) Good help is hard to find, but if anyone here can offer some learned or experience-driven wisdom, I would be so appreciative.

 

Also, I have a 50-watt attenuator. This amp lacks a jack and plug for the speaker, but I can not imagine any reason I could not install one. Will this amp do well load- (speaker) attenuated? I want power-tube OD, NOT pre-amp tube or stomp-box OD.

 

Thanks.

[stevieb]

bump. Anyone? Anyone? Bueler?

[Prairie Dawg]

Did you ever figure this out? I've got a SJ12T that has the same issue.