ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Smoking OT/ OScope

1/16/2004 9:51 PM
Greg	Smoking OT/ OScope I have a little 15 or so watt amp I have built that has an oscillation problem that I can't seem to fix. I have rewired the entire amp (to track down a grounding problem) and the problem persits (intermittently). When it is occuring, if I turn up the volume near wide open, it drops off, has a wierd hum and then within about 5 seconds smoke starts to appear at the OT. I have replaced the volume pot, have poked every wire, have switched the tubes, replaced and re-routed the shielded input wiring, retouched all of the solder joints. Could a tube socket be bad or could the OT itself be to blame? I have an OScope, but I have never learned how to use it (need to buy leads). Even if it is not calibrated, should I be able to use it to track the problem when it is occuring and if so, how?? Thanks in advance. Greg

1/16/2004 9:51 PM

Greg

Smoking OT/ OScope

I have a little 15 or so watt amp I have built that has an oscillation problem that I can't seem to fix. I have rewired the entire amp (to track down a grounding problem) and the problem persits (intermittently). When it is occuring, if I turn up the volume near wide open, it drops off, has a wierd hum and then within about 5 seconds smoke starts to appear at the OT. I have replaced the volume pot, have poked every wire, have switched the tubes, replaced and re-routed the shielded input wiring, retouched all of the solder joints.

Could a tube socket be bad or could the OT itself be to blame?

I have an OScope, but I have never learned how to use it (need to buy leads). Even if it is not calibrated, should I be able to use it to track the problem when it is occuring and if so, how??

Thanks in advance.
Greg

Replies:

Wild Bill Greg, a schematic reference would h... -- 1/17/2004 6:18 PM