Got a Music Man HD212 that has static on grids of power tubes but NOT before that. Replaced all wires, trouble-shot bias supply, replaced tube sockets, tubes... at a loss. Only thing left is OT. Anyone ever replace an OT due to this? Could a bad OT cause this?
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Static - Bad OT?
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What do you mean the only thing left is transformer?
I didn't see bad coupling caps from the earlier stages.
Pull the power tubes - is that noise still on the grid pins of the empty sockets?Education is what you're left with after you have forgotten what you have learned.
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Do you have any other output transformers around? Don;t worry about the impedances, we don;t care about distortion at this point, all we care about is does it make noise. Disconnect the existing OT wires from the B+ and tube sockets, clip or temporarily wire in the other transformer and clip a speaker to its secondary - don;t hook up the existing secondary stuff. Does it make static now?
I have an old Fender Bassman transformer I use for this test.Education is what you're left with after you have forgotten what you have learned.
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What melvin said.
If the coupling caps are lifted and the tubes are out and the static remains, it has to come from somewhere. If it isw in hte bias supply, that would make senseEducation is what you're left with after you have forgotten what you have learned.
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Originally posted by Enzo View PostWhat melvin said.
If the coupling caps are lifted and the tubes are out and the static remains, it has to come from somewhere. If it isw in hte bias supply, that would make sense
I'll try the sub OT.
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