Posted by hurdy_gurdyman [ 4.229.162.5 ] on August 17, 2005 at 21:38:16:
I have an old Scott LK-48-B integrated amp. I've had it in a cabnet since I bought it a few years back and had low speed fans cooling it. I moved it to the top of the cabnet with no fans a few days ago. Now I notice that the right channel output transformer runs hotter than the left, quite noticably. I checked with a VOM all the voltages. Each output tube plate has 420 VDC, as the schematic says it should (supposed to have 7189 tubes. I am running JJ EL 84's.) I have no way to accurately check bis current, but measure -31 VDC at the grids. both sides measure the same. I adjusted for 0 volts DC balance between the pair of tubes on each channel. Right channel still runs hotter. After running the amp for 16 hours, I can place my hand on the right tranny and count to 10 without burning, but it's very uncomfortable. The left side is not very uncomfortable, just warm.
My question would be if this sounds like it's within normal range for tube amp channel-to-channel variation, or do I have a problem? If I have a problem, what should I do next?
Dave
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