I'm finally fixing the broken Peavey VB-2 bass guitar amp. It had a bad output transformer, meant for 6 EL-34. And all the output and preamp tubes are physically broken. I have a new output transformer that's a replacment for a Trace Elliot V-6 which used 6 KT-88; it has much more iron than the original Peavey output transformer, in fact it has as much iron as the output transformer in the Trace elliot V-8 (but different windings, V8 meant for 8 KT88). So I'm hoping the new V-6 transformer may have improved bass compared to the stock VB-2.
I was originally thinking of beefing the amp up some, with a second filament transformer and stronger output tubes (dreaming of KT120), but I think I'd better just get it working. And the El34 are so much easier to drive, no need to re-bias or modify the filament supply. So now I'm just looking for 6 new reissue SED winged-c EL34 and see how it goes from there before I even do anything to the power supply.
Does this sound like a reasonable plan? Is the output transformer (designed to work with 6 KT88) likely to work OK (with 6 EL34 instead)? This ought to be a quick and easy one-weekend fix.
Next question: Without any tubes installed, I suppose I can't really get meaningful measurements of the power supply. But I would like to check each power supply section. Is that generally safe to do without ANY tubes installed? Should I bring it up on a variac (filter caps should be good, as amp is not very old) for testing the power transformer as my first step?
I was originally thinking of beefing the amp up some, with a second filament transformer and stronger output tubes (dreaming of KT120), but I think I'd better just get it working. And the El34 are so much easier to drive, no need to re-bias or modify the filament supply. So now I'm just looking for 6 new reissue SED winged-c EL34 and see how it goes from there before I even do anything to the power supply.
Does this sound like a reasonable plan? Is the output transformer (designed to work with 6 KT88) likely to work OK (with 6 EL34 instead)? This ought to be a quick and easy one-weekend fix.
Next question: Without any tubes installed, I suppose I can't really get meaningful measurements of the power supply. But I would like to check each power supply section. Is that generally safe to do without ANY tubes installed? Should I bring it up on a variac (filter caps should be good, as amp is not very old) for testing the power transformer as my first step?
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