I can undo what I've done and it will be back to EL34 specs, true. I did have a blown EL34, but I also have a pile of spare EL34s. The amp worked fine with EL34s.
All of my actual meaningful measurements have been without the limiter in place. Amp plugged straight into the wall and on a dummy load.
True, the 6550s are questionable and might be bad. I don't have a tube tester.
I'm trying to be as systematic and logical as I can. I'm trying to give the best info and implement the responses the best I can. Again, I am a novice. I have a rudimentary understanding of what's going on but I can read a schematic and take readings. I have successfully built, modified, and maintained amps before. I'm no expert, but I'm not totally green either. I'm like...green-ish.This thread is wandering all over the place. I think we all need to slow down and carefully execute some concise and understood measurements with known parameters, then allow time for responses and follow up questions before moving ahead at each step.
I agree. I'm also questioning the tubes, for now. Sadly this is the only set of 6550s I have and honestly I'd rather just put it back to EL34s and have it work than order another set of 6550s. Also, this is a 100 watt amp. Four 6550s.My guess is that one or both of the 6550's is questionable. and it's been missed in the jumpy tests. (Was the limiter there when BOTH sockets were tested? Only one of them? Are you sure? did you move ahead with anything and now aren't sure what your actual test conditions were?) And anyway, "I" also wouldn't adjust the amp for an anomalous set of tubes and call it good because I would always question those tubes. That's like adjusting your car's suspension for strangely wrong sized tires when the right tires are available.