[RodB]

OK, got it. I looked at the typical screen current for the two tubes and 2.5 ma should be the max. Your measurement of 110 volts across 22k is a fuzzy 5 ma, which is max for a half watt resistor (should be quite warm). This should have around a 60 volt drop, so something is causing more current than required to flow through it. First thing I would do is disconnect and/or replace C15. Monitor the voltage drop after doing that. Be sure the solder joints are good. Look for anything in the wiring that may affect the connections. I don't believe it would cause the symptoms but maybe the tube socket pins need cleaning. The drop across R4 s/b around 35 volts with the 6K7 out and around 25 volts with the 6A8 out. I'm trying to think of other things that may do this or ways to eliminate things.