My tube measurents are with 1.5 volts dc applied to probe -2 volts pin 3 and a little more -2.1 pin 8 and the wiper of R1 has -4 volts which don't tell me anything. If I had good meter or if they gave you readings on schematic it might help. As you apply more dc voltage to input before 3.3 meg resistor voltages on pin 3 and 8 get less negative. Thing works good on until you apply voltage. I had to apply 10 volts dc to make meter show 1.5 volts. I have two meters same readings on both, 5 tubes same readings can't all be bad, power voltages all good, pins in socket all test good or the way they should, resistors test good with 1 volt don't have high voltage resistor tester. I was going to change resistors R33. R34. R35 but it seems like if I can balance meter to zero that part must be working. Probably just have throw it off a cliff.