AA764 blackface Vibro Champ cooking cathode resistor.

[acorkos]

53 volts dc on the power tube cathode. Also high are the AC volts on the 5Y3...350 as opposed to the 315 on the schematic. All other DC voltages meter at about 10-15% lower than those listed in the schematic.

i tried different tubes, i replaced the cathode cap, a swapped in a new main filter cap can. the 470ohm 2 watt resistor still cooks, smokes and smells bad. how do i lower the cathode voltage?

[Euthymia]

If you have not already done so, measure:

Voltage at the "grounded" end of the cathode resistor.
Value of the cathode resistor.
Voltages at pin 5 (especially), pin 3, and pin 4 of the 6V6.
Value of the grid leak resistor (nominal 220K from pin 5 to ground) and voltage at "grounded" end.

[acorkos]

Value of the grid leak resistor (nominal 220K from pin 5 to ground) and voltage at "grounded" end.

good call....broken solder joint on the 220k ground @ the brass plate. thanks!

(solder joint broke from upwards pressure due to warping/lifting of the tagboard)