Classic 30 running hot?

[Jlillhannus]

Hi all,
Have a classic 30 that I’ve been trying to fix. I got it back in working order but the tubes seem to run hot. I haven’t got much experience with tubes so can you plz look at the attached pic?
If they are running hot - can I just change the bias resistor to a higher value one?

[g1]

Picture is not showing. You have to measure the idle current of the power tubes to determine whether they are running hot or not.
If they are red-plating, it is more likely a fault that needs to be repaired, not a bias adjustment.

[Jlillhannus]

Thanks! I have no equipment to meassure the current. The schematics says -14V after the bias resistor. Maybe I can check that and just see if it’s off?

Link to picture:
https://pasteboard.co/NRVVeq1hcg3E.jpg

[g1]

None of those power tube plates are red, so nothing is grossly out of whack. EL84 tubes in this configuration are generally run fairly hot, so it's not a big worry.
Yes, measure the -14VDC bias voltage if you want. You can check it directly across R64, assuming that is the version of Classic 30 you have.
Otherwise, if it sounds good, it's probably fine.

[Jlillhannus]

Thanks alot!