This sounds dumb, but....need help identifying a resistor value.

[52 Bill]

Not a chance.

But better ones will probably improve reliability, which is a good thing.

Well, if the caps are really bad and are causing oscillations in the preamp, etc., they could make the amp sound better.

[Ghostplanet]

I finally got around to checking the DC voltage across the 470 ohm resistors. It was 4.6 V. So using the formula in post #8 I get 0.045 for the power dissipation in the resistor. That is well under 1 watt. I will plan on using a single 5 watt 470 ohm resistor. Thanks everyone. Sorry it took me so long to get the reading. You know life sometimes gets in the way.

[MarkusBass]

The overheating could be caused by another failure like e.g. shorted tube, or shorted capacitor.

[Ghostplanet]

The overheating could be caused by another failure like e.g. shorted tube, or shorted capacitor.

The power filter caps are going bad. They must be the culprit.

[g1]

They must be the culprit.

No, they may be the culprit. Failing filter caps more often go open than short. Overheating of the resistor to the screen node is much more often due to excess current caused by defective power tubes. In this case, those tubes may have been replaced long ago, you will never know, but be careful in case the power tubes now in the amp have an intermittent problem.

[Ghostplanet]

No, they may be the culprit. Failing filter caps more often go open than short. Overheating of the resistor to the screen node is much more often due to excess current caused by defective power tubes. In this case, those tubes may have been replaced long ago, you will never know, but be careful in case the power tubes now in the amp have an intermittent problem.

Ah, good point. I'm still learning about tube amps.

[audiopete]

New caps will improve the tone by making instantly available the power the amp demands when reproducing loud passages and bass frequencies because they are able to properly charge and discharge with healthy, fresh electrolyte, not to mention the advancements in cap technology in the last 20, 30, 40 etc years. This means tighter and better defined bass frequencies because the amp is better able to physically control the push and pull, or inertia, of the speaker cones, and better overall transient response and dynamics by being able to react quicker and more powerfully when a loud passage or note demands it. This all translate into better tone.