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Re: Hum is driving me crazy!!!!

100K volume pots are usually fine. You've got noise getting from somewhere. You might try putting a resistor from the wiper to ground (right at the pot) with a value around 47K to see if that helps but you need to find the source of the hum.

FWIW a grid stopper is a resistor in series with the grid of the tube. Usually 100 - 1K and placed with the body of the resistor as close to the grid pin as you can get. Most of the time grid stoppers are only effective for high frequency oscillations.

You also need to look at those heater connections. You have several options there:
1. you can simply ground the center tap of the 6.3Vac
2. float the 6.3Vac but add a cap from the center tap to ground.
3. bias the 6.3Vac above the cathodes by using a resistor divider and bypass the lower resistor with a cap.
I like #3 and haven't had hum problems related to heater voltages.

Keep at it, you'll find a solution.

Pete.

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