6111 subcaster debug

[thermionix]

Here's the layout I used for the main build. The ground from the tube filaments and the tube cathodes are connected to the board ground strip to save space and reduce messy wiring. Not sure if that has anything to do with the hum

Cuts are not shown, but I assume you made them?

[amptramp]

Tried adding back in the 47ohm resistor after the input of the voltage regulator instead of before it. No luck. Didn't make any difference to the hum. The pedal worked as it did without it but still with the hum. I added it after c1 and c2. Would it being after those 2 caps make a difference compared to it being before them?

IL also add that the hum starts the second the power supply is plugged in, before the tube even heats up

Of course your hum starts before the tube warms up.  You have the output connected to the B+ supply through the coupling capacitor and the plate resistor of the final stage.  The tube is connected but appears to be open circuit before it warms up.

[HeavyFog]

Update

Picked up up a regulate 12vDC power supply from a local store to test it out and it worked without any hum at all! Even better is just how great it sounded without any humming obscuring the sound!  I should email small bear about the power supply and the issues i had with it.