Help Tone control on GGG tubescreamer not working

[tomnottom]

I have checked and verified all is connected correctly solder joints all look good. The pedal sounds and works well just the tone control not working. I am not sure how to check the status of the 20k tone pot? Could it be that the tone pot is bad? Or could I have missed something else? Thanks Tom

[MikeH]

What layout are you using?  I'd check the component values in the tone control area, as well as look for solder bridges/bad joints in the area.  You could also use an audio probe to see if you've got any signal reaching the lugs of the pot.  Since lugs 1 & 3 are tied to the opamps inputs, I assume you'd have signal there- if you don't that's probably it.  If not, the problem likely lies with the pot wiper of the pot (bad pot) or a bad connection with the .22uf tant cap or 220 ohm resistor to ground.

[MikeH]

Oh- GGG layout.  I just reread the topic.  Duh