Blue Shoe Gai Pan Distortion Jfet Bias

[Robusto]

Hello,

Are all three JFET in the pedal supposed to be biased to 9v? Q2 has 18V going to it, and I can't get it lower than 14V with the trimmer. Thanks!

 

[Robert]

Yes, you're shooting for around 9V on each one.

Unless you want Superbolt portion to behave like the Taco Bolt, then you'd bias Q1 at 7V, Q2 at 9V, and Q3 at around 0.6V.

If you can't get it below 14V (and you're sure R17 and the trimpot are both the correct values) then Q2 is likely out of spec.

 

[Robusto]

Thanks!