Super '64 trim pots

[Robusto]

What are they for? What am I measuring and where?

Thanks!

 

[phi1]

They are for biasing the jfets, and will affect the character of the distortion.

Measure the voltage on the drain of each fet. (Red probe on drain, black probe on ground). Adjust trimmer until drain is close to 9v. If you want, tweak from there and see if you like the sound at a slightly different voltage.

Where’d you get to jfets? I strongly recommend using smd j201 and 2n5457 with the adapter board (sold on this site), unless you know for sure that the ones you are getting are legit.

 

[Robusto]

They are for biasing the jfets, and will affect the character of the distortion.

Measure the voltage on the drain of each fet. (Red probe on drain, black probe on ground). Adjust trimmer until drain is close to 9v. If you want, tweak from there and see if you like the sound at a slightly different voltage.

Where’d you get to jfets? I strongly recommend using smd j201 and 2n5457 with the adapter board (sold on this site), unless you know for sure that the ones you are getting are legit.

Thanks for the info. I got those parts from Mouser and Small Bear, so they should be okay.