PastyFace Bias Knob

[rawkcraze]

Simple question:
How would i go about making the trim pot in the Pastyface into a external bias Pot? it might just be as easy as a 500k linear or Log pot, but i just want to make sure i don't burn out my germanium transistors.
Thanks!

[pryde]

Yep. A trim pot is just a tiny potentiometer. The three legs on the trim pot are the "lugs" of a regular pot.

[Om_Audio]

jkokura has cool suggestion below to get an external trim set to range you prefer. As pryde said, a trimpot is just a regular pot but small, board mounted, and inside enclosure. You simply use a regular pot and wire the 3 leads to the trimpot spot on the pcb.
http://www.madbeanpedals.com/forum/index.php?topic=3941.0
C

[frankie5fingers]

Hey rawk.  I did that very thing and I'm glad I did, although the sweet spot is pretty big on the Pastyface.  Depending on the enclosure you use, I might suggest something I found more useful than the external bias; a pre-gain pot mounted outside also.  Keefe (Haberdasher) suggested this and I really like it, it takes the Pastyface from great to greater.
Add a 50kb or 100kb pre-gain pot.  Take the input wire from the pcb and send it to lug 1 of a 50kb pot and then send lug 2 to where the input wire would normally connect to the 3pdt.  That reduces the amount of fuzz as the pot is turned CW.  If you want the fuzz to increase as the pot is turned up just move the wire from lug 1 to lug 3.
Just a suggestion, FWIW, I like having both pots outside the box.

[rawkcraze]

finding a volume loss with this pedal, not sure if its the bias knob or not. did the sola sound version and replaced R14 with a 20k instead of 10K but it still never meets unified volume..

[frankie5fingers]

So you jumpered and omitted R11 and R12?