LPB in guitar trouble.

[smoguzbenjamin]

Hey all, I built the LPB from ggg:



I fiddled the part values though because I didn't have that much left.

R1 = 390k + 39k = 429k
R2 = 39k
R4 = 1k + 100 ohms in parralel with 560 ohms = 371 ohms.

The volume pot of my guitar is 20k. And still when I flick the switch, this 'booster' drops the volume by a lot! I checked the transistor (BC547C) pins, if I got the pinout correct it's:

C - 7.36v
B - 0.81v
E - 0.05v

[smoguzbenjamin]

I got it allready. Forgot to connect the circuit board ground to the guitar ground. Why do you have to connect all the grounds together??? Why is that?