Sili Face debugging, sounds right but no unity gain

[Xavier]

Well, after building my first project I've gone for something (in theory) simpler, which is the sili-face, as for the one at the layouts gallery -INCREDIBLE source of projects for us pedal builder-wannabes .

I'm having some issues with it. I have been reading through the archives and some articles about the fuzz face and I can't seem to find where my problem is.

Sounds right, but has just a little volume. With both controls maxed there's only a 50% of what I have when in bypass.

When I close completely the guitar's volume I have some nice moroccan radio station coming out of the amp, but ONLY when it's totally closed, which is funny.

Transistors are 2n3904, though I could use BC109's , but that doesn't seem to make that difference, for what I've read.

I'm using a 9 volt adaptor, when I use the meter to see what's on the circuit, it reads 6,80 volt coming in, and if I measure the transistors it reads 7 volt in all the lugs?

Thanks for your help

[B Tremblay]

First off, are you building the Sili-Face as found here:
http://runoffgroove.com/sili-face.html

I ask because you mention having both controls at maximum, while the Sili-Face only has one external control: the output Volume.

If you are referring to the bias trimpot at the collector of Q2 as one of those controls, then that may be partly responsible for your problems.  The trimpot must be used in conjunction with your meter (or ears) to properly bias Q2.

Since you are also measuring the same voltage on all your transistor pins, you may have one or more wiring errors.

Which layout did you use?  (provide a link)