BSIAB II issue. Volume off when gain turned down. Tone knob also changes volume.

[davidjnichols]

I just finished the GGG BSIAB II.

http://www.generalguitargadgets.com/pdf/ggg_bsiab2_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I removed R8 for more bass and added the contour knob. It sounds awesome, but the volume is highly effected by the tone and gain knobs.  It gets really loud when the tone is turned up and super quiet when its all the way down.  The tone knob also changes the tone though, so that's good.  It gets a little louder when the gain is turned up (to be expected) but goes completely silent when the gain is all the way down.  Anyone else have a similar issue?  Any ideas on how to fix it?

Any help would be appreciated.  Thanks!

[slacker]

I don't know about the tone knob issues but that is how the gain is supposed to work. Look at the Drive control on the schematic, it is just a volume control after the first stage, if you turn it all the way down then no signal gets past it.

[davidjnichols]

I don't know about the tone knob issues but that is how the gain is supposed to work. Look at the Drive control on the schematic, it is just a volume control after the first stage, if you turn it all the way down then no signal gets past it.

Oh.  Duh.  Thank you.

(hangs head in shame)

[slacker]

No need for head hanging. If you want to set a minimum gain you can add a resistor between the bottom of the drive pot and ground, this will basically make a volume pot that can't be turned all the way down. Have a look at the sustain pot on the Big Muff for an example of this.