Hei, again. I cannot find a schematic of the preamp, Only a drawing of the connecting lugs. Since the limit to attach files here is 20kB (and the file is 72kB) it is impossible to send it. But as I can see , the bass pot can be connected directly to the print board. I tried that and got a bass boost when turning the pot. I have seen pics of the volume/tone Controls where on one it looked as a common tone Control With a capacitor. On another there was two leads (from each pot) going back to the preamp. Maybe mine is that "type" … I try carry on researching. Thanks for Your support so far. Regards Bjorn