Presence control not working at all on superbass build

[Jos]

Hello Gents, I have a problem on my superbass build where the presence pot makes no audible change at all. I have re-traced the circuit about 50 times now paying particular attention to the feedback circuit and phase inverter section. The kicker is that this is about my 20th build and this ones kicking my _ _ _! I have checked the caps and resistors as well as have the feedback wire hooked to the 8ohm tap off the speaker selector switch. I even tried disconecting the presence lead wire off the pot and no difference at all. To make it better.. The amp sounds amazing and absolutley everything else works correctly! Any advice on what could be causing this issue. I have checked my grounds and all is good there. Thanks a million. Jos

[bobtec]

show some pix and put it on the marshall build page

[Jos]

Problem solved! Jumper wire underneath board from 10k resistor to NFG resistor was pinched/shortaged to ground compliments of one of the circuit board stand-offs. No wonder the amp sounded a bit bright but very good. The pot was effectively turned all the way up then some by this fubar. Now back at it. Enjoy the 4th all . Jos