I built the wonder drive and tested it and all was good. When I put it in the enclosure I get a lot of noise. When I remove the jacks from the enclosure and leave them hanging the noise goes away.
I got it working by tightening the nut back and forth on the pot. It is working as it should and sounds great. I will reflow the pot when I get a chance just to make sure.
Try using a non metal probe & Jiggle the Solder Lugs on the Pads firmly on the suspicious Pot, ie Dry or cracked solder joint.
Sometimes the fibre panel cracks on the Pot holding the lugs back to to the Wafer inside the Pot.