My Tube Zipper is making bacon crackling static noise with the effect engaged. In bypass–no noise. Almost sounds like a dirty pot/switch or bad solder joint. Could it be the need for new tubes? I bought it used and don’t know how old the tubes are. It was working fine for a bit and just started acting up within the past week or so. I’ve isoloated it with known good cables and it still acts up. It also seems as though the “extremity” of the effect is not as accessible…ie self oscillation. I am new to the Zipper. Any ideas? I’ve emailed ehx to see if I should send it in. In the meantime I am hunting around….