Hi. It hums a bit with volume pot turned down, and the hum gradually dissapears as the pot approaches max. It's not that loud, but it bugs me.
It goes away completely when the master volume is turned down. It's still there when V1 is pulled, but it goes away when V2 (cathode follower pair) is pulled. I tried connecting the (shielded) lead straight from V2a grid to volume pot wiper to rule out the gain switch wiring, and also disconnected the bright switch wiring, but it still hums. I have tried messing with the lead dressing around the tubes in nearby stages. I have also checked the ground connection on the volume pot, and tried moving some of the ground bus around, and I'm kind of running out of ideas.
Any suggestions?
A schematic and pictures are attached. Thanks very much for your time.
It goes away completely when the master volume is turned down. It's still there when V1 is pulled, but it goes away when V2 (cathode follower pair) is pulled. I tried connecting the (shielded) lead straight from V2a grid to volume pot wiper to rule out the gain switch wiring, and also disconnected the bright switch wiring, but it still hums. I have tried messing with the lead dressing around the tubes in nearby stages. I have also checked the ground connection on the volume pot, and tried moving some of the ground bus around, and I'm kind of running out of ideas.
Any suggestions?
A schematic and pictures are attached. Thanks very much for your time.
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