Volume Box for HRDX hum

[Enzo]

box hums even with the pot turned off completely.

Well now there is a clue.

Did you go back and add the ground wire from the right end jack sleeve to the pot/left jack sleeve? With the pot all the way down, the wiper SHOULD be grounded. Yet it still picks up hum?

Also, when the metal bottom is on, is there electrical continuity from it to the body?

All your symptoms point to a lack of ground on the return path.

[Zouto]

Well now there is a clue.

Did you go back and add the ground wire from the right end jack sleeve to the pot/left jack sleeve? With the pot all the way down, the wiper SHOULD be grounded. Yet it still picks up hum?

Also, when the metal bottom is on, is there electrical continuity from it to the body?

All your symptoms point to a lack of ground on the return path.

Hi Enzo, thanks for chiming in. Yes, the wiper is grounded when the pot is turned down, the complete metal housing of the box has ground continuity. The box picks up hum from the PT like a single coil pickup, if I move it I can find some humfree spot/angle in distance to the amp or on top of it. It acts like a coil.

[Toft]

Do you actively try to find that humfree spot, Zouto?

[Zouto]

Do you actively try to find that humfree spot, Zouto?

Sure, I‘d like to use the box without any hum.

[Jazz P Bass]

Read this thread: https://music-electronics-forum.com/...l=1#post538932

[Zouto]

This double plug on pot construction also picks up some hum. It blocks the FX loop completely so you can‘t use any FX in the loop. With the box you can use FX like digital delays etc. before the volume pot, like send > digital delay> vol.box input> vol.box output > return.

[diydidi]

The fix is easy. Use slightly longer cables and place the box closer to the input of the amp far away from the power ttnsformerh side.