Uglyface - noise when bypassed

[theundeadelvis]

Hello! Just boxed up an Uglyface (with lfo), and if I turn threshold up to where it makes a constant tone, I can hear the tone even when the pedal is bypassed. It's quiet and my guitar signal is clean, but I can hear the tone in the background. If I engage the lfo, I can hear the lfo affect in the background? Any suggestions?

[theundeadelvis]

After poking around some more, I've discovered that if I ground lug 1 of the threshold pot, the sound goes away. So for the moment, I have it so the switch grounds that lug when bypassed. Obviously, I shouldn't have to do this, so I'm wondering if this might help indicate what the problem might be. Here's the layout I'm using:


and the schematic:

[earthtonesaudio]

Probably a layout issue.  The output from the 555 is rail-rail and will readily couple into nearby wires.  A picture of the inside of the pedal might help, but the usual advice applies:  shield sensitive leads, run low and high z physically far apart, etc.

[theundeadelvis]

Thanks man! I was thinking about shielding some leads, but I realized I was out of shielded cable. For the time being, grounding the pot lug when bypassed is working well.