[quote name='cheddatom' timestamp='1337585413' post='1662183']
I thought that swapping the wires over on one end of a jack lead would invert the phase. I'm pretty sure I learned it at uni?
EDIT: Ahhh, but that wouldn't solve the problem when the pedal is off. Surely there are another couple of wires inside the pedal you could flip over?
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There are two wires to the jack lead - one with varying voltage positive to negative, and one ground that stays constantly at zero. The ground is a common connection linking all the way from your guitar strings to the earth socket in the plug wall. It just would not work if you swapped them, you would probably just get a loud buzzing sound like when you half plug a jack plug in. You need another gain stage instead like a simple transistor buffer that can take the input and produce a voltage swing going in the other direction instead.