I no longer use the wah/volume pedal on my XT Live for the same reason. It's the wah/volume control board, not sure which component, but I noticed that the pedal sweeps from 0-100 very quickly which causes bad sound. My work around is to set both heel and toe to 100 in the settings. This allows me to use the unit with no issues to sound. If I ever get around to repairing mine, I'll come back and let everyone know specifics.