Hum on true bypass only?

Discussion in 'Effects [BG]' started by Adamixoye, Aug 20, 2013.

  1. Adamixoye

    Adamixoye A PT Pro is cool for worship, right?

    Apr 9, 2012
    Occasional Beta Tester for Confusion Studios, Singular Sound, and Source Audio
    I've been having a noise problem on my board. I have identified a few possible culprits. One of them seems to be an interesting case. It's a digital pitchshifting pedal for guitar (this is a combo bass/guitar board). I put it only in a chain w/ a true bypass dirt pedal and found the following results:

    Pitchshifting on---no noise
    Pitchshifting off---no noise unless the dirt is on, then I hear hum

    This is definitely hum and not the obvious hiss from the dirt pedal. The pitchshifter is allegedly true bypass. Does this make sense? Any chance a good isolated power supply will help?