I am trying to use it with a GNX 3 effects board. I run a cable from the send to the input of the GNX, then from the output of the GNS to the return on the amp. When I turn it on, there is a high pitched noise coming out of the amp. Like a really bad sounding one. What am I doing wrong?
Your pedal has signal problems is the only thing I can think of. I have a similary problems with my BOSS ME-70, so I ditched it...