Voodoo Lab

I recently picked up a GCP and trying to use dual expression pedals.

I am using TRS cables for each expression pedal and when setting up a preset on the GCP, they both seem to respond when I can get to the setup for each pedal.

The confusion lies in the fact that it doesn't matter which pedal I'm pressing, it seems to affect the one pedal assignment on the GCP. (ie. Both EXP1 and EXP2 will change the values when viewing the setup for Pedal 1 on the GCP)?

Any ideas as to why this would happen? I would have assumed that one pedal couldn't affect the other's setting? Is is it the expression pedals I'm using?

One or both of the pedals is connected backwards. You will need to swap the Tip and Ring connections on the cable or within the expression pedals. With only one pedal connected at a time, check that the Ground Control Pro shows a full 0-127 sweep range to find the correct connections needed for your particular pedals.