HX Effects-Latching for amp operating, but Loud pop when engaging/disengaging

[Michael_E]

Hey all, so I have an HX effects that I use for amplifier routing mostly. One of my amps has a tone stack bypass that I was able to configure to work with the expression pedal out and go into a foot switch on my unit. It all works fine in switching channels and does so hum-free. However there is a very loud pop that occurs when doing so. The passive box that I use otherwise to switch in/out of the tone stack is completely quiet when doing so. I have messed around with the global settings, etc., and I’m not been able to suss out how to get rid of that pop. Any ideas?