I'm new to this forum but I figured I would give it a shot since we are all musicians here. I've been having a problem with my Mark V and a chorus pedal in the effects loop. If I have either of my chorus pedals in the effects loop, the volume drops and it sounds muddy, regardless of the pedal is on or off. If I take it out it out, my other effects work perfectly. If I put either chorus pedals in front of the amp, both work flawlessly. I've messed with all the levels, batteries, power suppkies, new cables, etc. I don't know why it does it, and I even bought an MXR analog chorus because I thought the Boss CH-1 was the problem. I'm just looking for any type of suggestion to try. It is getting real frustrating since I paid $2500 for a head that I can't use the way I want. I've also hooked up both pedals to my Marshall JVM410 and I had no problem, so I have a strong feeling it is the Mark V causing my grief.