Nick, thanks again for your help. I did a little more research and found that my Marshall JVM410H comes both with a parallel and serial effects loop. I also read that when you turn the mix knob to 100% the “parallel” loop basically becomes like a serial loop. So again I ran effects send to PF, MF and TF back to amp. I set all stomp boxes kill dry to the OFF position and the bypass function to DSP+FW for spill over. Everything works again like before. The Marshall comes with a built in FX on/off button that can be channel assigned. When I’m playing bypassing the FX loop, the amp sounds amazing… But when I engage the FX loop, even if no effects are on at all, I have a volume /presence/brightness drop.
Not sure why routing the signal through the stomp boxes is causing this… Could it be the bypass selected?
