Yes I'm using a stereo Y cable coming from the stomp's send. The signal flow within the Stomp is Red Comp - FX Loop L - US Double Norm preamp - FX Loop R. When I engage FX Loop R it seems to cut the Send From FX Loop L. Meaning the signal is going straight to the Amp's loop and bypassing the preamp, so if I engage FX Loop R, my amp won't change channels nor do the EQ controls work. I have the FX Loop L set off when the US Double Norm preamp is engaged, and vice versa when it's on. Even if FX Loop L is on, engaging FX Loop R still seems to cut the send from FX Loop L. Hope this makes sense