I'm not sure exactly what the problem is, but I am trying to use the EX-1 (plugged in to exp2) to control the channel volume and it is not working on all of the models. IE: Dr Z model it's working fine but the J800 it's not. Even though the control is set to EXP2 it seems that EXP 1 is still controlling the volume. I tried using a Volume pedal block and result is the same. any ideas?