When I plug my multFX pedal to the Return of the amp the sound come out at MAX even with everything on Zero (Master, Volume and Pedal Output).
Why? How to fix?
I have a Code 100 head. I could be wrong, but in my experience Code amps don't do well with most digital multi effects devices, as well as connecting one multi effects processor to another often causes some kind of incompatibilly. I usually plug analog stompboxes on send/return like an equalizer or reverb. Overdrive/Dist stompboxes goes to amp frontal input.
Just reduce the volume of your FX Pedal output (in the FX Pedal). Please check it again.
The same works fine with my Lab Series L5 Preamp (analog) attached to return.
Does that mean, I couldn't use e.g. a Line6 Helix on the return of the 100H?