I go from the Frenzel line out to the instrument channel return on the Behringer’s send/return effects loop. I wish I could tell you how good it sounds, but I don’t know. I left the four button effects controller pedal plugged into the Behringer while I tried out the Frenzel running through it. My two year old kept coming over and stepping on an effects pedal button every 30 seconds. I just kept playing through it as he stepped on the pedal switching between the different effects. At one point he stood on the pedal with one foot on each button and kept switching back and forth. He was laughing. I was laughing. It was pretty entertaining.
Of course next time I try to seriously play the guitar, it won’t be so funny. .
Or maybe I’ll just not plug in the foot pedal. Genius. Pure genius.