Yeah, the interplay between the 2 sides is one of the things that makes it so unique. The middle toggle specifies what goes into the left (or old blood side). I believe that the right side (or drolo side) always just records whatever sound is in the pedal at that point, be it from the old blood side or input. At lease it seems like that’s how it works. Note that there is no overdubbing on the drolo side. Every time you record, you overwrite. Though you can piece together loops, you just can’t add to what’s already there. Have fun