Yes, every given volume pedal can in fact be utilized as an expression pedal. You might already know, but to me it's new. I found this piece of information while I was searching for some information of weather input 1 on a Boss FV-50H was connected to output 2, since I then intended to use it as a splitter pedal. Well, the bad news is it is not, the good news is that I don't really need it much, and that I found the piece of information I was telling about above. Since I don't really use my volume pedal for anything other than kind of an advanced mute button, and this function can be achieved by using my Zoom B3's tuner function, this is great news for me. Especially since I don't own an expression pedal for my B3 already. Well, and now to the trick: You simply need a 2 1/4" mono jack to 1 1/4" stereo jack cable. According to how the expression pedal input on the unit you wish to use it for is wired (tip/ring) you simply now just connect one of the mono jacks to the input of the volume pedal and the other mono jack to the output and then plug the stereo jack into the expression pedal input, and you are ready to use your new expression pedal, that originally was a volume pedal.