Digitech iStomp iOS Guitar Multi Effects Pedal While researching the rig I found a disturbing lack of stereo effect pedals that feature a stereo in! Most effects are mono and "stereo" usually means mono in and stereo out. Well.. I couldn't help but notice there were used iStomps around for $60. The deal is for between 99 centers and 10 bucks you can by virtual stomp bocks to an iOS divice, load them into the pedal, and switch them as the needs arise.