A nice (live) setup is to use your guitar synthesizer or modeler as an additional effect processor besides your regular amplifier (effects loop). The GKW system comes with an optional footswitch to switch between your synthesizer/modeler and your normal amplifier (stack / effects loop). It basically functions as an toggle switch with LED indication. When on, the dived pickup and normal pickup signals are routed through the 13 pin DIN cable to your synthesizer/modeler. When off, the normal pickup signal is routed to a jack amplifier output, which you connect to your amplifier (stack) and the 13-pin DIN output is muted. When no footswitch is connected, the GKW system operates in the on modus.