The GK-MIDI module is an optional Nexus add-on board that contains two combined modules: the GK module and the MIDI module.
The GK Module provides support electronics for the 13-Pin Roland connectivity including the main in-guitar controls: SW1, SW2 and SY-VOL (excluding MIX SW). Control channels are shared with the MIDI module.
The MIDI module converts control voltages (CV) and switch inputs (SW) from the guitar to MIDI. The basic firmware supports up to 6 analog (CV) and 3 switches (SW) inputs, directly accessible through the multichannel guitar input, and 4 more auxiliary switches (SW) that can be routed through the Input / Output Channels via the IO Module.