M13 Can definitely provide MIDI data and should be able to be used as a controller, that said, you need "something" to control, i.e. a rach FX switcher (GCX) or another rack FX unit. M13 Can definitely provide MIDI data and should be able to be used as a controller, that said, you need "something" to control, i.e. a rach FX switcher (GCX) or another rack FX unit.