Control
MIDI and Expression Control for Guitar Effects
A control message should have one documented purpose and a safe result when a device is missing or starts on the wrong state.
Research guide · Updated July 27, 2026Map messages before cables
Program Change selects stored states; Control Change adjusts or toggles assigned functions; clock communicates tempo. Manufacturer implementations determine exact numbers, value ranges and receive channels, so build a written map from the manuals.
Calibrate expression deliberately
Confirm connector type, polarity and resistance compatibility, then calibrate. Set minimum and maximum values so one treadle can move several parameters through musically useful ranges rather than their entire technical range.
Design a recovery state
Avoid control chains where one missed message leaves the rig silent. Give critical devices a known startup preset, provide direct manual access and save controller and processor backups together with firmware notes.
Shop by purpose
Explore control gear
Compare routing, connections and control requirements at the retailer before choosing.