CV/Gate controls analogue instruments with voltages: a gate switches notes on/off, CV sets a parameter such as pitch

CV/Gate is a purely analogue connection made of simple voltages, used to control analogue instruments, especially modular/Eurorack systems. A gate is a two-state (on/off) voltage that signals note-on and note-off — it says when a note happens. CV (control voltage) is a continuously variable voltage that can automate any parameter but is most often used for note pitch — it says which pitch or how much. The pair therefore separates timing (gate) from value (CV). Physically CV/Gate uses 3.5mm jacks on desktop gear, or quarter-inch or banana jacks on larger modular systems. Unlike MIDI it carries no channels or metadata; each cable is one control line, so a monophonic voice needs at least two cables (one CV, one gate).

Examples

A Eurorack sequencer’s CV out sets an oscillator’s pitch while its gate out triggers the envelope: pressing a step raises the gate (note on) and sets the CV to that step’s pitch.

Assessment

What is the division of labour between CV and gate in a CV/Gate connection? Why does a single monophonic voice usually need two cables rather than one?