CV carries continuous parameter values; gates carry binary on/off events

Modular synthesizers use two fundamental signal types for control. Control Voltage (CV) is a continuously varying voltage level encoding a parameter value — pitch, filter cutoff, LFO rate, envelope depth. Gate is a binary signal that jumps between a low level (typically 0 V) and a high level (typically 5 V) to signal events: note on and note off. When a key is held, the gate stays high; when released, it drops low. The ADSR envelope generator watches the gate: attack and decay happen when gate goes high; release happens when it goes low. Understanding the CV/gate distinction is prerequisite to reading any patch diagram and explains why some jacks control and others trigger.

Examples

A keyboard sends two outputs: a CV output tracking which key is pressed (e.g. 0 V = C0, 1 V = C1) and a gate output that is 5 V when any key is held and 0 V when no key is pressed. The gate connects to envelope generator gate input; the CV connects to VCO 1V/oct input.

Assessment

Explain why using a CV output where a gate input is expected produces wrong behavior. Draw a timeline showing CV and gate signals for playing two notes: C (hold 1 s) then E (hold 0.5 s) with a gap between.