Gate

A gate is a control signal used in modular synthesis that maintains a high voltage level for a specific duration of time. Gates are often used to signal when an event starts and ends. For example, pressing a key on a keyboard sends a gate signal that stays high for as long as the key is held down. When you release the key, the gate signal goes low. Gates are typically used with envelopes that have sustain stages, such as ASR (Attack-Sustain-Release) or ADSR (Attack-Decay-Sustain-Release), to control the length of the sustain phase based on the gate duration.