A control voltage can only do three things: rise, fall, or stay constant

All control voltage behaviour — from envelopes to LFOs to sequencers — reduces to three primitive states: voltage increases, voltage decreases, or voltage holds. This framing collapses the apparent complexity of modular CV into a single reusable model. An ADSR attack is a rise; decay is a fall; sustain is a hold; release is another fall. An LFO is a repeating rise+fall cycle. A gate is a hold at high voltage followed by a fall. Understanding CV as state-transitions rather than as named curve types transfers across all modules that generate or respond to control voltage.

Examples

Attack = rise; sustain = hold; decay/release = fall. An LFO rising slope = rise state; descending slope = fall state. A step sequencer jumping between values = instantaneous transitions.

Assessment

Given any standard envelope segment (A, D, S, R), label each as rise, fall, or hold. Then apply the same model to describe a square-wave LFO’s cycle.