Envelope follower

[Narcissus]

In synthesis, Envelopes are events that happen over time, have a particular shape of intensity over time, and can be triggered by other events.

The are usually triggered by note-on events, but on modular synths you can triggers envelopes from other events and modulators like sequencers, LFOs, etc.

An Envelope follower is an Envelope that is triggered by an incoming audio signal. In dedicated modular Envelope Followers you can set the threshold, that is, the volume level at which the Envelope will be triggered. You cannot set this threshold on the Virus.

The vast majority of DSP Envelope Followers are hard wired to control the volume (amplitude) and brightness (LPF) of the incoming signal.

In real modular synthesis you set an envelope to control anything even non-audio signals, and be triggered by anything even non-audio signals.