Envelope Follower

Audio or control signals input to the 9753 module are converted to 'envelopes' relative to the amplitude and triggers, Gate (step) or Pulse. The Envelope output is a CV that follows the dynamics of the input signal. The Gate-trigger occurs for the duration of the input signal. The Pulse-trigger occurs at the onset of the input signal. A Sensitivity control matches the signal source to the envelope and triggering range. This module is used with Guitars or Microphones, or other pick-ups and sensors (through 9754 Preamplifier module if necessary) to interface with a modular synthesizer, as sources for triggers and control of waveform dynamics. A thru-connector is provided so that audio from the sensed source can be split or tapped at the module for processing through other modules such as VCFs or VCAs.

http://www.paia.com/proddetail.asp?prod=9753K&cat=12