The Doepfer A-119 is an external input preamp, comparator, and envelope follower, allowing line level signals to be boosted to eurorack level and gates and envelopes to be extracted from them based on the amplitude of the input!
Note: The purpose of this module is more geared towards the gate extraction and envelope following aspects of the module rather than the input - as such the input preamp isn't quite as hi fi as many out there, showing some reduction of high frequencies, but is still plenty good and far from unusable - just worth mentioning!
"Module A-119 (External Input / Envelope Follower) is designed to allow external audio signals to be integrated into the System A-100. It comprises a preamp, envelope follower, and comparator.
The pre-amp has two inputs: an unbalanced input for line level signals, with a gain factor of from 0 to 20, and a balanced input with a gain factor of from 0 to 500, for insertion of low level signals, for instance from a microphone or electric guitar.
The Envelope Follower reads the signal level of the input, and puts out a proportional voltage as an envelope at its own output (see chapter 3. How it works).
The comparator generates a gate signal whenever the input goes above an adjustable trigger threshold (see chapter 3. How it works). Three LEDs help you keep track of overload, the envelope, and the gate signal."
30ma @ +12v
20ma @ -12v