The Doepfer A-119 (External Input / Envelope Follower) is designed to allow external audio signals to be integrated into the System A-100. It comprises a pre-amp, envelope follower, and comparator. The preamp 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.

The comparator generates a gate signal whenever the input goes above an adjustable trigger threshold.

Three LEDs help you keep track of overload, the envelope, and the gate signal.

Key Features:

• External input/envelope follower module for Eurorack
• Balanced and unbalanced inputs accept line level, mic level, and instrument level signals
• LEDs for visual feedback of overloads, gate signal, and envelope signal
• Size: 8hp, 45mm deep
• Power usage: +30mA (+12V)/-20mA (-12V)