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 pre-amp, 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.
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.

• Width: 8TE / 8HP / 40.3 mm
• Depth: 45 mm (measured from the rear side of the front panel)
• Current: +30mA (+12V) / -20mA (-12V)