The Optomix from Make Noise is a dual Low Pass Gate and Mixer. A low pass gate is a circuit which utilizes both amplitude modulation and filtering. It uses a vactrol component, which uses lights and optical sensors within the circuit, providing a very characteristic response shape. This is most famously demonstrated with the "Buchla Bongo" effect. An interesting addition to the newest version of the Optomix allows the volume curve to be used directly as CV, providing two snappy envelopes if the two audio inputs are not used. Finally, there is an Auxiliary input, which is summed to the mixer, giving three mix channels.
Dual Channel Low Pass Gate
DAMP parameter programs how low pass gate responds to falling control transient, continuously variable from long, slow and ringing to short, fast and muted
STRIKE INput allows use of Gate signal to trigger Low Pass Gate circuit, "plucking" or "striking" the vactrol
DAMP and STRIKE parameters combine to allow for easy programming of percussive sounds (sharp Attack w/ Voltage Controlled Decay)
Summing stage with an AUXiliary IN allows for chaining of multiple units creating larger mixes