The Doepfer A-118 is a noise and random voltage generator module for the Eurorack A-100 system. A great module for creating effects or for adding realism to audio sources such as snare drums, the A-118 generates white noise, coloured noise and random voltages. There are also controls for adding red, which adds low frequency harmonics, and blue which adds high frequency harmonics for the coloured noise output. There are also controls for the rate of change and amplitude.