Ult-Sound DM-4 is a small drum mixer 
in a eurorack format.
Based on classic Moog-style mixer circuitry, but tuned for drums.

Punchy summing, natural saturation, and a response that preserves transients instead of smearing them.
Width: 4HP
Depth: 25mm with connected cable
Current draw: +12V 5mA, -12V 5mA