The EcoLab Audio MS20 filter is an OTA-based filter with low-pass, high-pass and 3 CV inputs.

It is largely based on the circuit diagram of its template, but has some level adjustments and a switch for the various filter modes.

Its sound is very dark, screeching and has an unstable character - exactly the characteristics that have made its original famous. After about 50% resonance, the madness begins and it goes into self-oscillation! But you shouldn't expect tuning stability here, because it is simply an experimental device.