SEM 20

2 pole state variable filter

The SeM20 is a 2 pole state variable filter loosely based on the Oberheim SEM's filter with the resonance section of the MS20 grafted on for extra bit of grit. It won't self ocillate, usually, but with an input, or the High Pass out plugged into the Input, it will howl.

The Input section is set up much like the input of the OSCar, when the input is at 5 it's full volume. Beyond 5 the filter will begin to overdrive and distort.

12db high pass, low pass and notch filter
6db band pass
2 cv frequency inputs with attenuators
notch filter balance sweeps between high and low pass

http://bubblesound-instruments.com/sem20.html