Cwejman MMF-1 multi-mode filter

11 filter types are available, three of which are bandpasses or notch filters with dual peaks and thus two possible resonances with two sine waves when selfoscillating! The tricky thing is that the parameter SPACING can modulate the distance between the filter peaks with a CV. Very cool for vocal sounds!
Both audio inputs have separate level controls. Of course you can control the cutoff frequency and resonance manually and with voltages.

In general all Cwejman modules are protected against interspersions and have lots of calibration options on the back side.