Module is available as a DIY project only.
This Module is a prototype or in a concept phase.
Pole Mixing VCF
This is a pole mixing filter based on the SSI2140 filter IC (remake of SSM2040). What’s different here is that you have pole mixing for different filter responses (bandpass, highpass, etc.), and compensation for level loss on higher resonance settings. The PCB is fitted for an expansion panel not yet designed) that gives you reso CV and more filter types.
What I wanted, apart from different filter responses, was to utilize the internal resonance VCA of the 2140 for a trick I learned from SSI’s awesome paper AN701, namely that level loss on resonance can be avoided when using bandpass resonance. So, this is, strictly speaking, not passband level loss compensation by pumping more level in proportion to increased resonance, but actually bypasses the broader phase cancellations going hand in hand with classic LP feedback.
