so i implemented this state variable filter for my synth code:

https://arxiv.org/pdf/2111.05592.pdf

same topography as in Prophet and the Oberheim.

not the easiest thing to turn into a fourth-order (24 dB/oct) filter. normally you just chain two second-order (12 dB/oct) filters, but this is a multi-output filter, so if you did it naively, you'd end up throwing another whole filter on each output.

for the moment, my code just switches modes, i.e. the 24 dB/oct filter doesn't have multiple outputs, just multiple modes.

it sounds all right though.