The core filter block takes inspiration from the Oberheim OB-Xa filter, adding buffered inputs and outputs, and a slight gain increase to compensate for the amplitude reduction in the original. Distortion in the resonance path can be added with the 3-position switch:

A little grungy

Clean

Really gnarly

These 3 positions add some subtle or not-so-subtle changes to the timbre of the incoming signal when resonance is turned up.

Self-resonating, this filter tracks V/Oct and can itself produce pure sine waves and attenuators on the Cutoff and Resonance CV inputs allow you to dial in modulation.

Super easy to follow build guide is linked below, along with schematic, board view, and BOM.

This is a Full Kit, containing all the parts you need to build this module.

8HP

+12V: 15mA

-12V: 10mA