Sallen Key Filter BF-22

Korg MS-20 early version inspired Filter. Black panel

This is a dual Hi/Low pass filter. Inspired by the famous sallen key filter from MS-20 early version.
It has attenuverters (inverter-attenuator) as an addition to the normal CV control in Cut-Off and CV control for the resonance with a little more presence of the resonance than the original. The normal CV control for Cut-Off keeps tracking V/oct around trough 3 octaves.

The ‘Link’ switch connects the input of the second into the output of the first to have it in series

http://www.befaco.org/en/bf-22/