This filter design is inspired by the famous Moog transistor ladder filter. This module uses the traditional transistor ladder core circuit and exponential converter, but has a few circuit adjustments. Kaasutronics have also added a CV input with attenuverter and a Drive control. The drive allows the input saturation to be adjusted, which is a significant part of this filters characteristic sound.
The PCB fits behind an 8HP Eurorack panel with all through-hole components and no wiring required.