Filther is an Oberheim inspired 4-pole low pass Voltage Controlled Filter, with CV control over resonance, V/Oct Tracking, and 2 resonant filth modes waiting to be engaged.
The core filter block takes inspiration from the OB-Xa filter, using the ALFA AS3320 to add 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
- 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.
There is a super easy to follow build guide is here, along with schematic, board view, and BOM. This is a Full Kit, containing all the parts you need to build this module.
- Width: 8HP
- +12V: 15mA
- -12V: 10mA