12dB state variable VCF with voltage controlled resonance

Compact 6HP VCF for Eurorack Modular synthesizers

DIY - PCB AND PANEL ONLY

This is a state variable filter with a nice fat sounding low pass output. The two pole filter has simultaneous -12dB per octave roll-off for high pass and low pass and a -12 db wide (-6dB either side) bandpass output. It has voltage control of cutoff frequency (F) and voltage control of resonance (Q). F and Q are adjustable with panel controls and from external sources using three F CV inputs and two Q CV inputs.

The frequency response is exponential at 1Volt/Octave. The Q response is also exponential.

The design uses a positive feedback resonance circuit that maintains signal levels at high levels as resonance is increased. This enables low noise output regardless of the resonance. The input level control can be used to provide a smooth or clipped high pass output during reonance, further increasing the opportunities for sound experimentation.

-Two pole 12dB filter
-Simultaneous high pass, low pass and band pass outputs
-Exponential 1V/octave response
-Exponential voltage control of resonance
-Self-resonance adjustable
-Three frequency CV inputs
-Two Q CV inputs. This frees up one Q input to be used to track the frequency input allowing constant bandwidth on the BP output
-Input level control for smooth or overdriven sounds-6HP Eurorack with our panel

https://www.tindie.com/stores/pmfoundations/

• ? mA +12V
• ? mA -12V
• ? mA 5V

Module is available as a DIY project only.

This module is currently available.