The CGS749 offers a voltage-controlled filter based on the popular CMOS-based Wasp VCF and, in addition, features an adjustable post-filter distortion.

It has a 12dB slope generating Low-pass, High-pass and Band-pass outputs.

The CGS749 will not self-oscillate even at maximum resonance.

A little on how it works:

Of note is that the filter core is running between 0V and -5V, allowing a simple exponential converter to be used to give an appropriate response to the control voltage. The distortion channel and straight signal are mixed via a Segue circuit (reverse panner). The final stage is just a regular, inverting amplifier, but with a voltage divider in the feedback loop to avoid the need for an excessively high value resistor to achieve the required gain.

Build Guide