State Variable Filter
Jürgen Haibles clone of the EDP Wasp VCF. Its a state variable filter build around one CD4069UB CMOS inverter, that is used as opamp. This circuit is operated at a single 5V supply. It has a rather interesting distortion.
Original description...A useful addition would be to have a switch to have the distortion either pre or post filter.
Wasp filter clone
A 5V EG/LFO for use with this filter