Delight in the double sting of the Twin Wasp Filter!
This is actually two complete Multimode Wasp filter circuits joined together at the hip in a fascinating yin-yang relationship. There is only one input and one output to and from the pair of filters, so they work as a single Super Wasp with a variable internal signal relationship control that can be dialed from serial to parallel and all of the fascinating sonorities in between.
We've combined the really novel features of two different filters originally from the creators of the imaginative WASP and Oscar keyboard synthesizers manufactured in Oxford England back in the late twentieth century.
Unique to the delightfully quirky WASP is it's clever use of a CMOS logic chip in place of traditional op amps to form its 12db state variable type filter. They have adjustable resonance, but will not self-resonate. They do however have variable distortion controls!
You'll have to decide for yourself if you prefer, "pre-distortion" in the first filter section, or "post-distortion" in the second section, (you can even have it both ways of course)!
The Oscar Synthesizer used two filters of a more traditional design, however their relationship was quite unusual as it featured voltage controlled separation or divergence of the cutoff frequencies of each of the filters!
We've added exponential converters (in addition to Notch outputs) and reproduced that feature here. There is only one traditional cutoff frequency control voltage input to the pair of filters, so they track whatever relationship you set manually with the two cutoff frequency knobs.
There is also the new VC Divergence input to spread the two cutoff frequencies apart. This allows new techniques using the traditional CV input as a "Center Frequency" control, and the Divergence control to spread the two filter frequencies apart from center. Hot Stuff because now you can approach filter frequency control with X and Y polar coordinates, (joysticks anyone?)
Special thanks to Jurgen Haible for his design inspiration