Jurgen Haible Polymoog Resonator 3HP

3-band resonator

JH. Polymoog® Resonator Clone
("Moog" is a registered Trademarkof Moog Mucic (http://www.moogmusic.com). "Polymoog", as far as I know, is not. If you think this infringes anybody's rights, please contact me at jhaible@debitel.net, and I'll remove it immediately.)
The Polymoog, an early polyphonic synthesizer, featured a 3-band "Resonator" section that allows Formant-Filtering in addition to its dynamic Filters. Such a Resonator is a very useful feature for other analogue synthesizers, too, as Kenneth Elhardt expertly demo'ed on a youtube video he made.

http://jhaible.com/legacy/resonator/resonator.html