References https://forum.electrolab.fr/viewtopic.php?f=16&t=1944http://forum.anafrog.com/phpBB/viewtopic.php?f=36&t=18334https://forum.pdpatchrepo.info/topic/14016/track-played-on-diy-polyphonic-modular-synthhttps://www.synthe-modulaire.com/t4945-synthe-modulaire-polyphonique-bricole-a-la-maison