experimental hardware neurons by Grant Richter of Wiard , pcb layouts are tested and working  ,full schematics of the module can be found on the wayback machine ,the stop/start switch in the schematics is misslabeled and should be connected to groung instead of +V
https://web.archive.org/web/20140810101425/http://www.musicsynthesizer.com/DIY/Grant/grant_richters_synthdiy.htm

edit: i made new double layer version of this layout  with gerber files available here: https://synthesizerunderconstruction.blogspot.com/2024/01/experimental-hardware-neurons-by-grant.html

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