Fixed filter bank by Osamu Hoshuyama .

Original schematic for this module is here https://houshu.at.webry.info/201703/article_2.html

Bastle Kastl in 4U

 PCB layout for Bastl Kastle in 4U ,this includes additional 5.1V Zenner diodes for protection on each CV input ,the Panel is something i came accross at ModularGrid