well, it's still very under construction, but here's that modular info site i was talking about: https://modular.trashbyte.io
here's a few of the more-completed pages, including a build guide for the mixer module:
https://modular.trashbyte.io/modules/004
https://modular.trashbyte.io/buildguide/004
https://modular.trashbyte.io/wiki/Jack