Dove Audio has made a couple of projects available as open source, i.e. we have shared the schematics, bill of materials and PCB files. These are given below
D204 Quad AD/AR module
This was a simple 555 based AD/AR board that fitted four of these in a single 2U wide MU format module very nicely. The Gate inputs are daisy chained, so you can use one gate to trigger 4 EGs, 2 gates to two trigger two each or any combination up to 4 gates for 4 EGs.
Q119 Trigger expansion
I had a Q119 sequencer for a while and whilst I loved it’s features I found the gate output very limiting, so I created a module that would allow 24 switches to be connected and you could then chose which steps were gated or not.
I sold this module when I sold my Q119 sequencer. I do seem to recall some modifications though I cannot remember what, though I usually update the schematic, so be ready for some debugging. The files for this can be found here.
D501 2069VCF + VCA Module
The Module was designed based on some online schematics and a bunch of experimenting by myself. I thought it only fair to share the schematics, board layout and panel with the community.