I was able to test the ADSR this morning before work, and was able to fairly quickly find the issue when it wasn’t working. In reviewing the board, I found a single 100k resistor that was supposed to be a 100 ohm resistor. Replacing this component with the correct value got things working! This officially puts me at the ‘halfway point’ on the project, in that 8 of the 16 modules are now working. The VCA’s still need to be calibrated, but they do seem to be working as expected.
I started in on the 1st of the 2 LFO’s, and it did not immediately begin to work as soon as I swapped out IC’s. The 16mm pot cable is really loose, which may be the problem, but otherwise I’ll be reviewing the boards as soon as I get time to do so.