Picking this back up with that Yamaha CS-15.

Documentation

Thankfully the key documentation is easily available and attached to this project. Not much else is needed aside from possibly finding some datasheets if needed

Current State

Functional testing

Doing a bunch of testing, here are the notes of things needing attention

There are 3 mods with switches on the back panel that need to be addressed
- 1: Switch down seems default. Switch up increases the LFO frequency
- 2: Switch down seems default. Switch up seems to connect the output of Mixer 2 to the input of VCF 1
- 3: is less clear. It's impacting routing. Down seems to change noise, routing it to VCA2, and doubles the level of VCO 1. Up seems to disable the output of Mixer 2 so it doesn't go anywhere
EG1 and EG2 leds don't work
Pots and switches to clean
- Mixer 2, VCO 1 and VCO 2 pots
- VCF 1, LFO Mod and EG Depth pots
- VCA 1, EG Depth pots
- VCA 2, EG 1/2 switch
The main out, when outputting lower frequency square, the top/bottom droop, suggesting output cap is losing its capacitance.(Or was a limit to design)