Older Synths: My Second Synth
Hackaday: How to Make a Digital Synthesizer
2012. This article taught me so much, mainly because you're building in small sections and it's very clear what's being added at every new junction. For this synth I had access to a laser cutter curtesy of the UDK in Berlin, so the front panel was laser-etched onto some black perspex and enclosed in some stained wood.