I decided I wanted to learn more about how synths work. I can solder and replace tact switches and internal batteries, but the hows and the whys, well, they’re still elusive. I wanted to know more. I asked around on Facebook for a good starter synth and people suggested the Korg MS-10 and Yamaha CS-5, as their circuits are relatively simple. A CS-5 in bad shape came up on Yahoo Auctions for not much money, so I pulled the trigger. The CS-5 is a single-oscillator monosynth from 1978. It was released a year after its big brother, the CS-10 , and was likely intended to be one’s first synthesizer. As an entry-level synthesizer you could do a lot worse. Although it only has one envelope pulling double duty for both VCA and filter, it has mixable waveforms (sawtooth and square), as well as pulse width modulation. Of course, there’s only one LFO (for now) but with the CS-5 you get sample and hold, and it’s a great one to boot. But specifications don’t mean much if the sound isn’t there. H...