A VCO from Look Mum no computer. Basic but solid, they name this a “performance” VCO, which means (to me) that it’s intended to be stable in live performance without any tinkering. Though you can adjust voltage trims from the front of the unit, which is nice in a live setting.
Limited modifications, but what you’ll need.
Sounds pretty good.
Some finicky parts in the build. There is one surface mount oscillator chip, and one rotary switch that took me a bit to get on. And getting the trim pot screws through the front panel was tricky.
Calibration is straightforward, but may take you some time.
Build