DIY synth for circuits and signal processing

I came across this cool minimal synth kit called Labor from Erica synths. It’s great for learning about circuits and signal processing. There are videos online about it to get started. It looks great!

When I was a kid, maybe around 8 years old, I had a couple of toy like this, and they taught me a lot of basic rules and intuitions about circuits and signal processing. One was a Radio Shack electronics experiments kit, and the other was some sort of sound effects generator with lots of knobs and switches. Those toys and the mini notebooks by Forrest M. Mimm III gave me a lot to experiment with and learn from. This Labor synth could set a lot of people on a good trajectory for learning about circuits and signal processing too. In a fun way that connects with music as well, for those who might be into that. Some of the circuit design/analysis would be appropriate even for high school or early college circuit classes.