With a stupidly simple number of parts, you can make this oscillator on just a breadboard. Its inspiration is classic, vintage DIY gear from Heathkit.

Electronics class is in session with Synth Diy Guy, who has a detailed video explaining the hex inverter – the chip at the heart of this idea – and how it all turns into an oscillator.

His inspiration is quite clever: it’s the beautifully retro Heathkit model ET-3100 Electronic Design Experimenter. American builder Heathkit inspired early experimenters in computation and electronics – it even influenced some of the people who would go on to make the personal computer revolution. Their kits are laid out like consumer products, complete with handsome cases. And they’re models of simplicity – a fundamental notion in logic, wiring, and calculation would be laid out in spacious, minimalist demonstration boards. Built-in breadboards then let users modify the designs and learn more.

Here’s a breakdown of this particular model, on an equally retro (90s!) Website with other Heathkit models, as well:


You don’t need a Heathkit to try this, though – you can start with the hex inverter chip, and then try different resistors. He gives a complete, compelling explanation:

I’m posting this partly because I imagine we’ll get a lot of feedback from the electronics teachers and electrical engineers in our audience. (“No, that isn’t the simplest possible oscillator.” “That’s interesting, but it’d be better if you –“ Yeah, fire away.)

But I imagine even some of you with rudimentary skills could get going on this quite easily. Thoughts welcome!

Also, anything with hex in it is obviously cool. (Wait, hex inverter, that makes this less Satanic? Or … more?)