The first project I’m teaching in my DIY synth course is a 4-stage gated oscillator. It takes a couple of hours to put together, costs about $30 in parts, and is a good starting point for absolute beginners. So what’s going on in there?

Four square-wave oscillators are chained together. The first one is always on, in the video it can be heard driving the main rhythm. Each of the following three oscillators are switched on and off depending on the state of the previous one. The rate of each oscillator is controlled by its own knob. Adjusting the oscillation rate results in changes in rhythm, pitch, and timbre.

The circuit diagram and simulated output are shown below. Further detail is available in my lesson plans, which you will get when you sign up for you DIY Synth lessons with me! It’s cheap, and choice!