How to Build an Inexpensive “Fizzle Loop” Synthesizer

Today’s computers are more than powerful enough to act as digital synthesizers that you can use to create electronic music. But many people still prefer the sound and tactility of a “real” analog hardware synthesizer. The analog waves they work with produce a unique sound that is difficult to truly achieve through digital software. Commercial analog synthesizers are often overly complex and expensive, but you can follow Lonesoulsurfer’s tutorial to build an inexpensive “Fizzle Loop” synthesizer instead.

This design relies on 555 timer ICs (integrated circuits) that are very affordable, and popular for basic DIY synthesizer builds like the common Atari Punk Console. Take a listen to the Fizzle Loop synth, and you’ll almost certainly recognize the sound from music you’ve heard. This particular design utilizes three 555 timers to generate all of its sounds, and simple potentiometers and switches to control those sounds. There is also a built-in drum function to add simple beats to your music. Audio output is either through the onboard speaker, or an auxiliary jack.

To build your own Fizzle Loop synth, you’ll need the 555 timers, along with a handful of common components like resistors and capacitors. You’ll also need to make your own vactrol, which you’ll create using an LED and a photoresistor. That acts like a digital potentiometer that reacts to the LED’s brightness, and helps to generate the tones and rhythms. Once you have everything wired up, you can put it in an enclosure. Lonesoulsurfer upcycled an old flashlight case for that, which looks very cool, but you could also 3D-print an enclosure or use a simple electronics project box.