This is an introduction to generating sound and light using integrated circuits called hex schmitt triggers. Each little chip can output six square wave signals, which can be amplified, tuned, and modulated using basic components.
This site walks through the steps for building a simple square wave synthesizer. It also collects my favourite resources and links about this type of synthesis.
In a sense, the chip produces a signal that alternates between on and off, or full voltage (high) and no voltage (low). If this oscilation happens at a frequencies greater than 20Hz (20 oscillations per second) we hear a tone. Using resistors and a capacitors we can control the frequency of this tone. One Hex Schmitt Trigger IC can produce six seperate oscillator tones! Meaning from a single $1 chip we can get 6 voice polyphony, a swarm of angry buzzing electro bees. There are various ways to soften the edges of the square waves using filters and modulation circuits, but first we’ll focus on producing basic chip tune-esque tunable square waves.
It would be confusing to go over the function of every component on this site, but read through this page on basic electronics — it is a wonderful primer on diy electronics and the basic components and principles.
Also, here are a bunch of resources on building hex schmitt synthesizers. Use them for reference and/or inspiration. “Simple Synthesizers” is the little synth zine I hand out during workshops.
- Simple Synthesizers (pdf)
- Handmade Electronic Music (pdf)
- Logic Noise (webpage)
- CMOS Cookbook (pdf)
- Electronics Projects for Musicians (pdf)
- Sea Moss