Atari Punk Console
Now, this isn't a full fledged electronics blog, and I don't plan to turn it into one any time soon, but that doesn't mean I can't occasionally share some of my favourite circuits, and this is certainly one of them. I've always loved audio circuits, and one of the main reasons I actually got into electronics was because of music. I love electronic music and the idea of DIY-ing your own hardware has always fascinated me, and I also love guitar driven music like rock and metal, so naturally I'm interested in guitar pedal design too. I'm still no expert, just a self taught hobbyist, but my interest in electronics began primarily with audio, and one of the first audio circuits I learned to build was the Atari Punk Console.
The APC is a very simple circuit and a great introduction to the world of synthesisers, and you can build one yourself on a breadboard with just a handful of resistors, capacitors, a couple pots and a pair of 555 timers (or a single 556 dual timer). It was designed by the great Forrest Mims way back in the 80s (referred to as a 'stepped tone generator' in his mini notebook series, which you should really check out if you haven't already), and is one of the most enjoyable circuits you can build at any level of experience, beginner or not.
There's lots of fun to be had playing around and tweaking this circuit. I wont get into too much technical detail, but basically, both timers oscillate: the first timer, acting as a low frequency oscillator, and the second timer, acting as the tone generator which produces the square wave at an audible frequency while being controlled by the first timer. The potentiometers allow you to adjust the timing of the oscillators, producing a stream of rapidly changing stepped tones. If you don't know what that actually means, it's okay, because you can build it anyways and have just as much fun. Basically, you turn the knobs and it makes crazy retro arcade noises, hence the Atari name. It doesn't actually have anything to do with Atari, they didn't make it or anything, but it's very reminiscent of that era of video games, because those same games also generated sound using pretty raw sounding square waves.
Below I've provided the circuit diagram as it was originally designed by Forrest Mims, as well as a variation I drew up (I didn't design it myself, I copied it by hand from a post online, lost the original post and remade it in qucs based on my handdrawn copy)
Note: I didn't include a volume knob in the schematic, but if you want to adjust the volume, just put a pot in series with the speaker
Go Back