When you google for simple oscillators, you inevitably come across the stepped tone generator aka the Atari Punk Console (APC). The circuit was first published in 1980 by Forrest M. Mims III and was later slightly altered and renamed Atari Punk Console by Kaustic Machines. They gave it that name because its sound resembles that of the old Atari video game consoles.
When I did build my first APC, I quickly discovered why it is so immensly popular. It is very cheap and easy to build and it produces a lot of weird and funky noises with very few parts.
The only thing that, imho, is missing in 90% of the available circuits online, is a way to add an external voltage control. It can be done by adding only two extra female Jack connectors to the two free pins on the 556 timer. WIth these two extra connectors, you can add an external oscillator, LFO,...
Step 1: What do we need for this project?
- A 556 dual timer
- A 1K resistor
- An LED of your choice
- A resistor for the LED. In my case a 470Ohm
- A 100nF and 10nF capacitor
- A 10uF electrolytic capacitor
- 2 x 470K or 500K potentiometers
- A 100K Logaritmic potentiometer or a 100K and 4K7 resistor
- A switch
- 3 female jack connectors
- A DC connector
- A 9V powersource
- A case. I used a plain and ready available project box. But google for Atari punk console and be amazed about all the weird and wonderful housings for this device. I am sure that you can come up with one of your own.