Picture of Voltage Controlable Atari Punk Console
A while ago, I decided that I wanted to build an analog modular synth. After doing some research, I found out that I didn't know all that much about analog audio electronics at all. So the best thing to do was to start from the very beginning and to build all kinds of simple oscillating circuits to get a grip on the basics.

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,...

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Step 1: What do we need for this project?

Picture of 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.
where did you get the pcb?
janw (author)  skuishingbugs2 years ago
I designed and etched it myself.
Can you upload the file you used?
janw (author)  skuishingbugs2 years ago
I added the eagle file for you. Read the note that I added on the last step about the output.
gkakuk janw3 months ago

Any chance for the SCH file?

thank you!
crth2 years ago
could someone tell me what program the circuit was drawn on
janw (author)  crth2 years ago
I draw all my circuits in Eagle.
poofrabbit2 years ago
Congratulations on being a finalist in the DIY Audio Contest!! Good luck to you!
janw (author)  poofrabbit2 years ago
Thank you!
synthdust2 years ago
All the other APC only use one 556. Is the second one here need for the output mods? I am obviously very new to this, so please be kind ;)
Never mind, I just figured it out!!!
janw (author)  synthdust2 years ago
No problem, I myself am also sometimes confused when seeing those broken up IC schematics.
cool project - if you want to build another cool little instrument I have a stripboard layout for a theremin thats pretty easy to build - it's an Aerial version not an LDR one

janw (author)  Insonicbloom2 years ago
It makes a great sound! I've put it on my 'to make'-list.