Atari Punk Synth

This is a simple synthesizer based on the popular Atari Punk Console design. In addition it features:

• 8-Step Sequencer
• Echo/Reverb unit
• Sync-In (incl. frequency divider) for other analog synthesizers
• Sync-Out (repeating Sync-In only at this time)
• Manual Clock
• Internal Speaker
• Line-Out

Rough from the inside and from the outside.

...check out the Gallery.

How does it perform?

I intend to produce a better video later. But this one should give a good first impression. Some other music devices join in the second half of the video.

https://youtu.be/FOUyAVAhYBA

Sources

I thank all the great people out there who create and share fantastic circuits. Here are the most important sources I used:

Atari Punk Console with 8-Step Sequencer using two 555 and one CD4017 can be found here http://www.owyheesound.com/sequencer.php or here https://electro-music.com/forum/topic-37770-125.html This circuit diagram circulates in different versions. Be sure to pick the "November 4th, 2009" version.

Echo circuit, using PT2399: https://www.petervis.com/guitar-circuits/pt2399/testing-and-troubleshooting.html

Switch Debounce, using a 555: http://www.555-timer-circuits.com/switch-debounce.html

Frequency Divider, using a CD4017: https://www.electronicshub.org/frequency-divider-circuit/

Circuit -- WARNING!

WARNING!

I tried to create one single circuit diagram putting it all together. I tried to write down everything quite carefully. However I am not 100% sure that everything is correct. Please take it as an inspiration, think and think twice and be skeptical! This circuit diagram may contain errors. If you're going to build your own Atari Punk Synth, recheck everything and if you encounter any mistakes please let me know. Building circuits following this design is on your own risk!

Notes:

• The Volume potentiomenter is logarithmic (Type C)
• The 555s are CMOS

I am not really an electronics expert, so if you find mistakes or could suggest improvements I would be happy to hear from you.

Potentiometer Modules

The potentiometer module was drawn only for step 1. Just replicate seven it times, one module for each step.

Known Problems

• The capacitor in Switch Debounce seems to be too small. Switch still bounces.

3D Models

I added two alternative speaker grilles for the Visaton FR7 speaker that I used.