Hello, AE forums! I'd like to show you some work I've done on converting the Atari Punk Console (APC) to the AE Modular Format. I have a working initial prototype and an untested schematic that I'm planning on revising and building. I'm not sure if I'm the first one to do this, but I haven't found any other completed APC designs on the AE forums (though I did find 1 mention of it).
The original name for the APC was the "Stepped-Tone Generator". It was invented by Forrest M. Mims III; the schematic is available on the Internet Archive. Kaustic Machines modified this original design by adding line-level voltage capability and rebranded it as the Atari Punk Console.
This is what I have so far with adapting of Mims' original design to the AE format.
The capacitors and resistor are the correct original values from Mims' original design. The IC I'm using is the TLC556, the CMOS version of the NE556. The potentiometers in this image from left to right are 100KOhm and 10KOhm, because I don't have any R09-type potentiometers just yet.
I've completed a schematic below, but I haven't tested it yet. For input protection, I have two NZX5V1B zener diodes making sure that CV1 and CV2 are capped at 5V. For output protection, I have the MCP6002 rail-to-rail op-amp to buffer both the intermediate and output stages of the APC.
I'm planning on changing the potentiometers to 10kOhm to better comply with the AE standard, though this might affect what sounds it could make. I really want to call it the "AEtari Punk Console" once it's finished.
Funny, I just stumbled across this post while googling for APC stuff (because I'm making one for the new uModules). I was thinking "easy peasy", just replace the classic NE556 by a TLC556 to save power, I don't even breadboarded it but made a PCB right away. And, then, this most simple synth circuit doesn't work properly Electronics can be surprising sometimes...
I wonder if this project has come to life, as vm70 states he hasn't tested it yet... Anyway, I will get it running (hopefully... *shivering*)