I’m in the process of creating an analog step sequencer. It’s not a new idea, I would just like to experience building my own and add my own personal touch.
It’s going to be based on the APC NE556 tone generator circuit, along with a NE555 and CB4017 counter for stepping. I would like to design it with the future in mind, so I will add inputs and outputs for added features such as an external clock source.
This project so far has been made possible by inspiration from many other projects on the net, primarily one by Ezer Longinus and Mark Kleback found here.
So far I have built a simplified 4-step prototype version of this on a breadboard. Works great so far, I just need to make adjustments for tone now that I have added step LEDs.
Only having two diodes on hand, I had to salvage two more from a dead ATX PSU. There are about 4-6 more to salvage, which beats running to Radioshack.
The APC’s tone is pretty dirty, there is a chance I might swap it out down the road for something cleaner and more stable. I even had the idea of making the tone generator modular to swap out other tone generators. Maybe something similar to what Arduino does with shields, or possibly some type of modular game-cartridge-like system.
I have a few other ideas that I’ll wait to share until they’re on paper (easier to explain).
Here is the work-in-progress schematic: