Unrealtone is an universal programmable sound card for electric guitars. It allows you to connect your guitar or bass to a PC and use it with any type of software.
The main feature of this board is that it can be programmed to emulate many other types of sound cards. It can therefore be used in place of other proprietary hardware. It is also fully open-source, so you can build your own, or modify it in any way.
It is based on the CM108 integrated circuit, which takes care of voltage regulation, serial, A/D conversion and all the rest. It also allows us to pass data from connected EEPROM trough serial, which enables us to "fake" other hardware.
The board itself features a sturdy 6mm JACK connector from Neutrik and USB-C. This allows for several types of usage, such as mounting the board to a guitar strap, or just leaving it on the floor.
The current version (v2) is the first production-ready revision. Past experiments and revisions were not tracked in Git. There is ony a single physical v1 prototype, which was quickly modified to fix some issues.
Older experiments were mostly done on other repurposed generic CM108-based sound cards by removing power for piezo-electric microphones and adding the EEPROM. Though the cheap sound cards ommit most filters and the result is just horrible and noisy, albeit the proof of concept was confirmed.
The included EEPROM is a common CM108 chip, which can be programmed externally using many different flashers, including a spare Arduino, or even Flipper Zero. Unrealtone board features direct connection to the memory chip for easy access. An alternative would be to use a standard SOIC-8 clip. The board is also ready to use a PIDP socket instead of the SMD package.
