This is the fraAngelico synth by Standuino. He writes:
FraAngelico 8-bit PWM digital synth is unique by the means of its sound generation. It does not use any D/A convertor but the sound is generated by just one digital output pin using Pulse With Modulation which means that by fast changing of different lenghts of pulses we can make different output voltages. Resolution of this technique to achieve different voltage levels is 8-bit but in the true essence the output form the synth is just 1-bit because the output pin does jus 1 or 0 which makes distinctive digital character to its sound.
Although this puristic and minimalistic approach to sound generation, FraAngelico is able to make wide range of different sound colours from powerfull bass to glitchy noises as well as complex rhithmic structures.
This unprocessed raw digital output can be also synchronised with any MIDI device through its MIDI input. To connect standart midi cable use the Standuino MIDI conector (coming very soon) or see tutorial how to connect more standuino devices to you soundcard (coming soon).
This something I really dig about the way he’s laid the whole thing out — it’s got a clean but chaotic look at the same time, kind of like the sounds it produces. Nicely done!