Axoloti is such a cool project that I thought you might be interested in it : http://www.axoloti.com/
A 65€ board with midi in, midi out, stereo audio in, stereo audio out, usb midi host support, ten’s of gpio to connect your leds, pots, sensors, switches & displays.
Audio is CD-quality, latency is VERY low.
An audio focused patcher software to program it visually, runs on mac, windows and linux. Once the board is programed, no more computer needed, it runs stand alone, look mum
And it’s open source. And designed and shipped in Belgium.
Really you have to check this thing. I have 3 in the process of being added to my wip synth, bringing a complete synth voice (can be polyphonic), multi fx, and drums.
Any questions, just ask, I participated in a workshop around it and know my way moderately.