This time I found something, that I always want to create: A string synthesizer. On the page https://janostman.wordpress.com/2016/01/15/how-to-build-your-very-own-string-synth/ and http://bloghoskins.blogspot.com/2016/11/diy-arduino-string-synth.html is such a synthesizer described. It works on the basis of an Arduino. I do it without a keyboard, but with MIDI. It is with an original Arduino Nano as proposed.
The control of Modulation, Ensamble and Contour is direkt processed from the Arduino. The switchable filter, with Cutoff and Resonance, is built analog.
I build it on a breadboard and with a small enclosure.
On the rear panel is a plug for 9V DC, a MIDI input jack and a 3.5mm jack plug.
As last i create a Video to show how the String Synthesizer sound like: