CVpal

Cheap and cheerful DIY USB>CV/Gate interface

• Entry-level, fool-proof, DIY kit (only 25 parts to assemble)
• Plenty of modes (mono CV/Gate/Velocity/Square digital oscillator ; duophonic and dual channel modes ; 4 note trigger conversion ; CC to CV conversion...)
• Digital calibration provides better accuracy than offset/scale trimmers
• USB-powered

Caveat!
* Gate are 0..+5V ; CV are 0 .. +4V
* Decent latency on OS X and Linux only.

https://mutable-instruments.net/archive/#cvpal