I would like a solution for MIDI-to-USB-to-CV for analog synths.

It would be great to playback MIDI files as Control Voltages via the USB port. Any suggestions or possibly any already viable solution? I know there is a similar arduino project, as well as several MIDI-to-CV converters, but it would seem to be pretty straightforward to convert MIDI to Control Voltages output through USB. Any thoughts on the subject? Any existing solution? I seem to remember seeing a commercial product for this, but a homebrew version would certainly be welcome.