It appears that the voltage switch at least affects the output voltage for the MIDI out, but what voltage should be used on the VCC pin? Should it match the switch position? Will using 5v at VCC in with the switch in the 3v position cause any damage to components?
Ive always used it matched to whatever output that I had set the switch to. However, I would imagine that a 5V input is converted to 3V if you set the switch as such.