I've just ordered a parallel port DAC kit from "Norm".
The circuit diagram shows X+ (and y+) ranging from +10v to -10v. X- and Y- are connected to ground.
If I understand differential inputs correctly, then if I connect the X-and GND on the galvo amp to X- on the dac (GND) and then connect the X+ to the X+ input on the amp I should be OK.
Differential inputs on the galvos are like balanced audio line drivers, that is, in the galvo X- is inverted, added to X+ and the result divided by 2 (in my case (-GND + 10v) / 2 = +5v out).
Do you concur?
Steve