Controlling 20 kpps galvos

Hello, I have just registered but I've been lurking these boards for a while

I have just received a 20 kpps Galvo set I bought from ebay
20Kpps HightSpeed galvo scanner (max35Kpps) | eBay

Thing is, I have figured out how to plug everything but I am a bit at loss as to how to control it (And the pdf leaflet that comes with it is no help at all)

I know I need a soundcard DAC for the signal and I already have an external soundcard (with only a single output though), but I don't know what sort of signal I should be outputing

My final application is not related to light shows so I probably won't be using softwares such as LFI player in the end but I would use such software at least to begin with so I can tune my galvos with the ILDA test pattern

So far I have been quite unsure of what to plug where as to the control signal and what to output, so any help would be greatly appreciated

Thanks in advance

EDIT: From what I got by reading manuals of various systems, the input seems to be simply a DC voltage that tells the driver what angular position to get (I figure the driver then turns it into a PWM signal that feeds the galvo itself), thing is the input cable has 3 pins, IN+ IN- and G

I'm pretty sure G is ground and IN+ is probably my signal but what is IN-, the same signal but inverted? that would seem a bit weird

Gavlo's use differential signals, ie, to get them to move one way from center, you need to apply voltage to both + and -.

You can simply use G and + and ignore the -, but you'll only get 1/2 the scan angle.

Hi and welcome to LPF.
Usually a little introduction is requested before throwing out your first question but...

Try searching here for the Soundcard DAC tutorial.
You should find out all you need to know.

What I did for my galvos + sound card amp is build the correction amp Benm depicts in the soundcard DAC thread and connect the galvo +/- inputs (do not connect the ground) to the correction amp ILDA outputs, and the soundcard DAC output to the correction amp's inputs. Then go through the tuning procedure in that post. Voila! Instant projector (with software and laser).