focusrite scarlett 4i4 3rd gen audio interface

I use it with S/PDIF.

I would recommend using the Main Output and in the daw software (for example reaper) pen it to left and right. Because Kemper in stereo sounds so good.

I recommend using the main xlr, because it's better against noises. But you can also use the normal outs and put in in focus rite line inputs 3+4 on the back of the interface