PS Audio DigitalLink III has RCA and XLR on the back. As mentioned above, so do the Wyred 4 Sound units.
At my office, I have the balanced into my balanced headphone system, and the single end portion going to my desktop speakers.
At home, it is reversed, with the balanced going to the pre-amp and then on to the monoblock amps and speakers, with the single ended going to the Kicas Caliente. That way I can run the headphone system without spooling up the tubed power amps that don't need to be on.