Reply to S4 as Soundcard = No headphones ?

On my MAC, I choose the S4 as my output device. This routes all my audio (Traktor, Live, Computer) out to my S4 as it's what my monitors are connected to. The S4 main gain controls the volume to my monitors. This works for the most part until I pony up and get a standalone interface.

The problem is the S4 headphones don't work in this configuration.

Is there a way to use the S4 as the output device and listen with my headphones?