I didnt :-(. I bought external sound card ASUS Xonar U7 for multiple reasons.
At home have powered USB 3.0 hub with mouse, keyboard, soundcard and exteral hdd in it. So i just connect all my audio (5.1 speakers + headphones) and all my accesorry by one usb plug. 🙂
Its little bit shame G750 doesnt support surround. I had many hopes for optical ouput as that should support surround. I never found out how to set it from stereo to multiple speakers. Also the optical output in G750 is some new technology and it not in visible spectrum. My speakers are plaing it only in stereo however it says "no device" on the speaker controll unit. With Xonar everithing works 🙂 And sound is also a bit better. I use 3,5mm jacks to take advatange of Cirrus DAC that Xonar have 🙂