Hi Guys, I have a cMBP 13" and a Thunderbolt Display. I want to connect my Sennheiser HD518 headphones to the Mac, but not through the actual jack on the mac itself. Is it as simple as using a USB tp 3.5mm adapter? or does it need to have is own little sound card as well? When the headphones are connected, will they act as a separate sound output (Internal Speakers vs USB Thunderbolt Speakers) Can anyone suggest what I should buy?