USB S/PDIF adapter?

So I have a set of Steelseries H-Wireless. I like the head set but I had to keep moving the base station between my consoles and my laptop so to solve this problem I bought a really long optical audio cable and ran it to the S/PDIF switch on my tv stand so I could just keep the base station over there. One I got everything working I noticed that I was getting weird static coming from my laptop. At first I thought I might have a bad cable so I made sure all the connections where solid. When I moved the USB S/PDIF adapter I've been using (Witch is a Turtle Beach audio advantage micro 2) It got worse but all the connections between it and the cable are solid. The cable works fine plugged into anything else so my adapter must have a lose solder point or something on the inside. So I'm looking for another adapter, I don't want to get another Turtle Beach one unless I absolutely must. I would like any opinion I can get. The only thing I really need out of one if 7.1 surround sound support. I couldn't find any other ones besides the one I got so I'm hoping one of you guys might know of one. Thanks for the help in  advance.

USB defeats the purpose of S/PIDF .

My headset uses S/PDIF but my laptop doesn't have a S/PDIF port hence the reason I need a adapter. It can use USB as well but only supports stereo through USB for some reason, and my base station is 25 feet away from my laptop and the USB specification says the maximum length allowed for cables is 15 feet long.