I got an Emu-1820m sound card with Sennheiser HD650's headphones. I made the mistake(?) of spending a ridiculous amount on a HiFi, and I can say, without a doubt the headphones + sound card (~£500 total) match the quality of my hifi which costs well over 10x that. Apart from not having such a great sound stage, everything else is pretty much equal in detail, clarity and quality. I absolutely love my headphones and sound card. One benefit of a good quality soundcard is it blocks all interference from your hardware. Without a good soundcard, you might hear a hissing, whirring when your hard drive is spinning up and other such interference. Good sound cards are designed to block this out.