Hey there. I was wondering if i should get a dac or a soundcard if I plan on getting a sennheiser hd558. My onboard sound is Realtek ALC892. Thanks for your time. http://www.amazon.com/dp/B004FEEY9A/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=7LZONWSXHGIP&coliid=I19ZJD4KD9KPIJ Thats the link to the headphones
Try it and see how you like it. While it sounded 'good' to me, I wasn't happy enough with it, and ended up getting an ASUS Essence STX. Wasn't happy enough with that either, so I ended up running my Marantz 2325 to the Essence STX, and am much happier. I have very picky taste though, and have a feeling you may be VERY happy with the HD558's running on just the onboard sound. If not, you can always look to upgrading later.