If you can get your hands on the 80Ohm version you won't need an amp, especially with a Creative Labs souncard. I think Creative cards put out enough watts to drive anything from 32-100 ohms effectively. There really isn't a price difference between the two, as far as I have seen. I put them through the wringer tonight. Drum n Bass, House, Jazz, Classical, Rock, MIDI, James Brown, it all sounds so much cleaner than the sony MDR-CD780's I used to use. I have seen the light and have been converted! My "boycott" of Sony products may continue unabated!
The bass on these isn't punchy, or big and boomy like on the Sony MDR-V700DJ's, but it sure lets you know that it's there! Some low freq's (Dom&Roland's "Imagination") can be reproduced on these, that could not have been reproduced on my 700DJ's or CD780's. Absolutely incredible. I now need to reload FEAR and SS2 for game testing.