a simple google search will get you a lot of different reviews for them. keep in mind that if you have badly compressed mp3's or music/video files on your computer....it might sound better without the amp then it would with the amp just because you'll be hearing all the stuff thats not there aka "noise" (if you get what i mean)
btw, how do you like your hd600's?
For my desktop computer in my bedroom, I've decided to switch from my large stereo system to a good, simpler 2.1 system and an X-Fi sound card. All of that is fine, but at night, when I am at the computer most, I've used my Sennheiser HD600's connected to my stereo receiver with excellent results, but when I switch to the 2.1 system without any of this stereo equipment, what should I do to get the best results with these headphones? Equipment? I wouldn't think plugging them straight to the headphone jack of the 2.1 speakers would give them the best performance.. (Under $300 preferably)
(I could of course just use this receiver without the rest of the stereo's components, but I'd rather something more suited for this particular use, and smaller)