that's not possible with a portable player unless it was designed for audiophiles in mind. The iPod is more mainstream and the player that would be most capable to power it with no worries is the Hifiman, but even that benefits from an external amp. You have to understand, you don't really need an amp, it's just that with an amp, the sounds becomes more refined and better. It's better for you to experience it yourself, but since you don't have an amp, take my word for it. You can really power it with your iPod, but there's always something going to be lacking. You might find it okay, but for many of us, we keep our Ultrasone's at home or we have a portable amp connected with our players. Either way, they are powered by something other than just a player. So to summarize, you can get away with an iPod only setup, but you won't experience everything that everyone has talked about. The sound might not suit you later and you'll be wanting more, so i would say get an amp or get a lower model ultrasone. Lower model will probably be better since you can start on the lower tiers and work your way up like many of us have.
