I am trying to upgrade my source for my headphone DT 1350 but I don't know which one sounds better.   Ipod classic + amp or a unamped hifiman 603?   I normally listen to classic, jazz and some pop    Any ideas?  

I am currently using Hifiman 603 + DT 1350 headphones listening to FLACs, just wondering if I should get an amp ( not familiar with this area ) to push it a bit further. ( Not sure which one I should get ).    Should I get one? If I should, what kind of amp should i get?    ( I listen to...