When you consider that a good speaker needs to be paired with a good powered amplifier to sound its best, similarly a headphone, which functions as a miniature speaker would need a good miniature powered amp (i.e. a headphone amp) to bring out its best too.

You would be surprised at the level of audio performance you could get when a good set of headphones is paired with a good headphone amp and good audio source. While speaker systems out-perform headphones in terms of imaging and visceral impact, note that headphones can deliver more superior resolution and detail. The most common reaction folks have with their first experience listening to good headphones with a good amp is, “I’ve heard stuff I’ve never heard before, I’m going to have to listen to my whole music collection over again.”