I'm fairly new to higher end audio and have enjoyed myself so far. However, I'm a very scientific minded person and try to approach things as rationally as I can. So my question is this: provided an amp can provide enough power to drive my headphones, should there be any benefit to using a more expensive amp? I may not be understanding things correctly, but the amp shouldn't really do any audio processing besides amplifying the signal that it's fed, right? Same basic question for DACs: is there really that huge of a difference between cheap and expensive models? Based on some of the threads I've read on the other boards, more expensive amps and dacs will be either mind-blowingly better than the cheaper models, or will only offer a slight performance increase, depending on who you ask. I'm sure that at some point or another, we've all wanted to upgrade a component because a newer/more expensive/claiming to be better unit is released, but this can get pretty expensive to indulge, so I'm hoping to find some objective information on this.