Hi. I have an opportunity to buy a sennheiser hd600 for a good price. However, I keep reading online stuff about having an AMP. I plan on using the HD600 with my desktop speaker system (there's a 3.5mm jack). I currently have the HD515 and it works pretty well (the bass is very muddy though).
Anyway can someone tell me two things: in laymen's terms, what does an AMP bring to the table? And do I need one for use with a desktop? Thanks