I have decided to buy a Headphone Amp and I'm looking to the shiit amplifiers right now. I was wondering if the more expensive ones sound better or is it just a matter of personal preference? The price doesn't matter much as my father will buy it for me as a birthday present (still cheaper would...

Hi   I have got my Sennheiser HD-650 for a while now and I was wondering if an amp would make a difference? I have it plugged into the intergrated soundcard in my computer right now (I know the HD-650 shouldn't be) I am new to the world of amps and have no idea where to start. I would...