[3rdAmigo]

Hello all
 
I am new around here and I am suffering form information overload

 
I am considering some headphones for use when PC gaming (probably not much music) and would like to take advatage of the best positional sound I can get for my budget. Headphones I am considering are the Beyerdynamic DT990 or Sennheiser 598, 558, 518, 363 (included USB sound card), and Game One. I really have no idea what the differences are in these Sennheisers are?
 
As I have never used anything other than virtual surround with mediocre phones, I cant make an informed decision, nor can I unfortunately afford to order all models of Sennheisers above from amazon and try them all at the same time
 
I cannot decide between an AMP/DAC (not really sure what a DAC does to the sound when it converts it from analogue), internal soundcard or is there another option, is there not an affordable way I can have the surround option (Dalby surround?) if required with some kind of external USB (?) sound card which is also an AMP and a DAC?
 
Look forward to reading the replies, many thanks in advance!

 

[PurpleAngel]

For PC FPS gamers, like to push the Sennheiser HD558 headphones and the Creative Labs Sound Blaster Z sound card.
You can buy both used.