Im surprised to see this thread here, ive seen the same post all over the net and on other forums, pbirkett you have been busy
I decided to go the stereo integrated amp route and went with the popular Nad C352 amp since I heard from this post Nads tend to have good headphone outputs.
So I paired them with the Senn HD-595s, and with my X-fi soundcard front panel output for comparisions.
My conclusion may proove interesting.....
The X-fi headphone output jack is better then the headphone jack output on the NAD stereo amp.
Ive tried it dozens and dozens of times and my ears can notice the Vocals/mids are alot more sharper and detailed and the Vocals are clearer from the X-fi soundcard output.
Its almost night and day difference, so my plan is to return this Nad Stereo amp for a refund.
Im not saying its bad, the Nad amp sounds great and has slightly better bass extensions over the X-fis output and with the right speakers it may sound completly different!
Before this I had a Sherwood Newcastle RDS925 AV amp and oddly this had a very good headphone output, maybe not as strong bass as the Nads but better mids/higher trebles which the nad headphone output just cant match.
I think headfis gonna cost me! cos ive spent £350 and the Amps going back should get a refund no problem but now I wanna ditch my Senn HD595s since the open design expels too much noise for my liking!
Im gonna stick with the X-fis output till I research better but I may try a headphone amp or possibly a Denon AV amp and a decent closed pair of cans.