I was looking into buying the Creative Sound Blaster X-Fi Titanium HD, because i already have a astro a40 mixamp plugged into my pc and i don't feel like I'm getting the best sound out of my sennheiser pc360's. I was going to buy this card and plug the headphones directly into them, but after reading into some other forums, i have found people saying that a headphone amp would add greater benefit with this sound card and i don't understand why this is. (Sorry I'm rather new when it com,es to sound hardware)