I got this,
NCIX.com - Buy ASUS Xonar DG 5.1 Channel PCI Sound Card 24BIT Dolby Digital DTS 105DB SNR W/ Headphone AMP - XONAR DG In Canada.
Just for the headphone amp and I notice a pretty nice difference in the two, then again I also just upgraded my headphones as well but I believe the card does make a difference cause the amp (Seen it on linus tech tips)
You can also pricematch then for $16 as well.