creative sound blaster z

As the title suggests I'm wondering if I should pick up a sound card or an amp/dac for my Jubilees that I got recently. The one I'm looking at right now is the Creative Sound Blaster Z. Should I invest in one or should I just use my onboard soundcard? (My onboard sound card is Supremefx)

By the time Corsair shipped me a new one (my first one's lights didn't work) I had already gotten myself another Power supply, just trying to recoup some of the money I lost. Don't miss this chance to get yourself this BRAND NEW power supply! Corsair Product Page Items located and shipped...