[mrbungie]

Soundblasters and other discrete audio cards sometimes have specialized high quality components like amps and DACs/ADCs in them. I can drive my Beyerdynamics DT1990 Pros through the headphone high impedance port of my Soundblaster Z from almost 10 years ago while my mobo can't do so as well. I've upgraded almost 4 times already, but the SB always stays.

Supposedly there are some mobos with almost as good if not better audio than discrete cards, but that only happens in high end mobos.

Noise isolation is a thing though, consider a lot of stuff is happening in your mobo all the time. A discrete card should have a lower noise level than an onboard one, while an external through hdmi/toslink/spdif should offer the best noise isolation.

Most of that info is widely available online though, you can check if your old Recon3D is better than your mobos onboard one.

Finally, remember that audio is a highly subjective experience, even with newer and better specs you may find you like the Recon3D sound signature more.