Usb or Optical

When I had a DAC with an optical input, I found that it got me slightly better sound than USB when I connected it to the only other optical-equipped component in my system, a Sony CD player..

USB (though iFI Silencer and ViaBlue) sounds much better on mine. I think.

I would invest in a JCAT USB card ($495), though it’s probably more than you want to spend. Alternative, the Matrix Element H USB card ($329) or the SOTM tX-USBexp USB 3.0 card ($350) might be options. That being said, it’s hard to say whether the motherboard USB output would be better or worse than the motherboard optical output. You would just have to test to see.

If you are using an AMD processor, then look into a Pink Faun S/PDIF card ($360). That will likely be better than a USB card, since you are not looking for DSD.

I am using a AMD board, those are some pricey cards not looking to spend that much money.

You could buy a used Asus Xonar Essence STX on ebay for anywhere from $50 to $250.  There's an STX II card for $295 if you want the latest version.  These have an RCA S/PDIF output that is better than the optical on your motherboard.  Drivers are available on the Asus website.  However, it's not as good as the Pink Faun S/PDIF.