There are a few digital to digital converters on the market that really make a sonic difference.
The tiny and affordable Matrix, for example, converts the USB output of your computer to either coax (S/PDIF) or I2S.
This simple arrangement reduces the noise from your computer and gets the digital audio in a better form that out of USB (for most DACS).
Our new DirectStream MKII doesn't really benefit from the conversion, as its galvanic isolation and USB implementation is already state-of-the-art.
But, for everyone else relying upon USB, it's not a bad idea.
Want cheap and cheerful? Try something like a USB hub. Here's an example I found on Amazon.
Point is, if you don't have the luxury of the new PS Audio MKII yet, and you're using USB, it might make sense to check out a low cost isolator for better sonics.