USB if done right, is a great
way to connect your PC to your DAC.
However, outside of a quality USB cable, another thing to look at is a dedicated USB Card
with a linear of battery power supply. You do not
want to use system power, it causes all sorts of issues.
I have a Matrix USB 3.0 card, connected to a deep cycle 12V battery, using Neotech Legenburg 20 gauge OCC Copper cables. Even the quality of the metal of the DC plug used changes the sound coming out of your speakers, use pure copper ones if you can.
Everything in the Audio Chain affects sound, every connecter, piece of
wire, capacitors, inductors, Fuses, cables, shielding.... you name it :)
It's pretty fascinating really :)