My desktop worth more than $3k usd. It's a gaming desktop. I doubt my motherboard limits my usb connection quality.
High end gaming rigs are not the quietest systems for audio from what I've found when building custom gaming systems using Asus ROG, MSI G series, and Gigabyte gaming series motherboards. I don't know if tube amps are more prone to picking up electronic noise but there use to be a very faint buzz when I used my BH Crack and HD-800 with my gaming system.
For a system that is primarily for audio I've had much better results with workstation class motherboards using Xeon processors and ECC RAM, more stable and less electronic noise, one reason my gaming system is out on my lanai by its self. The 2 systems I use for audio are very simple Xeon based, ECC RAM, low power graphics, only USB devices connected are mouse and KB, gold or platinum rated PSU and SSD drives only. For USB cables I've found that those that have ferrite beads usually have not given me problems/issues but I try to limit using USB as much as possible.