Is USB straight from a Mac computer to a DAC really that bad?

[AnotherSpin]

I had a problem with the USB connection straight from the mac mini to the DAC. I found that any other devices, such as external drives connected to other USB ports, degrade the sound quality. I mean, best-case scenario required that only one port be used and the rest not at all, all external units disconnected. Including also the monitor via HDMI. Everything besides only USB connection to DAC from mini was easy to "hear". Eventually, I started using an external NAA connected to the mac mini via the ethernet.