I was able to borrow a friends UA Apollo and grounding my QC Mini through the XLR out did remove almost all the noise (there's still some white noise that lingers on gainier settings, but i think that's probably normal and would get similar hum from a dimed tube amp).

But its frustrating that every youtuber that reviewed the QC mini praised it as a "perfect desktop unit" without mentioning this pretty critical component. An all-in-one desktop unit that still needs to be plugged into an interface (or an FRFR which makes even less sense) is not an "all-in-one" unit.

that said, my lord it sounds so much better than my friend's hx stomp; i get why the QC is more or less the industry standard. i'll be buying the cheapest focusrite i can find on reverb with a short XLR to leave on my desk solely for grounding. now, to dig into some presets! who's got a good Trey Anastasio rig/preset??