Exactly the same problem here. I have tried everything and it still won’t go away when phantom power is engaged.
I’ve tested all of my leads with a cable tester, they are all fine. I’ve tested all of my condenser mics too. The mics are all fine. It isn’t there with dynamic mics, only with condensers and when phantom power is enabled.
I have also tried putting a ferrite core on the provided USB lead to shield any unwanted EMI (electromagnetic interference) from the laptop. Didn’t help.
The only thing that I haven’t tried is a different USB lead, which I will try now, and report back.
It sounds like a ground loop hum, but it can’t be, as it happens regardless of whether the laptop is plugged into the mains or not, and all of my monitoring is being done through headphones on the unit. There is no external speaker system connected. Just the UR22 and the laptop.
I am left wondering if either the unit itself is faulty, or it is very susceptible to EMI from laptops, which kind of renders the unit pointless.
It’s been a very frustrating couple of days for me testing all of my other connected hardware.
Any help or advice would be appreciated.