One of the conveniences of the UR 22 that I noticed is that there is no power supply. I’ve been used to having to plug most electronics in via the wall wart.
The noise is generated at various USB ports from my lap top. I’ve been running the UR 22 with no other devices connected. It is, however, interesting that you mentioned running my computer with main power. I’ve been running it with battery power. I’ll attempt with wall adapter. Thanks.
Where I’m at in trouble shooting the phantom power noise is my microphone. I’m in the process of purchasing a new condenser. From there I’ll determine if the noise was being generated by a defective condenser microphone.