This is an old revision of the document!
My Sound card does not have XLR output, so I pmseure yours has no too. I have two XLR inputs, one stereo out and one headphone out. I remember having buzz as well, not sure what condition it was in as I have tens of cables going through the wall here and there, The studio is much bigger than in the video above, more tools and equipment, it used to give some buzz but I illuminated it by separating the cables, I guess, not sure as it was long time ago. the sound card has to go to mixer