I recently purchased a Devine BM 400 Condenser Mic, but when plugging it in (XLR -> Audio Interface -> USB) I get a hum at around 50Hz, and some more peaks at 155, 2670, 365, and so on, with smaller peaks in between.
I already tried to: Change USB Cables from audio interface to laptop, playing from other speakers, taking out laptop power cable. Taking laptop somewhere else (same building), returning the mic and get a new one. But no results. Touching the mic or placing it elsewhere doesn't change anything, not even slightly.
I was hoping someone could help me based on the frequency spectrum.