Recently I noticed a high pitched noise in my recording setup in my new house, 5.5 kHz to be precise as you can see in the image below of me playing a bass note. This noise only is present when actually playing a sound. You can see the noise stopped when I muted the string.
I've tried to figure out what is causing this noise. The noise is present on both the XLR and the jack input on my Roland Tri-Capture, it does not matter which instrument I am recording (electric drums, bass guitar, electric guitar, acoustic guitar, vocals). I have tried unplugging all other electronic equipment from the power strip of the PC (except the PC and the monitor) and change to a different power strip and a different outlet but that didn't change anything.
Somewhere someone had a noise that changed pitch when he changed the sample rate between 48 kHz and 44.1 kHz, my noise stays the same regardless of the sample rate.
What are other steps I can take to find the source of this noise? Or any ideas how to get rid of the noise (aside from EQ'ing it)?