I'm having issues with this amp. When I plug my headphones into my DAC which is USB connected to my computer, there is no background noise of any type. When I connect my DAC into my amp and listen through it, I get noise when doing any activity on the computer - e.g. opening a program, scrolling my mouse wheel and watching a video. This noise increases when I increase the volume on the amplifier. I don't think it's a ground loop.
racsorracwas having this issue (mouse scroll and all) and wanted to give my fix in case someone runs into this thread looking for answers. Was a ground loop. Had my pc connected to the same outlet as the amp. Switch outlet on one of the devices and it went away completely.
racsorracI see that this post was from 2019, but in case anyone is reading this afterwards. I had this same issue with a newly acquired Darkvoice 336se. (I also own a Little Dot MkIII) I swapped from the USB table to an optical cable from my computer and the noise disappeared. I dont know exactly what the parameters are, but it seems like a PC form factor power supply causes interference that will be passed via physical connection from your PC to your DAC...and potentially other downstream devices. I also note that my MacBook Pro does not have this issue. So some fuel for people having buzzing issues with a desktop/computer setup like I do. Good Luck to you!