Hi, i have a pair of s12 and dunu titan S that if i use on my desktop pc connecting them to the audio jack or to a wired dac, they start buzzing like a mosquito, but if i use a dac with a battery like the btr5 (not connected via USB but bt) and my phone, i do not have this issue. Any idea?
Sounds like a ground loop issue. You might have to mess about with it a bit.
https://www.head-fi.org/threads/how-do-i-get-rid-of-a-ground-loop-with-my-pc-amp-what-exactly-am-i-hearing.927116/
a powered USB hub works great as well if you don’t mind the bulk and extra cables.