Kind of a weird question..
My motherboard has started producing weird static(buzzing) noises on the audio output(3.5mm jack), it's not noticeable when using headphones, but on speakers it gets quite annoying, and it gets louder as I start 3d games. This is not a problem at all if I output the sound via HDMI, to my TV and then my speakers, so I figured it should be a problem with interference after the DAC on the motherboard. In an attempt to fix this without changing motherboard I thought I could try an external DAC through USB. I tried the simple USB-3.5mm jack adapter that came with my headphones and the noise is still there. This confused me slightly as I though USB was all digital, and the adapter should have it's own DAC.
Can USB ports output analog audio to these small adapters?
Or do all USB to jack adapters have a DAC?
Is my DAC/Adapter outputting noise because there is noise on the USB power supply from the motherboard?
Would a new bigger DAC with it's own power supply fix this?
I tried looking at the USB 2.0 Specification but couldnt really find anything to help me there. This is my first question on StackExchange, and I don't know if this is the right section.