I have the O2 Amplifier, with the Asus Xonar DG soundcard (with a built in dac). Hear this buzzing when plugged into the O2, and when its plugged directly into my computer. Wanted to make sure that it wasn't my headphones breaking randomly and they work fine on my iphone. I've looked around at the cables, everything seems to be connected and working properly. I switched from using two powerbars to using only one for potential grounding issues, but I still had the problem. Decided I'm getting a external DAC because that will probably fix all my problems. I'm considering getting the Schiit Modi with my O2 amp. Problem is I noticed the Modi has a separate Left and Right connection, so if I bought it would I need a headphone splitter?