The 6s sound pretty awesome. I'm glad I went with the 6s instead of the 8s...I can barely fit the 6s on my desk as is. Question though, I've noticed that at the lowest volume level I've got no static/buzzing using 3.5mm->RCA. When dialing up the volume level on the monitors I've noticed that I'll start to hear some buzzing/chirping etc. Is this related to my sound card and the unbalanced cables or is this more to due with the power and some wonky ground loop issue?
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The the buzzing/floor noise is due to using unbalanced connections. I had the same issue when I was using a TS 1/4 connection and when I want to a TRS 1/4 the noise floor is virtually eliminated unless you put your ear practically on the tweeter.
I am not sure about the DAC part, but this is what I use.