I've tested the srh940 through different mp3 players, onboard soundcard, and xonar stx. Only the xonar stx was able to provide me the WOW in term of detail profusion/ explosion of details. I was impressed especially when listening for instance the album reise reise by Ramstein, or the Downard spiral by nin.
Now I'm just missing the incredibly sharp sound I got from my xonar stx (and sharp to the point of being occasionally painful).
I tried from different sources, and just couldn't have the same enthusiasm I got from my Xonar STX.
Even the bass was somehow cleaner.
I'm 100% sure that my xonar stx , is more optimal regarding the srh940, because of every other source I tried, I didn't manage to get slightly painful highs , nor profusion of details.
I moved to an other town, can't get the xonar stx with me.
Now that I see miceblue, testing his srh940 out of an ipod rouch, I can't stop thinking that it's quite suboptimal.