I am looking for a DAC that I could use for gaming and music within 500EUR. The requirements for the DAC are that it can produce a big 3D soundstage and good imaging, and works well with my current gear: Meridian Explorer 2 -> Massdrop CTH -> HD6XX/K7XX and hopefully upcoming gear I've helped...

Using audio processing objects (APOs) in Windows is possible since Vista. Those provide customizable, software-based digital signal processing (DSP). A freeware called Equalizer APO makes use of that infrastructure and allows to real-time-convolve 7.1 input sounds down to binaural stereo audio...