Help with fatiguing sound in my PC system

stereo 5, agree that iTunes is terrible by itself. This is why I purchased Jplay, tried it with both Jriver and Foobar, and could not hear a difference compared to iTunes with Jplay, so I stuck with iTunes as my software of choice. I have been managing an iTunes library since the iPod 5th gen came out, so I'm used to and like the interface. Jplay gives bit perfect output using kernel streaming and loads the tracks into RAM, the HD is never touched for playback, and it sounds really good.
First reflection points and maybe a bit of dampening overhead would be the only places I'd put absorption. Thanks for the mirror trick, Steve. I have a window on one side with a double cell fabric blind, might add drapes there.
And yeah, the off ramp is better than the audiophilleo, I'm sure, But it's also got a much higher entry level price point ($1200?).. I don't want to totally out pace the rest of my system, once the interface is upgraded, I'll have some more work to do to bring the rest of the system up. I never really thought i would take the Pc audio plunge, but the convenience and fun of the iPad interface made it irresistible, and there really hasn't been that much tinkering.

I'll be honest. There is no single magic bullet in my experience for listening fatigue. I have found all of these to matter for digital music

1. use PC source with asynch USB (check, you are doing that)
2. use a quality DAC (check, you are doing that)
3. use quality interconnects (check you are doing that)
4. use a quality PC media player (no, you are not doing that... consider JRiver or Foobar2000. At lower processor speeds Foobar is better but with the latest generation of CPU's JRiver is as good or better and much more user friendly. Itunes is pleasant but shallow in musical detail)

At this point your PC audio out shouldn't be the source of fatigue. Look to the rest of the system. Consider a Rogue Cronus or a Prima Luna integrated tube amp as a safe choice to bypass solid state issues that commonly cause listening fatigue. Leave speakers for last.. buying better speakers at this point will likely expose more to hate.

Davide256 - I use the Jplay plugin with iTunes. This plugin loads the tracks into RAM, then plays them back from memory without ever hitting the HD. It uses kernel streaming or WASAPI, and has several other adjustments for memory management, also features a bit-perfect volume control in 6dB increments. Sound improvement over stock iTunes is astounding. I tried this plugin with Foobar and JRiver trial software and could not hear a significant difference, so I stuck with itunes as the interface. That might change later, Jplay and iTunes don't play so nice together.
The immediate, in-reach upgrade is a converter that has dual clocks, so I am not synthesizing a 48kHz stream from 44.1kHz data. If that does not improve things, you're right, I have to consider going to a high-quality integrated, upgrading speakers, etc.

since both of us use Dlink III's let me share that I didn't find that DLink direct to amp worked well, partially for the fatigue symptoms you describe but also for lack of richness in the midrange. I don't think the Dlink III is an optimal impedance match for an amplifier. I prefer the sound of the Dlink through both the CJ pre and the pre section of the Prologue to the Dlink III feed direct to the Prologue Home Theater inputs for direct to amp. The CJ being an older unit did require some capacitor replacments to be as fast as the newer Prima Luna.

agree, Davide256, I have placed my Halo pre back into the signal chain after purchasing the Jplay plugin. I did mess around with the volme control in the plugin, but 6dB steps don't do it for me. I am running the signal into the direct inputs on the Halo, this bypasses the tone control circuitry and goes straight to the volume pot. Still have to try it through the tone controls, see what that does. I'm having a ball though, headaches or not!