Help with fatiguing sound in my PC system


I replaced my Halo Pre and Denon changer with a PS Audio DL III. I run lossless music into it from iTunes on a PC (Windows 7 64bit, core i7, 16MB RAM), I use a Pangea USB cable into a MF V-link, then go into the DAC with a Wireworld ultraviolet coax. The increased detail, clarity, resolution and extension are remarkable, but so is the amount of listening fatigue. The highs are too much, but the music sounds muffled if I add the pre-amp back. My system is profiled in the link below. I have some ideas, let the voting begin:
1 - buy an offramp or a pacecar (can't afford it!)
2 - use better USB/coax/interconnects/speaker cable
3 - apply acoustic treatments to the room
4 - use a software player (Jplay) that sits on top of iTunes
5 - buy speakers with different tweeters (Quad 22L2/Focal 826v, this is happening, but not any time soon)
6 - get a better amp (McCormack/Odyssey, distant future)
7 - tweak Windows 7/iTunes settings (WASAPI exclusive mode?!?)
8 - adjust speaker position/toe in (already did this and it helped a little)
I am thinking about trying #3/#7 next. Ideas? Thnx in advance.
realremo
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!
Also having the PS Audio DL III -- I would have to disagree with it as a cause for the fatiguing sound. I run from a SONOS digital coax out to the DLIII, to an AYRE integrated amplifier (vial XLR balanced ICs) to a pair of PSB Sync 1 speakers. The sound is warmer and gentler then my Ayre CDP in most cases. From the SONOS I am playing both my own Apple lossless files, and online music sources (XM, Pandora, etc...) I would just definately say that from SONOS to the DLIII with digital coax is a warm stronger source then my CDP.