Thank you all for the help.
I've made a number of changes based on the suggestions and the harshness has definitely diminished.
I've connected the DAC to the preamp of my NAD amp and switched the W4S to fixed mode. That automatically moves the DAC volume to Max so there shouldn't be anymore bit dropping from trying to control the audio with digital.
I disassembled the outlet and cleaned all of the wires with deoxit
06-27-14: Almarg
What settings of the DAC's volume control do you typically find yourself using, within its 0 to 70 range? And how have you set "USB minimum volume level" and "USB maximum volume level" in its menus?
I also checked the various digital volume controls on the computer and J River. I had J River volume dialed down to 25%. I pushed it back to max.
06-28-14: Stewie
Don't assume the problem is in your system. Pianos and violins often sound harsh live (pianos especially), and the "better" your system, the more you'll pick it up. Then too, recordings sometimes unwittingly add or just emphasize distortion in the upper register of the piano.
I spent some time comparing recordings and I suspect the ones I cited may have been carelessly produced. But I find most piano and violin solos hard to listen to for long periods. Some like Chopin are really obnoxious
06-27-14: Elevick
Do you have a solid state hard drive? It made a huge difference on my laptop with jriver. Faster, quieter and runs cooler..
06-28-14: Zd542
Looking at your system, I would say that using your PC as a source is the most likely place for something to go wrong.
I take your point about the limitations of computer servers but I'm committed to this for the convenience and simplicity. This was my old general purpose laptop I repurposed as a server primarily by clearing most of the extraneous software and background processes.
I've resisted adding a SS hardrive to this laptop because my long term upgrade plan is to switch from a Wintel box to a Mac mini with external power and SS hardrive.
That includes addressing room acoustics by tweaking speaker placement and orientation
Positioning speakers in a small apartment is problematic. That's one reason I lean towards a near field system -- I think that's a more practical approach to my lifestyle. I could afford to buy a house but I just don't want the hassles. I have a similar approach to audio. I want good sound with minimal fuss. I wonder if I should sell the Vienna Acoustic floor standing and get a small Single driver monitor like Omega