Last week started using J River 14 instead of WMP, which led to a significant upgrade in sound quality. Audio setup with J River 14 granted my ASIO-supported RME HDSP 9632 soundcard exclusive access to the ASIO output mode of the J River application, meaning I'm bypassing 'Shared Mode,' and all that it may entail in possible sound degradation, instead now running in 'Exclusive Mode.'
For more on J River 14 and its setup, please follow below link:
http://www.computeraudiophile.com/content/Windows-7-Audio-J-River-Media-Center-14-Configuration
Below quoted test(from link above) assured me of the use of exclusive mode in my system via J River:
"Simple Test:
Users who have a DAC that displays the current sample rate being fed from the music server can run an easy test to determine which Mode is in use. Simply play two tracks with different sample rates. If Exclusive Mode is in use the sample rate on the DAC should change. If Shared Mode is in use the Default Format (sample rate) that is set in the audio device Properties >> Advanced tab will be displayed on the DAC. If the Default Format is set to 24 bit, 48000 Hz (Studio Quality), playback of a single 16/44.1 track will provide a quick answer to the Exclusive or Shared Mode question as well."
To begin with I wasn't aware of running in exclusive mode with the J River application, but simply noticed the sound being more saturated, allowing for a more colorful and ultimately lively performance. Space around voices is more pronounced as well, the voices appearing more solid and real, and the decay of high notes seems more extended and natural. The WMP-sound feels somewhat enclosed(soundscape-wise), monochromatic, slightly hollow, and a bit bright or "glassy" in comparison. We're not talking night and day here, but especially after listening via J River some days the difference shines through - when going back to WMP.
Moreover, J River enables you to playback Flac files, and if the DAC of the system houses the ability; high-res and -sample rate files as well:
http://www.2l.no/hires/index.html
I must point out that the J River 14 application, in my setup, functions as a preamp(via the internal digital volume control), if you will. That is, I'm using no preamp in the usual sense, but simply outputs directly from the RME soundcard analogue out into my poweramp - with great results.