You can get a a worthwhile improvement converting your Flacs to uncompressed format, noticable particulalrly if running Jriver.
JRiver 18 is the most transparent, most "audiophile" player out there imo and shows up any changes you make quite easily.
I tried Jplay, Cplay, XXHighEnd and...naa.
Using Jrivers inbuilt tools try converting a Flac album to Aiff.
Not Wav though, doesn't sound as good...
Apple do the whole audio thing a bit better than Microsoft.
(Aiff is Apple's version of a Wav file)
Yup, I know Flac is lossless and theres checksums and all that good stuff to ensure the original signal is outputted, but its the extra CPU load when uncompressing Flac back to PCM than can have an impact.
I've found that even with a powerful PC where you'd think this kind of thing would not matter it does.
In my experience with computer audio, getting the software right can make as much difference as changes in hardware.
Tweaked a mates server recently and the difference was quite a omg moment.
His speakers are doing bass like they shouldn't, just because of software.
Try converting a couple of favourite albums to Aiff in Jriver. It might surprise you.
I heard it for myself in my system, enough so that I converted 5000+ abums to Aiff. A major PITA but worth it.
Had to buy an extra 2TB drive mind you, but not that expensive in the scheme of things.
try it for yourself though..its worth doing and it's free.