Best Bang for the Buck Upgrade

I think it really depends on what state your system is in. If you have the end game speakers you love them I think DAC and the source (network player). 

Ha. I am definitely not end game anything! Probably never will be. Always lookin. 

GIK acoustic treatments and Isoacoustics Gaia feet.

There are "Purists" and there are people who just have fun and enjoy the "Music" and not the "electronics....The Schiit Loki mini and Lokius can tailor, for a few hundred bucks, your system to make every album sound great no matter the quality of the recording...They are called "Don't say the words".........Tone Controls!!!!...I've been ready to sell different speakers and amps , but after adding the $149 Loki....I'm keeping them because I can mold the sound of each component....and it's fun being your systems "mastering man". ...I even bought a second one just incase the first one breaks. My system cost over $12,000 and this little $149 beauty changes the whole Hi Fi game....I'm getting the most enjoyment out of my music, Now.

Why don't you demo a power conditioner, like the P12 from PS Audio.  I have a P20, only because I have a very hungry power amp but I found a significant difference in sound stage size and micro detail when adding this to my system.  It also gives me a very black background.  I think they will give you a 30 day free trial if I am not mistaken.  I am in no way affiliated with PS Audio but I am a big believer in power regeneration when it is done correctly.  .