Help wanted spending money and improving my system.

I’ve got the upgrade itch and would like feedback on what piece should be replaced or what should be added.  If this system was yours, which piece would you replace and what would you buy as a replacement or what would you add to improve the sound/experience.  I’m not considering replacing my cabling at this point in time.  Please, 1 item only.  So, what would you add or replace?  I’m very happy with what I’ve put together, but I’ve got the itch, and scratching is not enough!!  Current system:  Carver Crimson amp, Primaluna Dialogue preamp, Schiit Yggdrasil D/A, Schiit Lokius equalizer, Jays CD player Mk III, Oppo 103 (for SACD only) Thorens TD145 with Ortofon 2M Bronze, M&K V75 sub, Klipsch R-15 sub, Roon Nucleus, Mac mini server (for iTunes) and Goldenear Triton References, home made bass traps.

I would change the dac and try the Wyred 4 sound 10th anniversary dac much better than what you got very analog sounding dacs, has beaten much more expensive dacs, cost is $4, 500 US but the company gives you a 30-day trial.
Additional room treatment, specifically first reflection points.  You'll be amazed at the improvement.  I see you already have some DIY bass traps.  DIY if possible to save a few bucks.  I did years ago and was amazed.  Or, if you are just itching to spend money, do some research on the different companies out there.  Many 'philes speak highly of GIK. 
PS.  In case you explore this path, and need DC power supplies, check out iFi.  Best bang for the buck and though they are smps's, they have replaced all my fancy LPS's at a fraction of the price with much improved performance and convenience. 
Re the PS, apologies. It seems my long msg did not get posted...will rewrite later today