What will a preamp do for me?


Missing in the chain below is a preamp - I use the DAC to control volume.  This is my only source and will be for some time.  What could I gain by adding a preamp?

I have Thiel CS 2.3s driven by a BAT VK-55, sourced by PS Audio PW DAC, with bridge II, mostly tidal.  The DAC serves as a preamp in terms of volume control.  Mostly Audioquest cables, amp power cord is Cardas Clear m, all fed by PS Audio upc-200.

I am am hoping to improve the highs, which sometimes sound smeared, too much sibilance; would like more air and clarity.  Loud rock sounds flatter, less dynamic than I’d like.  I am not willing to give up the deep detailed and beautifully resonant mids.  Willing to spend up to $3000, used is ok.  Totally balanced is a must.  Not currently willing to entertain the idea of different speakers - my goal is to make the 2.3s sound as good as reasonably possible before moving on to other speakers.  It’s easy to find a really good preamp in this price range, so much so I am almost paralyzed by the choices.  Aesthetix , Ayre, ARC, several BAT, Parasound and more all have apparently excellent models in my price range.  Patience would put Atma-sphere and PS Audio within reach.  Which is best for my situation?  There’s no way to audition all of these, how could I avoid getting on a preamp merry-go-round?  Or should I spend my money elsewhere?
128x128thosb
Take your dac's output to any of the line inputs if your dac has a few extra inputs.have fun.
Superphon were very musical and one of the best values for the money ever made .They are very rare today and anyone you might find would need to be re-capped .
Benchmark Media had claimed the best connection was their DAC using their built-in hybrid gain control (HGC) direct to amp.  I agree that it sounds great, but they just announced a $2500 dedicated linestage for their DACs, so that implies there is a role for separate linestages but theirs is a very sophisticated passive.  Curious to hear the difference. I'm not convinced an active linestage does anything needed, but might create a sound that sounds more dynamic or sparkly than straight wire with attenuation.
Answer to question,  nothing, other than veil your sound,  pre-amplifiers are useless! 
thosb-
another +vote for a pre-amp. Look into a B.A.T. to mate with your power amp. Keep me posted.  Happy Listening!