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
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!
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
Could only sound more dynamic if the passive was hobbled with a serious impedance mismatch. As an active line stage cannot in any way improve the dynamics of the source unless it has a dynamic range ex-pander circuit in it, and they sound rubbish.

Cheers George
I owned a pair of 2.3's some years back and I think your problem is the VK-55. I had a pair of modified Threshold T-50's (converted to mono blocks). They were owned by a former employee at Threshold where they did the modification and my 2.3's came to life. High current solid state is the way to go w/2.3's. I was using is w/a Audio Research SP-16.