Dac, Preamp or Dac/Pre

I recently read the thread titled "What makes a bigger change, dac or preamp". I have a second system that I use in my study (that I listen to quite a bit) and am considering upgrading the front end. I have approximately 1k to spend. Similar to Daimbert who previously asked the question, I am using my Squeezebox Touch as my DAC/Preamplifier. From the thread it appears that the volume control is the limiting factor. My system is as follows:
a) KEF LS50
b) REL R-218 subwoofer
c) Odyssey Monoblocks upgraded (black boards, increased capacitance and transformers).
d) Squeezebox Touch into the Odyssey Amps

I will be listening to FLAC recordings or internet radio 98% of the time. I don't listen to vinyl but recently picked a cheap older turntable (Kyocera PL-601) that was in great shape to possibly listen to some of my records from high school/college (more nostalgia than anything as I have them all in FLAC) so having a phono input would be nice but not necessary.

I was leaning towards getting a preamp/dac like the NovaPre or the new Wyred Mpre which is within my price range. Would this be a significant upgrade?

My second notion was to get a better DAC such as the Wyred DAC-2 that I could pick up used for about the same price. The DAC would be used with volume control into the amps. I assume that this might be a better DAC than the integrated Mpre but would it make a difference?

My third notion was to get a tube preamp. I've never had any tube device (always ss) and thought this might be interesting. The tube preamp would likely be a vintage piece like an older CJ preamp, ARC, or other suggestions in the 1k range. My concern would be that it could be mismatched in my system.

I would also consider a solid state preamp with or without a budget DAC. For example an older Bryston preamp if continuity with my SS amplifiers would sound better.

So what are your thoughts would provide the best sonic improvement? I want to thank everyone for their input in advance.

Best Regards,
You have to do some listening. The questions you are asking are, for the most part, subjective in nature. It takes people years to figure this type of stuff out. Everyone has different tastes. Most of the time, there is no better, or right way to do something.
Thanks for the input. It is an education process. I think that I am going to try a vintage tube preamp (CJ, ARC, Audible Illusions, SF, etc...) or one of the newer inexpensive ones such as the mapletree, jolida fusion, or the like. The LS50s sound a bit bright to me now but they do sound good. I don't know if this is the squeezebox or the amps but I will start with the preamp.

I'll just throw out another model similar to the mPre. Parasound has a new pre amp with a built in DAC, the P5. Availability should be by the end of the month or so. It seems really well implemented, with bass management, a decent phono section, and analog volume, considered superior to the digital you'd get in a DAC.

I think Peachtree has a similar model too.
I was aware of the P5. Is it out yet? In function it is similar to the Wyred and Peachtree. Would you know how it sounds compared to the others.

I guess this thread should have been titled what preamp or dac works well with the KEF LS50s.