Upgrade advise needed please

I've asssembled a pretty decent system that started out as a HT system and is evolving into a combo HT/music one with more emphasis on music. I can only afford to make 1 last upgrade for awhile and need advice in which direction to go. I have about 1K to spend and don't know if that should go to a different preamp or a good outboard DAC. Which of these will yield the best improvement. I currently have all Vienna Acoustic speakers (Beethovens, Maestro & Haydns) with a Proceed AMP2 & B&k amp along with a B&K Reference 20 preamp processor. Sources are a Elite DV-05 and PD-65. Would a good preamp with a processor loop (keeping the Ref20 for HT)be better, or would adding an outboard DAC yield the most sonic improvement? I appreciate any advice you can give as this will probably be my last upgrade for the time being. Thanks all!
spend 1,400 or less and buy a mark levinson 36 dac. You will be floored when you hear the improvements. Good luck. thats the most bang for your buck.
A grand on a DAC would buy no real improvement over the DACs on the Pioneer and B&K. I'd buy a good used tube preamp and run the B&K through it. You'd be surprised at how much information is NOT passing through the B&K. You've got to spend a whole lot of money on a processor that would convey the music like a good used tube pre would.
I agree that a preamp upgrade will give you the biggest $$bang. B&K amps make a great entry level high end option but their preamps are lacking. Lot's of good preamp options out there. Do you prefer tube or solid state?
Thanks all for the response. I will be looking at new preamps and wanted to try a tube. It would be my first foray into tubes. I just don't know all thats available but I've read good things about a CJ 10, Rogue 66, etc. Any ideas would be appreciated. Thanks again.
I had a CJ PV12a line stage and loved it for a long time. Very musical. It was not until I tried my Audio Research LS22 that I realized how much I was not hearing and the transparency of the AR is amazing. The AR is more linear and less forgiving than the CJ product so it will reveal limitations from your other gear ruthlessly.