DAC choice


I admit it, I am a bit lost on the topic of DACs. I have a Rotel RB-1590 amp and some B&W 804S speakers. I like my CD transport so far, although I doubt its DAC compares to a more dedicated one.  I do not think the amp or speakers are bottlenecks in sound quality, but am not sure I am getting the best out of my music, and I would like to get into more digital. I am trying to decide between getting the Rotel RC-1590 preamp with its DAC or a different DAC/preamp. I would welcome advice on preamp/DACs for $2,000 or less.
kumakahn
I chose the NAD M51 over the Auralic Vega, PS Audio PerfectWave II and RME ADI-2, all of which I bought, tried and sold.  
More analog/natural sonic presentation (to my ears) than the others. Naturally, speaker pairing can influence one’s decision.  I have been using the Revel M106. 
There are a variety of filters you can use to shape your sound. The default filter Sharp followed by SD Slow, Slow and NOS. I use SD Slow, as it cuts down on the harsh digital hash. Also w/the RME you have dual EQ and Treble and Bass knobs. There is a learning curve to this DAC but the 68 page booklet is easy to follow. Detail from the instruments is very good.