Hi dastro. A couple thoughts. You did emphasize that you wanted a "warmer" type sound. The term "warm" does not always mean resolution. If you want more resolution, you might have to sacrifice some warmth because the higher resolution character may be towards the bright/forward side of things.
Also, what CD Players and interconnects are you using? I have been in situations where the interconnect is not able to show the true resolution of the source. I have compared two different DACs with a lower end interconnect. With that, there was hardly any difference between the two DACs. However, when putting a very excellent interconnect into play (i.e. solid-core OCC copper, Futurech XLR connectors), it became totally obvious that one DAC was highly superior over the other DAC.
Your CD players may not be able to provide a real high resolution signal. This may also be a limiting factor in things.
With everything else, I would not say the Krell KAV-250p is a super high resolution preamp. It is not forward/bright, but there are other preamps that are definitely superior. The Parasound P5 might give you higher resolution and also be just a little bit more forward than the Krell. I am interested in hearing your results with the P5.