Used Preamp on a budget advice please.

Well, the Krell KAV-250p has a "home theater passthrough" mode that can be configured on input #3.  You would just take the left/right pre-outs from the Yamaha and connect them directly into input 3 on the Krell.  This will save you the cost of the RCA switcher and extra RCA cable.  Also, I think you'd get a bit better performance from this 2-channel preamp then you would from the multi-channel Pre/Pros you listed.

http://krellonline.com/assets/support/KAV250P_V000_MAN.pdf

Referenced on page 8 of the user manual.

The 250P is the Krell item that was actually somewhat in-between the older Krell sound and the newer "bright/forward" Krell sound. The 250P had good resolution and definition, but had just a tiny bit of warmth there as well. If you’re really worried about this, maybe look for a Krell KRC-3 (it still has a home theater passthrough). The KRC series is older than KAV-250p and a bit warmer, but sometimes you can hear sibilance in vocals and a tiny bit of smear (from the warmth). I would avoid the Showcase / HTS7.1 / KAV-280p if you don’t want the forward/bright sound.

The 280p pushed for resolution and clarity and strength in signal.  This is actually what I love because the resolution reveals more realistic sounds.  Though, you will want to make sure you stay away from silver interconnects and speaker cables.

The older Classe preamps (like CP45 / CP60) were VERY VERY warm and slow. (way too warm/slow for me). I think the newer stuff is not as warm. I’ve read descriptions of the newer Classe as being very smooth, silky, liquidy (maybe the SSP-300 would have some of this).

I don’t know what the Simaudio / Parasound stuff sounds like.

Like gregkohanmim has said, you could really use any preamp here. If it doesn’t have a home-theater passthrough, you would have to reset the volume to a specific level every time you use the signals from the Yamaha. (maybe set at 50% / 75% / or a specific number on the preamp display).

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.