can a new amp amp tame my speakers?

Oh I will. Got my wife involved in some listening last night, on a variety of material, including some piano that was really interesting in that the staging was like a big piano, panning right (right hand) to left (left hand), listening for cohesion between the drivers, trying to discern changes, without being able to, which is good.

As I said, I'm not discounting any of the suggestions except ones I just can't afford. The point is well taken that the 400xi is not like other Krell's that can be bright, so if the right deal passes my way, I'm open. Klaus is familiar with the Kappa's, and swears his amp will make me hear them in a whole new way, so those are the front runners....

In truth, there are probably many brands that would warm up your Kappas. Klaus sounds like a true fan of audio but also a good salesman(not knocking him). I am in a similar situation as you and I plan add to my Halo A21 a NAD pre-amp(known to be on the warm side). The A21 did stop the sibilance I was experiencing, but I want to experiment with the warm side of things.

I ordered a tube pre amp kit (3 tubes) and I'm looking forward to the tinkering!

@ English210,there are no bright krell amps from 2006 and down at all!the newer krells are wide banwidth amps that are very,very,resolving!you need warm non analitical treble cables on those amps,thats all!cheers!

Runnin, I agree, and being in sales, I'm not unmindful of Klaus' bias :). It seems supported by what I read. I also agree that many brands could accomplish my goal. There have been a half dozen at least in this thread alone, and none were subsequently followed by argument from another poster, so they all seem like good options. It also seems that SQ overall can be improved in this upgrade, within my budget too, so that's where my research is taking me now. I probably don't have enough ear-time with enough variety of systems to be sure, but I'd guess my preferences lie toward a warmer sound, but the air around instruments is important to me too. I respond to that decay and echo in recordings of wind instruments and strings, the way notes hang in the air. That requires detail and resolving ability, but too much is too harsh....
I'd be surprised if my choice now was the 'right' one forever, as I'm likely to hear new things that need improvement, as is the nature of this hobby, but I plan to get it as close to 'right first time' as I can.

Thanks Audiolabytinth for the clarification of what vintages to avoid/aim for. There is one on fleabay I'm watching...

Ok, there's an upgraded Stratos on here, but it keeps telling me invalid username/password when I try to ask how old it is, etc....anyone else had issues like this?