can a new amp amp tame my speakers?


Just spent some time listening to what I've been planning to upgrade to for main speakers. PSB Synchronys. The Imagine T2's are close, but slightly veiled in comparison. My current, but old, Infinity Kappa 7's really don't give much away to the PSB's. My amp is an old Yamaha MX2, 125wpc, and I've heard them described as bright or harsh, and that's the only complaint I really have with the sound now. Can a well-chosen amp tame the highs on the Kappa'a, which use a ribbon-style tweeter? Or is the 'taming' I seek only going to happen with a speaker upgrade. I honestly don't mind upgrading the speakers, and fully expected to, but after today's auditioning, I'm wondering if I'm going to get that much benefit from that level of investment. $3500+ is a healthy chunk of coin for benefits of slimmer profile and tamed highs. In terms of imaging, weight, and bass, the Kappa's are equal, imo. The system is also the theater, but the avr can power the surrounds, so an amp upgrade could be 2 channel. A power boost is a must too, as the current 125wpc isn't enough for when wifey's not home and the volume gets wound up ;)
english210
I'm not elliminating anything yet, except things I just can't afford. I am also one prone to wait a little longer to get the $$ for what I really want, instead of compromise and then wish I'd spent the extra, but there are options that just aint gonna happen, too. That's part of what's going on now. I know that ultimately, until I pull the trigger, the 'answer' will remain unsure. I also feel that any of the amps suggested will likely serve the purpose, and there's not likely to be just one 'right' answer. Maybe part of it is the 'offer I can't refuse' that hasn't quite happened yet. But I do at least know of lots more options thanks to the answers I've received here.

So, anyone got a 400xi for $500?? :)
@acman3,I am glad to see someone agree with what I was tring to say!your post is well put!,I agree with you with what you are saying!as well,keep us posted english210,cheers!
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!