Amp for Acoustic Zen Crescendo 2 ?


Hello all,
I have these speakers for 2 months now and want to move on to a tube amp of 50 - 60 wpc or so, or a SS amp that fits the bill..  My current amp is an Ayre V-5xe.  I'm looking for an amp to sweeten up the top end and has a midrange that does vocals full and articulate, even if that means colored.  The Ayre is a great amp but I think there is a better match out there.  I'll have to save up for used, under $5K.  I'm especially interested with what actual owners would say, as well as their system specifics, but all comments welcome.  Acoustics and speaker placement are fixed and substandard.  That's just the way it goes at our house.
I'm using a steel arm VPI TT with Ortofon Cadenza Bronze, ARC PH-7 and REF 3.  Thanks.

wlutke
Here's the latest.  I did an in-home demo of the Pass Labs XA25.  The synergy is so good that I couldn't send it back!  Rather than reinvent the wheel, here's a review.  I wish I could white like this.  
http://www.xtremeplace.com/yabbse/index.php?PHPSESSID=7692066bdcef1c4f539b781eabee3280&topic=244...
Hi Folks,

I have the Crescendo Mk2 for sometime but the speaker placement is quite challenging. My room is 19x15x8. In all shows Robert places these speaker away of the front wall not every room will have the luxury of. At times I have seen that the listening position is way too close because of the speakers being away from the front wall. Wondering how far are the speakers from the front wall in your setup and what is the listening position ?
debjit_g,
Placement in my living room is dictated by the rooms use.  They are where they are, I'm between them.  Within the small footprint each speaker is allowed, there is one elusive placement and toe-in where tone, balance, focus and imaging coincide to my taste.  I say try every placement and toe-in until you find it to your taste.  I'm sure you've found they're very sensitive to set-up to a half inch and less.  
FWIW I've been to Mr. Lee's shop and listened to his Crescendo 2 set-up with the speakers well out from the front wall.  I was unimpressed, bored actually.  Too lean for me.
@wlutke thanks! Did you go into Robert's new facility in Escondido or the older place in San Diego ? I have also been to the newer one and find the sound is just ok compared to his setup in the shows with the Triode Corp.
I have been trying all sorts of placement, hearing it for couple of days and finding another position sounds slightly better. It looks like a forever daunting task. What I am generally finding is placing well out from the front wall increases depth but also losses room reinforcement and could sound lean depending on the room. I guess getting a balance is the key.
I have a question for those of you with the Line Magnetic 508ia. I've recently purchased this amp, and I'm using it with a pair of Acoustic Zen Adagios - soon to be Crescendos. My question for the 508ia users is are you using a preamp/linestage with the amp? Also, to those using the EML XLS 300B with the Psvane 805-ATs, what input tubes are you using?