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
@kdude66 

Did you ever get a chance to use the 508 from your friend?

I have a Pass Labs XA30.5 and PrimaLuna Dialogue Premium preamp that I think would net me some $$ for a new tube set if I were to get the 508. How are the stock tubes? Has anyone used Pass Labs before?
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 ?