Best amp for natural timbre of unamplified acoustic instruments & vocals w/ Revel F32?

I did try them briefly with my Manley KT90 Retro 100 amps.  I will try again. I thought less involving, less control than the CJ.

I might add that my Kef 104.2 have Morel tweeters.

So the Revels sound "hard, thin and sterile" with a VTL pre and a CJ amp???  You prefer tubes but these speakers are a tough load for tubes???  Um, what???  Short of you using awful interconnects and cables and/or some awful recordings that could be contributing to the problem, it sure looks like the writing's on the wall on several levels.  Dump the speakers.  Life's too short to spend precious time and effort solving inherent mismatches like these.  FWIW.  Best of luck. 

I don't understand how you conclude that the F32 is the more "neutral" speaker when you've identified it as sounding hard, thin and sterile.  That doesn't fit the definition on neutral. Rather it would seem that the F32 has glaring inherent sonic flaws. Neutral implies absence  (or certainly less) of contributing sonic characteristics. Neutrality is synontomous with chameleon like nature. 
Charles, 

I view speakers and power amps as a single unit.  The amp drives the speakers - so most certainly the issue could be with the amp.  It is possible but less likely to be earlier in the chain.  Your mission, should you choose to accept it, it to identify the problem (or problems).  Much like cars or health, once you have identified the problem it is then possible to take the appropriate steps.