although not a revel owner, i would conjecture that many preamps would work well with that speaker. it would depend upon your personal preference. i just reviewed a very interesting preamp which may interest you. it is the audio note kits l3 line stage preamp. it retails for $1699. the rason i find it interesting is that it is very uncolored without some of the unwanted qualities, namely frequency response imbalances and an etched presentation.
you can find the review on audiophilia.com .