Ayre V-5xe best tube pre-amp to match with?

Frankpiet - I had trouble with a DeHavilland Ultra Verve when matching with Ayre. This is in NO way a knock on the DeHavilland as it worked fine with another SS amp, and at it's price I think it's one of the best buys out there.. but for some reason it and the Ayre wern't compatible.(Hum) The deHavilland is single ended.

Just heard Hovland HP-100, Nagra PL-L and Aesthetix Calypso (have heard all before but never against each other in one system except of the latter one). Hovland (less dynamic and less resolution and tightness than the others but a midrange to die for). Nagra to analytical but extremely tight bass, great micro / macro dynamics and air around Instruments, tons of details - but surprisingly quite uninvolving. Calypso despite the glowing reviews quite flat and noisy (probably stock tubes were not burned in, but great ergonomics and nice to look at). I´m very keen to listen to CAT SL-1, Ayre K-1x and BAT VK-31 SE.

Check also Cary slp98, Audionet (the big one).

I found the 51SE to be quite a big step up from the 31SE. YMMV.

Keithr:
would you though say that the VK-31 SE is a bad product? The two other remaining products on my short list are Aesthetix Calypso and Ayre K-5xe.