Pre-amp that works good with Classe CA-400

Looking for a pre-amp that works well with a Classe CA-400?
Classe amps work well with both solid state and tube preamplification: Classe, Sonic Frontiers, Audio Research, Conrad Johnson, Joule Electra, Audible Illusions, Pass Labs, Plinius, Jeff Rowland, Mark Levinson, Blue Circle Audio, etc. The high input impedance of the Classe amps make them compatible with most anything you want to try. As with most things you will have to try some different things to see what you like....
Hi! I agree with Tswhitsel the Classe amps work well with alot of pre-amps.
I have a Classe CA-301 running Thiel CS6 speakers and find the Joule Electra LA100 MKIII pre-amp to be a very good match.I also have a Sonic Frontiers SFL-2 pre-amp but prefer the Joule. The sonic frontiers has a bigger soundstage of the two but the Joule beats it at everything else in my opinion. The CA40O is reported to have a bigger sound than the 301, so the Joule and ca400 might just be magic!

Good Luck!
Thanks for your responses. I have been thinking of adding a good tube pre-amp.
I'm a decade or so late in responding, but I would like to add that my Simaudio P5LE is a match made in heaven with the CA400. They're both fantastic amps. Nevertheless, as funds permit, I intend to convert all of my components to Simaudio, changing over to two W10 monoblocks. I can imagine that a high-end tube preamp would be a very nice match for the CA400 as well.
If I recall correctly, and I could be mistaken about this, some of the Classe' amps are a bit on the sensitive side (1.6V?)for full output. If that is indeed the case, some pre's volume control might have limited use. Usually more of an issue with tube pres than ss pres.
I have a Chris modified Sonic Frontiers Line 3 which works great with Classe Cam 350 monos. I am running them balanced and I very happy with the match.