Clearaudio Balanced Reference phono stage.

I have heard it. Its performance stands out among the rest -- by which I mean it sounded superior to the standard "good" phonos. Good tonal qualities and accuracy.
It's two "mono" boxes btw, you know that? On the up-side, it is very easy to fiddle with the input impedance to sort-of match to your cartridge.
I never used it without a line stage though...

www.needledoctor.com carries them.

I have one in my system and found it superior to the ARC PH7 phono stage. You can get loading plugs from Germany to match pretty much any cartridge, but as I use ClearAudio cartridges, it is probably a little easier for them to supply an exact loading plug.
I have dispensed with a pre-amp [maybe for the time being] and run both my Wadia 581 and the ClearAudio direct to the amps in fully balanced mode. Just means swopping cables when I want to change the music source.
Clarity and soundstage are a big improvement now.

I have a Clearaudio Balance (not the Plus and not the Reference). After comparing it to many phono stages, I find it to be truly excellent for both a Benz Ebony LP and a Shelter 90x, low-output MC straight-in. Plenty of gain and totally quiet. Also, very clean, lively, dynamic, great low bass, smooth but also detailed highs, and warm convincing midrange. I cannot find any fault at all with its sound, into a passive (transformer) preamp, tube amps, and electrostatic speakers. Its balanced outputs are noticably more lively and dynamic that its RCA outputs, which I believe is the nature of fully differential circuitry.