Using tube amp with electrostatic speakers.

Love my leak stereo 20 with my quad 63 using audio research pre. 
Then with my very efficient avant-garde garde duo omegas the transcendent minibeast otls as mono blocks with transcendent ground grid ore amp was mighty fine. 

I power my ML Electromotion ESLs with a Primaluna Dialogue Premium power amp (not the HP model) with KT-150 tubes (24 watts triode mode and 48w ultralinear) and it sounds great and I prefer triode mode. I also use the same amp to drive a pair of Spendor S2/3s (8ohm) and they sound great too. I don't care much about the tech specs, i just try the different ohm taps on the amp and whatever sounds best with the rest of my system is what I use. Sound is full, robust, detailed, natural, and I often get goosebumps. For me it is all about the music, but I like learning about the equipment, to a certain extent!! Lol. Interesting discussion, thank you!

One data point.

I use Martin Logan CLS (original) in one system and although I have auditioned tube amps with them, I have found that solid state amps with good power supplies work by far the best.  Mine are run with a stereo Classe DR3 VHC (a whopping 45 watts).

Not saying that the magic tube amp isn't out there, just that I haven't found it.

When I read all of the responses saying that tube amps will have problems driving Martin Logan speakers, I just had to make my first post on Audiogon.

I have 2 Audio Research VT100 Mk IIs bi-amping a pair of Martin Logan SL3s. These speakers have never sounded better. The sound is organic and natural sounding. If the recording has a lot of spacial information and depth, it is revealed in the presentation. If the recording is flat, that too is revealed. Cymbals sound the way they should. Vocals, including female, just sound right.

Before bi-amping the SL3s, I had one VT100 amp. The sound was similar but there was less depth and the stage wasn’t as wide. Also, large orchestral works just didn’t have the presence that they should have. This was the reason for a second amp. NOTE: I do not listen at high volume levels. The stereo is in a loft so the left and right speaker are not presented with the same wall configuration which just messes up the stage width and depth at high volumes. Plus, I want to be able to listen to my stereo for many years. ;)

BTW, my pre-amp is also tube based.

Recently, I wanted to get away from two amps and tubes. I read a lot about Pass Labs amps and purchased an X350.5. I liked some of what it did but ultimately the sound was just unnatural with overblown bass, etched highs and an odd midrange. Every time, I switch back to my VT100s, I found that I enjoyed the music more. I returned the Pass Labs amp.

I am now looking for a more powerful tube based amp so I can go to a single amp.

My experience for what it's worth.