Advice using electrostats with tube amp.

"Sfall, the room is about 15X20' with 8.5' ceiling but my listening position is only about 13' from the speakers and i dont listen at high volumes. I agree withyou, then, that it should be fine but because the purchase is not a small one for me, I'm trying for all the advice I can get. Thanks"

You'll be OK. I've powered ML's in a room that was a little bigger, and with an amp with less power than yours.

I need to make a correction.  Although it would have no bearing on the subject of impedance, the speakers in question are the Ethos (not Theos) which, as well as with the Odyssey's before them, I had been using with the Peachtree 220 amp. Today I'll be transporting the Cary to the guy's house who has my old  Ethos for a trial. Room acoustics there are significantly different than mine but I should get some idea about the overall sound. Also, I've been running the amp in triode mode with the reference 3a's and someone suggested that that switching to ultra linear may make a better match. Using the 4 ohm posts also came up in that discussion.  BTW, I've used mostly panel speakers for over 40 years (Acoustat, Magnepan and ML) so my familiarity with them is the only reason I'm even at trying this. I really thought my current setup would be the forever one. We'll see. 

I believe Ralph of Atma-Sphere recommends using a Zero Transformer when running difficult loads. He has a FAQ page on his website that will link you to it. Let me know if you can't find it.
B

I'm guessing you have an issue with high frequencies. If that's correct, I think the ML's are a pretty good choice. Personally, I find the main reason I'm drawn to an esl speaker is that they don't have a tweeter. The highs are much more realistic and natural sounding.

Jim (Broadstone), an impedance curve for the Ethos can be found on this page. My guess is that given the relatively small amount of energy that most music has in the top octave the 0.8 ohm impedance at the upper end of the spectrum won’t **in itself** be a problem, provided that you use the 4 ohm tap on the amp. And, as you mentioned, operating the amp in ultra-linear mode might turn out to be preferable.

However, I suspect that what stands a greater chance of being an issue is the effects on tonality of the interaction between the amp’s output impedance (which will differ between triode mode and ultra-linear mode), and the wide variation in the impedance of the speaker, within the range that is handled by the panels. Specifically, if you see this post prior to today’s audition I would suggest looking for signs of over-emphasis of the mid-range (where the impedance rises to around 18 ohms at 1 kHz), relative to the treble region (where as you realize the impedance gradually descends to very low values).

That interaction, btw, will vary widely among different tube amps, due to the widely differing output impedances among different tube amps. And given also that the output impedance of the 88R does not appear to be specified, nor does its damping factor from which output impedance can be calculated, it’s particularly good that you have an opportunity to audition the specific amp/speaker combo.

Best regards,
-- Al