Can single ended 211 or 212 amplifiers drive magnepan 20.7?

Short answer..........."NO."  But,  Wouldn't it be loads of fun if the 20.7's could be bi-amped!!!

I can't answer your direct question, but I did try to use a 45 watt SET (JAS Array 2.1) using 805/300B's to power the ribbon section of a pair of BG Corp Radia 520's  while biamping the woofers with a TEAC AI-3000.  I also did this a pair of VAS Citation II's monoblocks.  The VAS made it work at, up to, moderate levels and sounded delightful in the process.  Rated at the same power, the SET could only muster a diminutive sound.  It simply did not work.  I don't know if the Carys could do any better, but my 45 w SET would not drive the panels to more than a low background listening level.

No direct experience with the Maggies, but having a sensitivity of 86 dB...I wouldn't think what you're proposing will work, either option.  I once drove a 90dB set of speakers with 60 watts of (KT88) tube power.  Sounded..wonderful..but volume-wise..I could only get to moderately (low-ish) volume.  

By all means pursue the Maggies, but you'll need a tube preamp and some real power.  My current system, due to change completely in a couple months, runs a tube pre into a McCormack DNA1 power amp into 86dB speakers. It totally works. I've enjoyed this system for 10+ years..no complaints.   

@kennymacc hahaha exactly right! tubes for tweeters and mids, large beefy solid states for the bass! 

@lcherepkai oic, will go take a looks at your speakers and amplifier! thanks for sharing the experience!

@nogaps actually i have a different experience hence i am asking about this. haha my 25w cary monoblocks have no issues powering my 90db kef reference 5s, and I really love them. I also hahe a dali minuet se that is 86db in my bedroom powered by 7w 45 tube push pull amp. Both have enough volume to satisfy me :) I listen at 80-85 db levels. 

@thegreenman An SET based on a type 45 power tube might make about a Watt. Certainly not 7; if your amp really uses 45s and makes 7 Watts, its push-pull not SET. 

But to be clear on your original post, no SET made will drive Maggies. But FWIW there are class D amps now that compare favorably to SETs that will drive Maggies no problem. 

If Maggies could be driven by low watt SET amps, that could be an ideal match for many

Never tried. I ran MMGs on an original NAD 3020. It sounded great, but I moved to higher power amps to unlock Maggie’s magic.

my LRS eat up the 350 watts at 4 ohms I have currently.

enjoy the journey

To add to @atmasphere post above, there are Class D amps that will drive the Maggies and have a very nice tube like sound. I am referring to the Atmasphere Class D amps. I own a pair (Very reasonably priced even new) and they have almost all of the magic of my 45 SET amp. I am fortunate enough to be driving 106 dB sen. speakers, so about any amp works for my set-up. However, I have an awful room as it is a living room, dining room, kitchen area combined and space is 32' x 28' x 14'. When I am entertaining and need a bit more volume, the Class D substitute VERY nicely. I would not hesitate to recommend a pair. I have not heard them with the Maggies, but believe it would be a great sounding set up.

I occasionally see a pair on sale used, but probably because they sound so good, not very often. 

@atmasphere hehe you are right! its 7 watt push pull with 4 45 tubes. I mentioned in my original post! hehe normally 45 set is 1.5 watts

@atmasphere thanks for letting me know SETs wont work :( i know of those very rare stuff tt prob will, for example NAT audio large tube amps that output 120w class A, but the price is probably in the stratosphere. but yes I guess you are right in general esp these 2 tubes. Thanks for bringing me back to earth!

@kennyc yeah that would be the best! I guess the only way out is the maggies 30.7 where you can drive the high/mid with SET, and woofers with high powered solid state! but price is abit more, and room size can be a constraint for many. 

@dseltz will check them out, thanks! any experience w the class D driving maggies? thanks

I have not had experience with Maggies at all lol. At 4 Ohms, the AS Class D would be putting out 200 W, which I would think would be adequate, but those with Maggies can chime in. Following different threads through the years, it seems many Maggie owners answer is always 'you need more power'. 

If you are in my neck of the woods (New Orleans) I could lend you my AS Class D for a trial run.