Will a pair of Manley tube amps be a good match for Martin Logan ESL 11A's?

The answer could very well depend on which Manley amp is being considered. For example the Manley Neo-Classic 250 has a specified output impedance in the vicinity of 0.5 ohms (John Atkinson’s measurements reported in Stereophile were 0.6 and 0.7 ohms for triode and tetrode mode, respectively). Those are extremely low numbers for a tube amp and suggest that the effects on tonal balance resulting from the interaction of that output impedance and the speaker’s impedance vs. frequency characteristics will be relatively solid state-like. (The RM-200 mentioned by George and bdp24, by the way, has a comparably low output impedance on its lower impedance output taps). On the other hand the Snapper has a specified output impedance of 1.5 ohms, which everything else being equal will result in a less extended upper treble, compared to the Neo-Classic 250.

I have no idea which of those presentations is likely to be preferable with this particular speaker, or how desirable either presentation might be, or how problematical the deviation from the recommended 5 ohm load might be for the amplifier, but as Jafox suggested it would be a good idea to contact the manufacturers and solicit their thoughts about the specific pairing. If you already haven’t, I would also try to find user comments about amplification others have used with the ESL 11A or with its larger brethren in that series (the 13A and 15A). I would not extrapolate much if anything from generalities about ESLs, or from experiences involving other makes of ESLs, as in most cases the Martin Logans are different animals than other ESLs in terms of impedance characteristics, inclusion of powered woofers, and other respects.

Good luck. Regards,
-- Al

this is the full spec sheet for the Manley Neo-Classic 500 mono blocks. some of which I do not understand.

• LL-TUBE monoblock design 10 x KT90EH Electro-Harmonix Russian output tubes
• High current double 12BH7EH driver stage
• Tungsol 12AT7 large plate input tube
• BALANCED & UNBALANCED inputs
• MUTE switch
• TRIODE / Ultra-Linear switching
• SOFT-START/ EVER-WARM standby mode
• MANLEY Precision output transformer
• Factory set for 5 Ohms nominal
• Front panel bias measurement and adjust (hiding under the black insert)
• Large filter / reservoir capacitors 3800uF x 2
• Angled rear of chassis provides for easy connections
• WBT binding posts
• Input sensitivity: 1V
• Gain: 32dB tetrode; 30dB in triode
• Input Impedance RCA: 116 kOhm @ 1KHz
• Input Impedance XLR: 270 kOhm @ 1KHz; 20 kOhms @ 20KHz; 38 kOhm @ 20Hz

• Noise Floor: Tetrode: -67dB; Triode -65dB typical
• S/N Ratio: -80 dB
• Dynamic Range: 96dB
• FLAT frequency response: 10 Hz - 30 KHz continuous
• Power Consumption: 30 Watts in "EVER-WARM"
• Full power (tetrode): 500W
• Full power (triode): 275W
• Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.
• Operating Mains Voltage changeable with power transformer re-wiring and fuse value change.
• Mains Voltage Frequency:
• Dims: W=19", D=13", H=9"
• Shipping weight: 82 lbs. each

I was about to provide the same counsel as mijostyn above, and am gratified to read it here before I posted it. Roger Sanders excellent white paper on tubes vs transisters explains a lot.
My .02 is that you probably can pair Manleys with the Martin Logans, but at what cost? Which model in the range? I think you might find the Magtech equal or superior, at a very reasonable cost.

Two transformers is really uncomfortable for my brain.

Why the two transformer phobia here?

Years ago, I auditioned a pair of Sound Lab U1 speakers with three amps: Atmasphere MA1, CAT JL-2 and Parasound JC1.  First up was the JC1 and the sound was boring.  Had this been the only amp I heard that day, I never would have bothered again with the SL speakers.  Next up was MA1 and the sound was truly beautiful.  Dimensionality and harmonic structures was truly incredible.  The JC1's were absolutely broken in comparison.  Last was the JL-2 which did not have quite the lushness of the MA1 but with the CAT came far greater dynamic contrasts and a bigger bolder presentation.  The choice between the 2 tube amps was not easy, as both had excellent tonal coherency with the MA1 just having a little more presence in the lower mids.  But I went with the CAT as it controlled the SL speakers with incredible authority and I knew I could get some of that MA1 "magic" back with the right preamp and tube rolling efforts.  And ultimately I did with Aesthetix and later Aria preamps.  So the whole notion that transformers are "bad" was clearly disproven to me that day.

I still suspect that the VTL or Manley amps might be outstanding here as they too bring on an outstanding 3D quality that might work beautifully with the ML's.  If you want to consider SS amps that won't break your budget, look for a good deal on a BAT VK 600SE.  I have a pair of these in mono configuration and they are outstanding with the Sound Lab A1s.   But I gotta believe a single VK600SE would be plenty.  The result is not at all like I heard with the JC1's.  Why the obsession with the JC1's in these forums is beyond me!

Oh, and I did hear the RM200 amp several times at a dealer and every time, his system sounded wonderful.  So this too may be an option, but it might run out of steam when you require a louder volume setting or are in a big room.

Again, call VTL, Manley and ML to get the advice on these exact products and not be focused on white papers of other products.