Atma-Sphere M60 monoblocks + ML ESL 11 = Inferior combo

Hi Guys,

Thanks for your input! Indeed I know that the MLs are demanding when it comes to impedance, but I for sure has a learning curve ahead of me when it comes to OTL and Tubes in general. I guess I didn’t expect the same energy and presence in the room with only 60 OTL watts, but now I learned what is what. At least it was obvious that the MLs are designed in a way that they demand something else. Today I swapped the M60s in for a pair of MBL N15 monoblocks. These are designed to attack MBLs omnidirectional speakers and have plenty of power under their hoods to cater for Extremes etc. Going to be interesting to see how the ML fare under their command.

• Analog toroidal transformer with protective shield
• Weight. Ca 40 kg.

• Continuous power (<1% THD, 8/4ohm)	352W / 615W
  Dynamic power (<1% THD, 8/4/2/1ohm)	402W / 786W / 1.50kW / 1.0kW

Some sort of Class D.

@decooney Thanks!

@andy_wonderwall You've gotten good advice here. Martin Logans are traditionally hard to drive for any tube amp due to the 0.5 Ohm impedance at high frequencies- so an amp like the M-60 will sound muffled. You can fix this by using a set of ZEROs http://www.zeroimpedance.com

-which will be helpful with most tube amps on that speaker. MLs are designed to try to take advantage of the solid state market; the problem is the ESLs in general don't behave the way the usual driver in a box does. ML tries to get around this 'problem' (which normally is solved by a tube amplifier) by making their speakers very low impedance. This prevents the usual doubling of amplifier power that a solid state amp might otherwise do. It also means that speaker cables are critical to the sound; how 'open' the speakers are.

Other than the ZEROs, your other solutions are obviously a different amplifier, or a different set of ESLs that are not so low impedance. For example M-60s work quite well on ESL57s or ESL63s made by Quad (and several of the newer Quads too).

We do have customers using MLs, some for decades on now. All of them use the ZEROs.

@atmasphere

Thanks for reaching out. 

First all of. Let me tell you the M60s sounded just fantastic with a pair of Vivid Kaya S12 in my local hifi shop. So intimate, wonderfully vocals. Organic sound. A midrange to die for. Got me intrigued. Maybe the Zeroimpedance could be one way to solve the problem. I know MLs are hard on all Tube designs. People who have been successful on large MLs seem to be those who have invested in some heavy "hybrid-tube" stuff from ARC or VTL (like 250watts and above in strength). How do you think the ma-2 would handle the ESL 11? Zeroimpedance, still to be required?

Kind regards

Andy

Zero auto transformers may work BUT they also do change the sound. Definitely not as transparent. Yes I've heard them in a system.