KLH model 9 electrostatic Speakers

Today You would use a High power Class A amp with a lot of heat sink or an Atma-Sphere amp.
M60's would be perfect!

How much power is the atmasphere  M60?

@

While the power of the M-60 is fine (about 60 to 80 watts) the high frequency impedance will cause the amp to sound rolled off, which it is not. To solve this a set of ZEROs (www.zeroimpedance.com) should be employed. With the ZEROs the M-60s will make more like 80 watts.

Ralph thank you for your response, I checked the zeroimpedance unit $1149 a pair. 

Ralph it looks like my Art Audio concierto 40 w will be benefited from the Zero impedance, I think the KLH need to be using 16 ohm.Thanks again...

Ralph, why not just put 200 watt 2 ohm resistors in series with the speaker. Yes, they would absorb some power but they would cost only $40 dollars and I bet you would still get 60 Watts out of the M60's. The other thing is the roll off would be way up there and I doubt most of us could hear it?

Will Dynaco st 70 watt good enough power for the nines?