Driving 1 ohm

Rwwear, ESLs do not respond well if the amplifier can double its power as impedance is cut in half. It will result in no bass and too much highs. This is why tube amplifiers are often preferred for ESLs, despite the misguided attempts of several ESL manufacturers of making the speaker's impedance really low in an attempt to make them work better with transistors. The result is often a speaker that neither tubes nor transistors can actually make sound right.

For speakers like this tubes and a set of ZEROs are usually the best solution. See

http://www.zeroimpedance.com
and
http://www.atma-sphere.com/papers/paradigm_paper2.html
for more information.

I wasn't recommending anything just defining a high current amp.
The Zero Impedance device looks like an autoformer or a similar device. It doesn't seem like something an OTL amplifier design would promote.

Best amp to drive ESL?
Roger Sanders (http://www.enjoythemusic.com/magazine/manufacture/0702/index.html) of course suggest to use solid state amplifiers, specifically his own design.

I believe that Andr did not strated the tread asking advise to help him to find different amp then one he uses and enjoys - rather what harm it can endur by driving 1 Ohm load.

...of course when I owned Quad ESL 63 I used only tube amps (heh, heh, heh...)

Regards
Simon

Simontju is right on that one. The 2500A inherited the Acoustats. Long story short : I had Acoustat model 3 for a year and decided to have them rebuilt in 2+2 s. What I got back is something supposedly easier to drive but tremendously upgraded on the full range. And that brought me the concern. The rest of the electronics is probably forever : Simaudio Eclipse, CJ Premier 16,cables. The 2500A is here to stay until I get upgraditis again but for the time beeing, the WAF has been tested enough with the 2+2 s in the living room. I would not dare testing it again with large monoblocks,class A or tube amplifiers, at least for awhile. Class D maybe a solution but did not have the chance to audition some. In my vicinity(Canada), they remain quite scarce.

My Acoustat 2+2's do amazingly well driven by a PS Audio HCA-2 amp. Grab one here on Agon for $600 used.. you won't be sorry, and your back will thank you!