Well, I once was the proud owner of a couple of quads- the original ESL-57 and a pair of ESL-63s that I also pulled apart- their delay line/filter design to drive the annular segments was quite neat. However, I had serious reliability problems and I switched to Martin Logans and I've stayed with them ever since. I have Montis in the main audio room and a pair of venerable Prodigies in the home theater room and I've never had a problem with either of them.
Yes, I am aware of the fundamentals of their operation, but alas not the details so I really cannot help you out in this. Frankly, I'd be pretty leary about shipping the needed HV to the speaker from an external amp. Visions of lethally shocked dogs, maids, and kids spring into my mind. Having said that I believe that at one time Acoustat built ESLs without the transformer, instead using built in output transformer free tube amps
Yes, I am aware of the fundamentals of their operation, but alas not the details so I really cannot help you out in this. Frankly, I'd be pretty leary about shipping the needed HV to the speaker from an external amp. Visions of lethally shocked dogs, maids, and kids spring into my mind. Having said that I believe that at one time Acoustat built ESLs without the transformer, instead using built in output transformer free tube amps