Magtech. 100 percent. The only amp designed to follow the crazy impedance swings and capacitive nature of an electrostatic panel.Not so true with ML ESL's, do a search on SNA for Summits and the Magtech, it had problems blowing fuses when pushed with their loading, which is quite different and more tricky to the Sander ESL's, they even got a different Magtech from the supplier same thing happened.
Cheers George