Quad ESL 57 playing Prince

I have had ELS57s from 1977 (only quite recently replaced them by 2805s) and never did any harm to them. As it says in the manual, it is important to prevent higher voltages reaching them, so I never used any other amplifier than the Quad 303 that was the perfect match. If that is not loud enough for you, you have to move up to to the modern models, and/or add subwoofers (see my rcent post on subs with the modern models).

But beware: max peak voltage is 33 Volt, and the amplifier has to be unconditionally stable, also under capacitive load. These are speakers that have been known to destroy amplifiers, and some amplifiers have been known to destroy these speakers. Impedance is in the 15-30 Ohm range, and falling at higher frequencies. The Quad 303 has the perfect specifications.
The difference with the modern models is not at all night and day, but I do believe the modern 2805 is superior: lower and tighter bass, more power handling, and a spatial performance that is a vanishing act if there ever was one.