Innersound Electrostatic amp driving Quad esl 57's

The danger with the '57 is arcing damage due to too much power, hence the 25 watt thing.

But they are also very tube friendly (in fact were designed for tubes), and will make bass with a tube amp that they will not with transistors. If I were you I would consider tubes on that account. Its a classic combination.

No way I'd mate a 600 watt solid state with '57's. As Atmasphere suggests, stay with low power tubes!

I used to run Quads full range with Dynaco Mk IIIs, 50 watts/ch no problem. I used regulated everything, preamp power supply, tube filament supplies, etc. I ran the Quads naked - no metal grills, no dust covers. They are much more unrestrained and dynamic that way.

Ditto what others say about power. I've had a Bedini 25/25 with a single pair of Quads, and it was very good. One of my customers had a pair of Atma-Sphere M-60s with his Quads, and it was a terrific match. Two pairs of Quads connected in series driven by M-60s could be something.

You may want to try an ARC D70 Mk2. I own one and it's a wonderful tube amp. I'm pretty sure that David Chesky uses this amp to drive Quads.