Amplification for stacked quads?

Hello I have a pair of wonderful stacked ESL 57. Right now I am running them with a pair of EAR 509MKII monoblocks (100WPC) but I am considering Berning's ZH-230 (30 WPC) and the integrated Jadis DA-60 (60WPC). Has anyone had experience with stacked quads? Any recommendations in general? And how about the amps I mention here? Many thanks.
Berning EA230 or Levinson ML2's.
What don't you like about the EAR's on the Quads? Not a very practical recommendation, but to this day one of the most memorable systems I have heard was stacked Quads driven by Levinson ML-2 class A mono's; and I typically prefer tubes.
I like them a lot. It's just that not having other reference points I don't know if I am missing something. And I have always been a big fan of Berning. But certainly the 509's are quite good.
Hopefully the Quads don't have their metal grills on.

I owned the 509's with Quad 63's many years ago and as expected thet were magic. I was told the 509's were designed for Quads. In the course of selling them, I bumped into a real 509 fan who told me how much better the amps could be with some updates of the old materials. Since I was moving in another direction, I never took the time to update my 509's but he was talking about changing all the point to point wiring, tube sockets and some internal components as well as a total cleaning and detox etc. Since the 509's are one of the "cult" amps with the Quads, it would be a shame to give up on them when they could be better than new. I have never heard anyone make a serious case that ANYTHING is better with Quads than these old amps. I'm sure someone with more tech chops than I would love to tell you about the glory of these old amps made new. I have had great luck with Chris at Parts ConXection and tube projects for greatly improved sonics. Good luck.
They do have their metal grills on!...but still after a long period of search in which I tried all sorts of speakers (SF extrema, Living Voice OBX R2, Ocellia Kedros, Quad ESl 63, Devore nines and many others) I think I found my "definitive" speaker...I never heard anything like that.
Hi, My stacked quads were driven with the original Ampliwire II from Matti Otala ( Electrocompaniet now) I garee with the above poster the best I've heard the Stacked Q's was with Levinson ML2 monos.

We've had a number of customers with stacked Quads. 57s don't take a lot of power, but with 2 pair in series you can do well with a set of our M-60s.

The speaker really seems to work best with tubes- if you want to hear all its capabilities that is.
Thanks for all your answers. I am still processing. Interestingly, today I got a Sonus Faber Musica for my second system (I have a pair of SF Minima) and just out of curiousity I tried it with the quads...I was actually quite impressed. It's extremely precise and it images like crazy...not bad for something in the $2K range (used).