I sure miss my Quad ‘57s!


I owned Quad ‘57s and joyfully listened to them for 10 years! Still questioning my decision to pass them on to another music lover. But I do sadly remember the multiple times I blew up amps because of them and the sickening feelings of the many times I arched them before I had them rebuilt.
I did eventually opt for more bass and treble but have missed their incredible mids now for decades.
Guess there are some new rebuilders who have been able to get more bass and treble? But I now have evolved the feeling that good enough is good enough. And man, were they good enough!
mglik
Roger's (rip) RM-200 was the best, as it has 1 or 2ohm output taped transformers, with the 2ohm tap it drove the ESL63’s to perfection, but it’s 100w gets knocked way down from the 8ohm tap figure, but still enough to get decent level out of the ESL 57’s

Cheers George
True George, and the lower the tap, the lower the output impedance, a very good thing with the ESL (it's impedance swing is brutal, insane). Interestingly, in my last email with Roger, he recommended I use the 8 ohm tap on the RM-10 with the ESL, not the 4 ohm. I asked about his "light loading", and he said yeah, but the ESL is mostly a 16 ohm load, so the 8 ohm tap IS light loading with that speaker. When I get my Quads up here I'll try both amps (RM-10 Mk.2, RM-200 Mk.2), and all taps.
My Emotive Audio Vitas drove my Quad 57’s for 15 years without any issues. But I have also moved on the other speakers and right now find my Bache Tribeca speakers to be more satisfying. Maybe I should connect my Quads again during this lockdown. 

Two of the ESL's major limitations---low bass and maximum SPL capability, now have a common solution (okay, not complete, but significant): the GR Research/Rythmik OB/Dipole Subwoofer.

The ESL has long been known to be impossible to integrate with a sub to a degree acceptable with perfectionists. That is no longer the case: the OB sub is finding favour amongst owners of not just QUADS, but also Maggies, Martin Logans, Acoustats, Eminent Technology LFT's, even horn loudspeakers. Oh yeah, and dynamic/cone/box designs.

Taking the low bass out of the ESL panels (and the power amp driving them) allows them to play louder (okay, still not that loud) and cleaner.

Read all about the sub on the AudioCircle GR Research Forum.  

I can’t say whether the rebuilders get more bass and treble from the speaker, but there have been improvements to the power supply and the Zener clamp boards allow you to use a wider selection of amps without the fear of arcing the panels. As previously mentioned Electrostatic Solutions is a good resource to learn about some of the design improvements.

As for the RM10 and the ESL 57 well it was somewhat by accident that the amp was designed with that speaker in mind. It just so happened that was the speaker Roger was using at the time so he certainly wanted an amp that could play well with it (actually right to the very end Roger had his ESL 57 running in the shop for our music pleasure). The RM10 is very balanced with the ESL 57, but most amps will have trouble keeping up with the rise in the bass frequencies and the RM-10 could be perceived to be a bit lean there, but overall it’s one of the best tube amps to use with that speaker.

OTL amps can deal with that rise in the bass, and along with the RM10 I have used the Atma-Sphere M60 with these speakers and even though their output impedance is much higher than the RM10, it plays quite well.