I currently have both the Quad and Jazz Modules. I have always wanted to hear a set of Quad ESL-57s. Problem is finding a really good set or investing in a good restoration. I placed a WTB add on AC and a gentleman from TX offered me his set. Price was somewhat high for used, but they had an older QS&D refurbishing, including updated PS, clamp boards, Edison Price binding posts, IEC inlets, and original boxes. The cosmetics were excellent for their age as well and consecutive serial numbers. To be cautious I sent them to Electrostatic Solutions and Kent told me they were one of the best examples he has seen. Just as an FYI a complete restoration would have cost $2500 but Kent just cleaned them up and shipped them back.
Having both Atma-Sphere OTL amps and a Music Reference RM-10 I had two sets of amps that match up well with these speakers, much the same as they match up well with my Jazz Modules. I think the amp/speaker interface is most important and I have no issues with my combos. In any case the Quad ESL-57s are one of the best speakers I have ever heard. They do so much so well, even in the bass which is not supposed to be their strong suit. They do not play loud but anything over 85 db is too loud for me anyway. Bass is sufficient and I can play and enjoy a variety of music on them. I will say this, they remind me of my old Spendor 1/2e speakers, but without the box.
To invest in a set of Quad ESL-57s one should be prepared to restore them, so spending $4k is a good possibility. However, the suggestion to try the new Janzsen speakers is a good one. They were on my list too.
As for any comparison to the Jazz Modules I will say this. I am fortunate to have two sets of great speakers. The Jazz Modules are more dynamic, extend lower in the bass, and are quite musical, but the ESL-57s just plain make better music.
