QuAD ESL 57 Stators/panel - German ??

[dude007]

Hi

Checking out some used 57's. How can I easily tell if the panels are original UK or the german ones?

Whats everyone's opinion on the difference in sound between the two?

/.cheers
V

[StanJ]

Hi,
it is very easy to identify the origin of manufacture.

I am referring to the 57s.

The old panels are composed of deep-drawn matierial, looks like thermoplast, even though they break up easily. The spacers are not glued to the electrodes. The spacers are deep-drawn into the sheet, so spacer and electrod is one piece. They are of light grey color. Apparently, the holes are punched. The appearance is industrial like.

The new ones, produced in Germany, are made out of FR4-material (circuit board). I have only seen the mid/high-panel. The spacers are glued to the electrodes. There look is much more reminding on diy-quality, handcrafted. They are of yellow color. The holes are drilled.

Concerning the quality: I believe thoroughly they sound very much the same, as I listened to both of them extensively.

And, if anyone claimes a difference, where should it come from?

[wolf_moses]

Gary Jacobsen found a big difference both measuring and auditioning at

http://www.quadesl.org/Album/Intervi...angoffive.html

The review is a few years old and current German panels might be made differently.

[torroid88]

I understand that some of the molded stator panels were made of some kind of red thermoplastck that was later painted grey. Some of the refurb sites have photos showing the red plastic ...

As to the brittleness of the plastic used, I have seen no discussion of that. Those that have published about refurbing mentioned drilling out the multitude of rivets ( some 60 ?) without mentioning breakage.
Other refurb site advocate cutting off the rivet heads with cross-cutting wire cutters and compressing the shaft so the other side falls out, again without any warnings about breakage of the stator panels ...

[oshifis]

I have a pair of original ESLs (the company actually never used the 57 tag). The bass stators are made of white thermoplastic material, and the mid/treble is made of dark red, both painted grey after assembling. I ordered replacement trebles from the manufacturer some 20 years ago and they sent replacement of the same colour but the spacer was not deep-drawn from the same material. They must have changed something. BTW the grey paint peels off easily from the stators. I guessed they are sprayed after assembling, because the paint went through the holes onto the diaphragm sporadically. Also the sealing tape that holds the wooden frame and the dust cover itself was painted grey (I already replaced them). I know for sure that nobody disassembled the units before me.

[arend-jan]

At some point in time (very late production) Quad changed the treble panels from completely molded to machined out cavities. As a result the panel became more flexible (also because it was a little thinner I think; can't recall) and sounding somewhat different. But very close to the molded ones. They look 'funny' compared to the older ones because they are completely flat on the front opposed to the recessed borders and ridges that you normally see.

To my knowledge these are all replacement panels because the original production had already stopped by then.

[oshifis]

Correct. The Acoustical Manufacturing Company, Ltd. supplied the trable panels as replacement. They came with detailed assembly instructions, obviously keeping home installation in mind. The hair dryer method for tensioning the dust cover comes from the original instructions.
Since the ESL-63 appeared in or around 1981, I suppose the company stopped producing the original ELS around that time, but they still had been supplying replacement parts for some more years.

I found many useful info here:

http://www.quadesl.org/FAQs/faqs.html

Laszlo

[milosz]

This fairly extensive review found that the German ESL-57 panels did not sound as good, nor measure as good as refurbished original ESL-57 panels.

http://www.quadesl.org/Album/Intervi...angoffive.html