Yet another ESL57 rebuild

[ForsbackaKalle]

I started up with a pair from 1976. Bought them some years ago after reading about the special sound. Have been stacked before and show marks after that operation. I installed dustcovers for the treble panels sins they didnt have any also did some work on crossovers/input-trannies and EHT board. They sounded really great and sat back and just listen to the music. Had some issue with lower EHT voltage after connection to the boards. I measured speakers frequence Responce and quite obvius a leake i one of them. And there I started my total rebuild of those speakers.

 

[ForsbackaKalle]

I also made some protection units for the treble panel. Measured them up and they sure do clip over 2kV. Also had a conversation about suitable zeners for this board see https://www.diyaudio.com/community/threads/zener-diode-spec-in-treble-protection-unit-esl57.383126/

 

[ForsbackaKalle]

Did do some paintwork at the frames as they look quite tired. Also did fix some holes made by stacking rack earlier. Have had a conversation with a local carpenter for make some spiderlegs. Will be done so full orginal restauration will be possible. Will come back with picks of those legs later...

 

[ForsbackaKalle]

This is quite interesting to look at. This is the membrane of a bass panel put in a window. Qite sloppy drags with a pensil with this coating...

 

[ForsbackaKalle]

This work with getting rid of old rivets is really boring. I use the pliers method. I didnt get any grip with drilling.

 

[lcsaszar]

Keep up the good work! This is my restoration story:
Quad ESL restoration

 

[wout31]

This is quite interesting to look at. This is the membrane of a bass panel put in a window. Qite sloppy drags with a pensil with this coating...

It's not sloppy, it's just how Calaton/Elvamide works. You have to apply it fast, you can't touch it a second time, so you can't be accurate. Just my $ 0.02

 

[stokessd]

It's not sloppy, it's just how Calaton/Elvamide works.

It's an awful coating, as evidenced by the fact that it seemingly can't be applied evenly, and over time it evaporates and takes hours or days instead of minutes to charge up like they did when new. Also evidenced by the fact that they changed the coating and haven't looked back.

 

[rayma]

Keep up the good work! This is my restoration story:
Quad ESL restoration

Do you have any information on your stands, are they commercial or custom?

 

[ForsbackaKalle]

I did also do new railways for the EHT with some copper tape and silver paint

 

[lcsaszar]

Do you have any information on your stands, are they commercial or custom?

They are custom made from hollow square steel profile, filled with dry sand.

 

[ForsbackaKalle]

And here is my Bass panels ready after refurbish.

 

[lcsaszar]

What diaphragm material did yo use? How did you stretch it? What coating did you use?

 

[wout31]

It's an awful coating, as evidenced by the fact that it seemingly can't be applied evenly, and over time it evaporates and takes hours or days instead of minutes to charge up like they did when new. Also evidenced by the fact that they changed the coating and haven't looked back.

For the period (1955) it was the only coating, so the best coating available. Yes, times and techniques have changed since.
That it looks awful and uneven doesn't mean it sounds awful and uneven. Visual and technical are totally different matters here IMHO.
You can still build a great sounding ESL-57 with Elvamide.

 

[ForsbackaKalle]

What diaphragm material did yo use? How did you stretch it? What coating did you use?

Mylar C, Pulling tention Gauge and Elvamide 8063.

 

[stokessd]

Visual and technical are totally different matters here IMHO.
You can still build a great sounding ESL-57 with Elvamide.

But why would you? There are now many better and longer lasting coatings available to us. We all know that this coating is fundamentally flawed.

 

[wout31]

But why would you? There are now many better and longer lasting coatings available to us. We all know that this coating is fundamentally flawed.

Because most people don't know other coatings. What coatings they would ask. Longer lasting? What are the flaws of Nylon coatings?

 

[ForsbackaKalle]

I have done some more work at this panels. Now working on Treble panels and had some tiny arcs. Cant wait to power them up and have some real music playing.

 

[ForsbackaKalle]

I have done some more work and also tested them. Works really relly great. And a link so you can listen with me https://drive.google.com/file/d/1RrsZdyT_AUlWw6N7NW06wF77lzlOCnsw/view?usp=sharing

 

[woodturner-fran]

Nice work!!