The work on Upper and lower bass panel completed and re-installed back to the speaker. This is how it looks like now without the dust cover and the meter grille.

Sound test in progress......

The healthy ESL988 placed upside down in order to un-dress to gain access to the panels.

Interior circuit is clean and tidy. It is rather simple compared with ESL63. Everything installed in one circuit board.

EHT, protection circuit, signal path all in one board!

Speaker base removed.

Speaker base and base board removed. Showing coil boards

Panel assembly placed sideway, ready to un-dress

Panel assembly un-dressed, showing metal grille

The previous photo was the wrong one, it was out of sequence.

This one showing the panel assembly is un-dressed, showing the metal grille.

Dear Matthew.

Please refer to the following hyperlink for information.

http://audioart.audionet.com.tw/20/48-53.htm

Dust cover and metal grille removed showing naked panels. Ready to apply fresh Epoxy glue

Fresh Epoxy glue is being applied between stator and frame very, very carefully. One tiny mistake will ruin the mylar. and the entire diaphragm will have to tear off for fresh re-mount.

After all that, the panel assembly re-installed back to the speaker base.

After re-installed. Sound test.

Special thanks to CP for loaning me the Quad Pre-amp and the Quad 306 power amp.

Regds
Patrick

Thanks Dennis.
Seems like Quad ESL 63 Pro / US Monitor are the same but only having different name in USA.
I'm planning to buy an ESL, may be a 63. I saw some ESL 63 is in brown cover and some in black. May I know is there any different?
cheers
Matthew

Before I assemble the speaker, I have also checked the EHT for both speaker for its electrostatic output. The reading shows both of them are normal.

Both speaker re-assembled. Mission completed! Thanks to the owner for the chance and his trust on me. I appreciated it!

Regards
Patrick

I'm planning to buy an ESL, may be a 63
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Dear Mathew,

If you found an ESL you wish to buy, please let me know. I'll be happy to accompany you for the audition and inspection of the speaker before you make your decision.

Regards
Patrick

ESL63 speaker cloth color'
______________________

Dear Matthew,

I suppose the 63 owner could choose the color when buying new in 80s.

Warning. When buying used 63, you have to make sure no cracking noise when playing loud. Having said that, it is UNREALISTIC to expect used 63 without panel trouble after 20 to 30 odd years.

I have acquired 2 pairs of 63 myself, both have such panel problems even NOS. I am bloody lucky to have Patrick (PCS100) helped me through all the panel replacement issue. IMO, buying ESL57 is less troublesome, owner will only need to change the EHT boards.

Pro and ordinary 63 are different in term structural rigidity. The Pro is heavier and more rigidly built per Philips's requirement. I would say they sound different to some ears, but both are equally enjoyable.

Patrick,

Beautifully restored, a fine piece of work indeed. Without you, this thread ended bankruptcy light year ago. If convenient, I'll come this Thursday late evening to hear the 988.