Keeping the faith - Quad ESL surgery

[sqlsavior]

What's wrong with this picture?



Actually, there are many things wrong, but I'm refering to the missing Quad Electrostatic Loudspeaker, on the left, which stopped making music a month ago or so. These are speakers that need to be plugged into the wall, so they can develop the 6500 volts they need to work correctly. Knowing that a common failure mode of these now 51-year-old speakers is breakdown of the EHT high-tension power supply, I had previously purchased replacements, and now it was time to install one.



Off with the legs.



From tablelegs.com, with the rear leg screwed to the floor for stability.



Twenty-some screws to get the back grille off.


The high-tension supply is the box on the right, which takes line voltage (settable to 110, 120, 220, or 240 volts), and steps it up to 1.5kV for the center tweeter panel and 6.5kV for the two bass panels on either side. One must let the device discharge to work on it safely, but that happend weeks ago.

 

[sqlsavior]

The old unit is encased in beeswax to prevent miniature lightning storms! I love the little box they made for the beeswax.



The new units are from Electrostatic Solutions, already built, and coated to prevent coronal discharge.



I de-soldered the old wires.



And my visiting brother, the only Certified Solderer in the family, did the hard part.



Thanks, Bro!



New unit installed:

 

[sqlsavior]

We left it overnight, and waited for the next day to put the back grille on, the legs back on, screw the back one back into the floor, and plug it in to charge.

Three hours later came the test. Success!!!



Now I feel like a REAL Quad owner, and proud to keep the faith!

Peace.

 

[Powertech]

Nice job. Good to see someone who understands the hazards involved and safety precautions required to deal with HV circuits.
I've heard Quad ESLs in the past and in the right room setup they are absolutely breathtaking. There is nothing quite like them.