Refurbising Quad ESL57

[EmmiBr]

i all, i recently acquired four Quad ESL 57 that i want to refurbish. Number one pair is´74 and second pair '75 according to the serials that i want to refurbish. Number one is being disassembled and cleaned. I have a question about the resistors that i will replace, found some on digikey but not totally sure which ones to by? I would appreciate links so i can get the wright parts.
Br. Elmar

 

[Chris Daly]

Schematic is here: https://www.quadesl.com/origRefs/quad_schematic.pdf
Further info is here: Transformer for QUAD ESL57

 

[rayma]

I have a question about the resistors that i will replace, found some on digikey
but not totally sure which ones to by?

All these parts must be rated for unusually high voltages. Don't install any new parts
until you are absolutely certain they are suitable.

 

[stokessd]

I use the Vishay VR series of resistors for all the resistors in the original Quad ESL.

I use the VR68 for the crossovers:
VR68000001803JAC00 Vishay BC Components | Resistors | DigiKey

And I use the VR37's for the power supply front end.

Here's the data sheet on them:
http://www.vishay.com/docs/28907/vr25vr37vr68.pdf

I've also got some original ESL boards on my blog:
Sheldon’s World

Those boards are available for purchase directly from OSH Park.


Hope that helps,
Sheldon
quadesl.com

 

[EmmiBr]

Thanks i will buy these, the first one has no damage on the membranes so i will just clean them and and replace the resistors for now. I did not plug it in and test it before i dismantled it.
Shared album - Elmar Benediktsson - Google Photos

 

[AVWERK]

Make sure you install the protection boards to save your mid/tweeter panels from arcing
It is sonically transparent as well

Regards
David

 

[tubesguy]

I just read the thread from earlier, and have been looking for appropriate 560pf caps. (I already ordered some inappropriate ones.) I found some, ranging up to $90 ... each. I know they have to be high-voltage caps, but does anyone have specific recommendations?

 

[EmmiBr]

Make sure you install the protection boards to save your mid/tweeter panels from arcing
It is sonically transparent as well

Regards
David

Yes i will build the protection board from Sheldon's site.
Sheldon’s World >> Blog Archive >> Original Quad ESL Treble Protection Boards

Melted the beeswax from nr one EHT unit whith a hot air gun for eletronic bord work nice results.
Br Elmar

 

[stokessd]

Yes i will build the protection board from Sheldon's site.
Sheldon’s World >> Blog Archive >> Original Quad ESL Treble Protection Boards

The boards are available from OSH Park:
OSH Park ~

Sadly they are purple, but that's their only problem


Sheldon

 

[stokessd]

I just read the thread from earlier, and have been looking for appropriate 560pf caps. (I already ordered some inappropriate ones.) I found some, ranging up to $90 ... each. I know they have to be high-voltage caps, but does anyone have specific recommendations?

I haven't found a completely satisfactory solution. I generally keep the caps and replace the resistors, because I am of the (nonscientific) belief that the caps are part of the voicing and magic of the speaker. You can put a highish voltage 1200pf and a 1000pf film cap in series and make a 550pf cap that way.

I keep meaning to call Illinois Cap and ask about the cost of a run of 560 pf 4kv film caps.

Sheldon

 

[AVWERK]

I think you might be right about those caps..

 

[EmmiBr]

Morning all, i am making a shopping list of parts for the Quad´s i found GP02-40 Vishay diodes and will order the protection boards from oshpark.com but i would also like to replace the High voltage wires, what do you use there?

 

[EmmiBr]

Panels out.

 

[Nemeske]

Subscribed

 

[stokessd]

for all the bass panel wiring, I use this:
6733-0 Pomona Electronics | Cables, Wires | DigiKey

Sheldon

 

[EmmiBr]

https://www.diyaudio.com/forums/swap-meet/349104-quad-57-esl-trade-sale.html#post6070392

 

[legopart]

for all the bass panel wiring, I use this:
6733-0 Pomona Electronics | Cables, Wires | DigiKey

Sheldon

I ordered this type of cables
12M 18AWG 10KV Electric Copper Core Flexible Silicone Wire Cable Red for RC | eBay
15M Length 18AWG 10KV Electric Copper Core Flexible Silicone Wire Cable White | eBay

18AWG 10KV silicone Copper (Tin Plated)
Red+White

also got 20AWG 6KV silicone Copper (Tin Plated) RED+WHITE+BLACK
From ERAudio restoring kit

your suggestion looks really good (18AWG 10KV silicone Copper) [15M]
6733-0 Pomona Electronics | Cables, Wires | DigiKey
6733-2 Pomona Electronics | Cables, Wires | DigiKey
Black and Red

but I think that even with my passion to idialism, I not gonna by some.

and you know that I much happier when I made even the most shitty crossover with WIMA MKP10 Cap