QuadELS 63 a little help needed

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Hi all
I do have The Quad ELS 63 and I do love them
I bought them just they came out in UK
Now one is sometime fading of, sizzling a bit
and back again,t
what can this bee?

what is generally to do
if they are from the first day

as a car needs service to stay happy with
maybe they nedd service too

living in France but not french at all
Noise from an ESL-63 indicates one of three things, in order of least likelyhood:

1) a piece of dirt/dust has lodged between a diaphragm and stator. There is some arcing taking place which is what makes the noise, and also drains the charge off the diaphragm reducing the output from the other panels. This is unlikely because there are dust covers over the speakers (internal) that do a pretty good job of keeping stuff out of them. If the dust covers are torn or missing, this may be the problem. Quad used some foam tape for vibration damping at several locations in these speakers, and by now most of it has rotted away like an old foam woofer surround. That stuff can get in the speaker even if the dust cover is in place and intact.

2) the HV bias supply is having some problem. If the entire speaker is making the hissing/popping noise, this may be the problem.

3) you have a torn diaphragm- by far the most likely problem. When the diaphragm tears, the torn edges curl toward one stator or the other. The result is arcing that pops/hisses/buzzes. This sort of problem is usually localized to one area of the speaker panel- if you place your ear very close to the speaker and move your head around you may be able to locate it. This works best when you've opened up the speaker and can get real close to the drivers. If you turn the light out you may be able to see little blue sparks where the arcing is occuring.

Old Quad ESL-63s often have torn diaphragms. People sell these speakers when they start to make noise because they don't want to deal with the expense or hassle of getting them fixed. Some people don't realize that the speaker is broken, and think that things like humidity cause the hissing/popping because it is intermittent and they can't think of anything that would cause it, or they don't want to think the speaker is broken. Others are maybe a little less than honest. These speakers do not make any noise when they are working properly. If it makes noise, it broken and needs to be fixed.

You can fix these yourself, but if you're not equipped to do it, it will take some effort and a little expense. Whether it is dust or a torn diaphragm, it's nearly impossible to dismantle the speaker without tearing the dust covers. If you fix the speaker yourself, be prepared to replace the dust covers as well as any diaphragms that are needed.

... it's nearly impossible to dismantle the speaker without tearing the dust covers...

It is possible, they 'snap' off - just look carefully before you start and take your time, gently pry off the frame. Then put somewhere safe until you put back on. I find the hardest part is pulling the cover away from the speaker once they are 'off'.
Not explaining this very well - it will make sense if you try it, I hope!:)

Of course if it is your 1st time it might be wise to be prepared to replace the dust cover - that is how I learned - hopefully I can save someone a little trouble and $. Repaired/removed dustcovers several times since - no new dustcovers.

Quads are a pain the ***, but worth it?

I've used Quad ESL-63s for many years as my main speakers. I haven't heard another speaker that I like better overall yet, and I’ve heard most of the ones that cost as much as a luxury car.

But I have had a lot reliability issues with mine. It’s really a shame that these speakers are not more reliable. Despite using subwoofers to lessen the burden on the ESL panels, and using moderate tube power (both transformer coupled and direct-drive) with some discretion in volume levels, I have had to replace every single panel (8 in the pair) through the years. I have enough panels saved in a stack to build a new pair if I ever set up to make my own Quad panel repairs, with a few to spare. I do live on the ocean in Florida, so humidity and salt are concerns, but my speakers have always been in air-conditioned spaces with windows shut. I run mine “naked”, without the socks and metal grills (I do keep the film dust covers intact). While this greatly improves the sound, and shouldn’t impact reliability, I’ve found a particular problem that I should mention. In a prior room setting, the back side of one of my naked speakers would catch direct sunlight streaming in from a window at certain hours of the day. I had several failures on the stator sides facing the sunlight. It seems that the UV was sufficient to accelerate the aging of the adhesives holding the stator boards to the plastic louvers, or it could have been thermal expansion stresses too. The stator boards would come loose, especially at the corners, causing arcing onto the diaphragm, which if not caught in time would result in perforations and then tearing. This failure mode is not unusual even in panels not exposed to the sun, but clearly it was worsened by my situation. Needless to say, I draw the drapes now.

I removed the rubber plug covering the hole over the neon charging bulb. I am obsessive about watching the pulse rate of these bulbs. They are often the first indicator or arcing, before snapping sounds are heard. I am weary off fixing these speakers, but they sound so neutral that I haven’t switched yet, although I am working on my own DIY ESLs with the hope of one day making a design I like better than the Quads (a lofty goal, I know). So I cannot unconditionally recommend the Quads to my friends without making caveats about the virtual certainty of needing future repairs.
Hi Brian.

It sounds as if you have much experiences regarding reparing ELS panels.
I just bought a pair of ELS 63 as I like the sound very much. Unfortunately the top panel on one of the speakers were damished. Not just a hole, but a crack at the one end of the panel almost from one end to the other.

Can this be repaired - if so any good advices. Do I have to buy a new panel. If so where to buy second hand.

On beforehand thank you - and a happy New Year.


I can only tell you about the source I've used within the US. I don't know if this source is feasible for you or not. I purchased new and rebuilt panels from QS&D in Frederickburg, Virginia. They've been helpful and friendly to me. (I am a pretty good customer for Quad parts, unfortunately.)

QS&D Site

I just looked at '63 panel prices on this site and they are higher than I remember paying for mine. QS&D wants $425 per panel, $350 if you buy three or more. I seem to remember buying German rebuilt panels from QS&D for a lower price than new panels some years ago, but I don't see that option listed on the site. I must say that the German rebuilds did NOT work for me. The surface resistivity was just too high to feed leakage currents in my humid environment, and they were woefully insensitive, in fact, almost silent. I've had better luck with original new Quad panels.

An option for long-term '63 owners is to buy a "broken" pair of '63s cheap to use as a parts source. If you search the web, you will find plenty of information about repairing your own diaphragms, but in your case, you will need to replace that one cracked panel completely with a new or used panel. Good luck!
Brian -

Thank you for your quick response and advices. I have been searching the intranet already, finding a lot of useful instructions and pictures.
I believe your are right. It do not seems easy to repair a cracked panel.

Once again thank you and a Happy New Year to you.

I have had a pair of ESL63s for about 15 years now, they were bought second hand. I replaced the protection circuit with the later type and I have replaced 1 panel about 10 years ago as it was slightly noisy. I have driven them initially with a Quad 405 clone I built, then a 405-2 next a pair of 405-2s then a 606 and now a pair of 606s with active crossover and dipole subs. They have stood up to a considerable amount of abuse as I regularly drive them until the protection circuit activates then back off the volume. I did at one point have the 606s bridged and found that it was much more difficult to activate the protection circuit and the 63s were very loud. Using the subs I have not had the protection operate at all and they go loud enough for me to be concerned about my hearing.
I offered to repair one speaker for someone and on inspection it was obvious that the bottom panel was arcing and I ordered a replacement from Quad but when I fitted it I found that an other panel was now arcing and on inspection the diaphragm had become detached at one edge. At this point I decided to look for an alternative source of panels as Quad now charge about £200 each. I finally found Onething Audio who rebuilt all 4 panels for £300 and that solved the problem they have performed faultlessly for about 3 years now.
Flushed with success I bought a faulty pair on Ebay and replaced one faulty panel with the new one I had bought from Quad to again find that a second panel was faulty and I an not sure if opening the dust covers and exposing the panels caused the adhesive holding the diaphragm to fail or if this was coincidence. I would like to rebuild the faulty pair using 6 panels in each as in the 989s and to this end I have now got 6 ESL63s in various states of dis-repair but time and lack of funds have prevented me from making much progress so far and my original pair are still performing very well.

German parts supplier for Quad ESLs

I've found a German supplier of parts for your Quads. They may also perform full refurbishing if you are not technically skilled. Their prices seems to be better than their US counterpart.
Here's their web site: QUAD Musikwiedergabe

I'm into the same business as you. I've purchased two pairs myself (yes, four speakers!). And I have to replace the EHT circuit on one of them, and a bass panel on one of the others.

Please share your experiences when your speakers are up an running.

Good luck with your project.

Regards Khanate
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