ESL63 - help.
i...@netvision.net.il
I recently bought a pair of broken ESL63s. Both speaker make noise of small
expolsion as soon as I plug them to the mains. One is playing fine though.
(if you can ignore the explosions) while the other one is quite distorted.
I bought these speakers from a guy who lives in a city located in the desert.
I also bought a preamp from this guy, and I was amased to find plenty of dust
sand inside the preamp. I assume the Quads got a fair share of sand as well.
I took of the grill cloth and the metal grill on the one that plays fine.
Guess what, the protecting dust nylon was not there ....... I then switched
them on, and turn off the light .... There were some small firework sparks on
two of the four units.
I own a pair of ESL57, and I am know ML speakers quite well. The Quads are
totally different and therefore before I continue and try to fix them, I
wonder if any of you have experience in fixing these babies. Help will be
appreciated.
Regards
Danny
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i...@netvision.net.il
r_mac...@my-deja.com
i...@netvision.net.il wrote:
Hi Danny,
It seems your query has been hanging around a while. Sorry for not
being able to assist earlier.
> I recently bought a pair of broken ESL63s. Both speaker make noise of
small
> expolsion as soon as I plug them to the mains. One is playing fine
though.
> (if you can ignore the explosions) while the other one is quite
distorted.
>
With all problems on ESL's, it's a bit difficult to diagnose faults
without looking, hearing, seeing, first hand, so the following is a
bunch of problems that could have occurred.
> I took of the grill cloth and the metal grill on the one that plays
fine.
> Guess what, the protecting dust nylon was not there ....... I then
switched
> them on, and turn off the light .... There were some small firework
sparks on
> two of the four units.
>
The first thing to try is vacuuming out the panels. Use a vacuum
cleaner on partial suction setting.
Did the fireworks occur with no audio signal? If so the polarisiing
charge on the diaphragm is "flashing" to earth or a stator.
If it was occuring with audio signal, depending on the level
(loudness), it is likely to be "flashover" between stators or stator to
diaphragm.
If it's stator to stator, there will be a hole burned through the
diaphragm and the insulation on the stators will probably be charred.
You may be able to see this without stripping the panel.
In either case the stator insulation has broken down and will need to
be repaired before the panel(s) can be driven to full output.
The distorted sound from one of the speakers is probably due to the
polarising charge leaking away. It could also be a defective EHT supply
or audio transformer or part of the delay line.
A simple check of the eht supply is to disconnect the eht wire from the
panels in the defective speaker and connect them to the working speaker
with a jumper lead. (Use high voltage wire). If the speaker gives clear
sound the problem is the supply or internal wiring to the panels.
If there is no difference the panels will need to be checked for
leakage. This is easy to do but needs a decent multimeter.
With the panels disconnected from the eht supply and the audio delay
line, connect all three terminals of one panel (there are 4 panels in
the speaker)together. leave for 10 minutes. This is to equalise the
charge between the stators and the diaphragm. Set the multimeter on the
highest ohms setting, preferably 2000 megohms, and connect to the eht
terminal and to one stator terminal. The reading should be infinity.
Do this with the other stator terminal.
Any reading between the stator and the EHT terminal (diaphragm)
indicates a leakage path. If this occurs the panel will have to be
stripped and repaired.
Follow this procedure on all panels in the speaker.
If all appear ok, the problem must lie in the audio side - ie
transformer or delay line. This is less likely though.
If you find panels that need repair, you can do this yourself.
Alternatively I can do it for you.
I can provide the same gauge diaphragm material <4 micron, and a
suitable conductive coating and all the instructions.
Both have been used in many ESL 63 repairs / overhauls in the past.
If you need further assistance you can email me direct on
robmac...@iinet.net.au
Best Regards and good luck
Rob
Danny Bekhor
I never managed to thank you for the email below. I was constantly on
business trips, and even now I am writing to you away from home in between
flights.
I will try to follow your instructions, and the first stage was to vacuum
the speakers.
I did vacuum the speakers. One of the dust covers were missing (at least
the plastic was not there). This is of course not a good sign, but I guess
something else was wrong with these speakers, and the previous owner, who
knew nothing about them, tried to take them apart and removed the plastic
....
Well vacuuming did not help. I still get sparks with or without signal, and
music is distorted.
I am not sure I have done it the right way. Each driver is actually a
sandwich of 2 grid plastic (like chocolate cubes) and two stators and one
diaphragm. I was vacuuming through the plastic grid, and I am not sure I
got close enough to the stators. I really wanted to desolder the soldering
connections and release the screws that hold everything together, but I was
afraid to do it without consulting first. So, can I indeed release the
plastic grid, and vacuum the drivers more closely ?
In addition, I get the feeling the guy from whom I bought these speakers,
was listening to the in a rather load way. Is it possible he managed to
destroy the protecting circuit ? How can I tell if this circuit is fine ?
I am more hesitant to play with the electronics of this complex speakers,
but I will do it if necessary. I do enjoy the challenge of trying to fix
them, and I am really happy as this is a rather unique opportunity to
understand and learn about these speakers.
Thanks & regards
Danny
"r_mac...@my-deja.com" wrote:
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r_mac...@my-deja.com
Danny Bekhor <i...@netvision.net.il> wrote:
G'day Danny,
> I never managed to thank you for the email below. I was constantly on
> business trips, and even now I am writing to you away from home in
between
> flights.
>
I know the feeling, I travel a lot in my "normal" work, pain in the
backside isn't it? What country are you in??
> I am not sure I have done it the right way. Each driver is actually a
> sandwich of 2 grid plastic (like chocolate cubes) and two stators and
one
> diaphragm. I was vacuuming through the plastic grid, and I am not
sure I
> got close enough to the stators.
This can be difficult as the plastic matrix is bonded to the stators to
stiffen them.
I really wanted to desolder the soldering
> connections and release the screws that hold everything together, but
I was
> afraid to do it without consulting first. So, can I indeed release the
> plastic grid, and vacuum the drivers more closely ?
>
The plastic matrix will not (or at least, should not) be separate to
the stators. They are bonded together and have to be removed as a unit.
From what you describe, the cells will need to be repaired rather than
vacuumed. This is not difficult if you take it a step at a time.
Mark which cells have the fireworks display and where it occurs. A dark
room makes this easier. Having done this, its good practice to restore
all of the cells rather than just fix the faulty ones, but I'll leave
this to you.
Use the normal precautions when dealing with high voltages. Unplug the
speakers and leave them for a while to discharge. Before you touch the
connections, short them together with a jumper lead to discharge any
residual charge on the diaphragm or in the bias supply capacitors.
Disconnect all the wires connecting the 4 ESL cells to the drive
circuitry and EHT supply. Mark which wires go where and the order of
the cells in the enclosure.
The cells are removed from the front of the speaker. Undo the four
screws that hold the individual cells to the frame. Loosen one and
remove one screw that holds one of the vertical aluminium support
strips that the grille etc attaches to in the front of the enclosure.
This will allow you to slide the cell sideways a bit and then out
through the front of the speaker. Loosening the vertical strip gives
you a bit more room to get them past.
There are three screws that hold the panel together, remove these and
split the cell. NOTE, there is a spacer between each post that the
screw passes through, this preserves the air gap when the screws are
tight. Don't lose the spacers and don't forget to put them back when
you re-assemble the cell. Later models (white or cream matrix) don't
have these spacers, the post is moulded to the correct height.
You should now be able to see the offending damage. Expect a hole in
the diaphragm and possibly some charring of the stator. IMPORTANT..Also
check the bond between the matrix and the stator. Sometimes this fails
causing the stator to bow inward. This reduces the air gap and leads to
flashover. If this is the case it can be repaired with super glue or
similar.
You will need to scrape of the carbon around the charred area of the
stator until it is back to normal material. You can then varnish the
damaged area with high voltage varnish or you can spray 3 or 4 coats of
conformal coating over this area. This is available from any
electronics store.
Before I describe how you should replace the diaphragm, it may be
better to get to this stage so that the damage can be properly assessed.
Let me know what you find.
> In addition, I get the feeling the guy from whom I bought these
speakers,
> was listening to the in a rather load way. Is it possible he managed
to
> destroy the protecting circuit ? How can I tell if this circuit is
fine ?
>
This is a hard one. The protection circuit detects RF signal as the
ionisation of air is reached, this then clamps the input.
Unfortunately, high level transients can by-pass the protection before
it has time to operate, the result is pretty much the problem you
describe.
You can't substitute a dummy load capacitor to see if the circuit
works, cos it won't ionise the air. If you try it with the panels
connected and it's not working, you risk damage to them.
A solution is to contact Jerry Crosby, California (I don't have his
full address at present), to obtain his protection circuit. This works
somewhat differently to the Quad system, is better, and as a bonus
improves the sound quality (some say). This is because it only comes
into circuit when its needed, unlike the original, which is in circuit
all the time.
However, I believe it's very unlikely that the protection circuit will
be faulty.
One thing to bear in mind, these devices are not hard to repair and
just about everything is repairable, just take your time and make notes
of wire positions and component placement as you go. Do one speaker at
a time. You will then always have the other speaker to guide you if you
screw up.
r_mac...@my-deja.com
Danny Bekhor <i...@netvision.net.il> wrote:
> Hi Gary
>
> "r_mac...@my-deja.com" wrote:
>
> >
> > G'day Danny,
> >
>
> OK, here's what I found :
>
> First of all, there were 5 rather small holes in the diaphragm (a
diameter
> of 0.5-2 mm). Note that this cell is note a problematic one (no
fireworks).
> In addition to the above, there were many many (more than 20) tiny
burns on
> the diaphragm (no holes, though).
>
> Second, although generally, the diaphragm was tight, on the edge of
the cell
> (where it is glue to the stator) at one corner, there was an air gap.
as if
> someone used a knife and cut the diaphragm close to the edge of the
cell.
> It's a 2" or so of an air gap, and it's a 1-2 mm wide.
>
Due to the diaphragm being split at the suspended edge you will have to
replace it. this is because the tension at that section is now
different to the remainder of the panel.
> The diaphragm was not as dirty as I thought it would be, but then
again, it
> could use some cleaning (how ?)
>
Academic, as it should be replaced! Normally a soft lint free cloth
rubbed gently over the surface will suffice. Make sure you don't leave
bits of fluff behind. You could also use a "Tack" cloth as used in the
automotive respray industry. This is a cloth that has a tacky surface
which picks up all types of fluff etc.
> I was rather surprised to notice that the holes in the stators were
not
> fully "opened". As if there's some sort of a large sticker which
blocks the
> holes. Actually, this sticker does not fully block the holes. It
allows air
> and music to somehow flow through it .....
>
> Also, this "sticker" (or should I call it "The inside of the
stator" ), was
> not too clean. Again, it could use some sort of cleaning or dust
wiping ...
>
This "sticker" is important to the operation of the speaker. Its a
piece of very fine denier cloth which gives a degree of damping to the
diaphragm.
This can be cleaned using a vacuum cleaner with a fine nozzle. Make
sure it's stuck down tight.
>
> > You will need to scrape of the carbon around the charred area of the
> > stator until it is back to normal material. You can then varnish the
> > damaged area with high voltage varnish or you can spray 3 or 4
coats of
> > conformal coating over this area. This is available from any
> > electronics store.
>
> I'm beginning to loose you ......
This is to repair any damage to the copper coating on the stators.
Examine it closely to see if its burned anywhere. This will occur at
the position the little holes are in the diaphragm.
>
> From my description, and assuming the other cells are in not as good
status,
> as the one I took apart, would you say that I have to replace the
diaphragms
> ?
It looks like it! Don't worry - you can do it!
>
I think you should split the remainder of the cells in this speaker to
assess the damage.
Once we know how bad / good they are we can decide what action to take.
Let me know how you go.
Best Regards
Danny Bekhor
"r_mac...@my-deja.com" wrote:
>
> G'day Danny,
>
> > I never managed to thank you for the email below. I was constantly on
> > business trips, and even now I am writing to you away from home in
> between
> > flights.
> >
>
> I know the feeling, I travel a lot in my "normal" work, pain in the
> backside isn't it? What country are you in??
When I am home, I am writing to you from Israel ....
> The plastic matrix will not (or at least, should not) be separate to
> the stators. They are bonded together and have to be removed as a unit.
Yes. I confirm that this is indeed the case.
> >From what you describe, the cells will need to be repaired rather than
> vacuumed. This is not difficult if you take it a step at a time.
Yes. I am more than happy to take it slow, and do one step at a time. Boy,
am I happy I bought these speakers. It's a great experience to learn how
they are built and operate.
> Its good practice to restore all of the cells rather than just fix the
> faulty ones, but I'll leave
> this to you.
Well, I started with the upper cell on one of the speakers. It was the
easiest one to work on since I had very few soldering point to un-solder.
> NOTE, there is a spacer between each post that the screw passes through
> ... Later models (white or cream matrix) don't have these spacers, the
> post is moulded to the correct height.
Mine are cream matrix, and you're right, no spacers.
> You should now be able to see the offending damage. Expect a hole in
> the diaphragm and possibly some charring of the stator.
OK, here's what I found :
First of all, there were 5 rather small holes in the diaphragm (a diameter
of 0.5-2 mm). Note that this cell is note a problematic one (no fireworks).
In addition to the above, there were many many (more than 20) tiny burns on
the diaphragm (no holes, though).
Second, although generally, the diaphragm was tight, on the edge of the cell
(where it is glue to the stator) at one corner, there was an air gap. as if
someone used a knife and cut the diaphragm close to the edge of the cell.
It's a 2" or so of an air gap, and it's a 1-2 mm wide.
The diaphragm was not as dirty as I thought it would be, but then again, it
could use some cleaning (how ?)
I was rather surprised to notice that the holes in the stators were not
fully "opened". As if there's some sort of a large sticker which blocks the
holes. Actually, this sticker does not fully block the holes. It allows air
and music to somehow flow through it .....
Also, this "sticker" (or should I call it "The inside of the stator" ), was
not too clean. Again, it could use some sort of cleaning or dust wiping ...
> IMPORTANT..Also check the bond between the matrix and the stator.
> Sometimes this fails causing the stator to bow inward. This reduces the
> air gap and leads to flashover. If this is the case it can be repaired
> with super glue or similar.
No problem on the one cell I took apart.
> You will need to scrape of the carbon around the charred area of the
> stator until it is back to normal material. You can then varnish the
> damaged area with high voltage varnish or you can spray 3 or 4 coats of
> conformal coating over this area. This is available from any
> electronics store.
I'm beginning to loose you ......
From my description, and assuming the other cells are in not as good status,
as the one I took apart, would you say that I have to replace the diaphragms
?
> Before I describe how you should replace the diaphragm, it may be better
> to get to this stage so that the damage can be properly assessed.
>
> Let me know what you find.Best Regards and good luck
>
> Rob
>
Well, many many thanks for your help thus far.
I look forward to your email.
Best Regards
Danny
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>
> _____________________________________________________________
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i...@netvision.net.il
Hi Rob
This evening I disassembled the remaining cells on the first speaker. I
followed your instructions carefully and marked every wire with a sticker
concerning it's position.
Here what I have found :
2nd cell from the top - nice, nice indeed, a much better condition from the
1st one from the top described in my previous email.
There is only one 1 mm hole, and the diaphragm seems to be tightly held in
place. I am not sure, but in one of the corners the diaphragm is just a
little little not as tight. This is probably fixable with a hot blower or
something. I don't think this diaphragm should be replaced. And yet, if I
should really replaced all the other diaphragms on this speaker, maybe this
one should be replaced as well ....
3rd cell from the top - BAD, real BAD. This is the cell that causes the
fireworks. The diaphragm is torn exactly where I saw fireworks and there's a
3" by 0.5" opening ...... I am not sure how this opening was form. I see
one hole in this area. Is it possible I was vacuuming the cell to
aggressively at this location ....god knows ....
The Lower panel is in a rather ok situation, not to far for number 2 from the
top, but I guess it must be replaced due to the diaphragm being split at the
suspended edge ....
>> From my description, and assuming the other cells are in not as good status, as the one I took apart, would you say that I have to replace the
diaphragms ?
>It looks like it! Don't worry - you can do it!
Well it's party time .... What's next ???
Best Regards
And many many thanks
Danny
r_mac...@my-deja.com
i...@netvision.net.il wrote:
G'day Danny,
You seem to be enjoying this!!
> Here what I have found :
>
> 2nd cell from the top - nice, nice indeed, a much better condition
from the
> 1st one from the top described in my previous email.
>
> There is only one 1 mm hole, and the diaphragm seems to be tightly
held in
> place. I am not sure, but in one of the corners the diaphragm is just
a
> little little not as tight. This is probably fixable with a hot
blower or
> something. I don't think this diaphragm should be replaced. And yet,
if I
> should really replaced all the other diaphragms on this speaker,
maybe this
> one should be replaced as well ....
>
I'll have to leave this to your judgement Danny, Perhaps you could do
the really bad 2 first to get a bit of experience, but the procedure
I'll describe will allow you to re-diaphragm the four panels in one go.
This ensures that the tension is the same on all of them.
Using the procedure I've developed, it only takes a few minutes extra
to cover the additional 2 cells.
> 3rd cell from the top - BAD, real BAD. This is the cell that causes
the
> fireworks. The diaphragm is torn exactly where I saw fireworks and
there's a
> 3" by 0.5" opening ...... I am not sure how this opening was form.
I see
> one hole in this area. Is it possible I was vacuuming the cell to
> aggressively at this location ....god knows ....
>
As you saw a firework display in the region of the split I'd say it was
there from the beginning.
As this appears to be the worst panel, can you see any burning around
the edges of the holes in the stators? Look carefully on the inside and
on the outside particularly where there are holes in the diaphragm.
This goes for both stators on all cells you are going to cover.
It's important that you find any areas where the insulation has broken
down on the stator. These are what has allowed the high voltage to arc
from stator to stator, burning a hole in the diaphragm.
If the insulation is not fixed, they may arc across from stator to
stator burning a hole in your nice new diaphragm!
See if you can obtain any high voltage varnish locally. This is most
likely to be used in electric motor rewind and transformer shops. If
this is too hard to get you can use conformal coating from an aerosol.
You can use this to touch in any damaged areas. make sure you scrape
off any burned material first.
This is the ideal time to temporarily clamp the two halves together
without a diaphragm and do a high voltage breakdown test. If you don't
have access to high voltage equipment or are unsure how to avoid
electrocuting yourself (just joking), don't do it.
The object of this is to see if the cells will withstand around 12-15
kv without arcing. If you can't do this, don't worry about it.
Whilst I can describe the diaphragm tensioning procedure in this forum,
I can't include pictures. Therefore, to make this a lot easier to
follow, it would be better to email you some diagrams on how to tension
the film and how to apply it to the ESL cell. Are you able to read
Coreldraw 8 or Adobe files? If not let me know what type of files you
can open.
I'll also send the instructions for making the diaphragm conductive.
The other thing you will need is the proper gauge film, coatings,
tension scale and adhesives.
If you are unable to access these locally I can supply them. You could
email me on the address below for prices etc.
If anyone else has been following this discussion and would like to
continue with it, you can email me on robmac...@iinet.net.au I'll be
happy to pass on whatever info you wish.(as long as it's not the
formula for our coating!!)
Best Regards