Those of you who had tried out Licron Crystal, for how long have you had the bias voltage on since you coated your panels?
Just write down your experience.
1. How many hours have they been powered?
2. Bias voltage?
3. Spacing?
4. If you have had breakdowns, do you know the root cause?
From what i understand the oldest panel is about 12 years old by now?
I have not tried it myself, i must be the last one...
Martin
Just write down your experience.
1. How many hours have they been powered?
2. Bias voltage?
3. Spacing?
4. If you have had breakdowns, do you know the root cause?
From what i understand the oldest panel is about 12 years old by now?
I have not tried it myself, i must be the last one...
Martin
I first started using Licron Crystal 7 years ago. However, I've replaced my panels twice during that time, experimenting with different stator materials and segmentation. My most used panel (not currently using it) played about10 hours per week on average for about 5 years. The d/s spacing was .062 and bias voltage 2.7KV. Power to the bias supply was switched from the preamp so only on when the system was on. I never had any problems with the panels or noticed any degradation.
I have built many sets of ESLs using Licron Crystal with > 5 years on them, none showing any change in sensitivity.
Most were D/S = 0.07 in. with 3.5kV, however there are two full range panels using D/S = 0.12 with 5.2kV.
Most are setup to switch on and off with the preamp, however there are some where the HV is left on all the time.
The only failures of Licron Crystal conductivity I know of were related to prolonged exposure to direct sunlight.
Licron Crystal, and many other conductive coatings, are not 100% UV resistant.
Most were D/S = 0.07 in. with 3.5kV, however there are two full range panels using D/S = 0.12 with 5.2kV.
Most are setup to switch on and off with the preamp, however there are some where the HV is left on all the time.
The only failures of Licron Crystal conductivity I know of were related to prolonged exposure to direct sunlight.
Licron Crystal, and many other conductive coatings, are not 100% UV resistant.
I built my First ESL's (the Black Desktop model) in 2003 with the original Formula Licron 1755-10S and it was still on my original diaphragms when I documented refurbishing them in 2010.
I re-diaphragmed and coated one of the Units with the newer Crystal Formula 1756-8S to compare the two.
They both still played flawlessly until 2013 when I described burning them up due to stator coating failure and Extremely high voltage testing.
I typically ran a bias of 6.8Kv on them, and sometimes as high as 8.5Kv to 12Kv in some tests.
And as high as 20-25Kv p-p across the stator's when they caught fire after about 25 minutes constant playing under these conditions.
But I also had repeated the above test several times before that had finally given up as well.
I never experienced any peeling of the coating due to the forces being applied with either versions of the Licron coating.
When the one finally gave up the farm for the last time, Upon dis-assembly and inspection I was surprised to find the unit was the one that still had the Original Licron coating on it from when it was made in 2003!!
I started using the Newer Crystal Formula in 2010 when it First came out and those applications still work today.
In 2004 I had to take a break from the project due to Transformer issues and some stupid life mistakes in 2007.
During that time I had deliberately environmentally abused my original panels for 7 years just to see if the coatings would actually last that long until I could finally get some new transformers to continue with the project.
And that finally happened in 2010.
I mean "Extreme Summer Heat and Wintery Cold" in my car for several years with several layers of salt and road grime due to a rust hole I had in the rear wheel well as the stuff got slung all over the back of the inside of my 89 Formula Firebird.
And you know they still worked the Very First time I fired them back up in 2010 when I came back to DIYAudio and my ESL project.
I had not even taken them apart yet to inspect them and they just worked and still sounded great much to my amazement.
All of that is documented in the ESL (Diaphragm) Coating's thread (and many others) with many pictures showing the before and after conditions of the coatings of when I cleaned them.
Most of those post's can be found in the links of this post,
http://www.diyaudio.com/forums/plan...truct-cube-louver-acoustat-4.html#post3140847
I haven't had them exposed with 100% direct sunlight but they have had a good share of it in that 7 year period while laying in the back seat of my car and I never had any degradation of any kind yet.
FWIW !!
jer
P.S. I only had one little proplem with the original Licron cracking at times and that is explained here,
http://www.diyaudio.com/forums/plan...uctive-coating-esl-diaphragm.html#post3780413
I re-diaphragmed and coated one of the Units with the newer Crystal Formula 1756-8S to compare the two.
They both still played flawlessly until 2013 when I described burning them up due to stator coating failure and Extremely high voltage testing.
I typically ran a bias of 6.8Kv on them, and sometimes as high as 8.5Kv to 12Kv in some tests.
And as high as 20-25Kv p-p across the stator's when they caught fire after about 25 minutes constant playing under these conditions.
But I also had repeated the above test several times before that had finally given up as well.
I never experienced any peeling of the coating due to the forces being applied with either versions of the Licron coating.
When the one finally gave up the farm for the last time, Upon dis-assembly and inspection I was surprised to find the unit was the one that still had the Original Licron coating on it from when it was made in 2003!!
I started using the Newer Crystal Formula in 2010 when it First came out and those applications still work today.
In 2004 I had to take a break from the project due to Transformer issues and some stupid life mistakes in 2007.
During that time I had deliberately environmentally abused my original panels for 7 years just to see if the coatings would actually last that long until I could finally get some new transformers to continue with the project.
And that finally happened in 2010.
I mean "Extreme Summer Heat and Wintery Cold" in my car for several years with several layers of salt and road grime due to a rust hole I had in the rear wheel well as the stuff got slung all over the back of the inside of my 89 Formula Firebird.
And you know they still worked the Very First time I fired them back up in 2010 when I came back to DIYAudio and my ESL project.
I had not even taken them apart yet to inspect them and they just worked and still sounded great much to my amazement.
All of that is documented in the ESL (Diaphragm) Coating's thread (and many others) with many pictures showing the before and after conditions of the coatings of when I cleaned them.
Most of those post's can be found in the links of this post,
http://www.diyaudio.com/forums/plan...truct-cube-louver-acoustat-4.html#post3140847
I haven't had them exposed with 100% direct sunlight but they have had a good share of it in that 7 year period while laying in the back seat of my car and I never had any degradation of any kind yet.
FWIW !!
jer
P.S. I only had one little proplem with the original Licron cracking at times and that is explained here,
http://www.diyaudio.com/forums/plan...uctive-coating-esl-diaphragm.html#post3780413
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lLicron Looks like this is the real deal......thanks for the years of input...this is from real ESL bilders.......highly trusted...........well by me!
1756-8S - Techspray - Chemical | Galco Industrial Electronics
1756-8S - Techspray - Chemical | Galco Industrial Electronics
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Bolserst
I experienced UV exposure damage on QUAD ESL 63 in 1994, i had stripped them from cloth and grille and even protective foil.
3 panels on that speaker broke down quickly. So it's not only licron that has problems with UV. bear in mind the charge and OZON generation as well! Ozon and UV quite difficult task to manage. I have seen mylar foil in old speaker looking like a mesh. thousands of small holes. Probably due to age.
I wonder if mylar foil from early eighties was considerable less stable than todays foil?
Maybe the purity of the foil has been improved the last 35 years?
I experienced UV exposure damage on QUAD ESL 63 in 1994, i had stripped them from cloth and grille and even protective foil.
3 panels on that speaker broke down quickly. So it's not only licron that has problems with UV. bear in mind the charge and OZON generation as well! Ozon and UV quite difficult task to manage. I have seen mylar foil in old speaker looking like a mesh. thousands of small holes. Probably due to age.
I wonder if mylar foil from early eighties was considerable less stable than todays foil?
Maybe the purity of the foil has been improved the last 35 years?
My Mylar was probably made in the 80's sometime as I had got it in 1990 or so, and, I still have it and use it to this day.
The holes are most likely have been caused from Corona burns from the inadequate Stator coatings that were used back then.
For my Best ESL's the Window Screen Stator's were originally powder coated and then coated with clear acrylic when I refurbished them.
Even when I was testing them at very extreme voltages the air in the gap would ionize, but it never burned any holes in the diaphragm.
I can't say that for my original Painted WIndow Screen Stator's as the paint I used was white and became very conductive and arced a lot with any voltage not much over about 3.5-4kv.
That coating was quite thick and the more I added made no difference at all.
It used Titanium Dioxide as a pigment and so does any of the Gray primers or paints that are available, I suspect that this is the same type of gray coatings I have seen In pictures of the 57's.
And for the 63's I believe the clear stator coating just may be a little on the thin side although not as bad.
They didn't have the kind of high power amps that can produce the voltage swing with the current to back it, back then, like most everyone are using these days.
Also the practice of not using a primer and then clear coat as in the 63's is not good IMHO.
In my coating tests I have had plain clear acrylic paint lift off of my TIG rod test piece with enough static potential applied to it.
I should have posted those test pictures but it had pulled a perfectly round plug right out of the coating while creating stress cracks around the perimeter of the hole that was left.
The edges of the walls of the hole were perfectly square and sharp and looked like a bullet had went through a pane of safety glass.
No, This was not a burn hole as the evidence purely showed that this was a mechanical failure of the coating due to the static forces applied lifting the coating off of the sample at about 6-8Kv and above.
The idea of using such a high resistance stator coating limits of amount of punch through current that causes damage.
Even though the air can get ionized the small amount of heat it produce is dissipated instantly.
High current punch through causes the most damage.
I ran those Black PC ESL's at much higher voltage and never got any pinholes in the mylar like I did with my poorly painted stator's at test of <4Kv, bias or drive voltage otherwise.
FWIW
jer
The holes are most likely have been caused from Corona burns from the inadequate Stator coatings that were used back then.
For my Best ESL's the Window Screen Stator's were originally powder coated and then coated with clear acrylic when I refurbished them.
Even when I was testing them at very extreme voltages the air in the gap would ionize, but it never burned any holes in the diaphragm.
I can't say that for my original Painted WIndow Screen Stator's as the paint I used was white and became very conductive and arced a lot with any voltage not much over about 3.5-4kv.
That coating was quite thick and the more I added made no difference at all.
It used Titanium Dioxide as a pigment and so does any of the Gray primers or paints that are available, I suspect that this is the same type of gray coatings I have seen In pictures of the 57's.
And for the 63's I believe the clear stator coating just may be a little on the thin side although not as bad.
They didn't have the kind of high power amps that can produce the voltage swing with the current to back it, back then, like most everyone are using these days.
Also the practice of not using a primer and then clear coat as in the 63's is not good IMHO.
In my coating tests I have had plain clear acrylic paint lift off of my TIG rod test piece with enough static potential applied to it.
I should have posted those test pictures but it had pulled a perfectly round plug right out of the coating while creating stress cracks around the perimeter of the hole that was left.
The edges of the walls of the hole were perfectly square and sharp and looked like a bullet had went through a pane of safety glass.
No, This was not a burn hole as the evidence purely showed that this was a mechanical failure of the coating due to the static forces applied lifting the coating off of the sample at about 6-8Kv and above.
The idea of using such a high resistance stator coating limits of amount of punch through current that causes damage.
Even though the air can get ionized the small amount of heat it produce is dissipated instantly.
High current punch through causes the most damage.
I ran those Black PC ESL's at much higher voltage and never got any pinholes in the mylar like I did with my poorly painted stator's at test of <4Kv, bias or drive voltage otherwise.
FWIW
jer
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Hmm i am in the middle of again getting al my panels out of my quad. ESL63 since output was going down. i used licron as coating.. BUT i forgot to ad extra conductife layer under the aluminum strips that contact the membrane. i am not sure yet if it has eaten the licron away at that particular point. i added a graphite solution directly under the contact point. output increased. but if i measure them against a original panel i am still 2 db down. i then recoated the old panel over the graphite solution as well, and gained the last 2 dB. they are now exactly as loud as an original. but this whole thing still worries me. ALLOT since i want to get rid of them since i need money badly. but i definitely dont want to sell someone speakers that crap out after a year. since its still a shitload of money for a set of second hand speakers. i probable give them a 1 r 2 year warranty.
getting pissed
getting pissed
maybe i used to little ? since they look transparent. i cant measure any resistance either..... usually with 2 coins and a meter on 2M i should have a reading. somehow the coating vanished. not only at the point where the aluminum made contact. also in the middle of the membrane there is no reading on my meter. of course there is something since they do play. a benefit of having a coating with carbon is at least you can spot faults more easy
maybe i used to little ? since they look transparent. i cant measure any resistance either..... usually with 2 coins and a meter on 2M i should have a reading. somehow the coating vanished. not only at the point where the aluminum made contact. also in the middle of the membrane there is no reading on my meter. of course there is something since they do play. a benefit of having a coating with carbon is at least you can spot faults more easy
It's been my experience that one wet sprayed coat of Licron Crystal dries to an almost clear 2 microns thickness (cloudy if applied in high humidity). I've never applied any additional coupling between it and the bias supply contact and I've always used a full perimeter copper foil contact ring. I've not had any problems with this arrangement. A small local contact might be OK but I wouldn't be as confident with it.
Then again; I recall seeing a video of a ML panel being assembled at the factory where the contact was merely a wire taped in place on the diaphragm, and I was flabbergasted that ML would consider this a robust connection. And then later I saw photos of some other ML panels opened up, wherein the contact was a length of copper foil. I wonder if there might have been issues with ML's earlier panels that prompted them to use a foil strip on other panels.
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You may have used to little of the coating, I have had some earlier coated diaphragms do this when I First started using the Crystal version of Licron.
I also use a graphite charge ring painted on the diaphragm and never had a problem with it as well.
http://www.diyaudio.com/forums/planars-exotics/109789-esl-diaphragm-coating-7.html#post2142822
jer
I also use a graphite charge ring painted on the diaphragm and never had a problem with it as well.
http://www.diyaudio.com/forums/planars-exotics/109789-esl-diaphragm-coating-7.html#post2142822
jer
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Techspray literature states that the conductivity of Licron Cyrstal is unaffected by humidity. It's quite humid in Savannah during the summer months but I haven't noticed any sensitivity difference with changing seasons.
Licron is ITO or just IO based.
They don't say it now in their spec sheet but it used to many moons ago.
https://en.wikipedia.org/wiki/Indium_tin_oxide
https://en.wikipedia.org/wiki/Indium(III)_oxide
or TO2 but I am pretty sure it uses Indium,
https://en.wikipedia.org/wiki/Tin_dioxide
jer
They don't say it now in their spec sheet but it used to many moons ago.
https://en.wikipedia.org/wiki/Indium_tin_oxide
https://en.wikipedia.org/wiki/Indium(III)_oxide
or TO2 but I am pretty sure it uses Indium,
https://en.wikipedia.org/wiki/Tin_dioxide
jer
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i live near the sea, so humidity should not be an isue
well must be to thin coating i guess. but it just does not feels right to wait and see what happens i want to be fair and confident when i sell my speakers.
but i must say this time is the first time i checked every panel against a original in the testing jig. i keep the tested curves of every panel with there serial number in holmimpulse so if i ever get one back i can check the specs they left with.
well must be to thin coating i guess. but it just does not feels right to wait and see what happens
i want to be fair and confident when i sell my speakers.but i must say this time is the first time i checked every panel against a original in the testing jig. i keep the tested curves of every panel with there serial number in holmimpulse so if i ever get one back i can check the specs they left with.
Licron Crystal can not be Tin Oxide based.
1. It's harder than glass and sometimes used for metal polishing: if you try to smear polishing paste on a plastic film the latter will be scratched.
2. It's not soluble in water or organic solvents
3. It's really heavy i.e. it's density close to one of iron.
Good luck
sorry
"It" stays for SnO2 or tin dioxide or stannic dioxide.
1. It's harder than glass and sometimes used for metal polishing: if you try to smear polishing paste on a plastic film the latter will be scratched.
2. It's not soluble in water or organic solvents
3. It's really heavy i.e. it's density close to one of iron.
Good luck
sorry
"It" stays for SnO2 or tin dioxide or stannic dioxide.
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I have just finally found the original data sheet and it states that it is Tin Oxide.
http://datasheet.seekic.com/PdfFile/175/TechSpray_1755-10S200734.pdf
jer
http://datasheet.seekic.com/PdfFile/175/TechSpray_1755-10S200734.pdf
jer
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