Hello All,
Well much has happened since I built my first ESL's earlier this year (the bug has bitten hard!) but I have now an issue.
I have built about 10 panels and I seem to have a 33% failure rate and the failure is usually the same, a constant steady approximately 2 clicks per second sound. The source of the failure is definitely with the panels construction, but exactly what I can not pin point!
Yesterday I constructed 3 panels, and one failed making the sound as I descibed earlier. since this the exact problem/panel failure we had during another run I would like to know what exactly is the source of the failure so I can correct this.
we are at the point where we can simply tear it apart and build another, but I would really like to correct the problem and learn just whats the cause....?
Thanks
Doc
Well much has happened since I built my first ESL's earlier this year (the bug has bitten hard!) but I have now an issue.
I have built about 10 panels and I seem to have a 33% failure rate and the failure is usually the same, a constant steady approximately 2 clicks per second sound. The source of the failure is definitely with the panels construction, but exactly what I can not pin point!
Yesterday I constructed 3 panels, and one failed making the sound as I descibed earlier. since this the exact problem/panel failure we had during another run I would like to know what exactly is the source of the failure so I can correct this.
we are at the point where we can simply tear it apart and build another, but I would really like to correct the problem and learn just whats the cause....?
Thanks
Doc
I'm assuming that the clicking is the result of a tiny arc somewhere inside the panel. Probably somewhere on the frame particularly where the polarizing voltages and drive are applied. Perhaps you can see it occurring in a dark room or if you increase the available current from the HV supply.
Did you do a High Yoltage stress test of the whole surface of the stator before you assembled it?
What happens if you lower the bias voltage?
It seems that there may be some leakage of the stator coating and is arcing somewhere.
Does the diagphram stay stable or does it collapse to one of the stators and then snap back ?
jer
What happens if you lower the bias voltage?
It seems that there may be some leakage of the stator coating and is arcing somewhere.
Does the diagphram stay stable or does it collapse to one of the stators and then snap back ?
jer
Both reasonable questions, first i don't think it is arcing since I have experienced this bacon sizzling sound. This sound remains constant throughout the panel and no arcing is seen in the dark.
Jer, I have done the Arc test in the past however I read on this forum that sanders believed an uncoated /insulated panel would work fine. To answer your question with regards to the diaphragm collapse...I have seen that issue as I had one panel fail when i tried to salvage a panel by "hand stretching a corner that peeled up".....it was visibly stuck to one side.
The leakage sound plausible but I built 3 in a row all exactly the same, could some of the Licron possibly leak past my 1/4" mask and is shorting against the stator?
Jer, I have done the Arc test in the past however I read on this forum that sanders believed an uncoated /insulated panel would work fine. To answer your question with regards to the diaphragm collapse...I have seen that issue as I had one panel fail when i tried to salvage a panel by "hand stretching a corner that peeled up".....it was visibly stuck to one side.
The leakage sound plausible but I built 3 in a row all exactly the same, could some of the Licron possibly leak past my 1/4" mask and is shorting against the stator?
Yes ,Jerry ,overspray can be a Factor, As it is something that I try to keep control of by heavily masking every thing before spraying the coating, it is very undetectable by sight.
Since it is permanent I have not yet had the chance to test if any solvents can/or will wash it off.
I have used Denatured alcohol to clean them with know degradation in the coating.
I have had a similar issue happen as when I started to raise the bias it would crackle through the midrange of the voltages until I get to full voltage and then then the crackling stopped.
I was then able to vari the bais voltage without the crackling throughout its range 0v to 7kv.
I have not yet determined the reason for this yet except that there must be some leakage some where and when the voltage gets high enough the difference in the imbalance becomes low enough to stop the arcing.
I have found that even after discharging the panels that they still worked and it took them a few days of no bias voltage at all to finally stop producing sound of any kind until the bias was re-applied.
This is most prevalent on my White painted panels as I can't seem to use a bias more than about 3.2kv because the white paint starts to conduct at levels above this regardless of its thickness.
And they start to click as you are describing and lowering the bias voltage on those panels makes it stop.
This is why I had stressed that you can't have the coating to thin and more is better providing that the pigments don't cause it to conduct.
Even with such a small leakage this can happen and it will sound large as it is moving the whole diagphram.
You may not be able to detect it by eyeball and will be very hard to do so.
Some of them I could see and a lot of them I couldn't.
And it just seemed that the more clear coating I had put on, the better it got,until a certain point of course.
Also I just remembered that you are in Florida and that the humidity may be an issue as well,But this is something that you will have to determine by the use of your other panels as a control.
Does it do it all of the time or does it eventually stop?
jer
P.S. Any kind of sharp edge or points are the biggest culprit regardless of how thick the coating is sometimes, as my worst mishap and arc over occurrd at the edge and was a from a sharp point that was buried in some insulation but not deep enough apparently.
Since it is permanent I have not yet had the chance to test if any solvents can/or will wash it off.
I have used Denatured alcohol to clean them with know degradation in the coating.
I have had a similar issue happen as when I started to raise the bias it would crackle through the midrange of the voltages until I get to full voltage and then then the crackling stopped.
I was then able to vari the bais voltage without the crackling throughout its range 0v to 7kv.
I have not yet determined the reason for this yet except that there must be some leakage some where and when the voltage gets high enough the difference in the imbalance becomes low enough to stop the arcing.
I have found that even after discharging the panels that they still worked and it took them a few days of no bias voltage at all to finally stop producing sound of any kind until the bias was re-applied.
This is most prevalent on my White painted panels as I can't seem to use a bias more than about 3.2kv because the white paint starts to conduct at levels above this regardless of its thickness.
And they start to click as you are describing and lowering the bias voltage on those panels makes it stop.
This is why I had stressed that you can't have the coating to thin and more is better providing that the pigments don't cause it to conduct.
Even with such a small leakage this can happen and it will sound large as it is moving the whole diagphram.
You may not be able to detect it by eyeball and will be very hard to do so.
Some of them I could see and a lot of them I couldn't.
And it just seemed that the more clear coating I had put on, the better it got,until a certain point of course.
Also I just remembered that you are in Florida and that the humidity may be an issue as well,But this is something that you will have to determine by the use of your other panels as a control.
Does it do it all of the time or does it eventually stop?
jer
P.S. Any kind of sharp edge or points are the biggest culprit regardless of how thick the coating is sometimes, as my worst mishap and arc over occurrd at the edge and was a from a sharp point that was buried in some insulation but not deep enough apparently.
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I have a similar problem before, and it comes from the power supply. In my case, one of the transformers that I connect back to back in the power supply is getting bad and eventually burnt. After I replace that burnt one, the problem goes away. You might try to check to see if your transformers are getting hot.
Wachara C.
Wachara C.
Hey Guys!
Good to hear from you all,
Jer, I would agree that it is likely a leak somehow from the Licron sprayed diaphragm to the front panel. Switching cables and power from the other channel revealed it was an isolated issue affecting only that panel, and since I am doing a production run of another 8 panels, I have several to test from. I am trying to figure this phenomena.
Oh BTW, Jer I the humidity level is very high....outside, however we were fortunate enough to have AC installed just after we got indoor plumbing, I was also getting a rash from the banana leaves.....LOL
Today I will play with the suggestions from Wachara C., and Charlie M with regards to the power supply. I don't actually believe this is the issue however since this is my second failure with the exact same symptoms I believe it could be related to the power connections to the spade connectors, or the panel itself...I will report back shortly from the banana republic as we all know as Miami.... LMAO
Jerry/Doc
Good to hear from you all,
Jer, I would agree that it is likely a leak somehow from the Licron sprayed diaphragm to the front panel. Switching cables and power from the other channel revealed it was an isolated issue affecting only that panel, and since I am doing a production run of another 8 panels, I have several to test from. I am trying to figure this phenomena.
Oh BTW, Jer I the humidity level is very high....outside, however we were fortunate enough to have AC installed just after we got indoor plumbing, I was also getting a rash from the banana leaves.....LOL
Today I will play with the suggestions from Wachara C., and Charlie M with regards to the power supply. I don't actually believe this is the issue however since this is my second failure with the exact same symptoms I believe it could be related to the power connections to the spade connectors, or the panel itself...I will report back shortly from the banana republic as we all know as Miami.... LMAO
Jerry/Doc
When you say you switched out the cables and power, does that mean you also switched out the step-up transformers? I'm very curious about your clicking problem and hoping the source isn't a arcing across the transformer windings.
My concern is that I had only briefly sound-tested those Antek trannys before posting them on my web page. They sounded great and didn't go up in smoke when I momentarily pushed the volume to insane levels-- but I also haven't thoroughly tested them over time in real-world use. I would not want to continue recommending those trannys if it turns out they are the source of your arcing problem.
Keep us posted, please, Jerry.
Let me clarify, I merely swapped cables (using XLR cables) to each speaker. The transformers have been working flawlessly, even in my best attempts to overpower them at extremely loud volumes.... I can testify that I gave been running these trannies for several months nearly every day, and loud as hell on the weekends.....They are articulate and definitely a great value. I did however change to an 8ohm power resisitor (no noticeable high frequency loss as one would expect.... Awesome!!
Now moving forward....with that clicking panel, I have observed that once it is biased and then the power is removed, the clicking will stop and the speaker will sound perfect. (BTW for those reading this an wondering what I am talking about ESL's act as large capacitors).
I know it may be easier to just rebuild this panel....but I have a feeling I/we will see and most definitely hear this issue again!
Regards,
Jerry
Now moving forward....with that clicking panel, I have observed that once it is biased and then the power is removed, the clicking will stop and the speaker will sound perfect. (BTW for those reading this an wondering what I am talking about ESL's act as large capacitors).
I know it may be easier to just rebuild this panel....but I have a feeling I/we will see and most definitely hear this issue again!
Regards,
Jerry
have you tried giving the panel a good vacuum on both sides? what you are discribing sounds like the panel is arcing because when you disconnect the swupply the problem is resolved. any small bit of matter which bridges the stator to the charged side of the diaphragm will conduct easily. any bolts or screws through the stator could also be you shorting point. you may well have to bite the bullet and rebuild if you cannot locate the source of the short. check to see if there is any chance there is any diaphragm with charge making it to the stator spacers. you are going to have to play dective and the old process of elimination of possibilities. best of luck and best regards moray james.
Wachara C., I am using Charlies configuration which is approximately 2.7 KV.
James, I would also tend to agree that the root cause is most likely a leak between the diaphragm and front panel.
With these two suggestions I will use a leaf blower remove any possible debris, and reduce the power off the ladder taps if unsuccessful with the first solution.
James, I would also tend to agree that the root cause is most likely a leak between the diaphragm and front panel.
With these two suggestions I will use a leaf blower remove any possible debris, and reduce the power off the ladder taps if unsuccessful with the first solution.
I was not aware that you are using XLR cables to feed the panels.
I like the Idea but it seems that this would add a lot of extra residual capacitance therefore wasted amplifier power (depending on the type of cable).
Also I wonder if the connectors could handle such high voltages as they are quite tightly spaced and is the reason I never tried it, But if it works well that is very cool!
When you start cranking these things up you are getting in excess of 15kv P-P,I have pushed mine past 25kv and was when the one panel broke down and ignited (oops,he,he)!
This would/could also lower the resonate frequency of the transformer closer to the audio band and can cause excessive voltages and an extreme load on the amp should you have a pulse at that frequency (tesla action).
This was my issue last year when I was testing my transformers and it created much havoc as crossover distortion set in due to the very high current demand.
Second,What are you using for cable is it may be breaking down at such high voltages.
What happens when you try a different cable?
You did not specify if it is happening while it is sitting idle or while it was playing.
It seems that if it is just the one panel (or few) it may be the panels at fault .
Just a few things to consider.
jer
I like the Idea but it seems that this would add a lot of extra residual capacitance therefore wasted amplifier power (depending on the type of cable).
Also I wonder if the connectors could handle such high voltages as they are quite tightly spaced and is the reason I never tried it, But if it works well that is very cool!
When you start cranking these things up you are getting in excess of 15kv P-P,I have pushed mine past 25kv and was when the one panel broke down and ignited (oops,he,he)!
This would/could also lower the resonate frequency of the transformer closer to the audio band and can cause excessive voltages and an extreme load on the amp should you have a pulse at that frequency (tesla action).
This was my issue last year when I was testing my transformers and it created much havoc as crossover distortion set in due to the very high current demand.
Second,What are you using for cable is it may be breaking down at such high voltages.
What happens when you try a different cable?
You did not specify if it is happening while it is sitting idle or while it was playing.
It seems that if it is just the one panel (or few) it may be the panels at fault .
Just a few things to consider.
jer
I found the problem!!!
It was arcing from the front panel through to the diaphragms center conductor wire, this was barely visible from the top spade connectors.
Jer, I know it sounds unlikely to use XLR connectors however, they have worked well. after quite a bit of experimenting with different cables an removing the ground shields to run separate independent contacts has resulted in impedance issues observed with several cables ultimately using standard cables are unstable.
The XLR connectors are perfect...as long as you heat shrink the ends well. We are using my buddies idea of making our own wires by braiding together three 10 foot lengths of 16G multi stranded wire ti the XLR connectors. This not only works well but looks great!
Thanks for everybody's suggestions,
This will go a long ways since I have more to make!!
Doc/Jerry
It was arcing from the front panel through to the diaphragms center conductor wire, this was barely visible from the top spade connectors.
Jer, I know it sounds unlikely to use XLR connectors however, they have worked well. after quite a bit of experimenting with different cables an removing the ground shields to run separate independent contacts has resulted in impedance issues observed with several cables ultimately using standard cables are unstable.
The XLR connectors are perfect...as long as you heat shrink the ends well. We are using my buddies idea of making our own wires by braiding together three 10 foot lengths of 16G multi stranded wire ti the XLR connectors. This not only works well but looks great!
Thanks for everybody's suggestions,
This will go a long ways since I have more to make!!
Doc/Jerry
Jerry: I think that a vacuum is the way you want to clean your panels as it will with luck remove anything that should not be there while a blower could push matter into tight places and probably just blow dirt onto the panel. Good you found the problem. Keep in mind you can also wash your panels to clean them. I have washed a good number of old Acoustat panels that were stored in a garage open for years and were a mess and they came out great looking like new. The only thing you have to remember when washing panels is DO NOT USE DETERGENT as it WILL leave a film which is conductive. Keep the panels on edge so as not to stress the diaphragm with the weight of the water and you will be good to go. Best regards Moray James.
Hello James,
I was able to localize the problem as I wrote in my reply (#17),
I did however try the blower first.
The cleaning option is a great idea to remember. At one point during our build we were using cornstarch as a natural lubricant on the film stretcher which and we mistakenly got some on the opposite side. We took it outside and lightly hosed it down, and it worked perfectly fine. I never thought to use it as cleansing option and for dust and debris, rather than use it as an option to salvage a build with the possibility of producing a less than visually perfect panel!
Thanks for your suggestions,
Doc
I was able to localize the problem as I wrote in my reply (#17),
I did however try the blower first.
The cleaning option is a great idea to remember. At one point during our build we were using cornstarch as a natural lubricant on the film stretcher which and we mistakenly got some on the opposite side. We took it outside and lightly hosed it down, and it worked perfectly fine. I never thought to use it as cleansing option and for dust and debris, rather than use it as an option to salvage a build with the possibility of producing a less than visually perfect panel!
Thanks for your suggestions,
Doc
Great fix, Jerry. You sure are building a lot of panels.... going into business or just helping friends build speakers? Anyway, it's good to hear you solved the clicking problem and it wasn't the transformers-- I was pretty darned impressed with those cheap $13 toroids and feeling even better about them now.
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