I didn't want to trash someone elses post, I'm new to the whole forum thing. But I share Steve M's sentiments.
I took a second look at your original post. Whats happening is that the power supply is charging up, and once it reaches a certain voltage (it only takes a few seconds), its arcing, and the process starts over. The volume is low because the panels arent charging properly. Somewhere the insulation between the wire that charges the panel, and one of the wires that carries the signal, has been compromised, and the electricity is jumping across. You need to find out where this is happening. The spark will be visible. If you cant see it from the outside, you are giong to have to get inside. Unplug it for 30 minutes before you go to work on it, to allow the charge to dissipate. If I recall correctly, the sl3 has a big wood piece on the back with screws all the way around. Is this correct?
I took a second look at your original post. Whats happening is that the power supply is charging up, and once it reaches a certain voltage (it only takes a few seconds), its arcing, and the process starts over. The volume is low because the panels arent charging properly. Somewhere the insulation between the wire that charges the panel, and one of the wires that carries the signal, has been compromised, and the electricity is jumping across. You need to find out where this is happening. The spark will be visible. If you cant see it from the outside, you are giong to have to get inside. Unplug it for 30 minutes before you go to work on it, to allow the charge to dissipate. If I recall correctly, the sl3 has a big wood piece on the back with screws all the way around. Is this correct?
I also agree with nac134. You need to read the beginning of the post to understand what is the problem here. Hence why I suggest using this none intrusive test to see if the static charge does not reach the membrane. The test is audible which will allow you to hear where the discharge is happening the fastest. Any discharged area will produce little or no sound. The other areas will sound normal (with the music playing). Sometimes you need to hear what you can’t see.
It's not the stators you are going borrow the charge from, but the statically charge membrane. The stators on the ML's are very well insulated and I doubt anyone will get zapped from the stators unless they break the insulated coating. If anyone has been electrocuted from an electrostatic speaker it was not a Martin Logan as far as I have heard.
A mosquito zapper can also be used to charge the membrane if you don’t feel comfortable using the other panel. Just connect a crocodile clamp to the center feed on the mosquito zapper and lead the charge to the membrane using a test cable with a flat metal tip. Mosquito zappers can be purchased almost everywhere these days and are powered by a couple of AA batteries. They also produce thousands of volts but if handled carefully should not pose any harm to people.
BTW. Both these methods have been tested by myself on ML speakers with great success.
It's not the stators you are going borrow the charge from, but the statically charge membrane. The stators on the ML's are very well insulated and I doubt anyone will get zapped from the stators unless they break the insulated coating. If anyone has been electrocuted from an electrostatic speaker it was not a Martin Logan as far as I have heard.
A mosquito zapper can also be used to charge the membrane if you don’t feel comfortable using the other panel. Just connect a crocodile clamp to the center feed on the mosquito zapper and lead the charge to the membrane using a test cable with a flat metal tip. Mosquito zappers can be purchased almost everywhere these days and are powered by a couple of AA batteries. They also produce thousands of volts but if handled carefully should not pose any harm to people.
BTW. Both these methods have been tested by myself on ML speakers with great success.
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You can use a cheap contactless voltage tester to check if there's a charge on the membrane, at least I can do it on my Diy speakers with M-L membranes.
Picasa Web Albums - Jonas - Drop Box
Yes, I know that these testers are for AC voltage, but they work on Esl:s also! (Maybe due the high voltage or the ripple from the HV ladder.
Picasa Web Albums - Jonas - Drop Box
Yes, I know that these testers are for AC voltage, but they work on Esl:s also! (Maybe due the high voltage or the ripple from the HV ladder.
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I disagree. You must first exclude any discharge (arcing) in the panel itself before poking around inside the electronics. ML speakers can discharge the static charge anywhere around the perimeter or where the spacers are located. This doesn't have to show up as a blue flash of light like in other electrostatics.
Once you confirm that the membrane can hold a charge over the whole panel you can proceed to investigate else where. This would involve dismantling the speaker.
Currently we only assume the popping sound is cause by arcing, but the other clue Per Anders said was the low volume from the panel. This is a typical sign when the static charge does not reach the membrane.
Some causes for this are:
1. The aluminum strip and wire at the bottom of the panel does not conduct the static charge to the membrane. (old conductive coating no longer works)
2. High humidity in the room has made the exposed spacers conductive thus draining the static charge to the stators. (de-humidifies will fix this)
3. Some one got water on the speaker itself and this has run down the membrane into the bottom spacer. (in 2 to 3 weeks it might start working again)
4. The speaker has taken on a new roll as a giant mosquito zapper and is finally saturated with insects. (I suspect Per Anders thought about this when he vacuumed the panel)
Once you confirm that the membrane can hold a charge over the whole panel you can proceed to investigate else where. This would involve dismantling the speaker.
Currently we only assume the popping sound is cause by arcing, but the other clue Per Anders said was the low volume from the panel. This is a typical sign when the static charge does not reach the membrane.
Some causes for this are:
1. The aluminum strip and wire at the bottom of the panel does not conduct the static charge to the membrane. (old conductive coating no longer works)
2. High humidity in the room has made the exposed spacers conductive thus draining the static charge to the stators. (de-humidifies will fix this)
3. Some one got water on the speaker itself and this has run down the membrane into the bottom spacer. (in 2 to 3 weeks it might start working again)
4. The speaker has taken on a new roll as a giant mosquito zapper and is finally saturated with insects. (I suspect Per Anders thought about this when he vacuumed the panel)
Per-Anders,
Your problem might be due to the high-voltage step-up transformer contained within each speaker. If this transformer has turns which have become shorted this could produce both the 'pop' noise and the reduced panel volume. Temporarily swapping this transformer with the identical one from the other speaker would prove or disprove this possibility.
Your problem might be due to the high-voltage step-up transformer contained within each speaker. If this transformer has turns which have become shorted this could produce both the 'pop' noise and the reduced panel volume. Temporarily swapping this transformer with the identical one from the other speaker would prove or disprove this possibility.
Hi Per Anders
I have the exact same problem with one of my dad’s SL3 speakers.
I just found this forum treed when I searched for some information about Martin Logan, and I saw that you also live in the same town as me, I was thinking about if this could be some kind of virus?
Therefore I’m very interested to hear if you managed to solve this problem?
Dan Tibell
I have the exact same problem with one of my dad’s SL3 speakers.
I just found this forum treed when I searched for some information about Martin Logan, and I saw that you also live in the same town as me, I was thinking about if this could be some kind of virus?
Therefore I’m very interested to hear if you managed to solve this problem?
Dan Tibell
Hey all, I have just acquired some old CLS Panels, and have built a bais and power supply - a hybrid from Jazzman's site and Mark Rehorst's site. A 20VDC Laptop power Supply to a LM317 Voltage regulator to a Emco DC50 DC to HVDC converter to get the 5KV Bias (a la Rehorst). Works great. The Audio Transformer is a pair of 120V - 6V transformers (Antek AN-1206, a la Jazzman).
My panels are low output and a bit distorted. My plan is to open the panels and clean / recoat them. I hope that the mylar is intact and still glued all around.
My panels are low output and a bit distorted. My plan is to open the panels and clean / recoat them. I hope that the mylar is intact and still glued all around.
I'm anxious to hear your impressions of how they sound once you get the panels refurb'd. I've only tried the smaller AN-506 Antek's driving hybrid panels above 200 hz with very close d/s spacing and 48db/oct crossover cutoff. The larger [100VA] AS-1206's should perform much better-- still, I'm thinking the d/s spacing would be wider on full range CLS panels, so I'm wondering if the 75:1 step-up you'd get from a pair of those Anteks would be sufficient for decent output with the greater d/s spacing. If you don't get the efficiency you want after the panel refurb, you might try wiring up four of those Anteks (all inputs parallel and outputs in series), which would double the step-up ratio. BTW, when you take those panels apart for refurb, I would like to know the d/s spacing if you can measure it. Good luck with your project!
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I want to try the panels at 200Hz and higher before I tear into them. The transformers may be overwhelmed by driving them full range, causing the distortion. As Bolserst indicated, these AN-1206 transformers cannot drive the panels full range. The distortion could be due to these trannies saturating, and if left to run 200hz and higher, they may play fine, with no distortion, and plenty loud.
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Even wired for full range, they should sound good at low volume (below saturation)-- if they don't, that would suggest other problems-- like a deteriorated diaphragm coating or loose diaphragm tension or a leak path draining charge of the diaphragm.
I have opened a lot of Ml panels. If you open the cls panels you well need to redo the mylar...never new any one that got a cls panel open without a rip...even the 12" wide rip if your not real caful...the new panels like the Ascent up the line are diff..you can pop them open eze..i have some pic posted of 12"panels..you mit have seen....have you washed the panels this can help with dust...this is the frist thing i do when i get a pr....the only reason that panels die is the bias feeds only on one side..i run new feeds up the left an right sides of the panel, this give 2-3 more out put pr panel...goodluck
I will stay on my current CLS Thread. When I saw Per Anders discuss opening his Martin Logan Panels to correct his diaphragm, I jumped in - sorry.
I will watch this thread for further progress.
http://www.diyaudio.com/forums/planars-exotics/203993-martin-logan-cls-power-supply.html
I will watch this thread for further progress.
http://www.diyaudio.com/forums/planars-exotics/203993-martin-logan-cls-power-supply.html
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