Hey all, One more question...are the stock ML CLS wired with HV on diaphragm or Center Tap of step up transformer? Safer bet seems to be on the diaphragm...I have schematic from Rehorst ESL which has HV bias on CT of transformer, while Jazzman ESL has HV bias on diaphragm.
Aside from safety, does it make a big difference?
Aside from safety, does it make a big difference?
For the Best sound
I well be the frist to say that if you have a dog or a baby that may pee on your ESL.....An most DONT... you better get the earth in the Audio side of the setup transfourmers......but for all other its full of noise!...An the bias AC has no place on the audio side of the stepup tranfourmers.. at the centap or any other place... for good sound.. Bias feeds only the Mylar..ONE red wire!.you can see in the pic of the CLS i have, Who elce here has a pr of CLSs? one side is on the neg come in from the amp only gose to one of the panels.
the otherside get the full winding...
. I have had my CLS setup this way for years an thay can be driven to full output with a 100watt tube amp an sound sweet.... I redo all the ML panels bias feeds....No earthing An no bias on the setup tranfourmers just to the mylar...goodluck
I well be the frist to say that if you have a dog or a baby that may pee on your ESL.....An most DONT... you better get the earth in the Audio side of the setup transfourmers......but for all other its full of noise!...An the bias AC has no place on the audio side of the stepup tranfourmers.. at the centap or any other place... for good sound.. Bias feeds only the Mylar..ONE red wire!.you can see in the pic of the CLS i have, Who elce here has a pr of CLSs? one side is on the neg come in from the amp only gose to one of the panels.
the otherside get the full winding...
. I have had my CLS setup this way for years an thay can be driven to full output with a 100watt tube amp an sound sweet.... I redo all the ML panels bias feeds....No earthing An no bias on the setup tranfourmers just to the mylar...goodluck
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OK. I have finished the two power supplies all set up and tested. But I have one question that just doesn't seem right. I am using the Enco D50, and checked everything - input voltage is 1.1VDC to 11.5VDC. Perfect. The 1.1VDC input yields around 450VDC out of the D50. My DMM only goes to 1000V, so I turned the pot and easily got to 1000v and stopped - still had plenty of knob left to go all the way to around 5000V. Perfect.
Thing is, when I put the probe on the other side of the two 10Meg ohm resistors (in series), I am dropping quite a bit of voltage - at 1.1V into the DC50, I get 450V out of the D50, and about 150V after the two 10Meg resistors. Now I have nothing after these two 10meg ohm resistor to draw current to drop voltage.....this has me stumped...am I missing something elemental here? How can I be dropping that voltage not connected to anything? I am measuring between this before and after two 10Meg resistors reference to the bias supply Ground.
Thing is, when I put the probe on the other side of the two 10Meg ohm resistors (in series), I am dropping quite a bit of voltage - at 1.1V into the DC50, I get 450V out of the D50, and about 150V after the two 10Meg resistors. Now I have nothing after these two 10meg ohm resistor to draw current to drop voltage.....this has me stumped...am I missing something elemental here? How can I be dropping that voltage not connected to anything? I am measuring between this before and after two 10Meg resistors reference to the bias supply Ground.
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Find the load
Have you considered the loading effect of your DMM ? Typically this can be 10 Meg ohms.
Have you considered the loading effect of your DMM ? Typically this can be 10 Meg ohms.
OK, fired everything up - sounded OK, a bit distorted. I noticed that if I didn't charge up the CLS panels for a 30 seconds or so first, I would blow the 3A slo Blo fuse I have on the Amp input of the power supply after connecting amp / turn up preamp.
Anyway, I played around with different amps - my Aleph 5 clone, an Push Pull EL84 amp, and my Krell Clone - all sounded a bit distorted at higher volumes, and needed to really turn up the volume on my pre to get any volume at all. Maybe needs new coating?
All in all a bit disappointed. I know its the ML CLS Panel (I bought it used, and previous owner said they were a bit "worn") and not anything on the power supply or anything else...Anyway, I stashed it away until I have some free time. I my split the stators and wipe off the mylar and reapply some fresh conducting film coating someday.
Thanks for all the help!
Anyway, I played around with different amps - my Aleph 5 clone, an Push Pull EL84 amp, and my Krell Clone - all sounded a bit distorted at higher volumes, and needed to really turn up the volume on my pre to get any volume at all. Maybe needs new coating?
All in all a bit disappointed. I know its the ML CLS Panel (I bought it used, and previous owner said they were a bit "worn") and not anything on the power supply or anything else...Anyway, I stashed it away until I have some free time. I my split the stators and wipe off the mylar and reapply some fresh conducting film coating someday.
Thanks for all the help!
I know that older Martin Logans have issues with the coating, but this would not cause distortion, just lower output.
If i am understanding your setup correctly, you are using 2 of the Antek transformers to try and drive the CLS full range. Remember, the voltage input of the Antek's is very limited below 200Hz. Perhaps the distortion(and fuse blowing) is because the cores are saturating as the volume is turned up.
If you put your ear next to the Anteks while the volume is turned up, can you hear/feel them buzzing in sync with the distortion?
If your preamp has a bass control, you might try turning it all the way down to see if this alleviates some of the distortion you are hearing. Or, better yet, use an active crossover to feed it only frequencies about 300Hz. Then see if you can play it louder without distortion.
I had planned on them being used for 250hz and higher, so this could work. I could also add a 200uf cap in series to have hi pass only.
Still wouldn't mind tearing into the panels to recoat...
The 3A fuse blows soon after I apply a signal to the amp taps. I found that If I let the panels sit for a few seconds (20 - 30) to get them up on charge, then apply signal, then the fuse does not blow.
I also found that at highish volume, my amp cuts out, until I lower the volume. Now this is an Icepower 1000ASP amp with 1000w@4ohms. Is it possible this panels can bring it down to its knees? I also tried my Aleph 5 clone and it didn't fare that much better, but didn't shut down, as there is no protective circuitry...
I can try just sending 250hz and higher signal to see if it still distorts.
The original CLS power supply and transformer enclosure had a series of 10uf caps, 10R resistors and a pair of inductor coils, which I do not have...maybe a 3rd order high pass? The original specs were down to 45hz
Still wouldn't mind tearing into the panels to recoat...
The 3A fuse blows soon after I apply a signal to the amp taps. I found that If I let the panels sit for a few seconds (20 - 30) to get them up on charge, then apply signal, then the fuse does not blow.
I also found that at highish volume, my amp cuts out, until I lower the volume. Now this is an Icepower 1000ASP amp with 1000w@4ohms. Is it possible this panels can bring it down to its knees? I also tried my Aleph 5 clone and it didn't fare that much better, but didn't shut down, as there is no protective circuitry...
I can try just sending 250hz and higher signal to see if it still distorts.
The original CLS power supply and transformer enclosure had a series of 10uf caps, 10R resistors and a pair of inductor coils, which I do not have...maybe a 3rd order high pass? The original specs were down to 45hz
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Adding a cap in series to form a hi-pass doesn't work particularly well on ESLs since the impedance of the transformers varies widely with frequency. I would recommend using an arrangement similar to what Acoustat used with the Spectra 11(see attachment) where they have a 10 ohm 50Watt resistor shunted across the transformer primary to give the crossover capacitor a nice solid load to work against. In your case, a 15ohm shunt resistor and 47uF series capacitor should put you 3dB down near 250Hz.
You might build yourself a neon light charge indicator to determine the health of the coating and whether or not you have leakage in the panel that is drawing down the bias voltage. More details here:
http://www.diyaudio.com/forums/planars-exotics/153773-esl-technical-questions.html#post1958015
If the charge indicator shows you have a leaking panel, you might try washing the panel as tyu suggested to see if you can remove the leakage path.
This is curious behavior. Do you have the amp playing music at the time?
The 3A fuse you mention is on the ICE amp correct? Perhaps it is unstable with the big capacitive load. You might try upping the 1 ohm series resistance to 2 ohm and see if that helps. The 15 ohm shunt resistor mentioned above for the crossover would also help provide a more friendly load to the amplifier.
Not the panel, but the transformers. When the cores saturate, the amp load is reduced to just the 1 ohm series resistance and the resistance of the primary windings(which are just a fraction of an ohm). Not to many amplifiers like being driven hard into a 1-2ohm load.
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OK, I may be having amp issues due to saturating the cores, due to running the speakers Full Range from the amp, so I will try sending only 250hz and up to the panels to see if the amp can handle it better. If it is loud enough, and no distortion, I have solved my issue.
The neon bulb detector - I may go ahead a build one anyway - All the neon bulbs I see are low voltage (12v), will this be an issue?
The neon bulb detector - I may go ahead a build one anyway - All the neon bulbs I see are low voltage (12v), will this be an issue?
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Yes, thanks tyu..I did not have that schematic - that was the last piece of the puzzle for the stock ML CLS XO / bias circuit / stepup trannie box.
I have my Magnepan XO-1 crossover that sits between the amp and preamp. I have the cap in there for 380hz hi pass cutoff (for my 9k input impedance of my Icepower 1000ASP amp). If the plan is to use the CLS on HF anyway (over 250hz), I shouldn't need the internal XO that tyu has drawn, but at least I now have it.
I will try the panels at 380hz cutoff later today to see if it is any better, and also will install the Neon Bulb too to check the panels. I will leave the neon lamp on the external box, so I can always detect issues with the panels.
As a side note, I have built a Hi Power JLH Amp for ESL (about 50wpc @ 6ohms, class A) specifically for these panels (this amp is quite impressive BTW). That 1 ohm resistor on the amp input has me a bit worried... but the Aleph 5 handled it fine, and you can literally short the speaker out leads on an Aleph 5 with no issues (I won't try it, tho...)
http://www.tcaas.btinternet.co.uk/jlhupdate.htm
I have my Magnepan XO-1 crossover that sits between the amp and preamp. I have the cap in there for 380hz hi pass cutoff (for my 9k input impedance of my Icepower 1000ASP amp). If the plan is to use the CLS on HF anyway (over 250hz), I shouldn't need the internal XO that tyu has drawn, but at least I now have it.
I will try the panels at 380hz cutoff later today to see if it is any better, and also will install the Neon Bulb too to check the panels. I will leave the neon lamp on the external box, so I can always detect issues with the panels.
As a side note, I have built a Hi Power JLH Amp for ESL (about 50wpc @ 6ohms, class A) specifically for these panels (this amp is quite impressive BTW). That 1 ohm resistor on the amp input has me a bit worried... but the Aleph 5 handled it fine, and you can literally short the speaker out leads on an Aleph 5 with no issues (I won't try it, tho...)
http://www.tcaas.btinternet.co.uk/jlhupdate.htm
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The neon bulb or lamp you are looking for should look like the picture below.
I believe the 120V neon bulb modules from Radio Shack you mention contain this type, so should work fine.
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OK. Finished. I put the Neon Lamp in with .22uf 1000V cap (only one I have). Both lights blinks once every 25 sec or so at full voltage (5kv). I have the panels limited to 300hz and higher - no distortion, or any problems and plenty of SPL. Tomorrow, when I have the house to myself, I will try to see what higher volume sounds like - I am listening to David Gray - White Ladder - and it sounds incredible without any low end. Image is impressive. This may end up replacing my Tympanis...
I bought some 3" x 4' x 1" oak rails and sandwiched the panel ends together. The legs are shelf angles. I stained the oak panels with a Cherry stain we had left over...even the wife is impressed, which never happens.
Currently have them driven by a High Power JLH (JLH for ESL - Class A and about 40wpc) I built a few months ago and it sounds excellent.
I will leave the diaphragms in the panels as is for now, as I am enjoying them immensely just as they are.
I bought some 3" x 4' x 1" oak rails and sandwiched the panel ends together. The legs are shelf angles. I stained the oak panels with a Cherry stain we had left over...even the wife is impressed, which never happens.
Currently have them driven by a High Power JLH (JLH for ESL - Class A and about 40wpc) I built a few months ago and it sounds excellent.
I will leave the diaphragms in the panels as is for now, as I am enjoying them immensely just as they are.
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You do no the ML runs there CLS Bias at 3500-3700....but if you hear no sizel an the sound fine go for it....Can you set the bias?...or is it just set at 5k...i have a pr of CLS here an am looking for a nother pr of panels too stack...have you seen stack pr ?
An did you use the ML cap res. setup i posted as input for the tranfourmers?An what dose the bulb do?just tell you it works?
Thanks for your time
An did you use the ML cap res. setup i posted as input for the tranfourmers?An what dose the bulb do?just tell you it works?
Thanks for your time
Tyu,
Yes, original design is 3.5kv. I posted the power supply and bias circuit earlier in this thread. I have the Emco DC to HVDC converter with a pot to dial in anywhere between 400V to 5KV. One speaker has a little sizzle at 5kv when first powered up, then goes away. I do not leave the power supply on all all the time.
The bulb circuit was posted by Bolserst a few posts back...apparently, rapid flashing is not good - mine flashes once every 25 - 30sec, which, I hope, is good (indicates no leakage?).
Yes, original design is 3.5kv. I posted the power supply and bias circuit earlier in this thread. I have the Emco DC to HVDC converter with a pot to dial in anywhere between 400V to 5KV. One speaker has a little sizzle at 5kv when first powered up, then goes away. I do not leave the power supply on all all the time.
The bulb circuit was posted by Bolserst a few posts back...apparently, rapid flashing is not good - mine flashes once every 25 - 30sec, which, I hope, is good (indicates no leakage?).
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