I have been working on some 16"x48" panels....thay are crossover at 200h up to 20k....After haveing the Tranfourmer set up like most.....with the centertap grounded an one end of the winding going to the front an the other end of the winding going to the back of the panels..I found that when driven hard the panels would buzz...at frist i thought that this was just the wood i had the panels in....So i put in a diff. Tranfourmer panel set up...
You can see that with this setup the the whole Transfourmers winding is now used to drive the front of the panel only.....So you see the centap is out...Well there is No ESL panels that i can find that have Bias coting on the back side of the mylar...So driving the panel in the nom. way with the centap grounded the one end of the winding on the back has to work harder than the front winding....this makes the Tranfourmers pull harder an harder till it was buzzing... an made the panel buzz....Now this is not the frist time i have used this an have found this in other ESL speakers....so this is a time tested setup...I have put this set in Soundlab,Acoustats,Martinlogans...This is the frist time that with this setup i could hear how it helps the tranfourmer with over load....So what other Good thing dose this do....It give about 2-3db more output....an it takes the stress out of the transfourmers an thay can play louder...An it sounds vary good.....
For give my art...
Has anyone done this setup?
Thanks for any feedback
You can see that with this setup the the whole Transfourmers winding is now used to drive the front of the panel only.....So you see the centap is out...Well there is No ESL panels that i can find that have Bias coting on the back side of the mylar...So driving the panel in the nom. way with the centap grounded the one end of the winding on the back has to work harder than the front winding....this makes the Tranfourmers pull harder an harder till it was buzzing... an made the panel buzz....Now this is not the frist time i have used this an have found this in other ESL speakers....so this is a time tested setup...I have put this set in Soundlab,Acoustats,Martinlogans...This is the frist time that with this setup i could hear how it helps the tranfourmer with over load....So what other Good thing dose this do....It give about 2-3db more output....an it takes the stress out of the transfourmers an thay can play louder...An it sounds vary good.....
For give my art...
Has anyone done this setup?
Thanks for any feedback
Attachments
so you say
I still choose to keep things even and symetrical by using the center tapped version.
I think that the deal.....there not symetrical...maybe on paper...Or if you wind your own tranfourmer... or can spend the big $$$....but with all the ESL transfourmers i have there is a diff. in one winding An the other winding from the centap... an i well say most tranfourmers have this diff.
I have two panels that Arc.....One pops eze,little input...the other has to be push hard.
I am finding with this tranfourmer setup.....the center tap out...the one that pop all the time now has to be pushed harder....an the other stop Arcing...There arc is in the front of these panels .....This tell me that this diff. in the tranfourmer windings must have some thing to do with this....But as with all the mods i do.....you can go back...an see if the sounds better to you...it give better sound when in a two way ESL....the bass driver an the esl panel match better..with this littel more output of the panel...To me it sound like a SE tube amp....or like one of pass SE fet amps...
But this is just one mans O-pine ....newyeardiy,er
thanks for any input...
I still choose to keep things even and symetrical by using the center tapped version.
I think that the deal.....there not symetrical...maybe on paper...Or if you wind your own tranfourmer... or can spend the big $$$....but with all the ESL transfourmers i have there is a diff. in one winding An the other winding from the centap... an i well say most tranfourmers have this diff.
I have two panels that Arc.....One pops eze,little input...the other has to be push hard.
I am finding with this tranfourmer setup.....the center tap out...the one that pop all the time now has to be pushed harder....an the other stop Arcing...There arc is in the front of these panels .....This tell me that this diff. in the tranfourmer windings must have some thing to do with this....But as with all the mods i do.....you can go back...an see if the sounds better to you...it give better sound when in a two way ESL....the bass driver an the esl panel match better..with this littel more output of the panel...To me it sound like a SE tube amp....or like one of pass SE fet amps...
But this is just one mans O-pine ....newyeardiy,er
thanks for any input...
SE info from others...
JonFo....he talk about....His SE setup.Just like the Art i have posted....
After that, it’s basically a stock ML ESL circuit topology. The Signal positive goes to the red lead on the step-up transformer, the signal negative goes to the black lead.
The transformer outputs the positive signal on the gray wire, which in turn routes straight to the rear Stator of the ESL (since the factory passive 2 nd order x-over inverts phase).
The Orange output of the transformer goes to the high-voltage board to provide a reference signal for the Diaphragm and to supply the negative Signal for the Front Stator via the Blue line on BB4.
Additionally, a reference signal ground is fed to the BB4 on the High-voltage board and another is fed straight to the front stator via the second blue lead.
tyu
So we no this can be done but think about it..........any one would put the amps neg. on the ACv
leg of the bias tranfourmer....only if the earth grond was also put in so it would be at 0 but no earth is in.....So the amp would see...300vAC....i dont think wount that noise... if he would have look at the bottem of the board he would have seen that only the neg from the amp is in the mix...Or he had a diff setup than i have had in the SL3s i have had...not
Most set are in pushpull
Double check the high voltage wiring. The ML's I've seen have the transformer outputs going to both stators, and the bias high voltage between the transformer output center tap (that you haven't shown) and the diaphragm film. That way the transformer signal drives one stator negative, the other stator positive, and vice versa for the other half of the waveform, for a push-pull effect on the diaphragm.
jonfo
You are correct that some models have the step-up wired as you describe. There are schematics floating about that depict the orange tap feeding the front stator and the gray wire feeding the rear, with a center tap feeding the high voltage board.
tyu
I have pointed this out over an over.....Mr power told me that it was some thing ML had to do to ship there speakers to the UK....
jonFo
However, the SL3 units I have are wired as I described. I didn't even disconnect the stock wires from the High-Voltage board, xformer nor the connector.
On my xformer, all other taps are wrapped down and unused as you can see in the pic. So no center output tap was ever used.
{This had me scratching my head for a while, but given that it’s the stock wiring (and I have pics of ‘before’ to double-check, plus the other SL3 unit, I feel comfortable this is correct.}
It looks like ML had a design change in the HV board at some point as my boards are from Feb of ’98.
So anyone reading this and planning a mod to their ESL drives should take this into consideration, as there are various modes of wiring these things depending on which rev of the HV board you have.
thanks
JonFo....he talk about....His SE setup.Just like the Art i have posted....
After that, it’s basically a stock ML ESL circuit topology. The Signal positive goes to the red lead on the step-up transformer, the signal negative goes to the black lead.
The transformer outputs the positive signal on the gray wire, which in turn routes straight to the rear Stator of the ESL (since the factory passive 2 nd order x-over inverts phase).
The Orange output of the transformer goes to the high-voltage board to provide a reference signal for the Diaphragm and to supply the negative Signal for the Front Stator via the Blue line on BB4.
Additionally, a reference signal ground is fed to the BB4 on the High-voltage board and another is fed straight to the front stator via the second blue lead.
tyu
So we no this can be done but think about it..........any one would put the amps neg. on the ACv
leg of the bias tranfourmer....only if the earth grond was also put in so it would be at 0 but no earth is in.....So the amp would see...300vAC....i dont think wount that noise... if he would have look at the bottem of the board he would have seen that only the neg from the amp is in the mix...Or he had a diff setup than i have had in the SL3s i have had...not
Most set are in pushpull
Double check the high voltage wiring. The ML's I've seen have the transformer outputs going to both stators, and the bias high voltage between the transformer output center tap (that you haven't shown) and the diaphragm film. That way the transformer signal drives one stator negative, the other stator positive, and vice versa for the other half of the waveform, for a push-pull effect on the diaphragm.
jonfo
You are correct that some models have the step-up wired as you describe. There are schematics floating about that depict the orange tap feeding the front stator and the gray wire feeding the rear, with a center tap feeding the high voltage board.
tyu
I have pointed this out over an over.....Mr power told me that it was some thing ML had to do to ship there speakers to the UK....
jonFo
However, the SL3 units I have are wired as I described. I didn't even disconnect the stock wires from the High-Voltage board, xformer nor the connector.
On my xformer, all other taps are wrapped down and unused as you can see in the pic. So no center output tap was ever used.
{This had me scratching my head for a while, but given that it’s the stock wiring (and I have pics of ‘before’ to double-check, plus the other SL3 unit, I feel comfortable this is correct.}
It looks like ML had a design change in the HV board at some point as my boards are from Feb of ’98.
So anyone reading this and planning a mod to their ESL drives should take this into consideration, as there are various modes of wiring these things depending on which rev of the HV board you have.
thanks
Attachments
![sl3xc%20crossoverdiagram[1].jpg](/community/data/attachments/240/240704-4b0c1bca8ea4680fea5c3b021e9991b0.jpg)
![sl3xc_esldrivejpg1[1].jpg](/community/data/attachments/240/240708-a19fdcb9a884b1d90be848fbb443ea4a.jpg)
bolserst
I wasn't disagreeing with your posts about ML moving the ground reference from the center tap to the front stator.
I was only trying to determine how they connected the bias supply since I could not figure it out from your comments or diagrahm in post#19
The bias dose not have be used in the stepup transfourmer.It can be free standing...if it is you can see it can sound better...right...This is a big deal an if it were not i would not be posting it...I am driving a pr of BIG ML Prodigy esl with a 50watt tube amp an get vary good output ....this can not be done with the pushpull setup...you lose output by 2-3db.
bolserst
An if you have been doing this for 20 years you no any thing in the Audio chan can kill the sound...an yes i would like yours an others help to even get better sound out of the esl...Ml did what thay did... but this is what i am doing to get better sound.
thanks for your time an any info you can give by anyone?
I wasn't disagreeing with your posts about ML moving the ground reference from the center tap to the front stator.
I was only trying to determine how they connected the bias supply since I could not figure it out from your comments or diagrahm in post#19
The bias dose not have be used in the stepup transfourmer.It can be free standing...if it is you can see it can sound better...right...This is a big deal an if it were not i would not be posting it...I am driving a pr of BIG ML Prodigy esl with a 50watt tube amp an get vary good output ....this can not be done with the pushpull setup...you lose output by 2-3db.
bolserst
An if you have been doing this for 20 years you no any thing in the Audio chan can kill the sound...an yes i would like yours an others help to even get better sound out of the esl...Ml did what thay did... but this is what i am doing to get better sound.
thanks for your time an any info you can give by anyone?
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Hello tyu,
Sorry for the late reply, I didn't realize you had posted a response here until today.
I agree that ideally for best sound you would apply a charge to the diaphragm and then remove all bias supply connections. But, all panels have some leakage, so the bias supply has to stay connected to keep the diaphragm charged up to the proper level.
The diaphragm can only be charged if one terminal of the bias supply is connected to the diaphragm, and the other terminal to the stators. The usual method is (+) bias connected to diaphragm, and (-) bias connected to center tap of step-up transformer which feeds it to both stators.
But, in the SL3 you pointed out that the step-up transformer has no center tap.
So, where did Martin logan connect the (-) bias supply? I didn't know until I saw your diagrams.
They hooked it directly to the front stator.
The rear stator is also connected to the (-) bias supply through the step-up transformer secondary winding.
Combining the power supply schematic and panel connection diagram you had previously posted, I highlighted the bias supply connections.
(+) bias supply connection to diaphragm is shown in Red
(-) bias supply connection to front stator and step-up transformer is shown in Green
.
.
Attachments
I'm a latecomer to this thread but can't find anything in it that warrants your most recent response to someone trying to help you, especially when they have done it in such a polite manner
Look bolserst can say what he likes..... but in this case he not right...well he may be right for him ...I have hands on here...hes just talkin...thanks
Look bolserst can say what he likes..... but in this case he not right...well he may be right for him ...I have hands on here...hes just talkin...thanks
Hi,
bolserst simply didn´t anything else but to draw a circuit diagram as described by Tyu. If he thinks that this is an offence and a reason to be rude, well Tyu, then I suggest You waste a thought about how Your slang english complies with rule no.10 of this forum
Anyway, it would be more helpful if You backed up Your claims with a clean theory or even better with some facts. Why and where lies bolsersts error? As long as You don´t defend Your claim with some flesh, there´s no reason to assume any advantage in the proposed setup, because:
* If the (-) of the bias supply and one stator are connected together, a constant static field will develop between membrane and this stator. A second constant static field will develop between the membrane and the second stator. This second field might be less strong by a miniscule amount, because of the copper resistance of the transformer.
But apart from this little difference there´s no difference dc-wise to the centre-tapped connection. Both stators see a gnd-connection, one a direct 0-Ohm connection, the second via the comparatively lowohmic secondary. So both stators take up gnd-potential within a fraction of Volts.
* AC-wise we can cut the gnd-connection of the bias and can think of it as a pure charge on the membrane moved around by a varying homogenous electrical field. Because of one stator beeing grounded this remains the ´safe´ stator. But the second stator now handles double the voltage. Regarding the driving forces for the membrane nothing changes, hence no difference in output. The only changes are the doubled voltage level on one of the stators, resp. the associated leg of the transformer. This may become a serious safety issue since flashover and arcing may occur to any nearing object to this stator. Since a holding frame will certainly be at gnd-potential, increased leakage and arcing may be an issue. Also the parasitic interwinding-capacitances of the tranny may suffer double voltage levels. The probability of insulation breakdown inside the tranny raises. Due to the increased voltage stress ageing of the insuation materials accelerates.
So far, the only advantage I see, would be, if the front stator would be grounded, as that stator is prone to be touched by humans or pets. In any other case only disadvantage remain.
jauu
Calvin
bolserst simply didn´t anything else but to draw a circuit diagram as described by Tyu. If he thinks that this is an offence and a reason to be rude, well Tyu, then I suggest You waste a thought about how Your slang english complies with rule no.10 of this forum
Anyway, it would be more helpful if You backed up Your claims with a clean theory or even better with some facts. Why and where lies bolsersts error? As long as You don´t defend Your claim with some flesh, there´s no reason to assume any advantage in the proposed setup, because:
* If the (-) of the bias supply and one stator are connected together, a constant static field will develop between membrane and this stator. A second constant static field will develop between the membrane and the second stator. This second field might be less strong by a miniscule amount, because of the copper resistance of the transformer.
But apart from this little difference there´s no difference dc-wise to the centre-tapped connection. Both stators see a gnd-connection, one a direct 0-Ohm connection, the second via the comparatively lowohmic secondary. So both stators take up gnd-potential within a fraction of Volts.
* AC-wise we can cut the gnd-connection of the bias and can think of it as a pure charge on the membrane moved around by a varying homogenous electrical field. Because of one stator beeing grounded this remains the ´safe´ stator. But the second stator now handles double the voltage. Regarding the driving forces for the membrane nothing changes, hence no difference in output. The only changes are the doubled voltage level on one of the stators, resp. the associated leg of the transformer. This may become a serious safety issue since flashover and arcing may occur to any nearing object to this stator. Since a holding frame will certainly be at gnd-potential, increased leakage and arcing may be an issue. Also the parasitic interwinding-capacitances of the tranny may suffer double voltage levels. The probability of insulation breakdown inside the tranny raises. Due to the increased voltage stress ageing of the insuation materials accelerates.
So far, the only advantage I see, would be, if the front stator would be grounded, as that stator is prone to be touched by humans or pets. In any other case only disadvantage remain.
jauu
Calvin
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bolserst simply didn´t anything else but to draw a circuit diagram as described by Tyu. If he thinks that this is an offence and a reason to be rude, well Tyu, then I suggest You waste a thought about how Your slang english complies with rule no.10 of this forum
No he did not...I did this a long time a go....you are finding time to come in now with you thinking....thanks for you time an the putdown
No he did not...I did this a long time a go....you are finding time to come in now with you thinking....thanks for you time an the putdown
calvin
The only changes are the doubled voltage level on one of the stators, resp. the associated leg of the transformer. This may become a serious safety issue since flashover and arcing may occur to any nearing object to this stator.
Here agin it not the case....you would think it would be but it cause less arcing...in some of the panels i have that arc on the Center tap setup...
If you put this on paper it looks that way ...just like it looks like that ML put the bias 0
on the centap....but thay did not in real life....I have the speakers her now...see how eze this is...i have shown the Art of there setup....That it...no more...no less
So far, the only advantage I see, would be, if the front stator would be grounded, as that stator is prone to be touched by humans or pets. In any other case only disadvantage remain....
Thay did put the 0 on the front panel i move it to the back ... i got more more output out of the panel... i say this because there is only bias coting on the front side of the mylar..an it gives more out put.....there are other post
Thanks for your time an info
The only changes are the doubled voltage level on one of the stators, resp. the associated leg of the transformer. This may become a serious safety issue since flashover and arcing may occur to any nearing object to this stator.
Here agin it not the case....you would think it would be but it cause less arcing...in some of the panels i have that arc on the Center tap setup...
If you put this on paper it looks that way ...just like it looks like that ML put the bias 0
on the centap....but thay did not in real life....I have the speakers her now...see how eze this is...i have shown the Art of there setup....That it...no more...no less
So far, the only advantage I see, would be, if the front stator would be grounded, as that stator is prone to be touched by humans or pets. In any other case only disadvantage remain....
Thay did put the 0 on the front panel i move it to the back ... i got more more output out of the panel... i say this because there is only bias coting on the front side of the mylar..an it gives more out put.....there are other post
Thanks for your time an info
Calven this is one of the frist post that Bolserst started...it in the ESL base anyone post..
An i have posted this more than one time...but it may in this post sound like..that i have had 100 people did this mod an i know them all an thay say it the way to go...No down side.. that was not my intent...Sorry for any mixup...thanks you help...here the post
tyu
On paper it looks that way....but
Forgive the Art....i have posted this in the past..i came across this with ML in 96....
An got in touch with Mr powers At ML to get more info and a schematic...
an when i got the schematic it was as you see in all there schematic... the nom. setup with the centap grounded....an one end of the winding going to the back an one going to the front of the panels..just like all ESL i had ever seen...Acoustats,Soundlab,so....i called to see what was up an was told that thay had came up with this setup to sale in UK...thay had to ground, well the neg input from the amp to the front panel...Safty.. thay even ran two wires from the same place to the same place...what i siad..thay have some panels with 4 wires... an two run to the front ....well i got to looking at the setup an siad just what you have... cant be right... but it work an whin i took out the setup an put in the one on the schematic from ML...i lost output??
So when i put the SE I call it... setup back in with the back panel gronded not the front i got even more output....so then i move on to my Acoustats an it did the same thing .....;sound great an gave more output....so thin i move on to my soundLabs A3s an got the thing...great sound an more output....so i pass this on to Moray....an he look at it an tride it an it workt for him all so...
So i gess that as we no, the paper is not right all the time...
I think it helps with the mismach in the tranfourmers windings...an it stops a fulx back an forth that come with the back of the panel that has no bias feed coting...all i can say is after trying it bouth ways ...i alway endup here At whats in the art... give it a try...you can always go back!....an i have never found any one that thinks more output out of a ESL is a bad thing...
To me how it sounds is the same way a SE tube amp sounds vris a pushpull
faster an sweeter....just one mans o-pine
Thanks for your time an all years of info on esl you have given
tyu
I have never siad that i came up with this setup....i only wounted to pass on to others this info.....the pic that bolserst putup.. i posted to show that some one other than i had saw this setup that ML had came up with...An used in his own board that he setup.. this setup was done in the Aerius i.. also
An it workt great....
An all i have said to Bolserst is[ what was done by Ml.]..An all he keeps saying is thay did not...it is what it is...no Bias 0 in the mix..center tap or not...i have two pr of the SL3s from ML here one with the center tap run only on the neg input from the amp....an one with the back of the panel on the neg input from the amp only! in the schematic it looks like the 0bias is in the setup...[but it not in real life...] i was not saying it should be or not..it not.
calvin
anything measured, any numbers or figures to back up Your claims...
tyu
This is all what i hear with two ears...An others that i no hear..With this setup in..no centap An the other..Centap in.. The none centap one wins ever time... dose this mean the ML was right to do this setup in ther speakers not for me to say...
I posted all this info an thought if someone like your self would like to give Some numers that would be great... you may not care an that fine but i have put this in other of ESls works
an it sounds better...thanks for you time
An i have posted this more than one time...but it may in this post sound like..that i have had 100 people did this mod an i know them all an thay say it the way to go...No down side.. that was not my intent...Sorry for any mixup...thanks you help...here the post
tyu
On paper it looks that way....but
Forgive the Art....i have posted this in the past..i came across this with ML in 96....
An got in touch with Mr powers At ML to get more info and a schematic...
an when i got the schematic it was as you see in all there schematic... the nom. setup with the centap grounded....an one end of the winding going to the back an one going to the front of the panels..just like all ESL i had ever seen...Acoustats,Soundlab,so....i called to see what was up an was told that thay had came up with this setup to sale in UK...thay had to ground, well the neg input from the amp to the front panel...Safty.. thay even ran two wires from the same place to the same place...what i siad..thay have some panels with 4 wires... an two run to the front ....well i got to looking at the setup an siad just what you have... cant be right... but it work an whin i took out the setup an put in the one on the schematic from ML...i lost output??
So when i put the SE I call it... setup back in with the back panel gronded not the front i got even more output....so then i move on to my Acoustats an it did the same thing .....;sound great an gave more output....so thin i move on to my soundLabs A3s an got the thing...great sound an more output....so i pass this on to Moray....an he look at it an tride it an it workt for him all so...
So i gess that as we no, the paper is not right all the time...
I think it helps with the mismach in the tranfourmers windings...an it stops a fulx back an forth that come with the back of the panel that has no bias feed coting...all i can say is after trying it bouth ways ...i alway endup here At whats in the art... give it a try...you can always go back!....an i have never found any one that thinks more output out of a ESL is a bad thing...
To me how it sounds is the same way a SE tube amp sounds vris a pushpull
faster an sweeter....just one mans o-pine
Thanks for your time an all years of info on esl you have given
tyu
I have never siad that i came up with this setup....i only wounted to pass on to others this info.....the pic that bolserst putup.. i posted to show that some one other than i had saw this setup that ML had came up with...An used in his own board that he setup.. this setup was done in the Aerius i.. also
An it workt great....
An all i have said to Bolserst is[ what was done by Ml.]..An all he keeps saying is thay did not...it is what it is...no Bias 0 in the mix..center tap or not...i have two pr of the SL3s from ML here one with the center tap run only on the neg input from the amp....an one with the back of the panel on the neg input from the amp only! in the schematic it looks like the 0bias is in the setup...[but it not in real life...] i was not saying it should be or not..it not.
calvin
anything measured, any numbers or figures to back up Your claims...
tyu
This is all what i hear with two ears...An others that i no hear..With this setup in..no centap An the other..Centap in.. The none centap one wins ever time... dose this mean the ML was right to do this setup in ther speakers not for me to say...
I posted all this info an thought if someone like your self would like to give Some numers that would be great... you may not care an that fine but i have put this in other of ESls works
an it sounds better...thanks for you time
Attachments
![sl3xc%20crossoverdiagram[1].jpg](/community/data/attachments/233/233802-4b0c1bca8ea4680fea5c3b021e9991b0.jpg)
Confusion...
Wow, gone 2 days and lots of confusion here...
I am confused why you would say I was just talking. Anybody who has read this forum knows that I always perform experiments and measurements to test theories. If I am posting just a thought, or suggestion, I say so. In this case, you posted a step-up transformer connection arrangement in another thread that I had not see before. You said it was used by Martin Logan in some of the SL3s. I tested it, and did not get the 2-3db boost you said you got. So, that is what I posted in my response.
Now, the figure you attached in post#1 of this thread did not show how the HV was connected, so I asked you where it was connected?
http://www.diyaudio.com/forums/planars-exotics/203990-esl-woofer-anybody-game-4.html#post2855920
You said it wasn't connected to anything. But, looking at the HV power supply schematic and wiring diaphragm you posted, it clearly is connected to the transformer and stators. The connection may not be obvious because it is on the circuit board rather than an external wire, but the connection is there. This is what Martin Logan did, so I don't understand what the argument is about.
OK, moving along.... A few measurements.
Attachment #1 shows 4 different connection arrangements I tested
(A) Standard arrangement where the HV is connected to the center-tap and the wall power safety ground. This was used in early ESLs by QUAD, Acoustat, Soundlab, and STAX that I know of.
(B) Another standard arrangement where the HV is connected to the center-tap and the negative audio input. This was used in later models by QUAD as well as most JansZen models.
As tyu has posted elsewhere, it is easy enough to switch from (A) to (B) if you have concern about ground noise entering the HV supply.
(C) This is the configuration tyu posted at the beginning of this thread. The HV supply connected to nothing but the diaphragm. Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
(D) This is the configuration shown in the ML schematics for the SL3. It was new to me and I appreciate tyu pointing it out. Always new things to learn.
Attachment #2 shows comparison of configurations (A), (B), & (D).
As you can see, there is no 2-3dB boost for configuration (D). The only difference in the response is a small droop of the high frequencies due to increased inter-winding capacitance with the primary connected to the end of the secondary winding rather than the center tap. I'm not sure why ML chose to use it, but it wasn't for increased sensitivity. I seem to remember tyu said it was to meet some European safety regulations...is that right?
Attachment #3 shows comparison of configurations (D), & (C) after various amounts of time.
As you can see, configuration (C) does not keep the diaphragm charged. Starting from configuration (D) to charge the diaphragm, then switching to configuration (C); As time passes the charge that was on the diaphragm slowly leaks away and output falls.
Hopefully this measurement summary removes some of the confusion.
Wow, gone 2 days and lots of confusion here...
I am confused why you would say I was just talking. Anybody who has read this forum knows that I always perform experiments and measurements to test theories. If I am posting just a thought, or suggestion, I say so. In this case, you posted a step-up transformer connection arrangement in another thread that I had not see before. You said it was used by Martin Logan in some of the SL3s. I tested it, and did not get the 2-3db boost you said you got. So, that is what I posted in my response.
Now, the figure you attached in post#1 of this thread did not show how the HV was connected, so I asked you where it was connected?
http://www.diyaudio.com/forums/planars-exotics/203990-esl-woofer-anybody-game-4.html#post2855920
You said it wasn't connected to anything. But, looking at the HV power supply schematic and wiring diaphragm you posted, it clearly is connected to the transformer and stators. The connection may not be obvious because it is on the circuit board rather than an external wire, but the connection is there. This is what Martin Logan did, so I don't understand what the argument is about.
OK, moving along.... A few measurements.
Attachment #1 shows 4 different connection arrangements I tested
(A) Standard arrangement where the HV is connected to the center-tap and the wall power safety ground. This was used in early ESLs by QUAD, Acoustat, Soundlab, and STAX that I know of.
(B) Another standard arrangement where the HV is connected to the center-tap and the negative audio input. This was used in later models by QUAD as well as most JansZen models.
As tyu has posted elsewhere, it is easy enough to switch from (A) to (B) if you have concern about ground noise entering the HV supply.
(C) This is the configuration tyu posted at the beginning of this thread. The HV supply connected to nothing but the diaphragm. Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
(D) This is the configuration shown in the ML schematics for the SL3. It was new to me and I appreciate tyu pointing it out. Always new things to learn.
Attachment #2 shows comparison of configurations (A), (B), & (D).
As you can see, there is no 2-3dB boost for configuration (D). The only difference in the response is a small droop of the high frequencies due to increased inter-winding capacitance with the primary connected to the end of the secondary winding rather than the center tap. I'm not sure why ML chose to use it, but it wasn't for increased sensitivity. I seem to remember tyu said it was to meet some European safety regulations...is that right?
Attachment #3 shows comparison of configurations (D), & (C) after various amounts of time.
As you can see, configuration (C) does not keep the diaphragm charged. Starting from configuration (D) to charge the diaphragm, then switching to configuration (C); As time passes the charge that was on the diaphragm slowly leaks away and output falls.
Hopefully this measurement summary removes some of the confusion.
Attachments
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THanks for your time an this is great info.....i have no way of saying for a min that any thing you have said is not right BUT....
You say
The connection may not be obvious because it is on the circuit board rather than an external wire, but the connection is there. This is what Martin Logan did, so I don't understand what the argument is about.
You keep saying....an i think this is what you think....in the pic..an the ML
schematic....showes that the 0 of the bias is in the mix....YES....but it not in the speaker it self....do you see this ....it gos to the board but all that at the boare is a lope... that takes the Neg input from the AMp [only]...Yes it looks like your right ...but not on the boards i have here...you can take it or levit
The frist thing i did was go to the board it see where bias 0 went ... as it looks like there is the 0of the bias... but it was just a place to bring the neg input from the amp...an then go to the centap or one end of the winding
This is the way that set it up.... I caled ask why...but like with what i thought was a limiter... mr powers call it some thing diff.. so that IT.
Now you say this is not good to do.... even thought i have had a lot of ESL setup this way with better sound.....I get your point ..thanks for the work.
Now as for the more out put 2-3 more output i have posted that i redo all the MLpanels that i have an when you give the panel more bias... an take the front of the panel of the neg an move it to the back of the panel you get more output...
Now you say no ..thats great ...now i no i am not right..thanks
You say
The connection may not be obvious because it is on the circuit board rather than an external wire, but the connection is there. This is what Martin Logan did, so I don't understand what the argument is about.
You keep saying....an i think this is what you think....in the pic..an the ML
schematic....showes that the 0 of the bias is in the mix....YES....but it not in the speaker it self....do you see this ....it gos to the board but all that at the boare is a lope... that takes the Neg input from the AMp [only]...Yes it looks like your right ...but not on the boards i have here...you can take it or levit
The frist thing i did was go to the board it see where bias 0 went ... as it looks like there is the 0of the bias... but it was just a place to bring the neg input from the amp...an then go to the centap or one end of the winding
This is the way that set it up.... I caled ask why...but like with what i thought was a limiter... mr powers call it some thing diff.. so that IT.
Now you say this is not good to do.... even thought i have had a lot of ESL setup this way with better sound.....I get your point ..thanks for the work.
Now as for the more out put 2-3 more output i have posted that i redo all the MLpanels that i have an when you give the panel more bias... an take the front of the panel of the neg an move it to the back of the panel you get more output...
Now you say no ..thats great ...now i no i am not right..thanks
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This is the way that ML setup miney ESL speakers like the ones i have here...
(C) This is the configuration tyu posted at the beginning of this thread. The HV supply connected to nothing but the diaphragm. Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
You say this..... but all the speakers i have set up with NO 0 in the mix... work great
Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
An are you right ?? sounds like your on the money thaks for the work....but it playing here now an has been for years just like you show in C...go figg...an if you say on paper this is not right ..you are right...good job....
I do find it funny that any one would put the neg. input of a amp on the 0of a bias when if like most setup well work with just the 0of the bias on the windings to charg the panel...in your theory?...this can not sound good...an would not bias 0 have the ac v there the bias is floting....no earth....an no amp neg amp input..if you were going to put the bias 0 in...that would be a nef right
Thanks
(C) This is the configuration tyu posted at the beginning of this thread. The HV supply connected to nothing but the diaphragm. Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
You say this..... but all the speakers i have set up with NO 0 in the mix... work great
Theory and experiments agree that the HV supply will not charge the diaphragm unless it is connected to both the diaphragm and stators.
An are you right ?? sounds like your on the money thaks for the work....but it playing here now an has been for years just like you show in C...go figg...an if you say on paper this is not right ..you are right...good job....
I do find it funny that any one would put the neg. input of a amp on the 0of a bias when if like most setup well work with just the 0of the bias on the windings to charg the panel...in your theory?...this can not sound good...an would not bias 0 have the ac v there the bias is floting....no earth....an no amp neg amp input..if you were going to put the bias 0 in...that would be a nef right
Thanks
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