on the CLX board
Con 2 is the AC input. The AC plug is an IEC 3 pin, but there is NO AC ground connection to anything.
The 8 pin Molex socket has a choice of 2 plugs to series or parrallel the Tamura transformers primaries for 120 or 240 VAC . ( the Audio pimp on Audiogon was charging $800 to reconfigure for 240 VAC - a pimp's got to make a living somehow).
The red LED comes on as soon as the music sense circuit (IC U 201) turns on the HV supplies.
the other 2 of 8 pin chips (dual fet opamps) are the low and high frequency inverters. The misssing ic is where Martin Logan plug in a ribbon cable that runs over to the limiter board. The limiter board passes the incoming audio to the music sense portion of the main board by the same ribbon cable. The ribbon cable also provides power to the limiter board and turns on the gates the 4 heatsinked power fets for low frequency positive and negative and high frequency positive and negative leads that feed the 2 audio step up transformers
Con 2 is the AC input. The AC plug is an IEC 3 pin, but there is NO AC ground connection to anything.
The 8 pin Molex socket has a choice of 2 plugs to series or parrallel the Tamura transformers primaries for 120 or 240 VAC . ( the Audio pimp on Audiogon was charging $800 to reconfigure for 240 VAC - a pimp's got to make a living somehow).
The red LED comes on as soon as the music sense circuit (IC U 201) turns on the HV supplies.
the other 2 of 8 pin chips (dual fet opamps) are the low and high frequency inverters. The misssing ic is where Martin Logan plug in a ribbon cable that runs over to the limiter board. The limiter board passes the incoming audio to the music sense portion of the main board by the same ribbon cable. The ribbon cable also provides power to the limiter board and turns on the gates the 4 heatsinked power fets for low frequency positive and negative and high frequency positive and negative leads that feed the 2 audio step up transformers
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Ha! I was typing in that very question last night, but got interrupted and never finished.
Thanks for the very nice pic of of the HV board and anticipating my question.
The other question I had was concerning the opamps, you mentioned they were dual FET.
Can you remember the part number? The opamps used in the HV supplies of lower models is the LM358.
Oh, also do you happen to have a similar quality pic of the limiter board?
The 2 black cylinders on each side potted in white silicon are inductors.
I 'll get an underside shot of the Power supply board and both sides of the limiter board.
A little later the crossover boards as well.
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Thanks for posting the info on the ML CLX
I find there setup to be weard...........an for sure the 6ea 15meg 1/4 watt carbons at the output to the panels... have no place in this $$ a speakers....chang these chep rolled off sounding res. to any other mf type...an drop one are two of them like i have.... an you may think you have a diff speaker....an get way better sound.....an more outpot......
I find there setup to be weard...........an for sure the 6ea 15meg 1/4 watt carbons at the output to the panels... have no place in this $$ a speakers....chang these chep rolled off sounding res. to any other mf type...an drop one are two of them like i have.... an you may think you have a diff speaker....an get way better sound.....an more outpot......
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Dropping a few of the resistors can actually raise the Bias voltage feeding the Diaphragm depending on the leakage resistance that the panel may have.
I found this to be true with some of my earlier painted panels that I had made compared to my last best little ones (The black ones with powder coated stators, the ones that burn't).
They had very very little leakage and would play for about a day and a half or more before the charge would finally dissipated to nothing.
Changing the feed resistor to a higher value from 10Meg to 60Meg had no effect on those particular panels.
FWIW
jer
I found this to be true with some of my earlier painted panels that I had made compared to my last best little ones (The black ones with powder coated stators, the ones that burn't).
They had very very little leakage and would play for about a day and a half or more before the charge would finally dissipated to nothing.
Changing the feed resistor to a higher value from 10Meg to 60Meg had no effect on those particular panels.
FWIW
jer
jer..............your the best..thanks for alway being there.. so you say........
Dropping a few of the resistors can actually raise the Bias voltage feeding the Diaphragm depending on the leakage resistance that the panel may have.
I found this to be true with some of my earlier painted panels that I had made compared to my last best little ones (The black ones with powder coated stators, the ones that burn't).
Frist are these the panels you run 4-7k bias V on? tell us..... what high bias do you like ?
an i know you no ML runs there panels at 3.4-5kV on there bias?
I have re-.worket on 20 ML panels....never had any burnt panels even when i test them with a bias setup for tesing panels that well go up to 4-5 k bias!
An i say just put better....of the same 6ea 15meg !
I have done this Mod to 4 pr of ML.....3 pr Acoustats......With the Acoustats being fullrang.....best sound i have had...what ever 15meg res.....is put at the point were the bias feed the panels has a BIg efect on the sound more than any cap...wire you well ever come up with .....dont miss this big up gread....hell go to ratsck get 1/4 MF ....
any res. would be better than these carbon that did not cost a 1 US penny.......... it all about geting the best sound.....well to me...good luck
Dropping a few of the resistors can actually raise the Bias voltage feeding the Diaphragm depending on the leakage resistance that the panel may have.
I found this to be true with some of my earlier painted panels that I had made compared to my last best little ones (The black ones with powder coated stators, the ones that burn't).
Frist are these the panels you run 4-7k bias V on? tell us..... what high bias do you like ?
an i know you no ML runs there panels at 3.4-5kV on there bias?
I have re-.worket on 20 ML panels....never had any burnt panels even when i test them with a bias setup for tesing panels that well go up to 4-5 k bias!
An i say just put better....of the same 6ea 15meg !
I have done this Mod to 4 pr of ML.....3 pr Acoustats......With the Acoustats being fullrang.....best sound i have had...what ever 15meg res.....is put at the point were the bias feed the panels has a BIg efect on the sound more than any cap...wire you well ever come up with .....dont miss this big up gread....hell go to ratsck get 1/4 MF ....
any res. would be better than these carbon that did not cost a 1 US penny.......... it all about geting the best sound.....well to me...good luck
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I typically run my DIY panels about 6.8KV and have pushed them as high as 8Kv or so with no issues.
Above that to 10Kv I started to run into coating breakdown issues and high coating leakages in which finally ended them in their ultimate demise.
I haven't tried the new build yet, and it has been a year since I made it.
Hmmmmm..........
I have too many chips on my bench right now to have any HV flyin' around.
I am working on a preamp and amplifier system so that I can wrap the project up as finished.
I discovered the resistor issue back in 2010 when I First got back into it and before I had finalized my variable HV Bias supply.
But I was running up to about 0v to 5.5Kv at the time.
The differences in leakage of several panels hooked in parallel had strange effects as I varied the bias voltage.
The sound would pan from left to right between the three panels as I varied the bias voltage.
It was a fluke that I had the panels in the right order as it panned from Left to center to right and back again!!!!
Adding the resistors to feed each panel separately solved that issue.
That is when I tried different values to find out if there was any optimum value to use to feed them with.
The panels that leaked the most needed a lower value than my best performing ones did else each one would have a slightly different SPL.
I didn't have an SPL meter at the time so I can't tell you exactly how much of a difference there was but it was noticeable by a 1db or 2db or so.
I also found out that they are needed to eliminate any L&R channel crosstalk that would occur when I was powering two panels in stereo from the same bias supply.
This was one of the very few (maybe two) times I had ever ran them in stereo because I only had one amp and I needed to use one channel to power a woofer.
I also discovered that the crosstalk was virtually eliminated completely when I used another set of resistors feeding the step-up transformers center tap from the ground as well.
Although, It was quite acceptable with just each diaphragm fed with its own resistor, as it was just something I could only see by using my scope through a HV resistor divider.
At the time the earlier version of my supply was variable, but it was not regulated and the lower frequncy's would modulate the bias voltage if the resistors were not used.
I am thinking that this was caused by an increased leakage when the diaphragm was closest to a stator during extreme excursions of movement and dragging down the bias voltage a bit.
It is only necessary if you are feeding a stereo setup from the same bias supply, or several panels each being fed a different set of frequency's as some multi-panel configurations are set up to do.
My very First painted panels have a lot of leakage and would stop playing within a few seconds upon the removal of the bias voltage compared the ones with powder coated stators.
jer
Above that to 10Kv I started to run into coating breakdown issues and high coating leakages in which finally ended them in their ultimate demise.
I haven't tried the new build yet, and it has been a year since I made it.
Hmmmmm..........
I have too many chips on my bench right now to have any HV flyin' around.
I am working on a preamp and amplifier system so that I can wrap the project up as finished.
I discovered the resistor issue back in 2010 when I First got back into it and before I had finalized my variable HV Bias supply.
But I was running up to about 0v to 5.5Kv at the time.
The differences in leakage of several panels hooked in parallel had strange effects as I varied the bias voltage.
The sound would pan from left to right between the three panels as I varied the bias voltage.
It was a fluke that I had the panels in the right order as it panned from Left to center to right and back again!!!!
Adding the resistors to feed each panel separately solved that issue.
That is when I tried different values to find out if there was any optimum value to use to feed them with.
The panels that leaked the most needed a lower value than my best performing ones did else each one would have a slightly different SPL.
I didn't have an SPL meter at the time so I can't tell you exactly how much of a difference there was but it was noticeable by a 1db or 2db or so.
I also found out that they are needed to eliminate any L&R channel crosstalk that would occur when I was powering two panels in stereo from the same bias supply.
This was one of the very few (maybe two) times I had ever ran them in stereo because I only had one amp and I needed to use one channel to power a woofer.
I also discovered that the crosstalk was virtually eliminated completely when I used another set of resistors feeding the step-up transformers center tap from the ground as well.
Although, It was quite acceptable with just each diaphragm fed with its own resistor, as it was just something I could only see by using my scope through a HV resistor divider.
At the time the earlier version of my supply was variable, but it was not regulated and the lower frequncy's would modulate the bias voltage if the resistors were not used.
I am thinking that this was caused by an increased leakage when the diaphragm was closest to a stator during extreme excursions of movement and dragging down the bias voltage a bit.
It is only necessary if you are feeding a stereo setup from the same bias supply, or several panels each being fed a different set of frequency's as some multi-panel configurations are set up to do.
My very First painted panels have a lot of leakage and would stop playing within a few seconds upon the removal of the bias voltage compared the ones with powder coated stators.
jer
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