I would probably use about 16 or 14 gauge wire.
I have used 14 gauge house wire before as it is practically self supporting and can handle the very large currents without heating up (20Amps).
Although it is very stiff and sometimes hard to work with.
You could use some say 1/4" or 3/8" plywood or thick plexiglass and drill holes in it for the component leads or just glue them to it with some construction adhesive and then wire it with the 14ga.
Not very pretty but functional.
I have used Silicone for mounting components with great success.
it is not as permanent but will hold very nicely once it is set.
I use it for mounting my drivers all of the time.
I used to use it to mount my project PCB's in their box's as well.
it sure beats drilling holes and messing with screws and such.
Since you already have the standoffs a piece of 3/32" or 1/8" plexiglass will suffice and should hold every thing including the step up transformer.
They have four sizes that are thick .093", .115",.157" and .220" that you can get and some times you might find the perfect piece in there throw away bin and if you ask them they may give it to you.
I have done this before and got some nice long strips to build my smaller DIYesl's with.
I grabbed all of the ones I could use and got about $20 worth for free because the guy was just taking it to the crusher anyhow.
Or you can take some PCB material and cut some lines in it with a fiber wheel to make some large pads to solder the components to it dead bug style.
This is basically the style that most crossover boards look like.
Very simple but with large pads they will certainly handle the currents better than the puny traces that where used in the original one in the First place.
You could do this to make some strips and then glue it to the plexiglass with the silicone or epoxy or bolts and then it would look much neater.
Finding solder lug terminal strips my be hard to find locally, But they can be found from Vacuum Tube suppliers and surplus electronics stores online.
jer
I have used 14 gauge house wire before as it is practically self supporting and can handle the very large currents without heating up (20Amps).
Although it is very stiff and sometimes hard to work with.
You could use some say 1/4" or 3/8" plywood or thick plexiglass and drill holes in it for the component leads or just glue them to it with some construction adhesive and then wire it with the 14ga.
Not very pretty but functional.
I have used Silicone for mounting components with great success.
it is not as permanent but will hold very nicely once it is set.
I use it for mounting my drivers all of the time.
I used to use it to mount my project PCB's in their box's as well.
it sure beats drilling holes and messing with screws and such.
Since you already have the standoffs a piece of 3/32" or 1/8" plexiglass will suffice and should hold every thing including the step up transformer.
They have four sizes that are thick .093", .115",.157" and .220" that you can get and some times you might find the perfect piece in there throw away bin and if you ask them they may give it to you.
I have done this before and got some nice long strips to build my smaller DIYesl's with.
I grabbed all of the ones I could use and got about $20 worth for free because the guy was just taking it to the crusher anyhow.
Or you can take some PCB material and cut some lines in it with a fiber wheel to make some large pads to solder the components to it dead bug style.
This is basically the style that most crossover boards look like.
Very simple but with large pads they will certainly handle the currents better than the puny traces that where used in the original one in the First place.
You could do this to make some strips and then glue it to the plexiglass with the silicone or epoxy or bolts and then it would look much neater.
Finding solder lug terminal strips my be hard to find locally, But they can be found from Vacuum Tube suppliers and surplus electronics stores online.
jer
Last edited:
I gave the crossover a quick visual and everything,while still ugly, looked fine so I hooked it up again.
It worked but there are issues. The panel is very low especially compared to the woofer. I've read this usually indicates failed coating. Also there was some slight distortion. It almost sounds like a blown tweeter. Kind of crackle/scratchy. I can see no physical damage to the Mylar.
Thoughts?
Thanks
Eric
It worked but there are issues. The panel is very low especially compared to the woofer. I've read this usually indicates failed coating. Also there was some slight distortion. It almost sounds like a blown tweeter. Kind of crackle/scratchy. I can see no physical damage to the Mylar.
Thoughts?
Thanks
Eric
Yes, you could do something like that.
Just remember that rivets do tend to corrode and rust over time and cause issues as in the photo that I posted of the IFT section in my monitor.
This is why I suggested to use some small square pads made out of some PCB material 1/2" square or so glued to your mounting plate (be it whatever material you choose to use).
18ga. wire I think will be okay as well since they will all be short.
But remember the the currents will be close to 10 to 20 amps or more with a >20V input signal at times when the impedance drops to 2 ohms and lower.
As mentioned ML's do have coating issues.
Some of this can be caused by a poor connection to the diaphragm (ie~charge ring or lack of).
And sometimes if they are washed off their efficiency can be restored as well.
jer
Just remember that rivets do tend to corrode and rust over time and cause issues as in the photo that I posted of the IFT section in my monitor.
This is why I suggested to use some small square pads made out of some PCB material 1/2" square or so glued to your mounting plate (be it whatever material you choose to use).
18ga. wire I think will be okay as well since they will all be short.
But remember the the currents will be close to 10 to 20 amps or more with a >20V input signal at times when the impedance drops to 2 ohms and lower.
As mentioned ML's do have coating issues.
Some of this can be caused by a poor connection to the diaphragm (ie~charge ring or lack of).
And sometimes if they are washed off their efficiency can be restored as well.
jer
So as I understand it the Mylar is permanently coated with something that makes them electrostaticly attractive to the two screens. They start to become with atmospheric pollutants and dust collects between the screens and the Mylar shorting the electrostatic charge that would otherwise be attracting the Mylar to the screens.
What I want to know is if when I rinse off my panels if I should use any cleaners like diluted Simple Green and if there is any need to do a final rinse with distilled water to remove any tap water contaminants.
Thanks
Eric
What I want to know is if when I rinse off my panels if I should use any cleaners like diluted Simple Green and if there is any need to do a final rinse with distilled water to remove any tap water contaminants.
Thanks
Eric
So I rinsed them off yesterday afternoon and don't have time today to reinstall them and give them a try but I have two questions. The sides of the front stator are not attached to the rear ones with the Mylar sandwiched in between. They are attached top and bottom and there is the foam tape holding the Mylar to the rear stator and a layer on the front of the Mylar but it still has the backing on it so the sides are open. Is this OK?
Also how much should the front stator be mounted higher than the rear? I have about a half inch showing of rear stator on bottom.
Thanks
Eric
Also how much should the front stator be mounted higher than the rear? I have about a half inch showing of rear stator on bottom.
Thanks
Eric
No, don't any cleaners or soaps, use distilled water to start with, or if you need to have some sort of solvent then use denatured alcohol.
Soaps have sodium lauryl sulfate and can leave a conductive film on them as well.
Some may be able to be used but very very very diluted.
There are a few threads describing the washing methods that many have used in order to give you more info.
They weren't to long ago so the threads shouldn't be buried to deeply.
Many have had very good success and some that haven't and had to recoat them with some Licron Crystal or other suitable liquid staticide (coating).
I have never had my hands on one to take apart but there are many others here that have.
Hopefully they will chime in to give you more insight on this.
If the two stator's are different in length then I guess this would be normal.
If they are the both same length then I would say no this is not normal.
The only ML I ever saw and heard was the Aerius, But it is brand new sitting in a show room.
I examined it very closely and I don't recall any offset mounting of the stator pieces to one another.
Nor have I seen this in any of the closeup pictures that others have posted.
Sounds like they may have been taken apart at sometime.
If they are separating this can cause the charge ring or wire (if it has one) to not be contacting the diaphragm properly.
They may need to be in their frame to have the proper pressure to hold them together.
jer
Soaps have sodium lauryl sulfate and can leave a conductive film on them as well.
Some may be able to be used but very very very diluted.
There are a few threads describing the washing methods that many have used in order to give you more info.
They weren't to long ago so the threads shouldn't be buried to deeply.
Many have had very good success and some that haven't and had to recoat them with some Licron Crystal or other suitable liquid staticide (coating).
I have never had my hands on one to take apart but there are many others here that have.
Hopefully they will chime in to give you more insight on this.
If the two stator's are different in length then I guess this would be normal.
If they are the both same length then I would say no this is not normal.
The only ML I ever saw and heard was the Aerius, But it is brand new sitting in a show room.
I examined it very closely and I don't recall any offset mounting of the stator pieces to one another.
Nor have I seen this in any of the closeup pictures that others have posted.
Sounds like they may have been taken apart at sometime.
If they are separating this can cause the charge ring or wire (if it has one) to not be contacting the diaphragm properly.
They may need to be in their frame to have the proper pressure to hold them together.
jer
Ok so riddle me this: I washed the panels, let them dry, reinstalled them. They sound the same as they did before I washed them AND I came to realize that with the power disconnected there is no drop in volume. That's right. They play the same with no outside power. I think my power supply is working.
Ideas?
Thanks
Eric
Ideas?
Thanks
Eric
They get to low normal listening levels. They played for 10-15 mins easy after I unplugged the power supply.
I was using an old Marantz integrated I have. To get this much volume I needed to turn it up half way. The amp when's into protection a few times at this level.
I think I'm going to completely tear down and rebuild the crossovers.
Any other ideas?
Thanks
Eric
I was using an old Marantz integrated I have. To get this much volume I needed to turn it up half way. The amp when's into protection a few times at this level.
I think I'm going to completely tear down and rebuild the crossovers.
Any other ideas?
Thanks
Eric
Everytime you double the bias voltage you get +6db more of efficiency.
Being that the supply has 4 stages (8 diodes) then two more stages would be a good place to start (4 diodes and associated caps).
This would get you to about 3-3.6Kv of bias voltage and you wouldn't have to turn your amp up as high either.
This should be a good value not knowing what the maximum voltage the stepp-up transformer is designed for, but it should be able to handle that range.
As far as a crossover rebuild I would seriously consider an active system first, But that is your call.
FWIW
jer
Being that the supply has 4 stages (8 diodes) then two more stages would be a good place to start (4 diodes and associated caps).
This would get you to about 3-3.6Kv of bias voltage and you wouldn't have to turn your amp up as high either.
This should be a good value not knowing what the maximum voltage the stepp-up transformer is designed for, but it should be able to handle that range.
As far as a crossover rebuild I would seriously consider an active system first, But that is your call.
FWIW
jer
Unfortunately an active crossover isn't in the cards. Since I have all new components for the crossovers save one inductor and one capacitor it would be a lot cheaper to make what I have work.
Either I'm not getting sufficient voltage out of the power supply or something in the crossover is attenuating my mid/high frequencies. The woofers are easily twice as loud as the panels. Maybe more.
I'm going to try and pick up the resistors I need to directly check the PS voltage. If/when I do how many volts am I looking to get if the PS is up to spec?
Thanks
Eric
Either I'm not getting sufficient voltage out of the power supply or something in the crossover is attenuating my mid/high frequencies. The woofers are easily twice as loud as the panels. Maybe more.
I'm going to try and pick up the resistors I need to directly check the PS voltage. If/when I do how many volts am I looking to get if the PS is up to spec?
Thanks
Eric
When you get it all setup, Measure the voltage at the point directly out of the multiplier before the other resistors feeding the diaphragm.
It shows a 30Meg in the schematic but by the looks of your photo this is made up of several resistors.
You can however use those as well as long as you can verify their actual value and include that in to your computation of the voltage divider to get an accurate reading.
In all of the dividers I have made I measured each individual resistor and added them all up in order to add the proper amount at the bottm inorder to get the best accuracy I could within 1% or better and then I use a small trimmer to get an exact adjustment.
But you can still get within 5% or better just using off of the shelf parts with out going to such extremes.
If you don't use an opamp buffer you must include your meters input resistance in to the equation.
I have shown in an example that this can be as much of 5% or more error (less voltage than there actually is) in your voltage reading in the posted link below.
Refer to post #37 where Bolserst has calculated the values you should be looking for,
http://www.diyaudio.com/forums/plan...me-fix-these-poor-ml-sequels.html#post3787326
And, Refer to this thread for more info on this exact same matter (particularly starting as post #5),
http://www.diyaudio.com/forums/plan...easure-bias-voltage-acoustat.html#post3791120.
If you already have the crossover components that is fine just make sure that they are of the same values that where already in it.
I don't think that there is any issue with them anyhow unless you actually know that one of the parts is faulty.
ML's are not know for bright sizzling highs from what I gather and remember (11 years ago).
All the FR graphs I have seen, They seem to roll off early quite a bit on the high end.
jer
It shows a 30Meg in the schematic but by the looks of your photo this is made up of several resistors.
You can however use those as well as long as you can verify their actual value and include that in to your computation of the voltage divider to get an accurate reading.
In all of the dividers I have made I measured each individual resistor and added them all up in order to add the proper amount at the bottm inorder to get the best accuracy I could within 1% or better and then I use a small trimmer to get an exact adjustment.
But you can still get within 5% or better just using off of the shelf parts with out going to such extremes.
If you don't use an opamp buffer you must include your meters input resistance in to the equation.
I have shown in an example that this can be as much of 5% or more error (less voltage than there actually is) in your voltage reading in the posted link below.
Refer to post #37 where Bolserst has calculated the values you should be looking for,
http://www.diyaudio.com/forums/plan...me-fix-these-poor-ml-sequels.html#post3787326
And, Refer to this thread for more info on this exact same matter (particularly starting as post #5),
http://www.diyaudio.com/forums/plan...easure-bias-voltage-acoustat.html#post3791120.
If you already have the crossover components that is fine just make sure that they are of the same values that where already in it.
I don't think that there is any issue with them anyhow unless you actually know that one of the parts is faulty.
ML's are not know for bright sizzling highs from what I gather and remember (11 years ago).
All the FR graphs I have seen, They seem to roll off early quite a bit on the high end.
jer
Ok. We may have a problem. I measured the primaries of the audio transformers and I only get .3 ohms. Exactly on both. I switched to new dmm leads and put in new batteries to make sure.
I read a post by Calvin that says this should be less than 10ohms. Well this is less than ten and not a dead short. I also know I get a significant increase in voltage out of them.
Am I OK?
Thanks
Eric
I read a post by Calvin that says this should be less than 10ohms. Well this is less than ten and not a dead short. I also know I get a significant increase in voltage out of them.
Am I OK?
Thanks
Eric
What you are measuring is the DC resistance of the winding.
The inductance of the primary winding will determine the impedance that the amplifier will see at the lowest frequency's.
I explain some of that in this post,
http://www.diyaudio.com/forums/plan...nolith-iii-transformer-specs.html#post3811926
"At the lowest frequency's the ESL's reactance is very very high, and, has little to no effect on the impedance at the lowest frequency's and it is the Transformers primary inductance that determines the impedance at this point."
jer
The inductance of the primary winding will determine the impedance that the amplifier will see at the lowest frequency's.
I explain some of that in this post,
http://www.diyaudio.com/forums/plan...nolith-iii-transformer-specs.html#post3811926
"At the lowest frequency's the ESL's reactance is very very high, and, has little to no effect on the impedance at the lowest frequency's and it is the Transformers primary inductance that determines the impedance at this point."
jer
I can't help you with getting them apart except that, "Do it Very Very Carefully" so that you don't lift or rip the Diaphragm.
Then once you have them apart clean the diaphragm with some Acetone and/or denatured alcohol.
If you do use acetone make sure that you don't get it on the stator's or any other parts except the diaphragm.
It can/will melt plastics and paints.
But, It won't hurt the Mylar.
Else, Just use Alcohol as it is safer in this matter.
Make that it is absolutely clean with no discolorations coming off on to your cleaning pad.
As according to "How its Made TV" they where lastly coated with a graphite slurry and this has been discussed many time before.
Any that is left over will get encapsulated in the new coating but it is the loose surface particles and residual oils, smoke tar, Finger Prints and dirt that we are concerned about at this point.
Use a lint and oil free cloth or paper towel.
I just use a soft paper towel or something as long as it can't scratch the Mylar.
I have used toilet tissue papers as well.
Again just make sure that it is a lint free type that is not oily, and, doesn't break apart easily.
Or else you will have extra work getting the fibers off.
A vacuum cleaner with a soft brush attachment works nicely a well for this.
Before you start coating, "Shake the can Well" !!!
I would also spray some out First to get the supply tube filled up with the consistency of the material that is in the can.
As it will be thinner and not have the same characteristics when you start at the top of your panel by the time you get to the middle and bottom of the panel.
This would be a good time to use that waste, to spray a folded up paper towel or Foam brush with.
If you use a paper towel you will see how the color of the stuff coming out will darken as the mixed material starts to fill the supply tube.
"Do Not Discard This" as you may need to use it shortly!!
As you start spraying use the same overlapping methods that you would use with a can of spray paint.
To insure a nice even and wet coat.
Watch the coating against the light to make sure that the panel is evenly covered and wet.
You may notice it start to bead up causing some dry some spots and there is two things you can do about this.
1#~You can add more to this area or wait for it to cure some and give it a second coat.
Or,
2#~ You can use the paper towel or foam brush that you just wetted and swab the panel as you go.
This may cause some streaking of the coating, But it will still dry pretty very clear for the most part.
Charlie M has more experience at coating larger panels then I do.
But this is the basic process that I used when I reported my first use upon my discovery of the newer "Crystal" version of Licron before anyone else has ever tried it.
Charlie does say that humidity plays the most important role of any cloudiness that may occur.
The very First time I ever sprayed it on to some scrap Mylar to test its durability it was very dry at the time (winter), and, there was no visible indication that there was even a coating on it to begin with !!!
That is how thin the stuff cures too!!
Charlie has confirmed that the coatings thickness is in the order of only a few microns or 1/1000 of a mm!!!
Replacing the copper strip may not be necessary.
But, I would definitely rub it down with some fine steel wool to get it super clean with no oxidation on it.
Else, you can consider using aluminium foil tape or even a simple painted on DIY graphite charge ring if corrosion is a major concern for you.
I have used both of the above methods with no issues of degradative corrosion issues.
Just make sure that you scuff up the aluminium real good as well and it will last for many many years to come.
Using copper for a charge ring is only a purative thing.
It makes NO difference in performance of the panel at such high voltages whether you use a charge ring of a bit more resistance to it or not!
Having to re-do everything because of a poor choice of materials is of the most major concern here!!
When I First built my panels in 2003 I was going to use some Pure Gold conductive spray paint (as a can of it was a bit affordable then) for a charge ring, so that it would never ever corrode!!
Later I found the Nickel Print conductive paint, and, that was a more cost effective solution as it never tarnishes either.
I never did get a can of it and I used aluminium foil instead.
Then in 2010 I discovered my graphite technique and it has yet to fail me since then as well.
Not to mention that it is by far the cheapest method in the cost of materials.
I suppose that it could be made out of a single soft grade pencil.
But I have had a huge jar of it for about 30 years now from when I had First learned to use it as a diaphragm coating.
jer
Then once you have them apart clean the diaphragm with some Acetone and/or denatured alcohol.
If you do use acetone make sure that you don't get it on the stator's or any other parts except the diaphragm.
It can/will melt plastics and paints.
But, It won't hurt the Mylar.
Else, Just use Alcohol as it is safer in this matter.
Make that it is absolutely clean with no discolorations coming off on to your cleaning pad.
As according to "How its Made TV" they where lastly coated with a graphite slurry and this has been discussed many time before.
Any that is left over will get encapsulated in the new coating but it is the loose surface particles and residual oils, smoke tar, Finger Prints and dirt that we are concerned about at this point.
Use a lint and oil free cloth or paper towel.
I just use a soft paper towel or something as long as it can't scratch the Mylar.
I have used toilet tissue papers as well.
Again just make sure that it is a lint free type that is not oily, and, doesn't break apart easily.
Or else you will have extra work getting the fibers off.
A vacuum cleaner with a soft brush attachment works nicely a well for this.
Before you start coating, "Shake the can Well" !!!
I would also spray some out First to get the supply tube filled up with the consistency of the material that is in the can.
As it will be thinner and not have the same characteristics when you start at the top of your panel by the time you get to the middle and bottom of the panel.
This would be a good time to use that waste, to spray a folded up paper towel or Foam brush with.
If you use a paper towel you will see how the color of the stuff coming out will darken as the mixed material starts to fill the supply tube.
"Do Not Discard This" as you may need to use it shortly!!
As you start spraying use the same overlapping methods that you would use with a can of spray paint.
To insure a nice even and wet coat.
Watch the coating against the light to make sure that the panel is evenly covered and wet.
You may notice it start to bead up causing some dry some spots and there is two things you can do about this.
1#~You can add more to this area or wait for it to cure some and give it a second coat.
Or,
2#~ You can use the paper towel or foam brush that you just wetted and swab the panel as you go.
This may cause some streaking of the coating, But it will still dry pretty very clear for the most part.
Charlie M has more experience at coating larger panels then I do.
But this is the basic process that I used when I reported my first use upon my discovery of the newer "Crystal" version of Licron before anyone else has ever tried it.
Charlie does say that humidity plays the most important role of any cloudiness that may occur.
The very First time I ever sprayed it on to some scrap Mylar to test its durability it was very dry at the time (winter), and, there was no visible indication that there was even a coating on it to begin with !!!
That is how thin the stuff cures too!!
Charlie has confirmed that the coatings thickness is in the order of only a few microns or 1/1000 of a mm!!!
Replacing the copper strip may not be necessary.
But, I would definitely rub it down with some fine steel wool to get it super clean with no oxidation on it.
Else, you can consider using aluminium foil tape or even a simple painted on DIY graphite charge ring if corrosion is a major concern for you.
I have used both of the above methods with no issues of degradative corrosion issues.
Just make sure that you scuff up the aluminium real good as well and it will last for many many years to come.
Using copper for a charge ring is only a purative thing.
It makes NO difference in performance of the panel at such high voltages whether you use a charge ring of a bit more resistance to it or not!
Having to re-do everything because of a poor choice of materials is of the most major concern here!!
When I First built my panels in 2003 I was going to use some Pure Gold conductive spray paint (as a can of it was a bit affordable then) for a charge ring, so that it would never ever corrode!!
Later I found the Nickel Print conductive paint, and, that was a more cost effective solution as it never tarnishes either.
I never did get a can of it and I used aluminium foil instead.
Then in 2010 I discovered my graphite technique and it has yet to fail me since then as well.
Not to mention that it is by far the cheapest method in the cost of materials.
I suppose that it could be made out of a single soft grade pencil.
But I have had a huge jar of it for about 30 years now from when I had First learned to use it as a diaphragm coating.
jer
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.