I was thinking about trying a few months ago. To do a good lightweight job you need a mill. Bass should not be a issue, since the ribbon won't have enough length to flap it can be driven hard. I might start thinking about it again, i don't see any reason it wouldn't work.
In any case its going to be heavy and require a few watt or so to drive.
Edit: How about 20 1" x 1/2" x 1/8" to form 4 5" strips? Might not be too heavy.
In any case its going to be heavy and require a few watt or so to drive.
Edit: How about 20 1" x 1/2" x 1/8" to form 4 5" strips? Might not be too heavy.
It would be fine to try 2,5um thick, 3/16"x1,5" foil with offset:
http://tinyurl.com/2sjb33
One strip in microphone mode and horizontals stack in reproduction mode (if necessary).
http://tinyurl.com/2sjb33
One strip in microphone mode and horizontals stack in reproduction mode (if necessary).
Hi setmenu,
Could you write me in private how did you photocopied and etched the coil? I want to repair my Technics orthodynamic headphones. The diphragm of one side is damaged, the other is intact, and I intend to use the intact diphragm as masking film in order to produce the copy. But I have no experience in photoresist copying process.
Thanks,
Laszlo
Could you write me in private how did you photocopied and etched the coil? I want to repair my Technics orthodynamic headphones. The diphragm of one side is damaged, the other is intact, and I intend to use the intact diphragm as masking film in order to produce the copy. But I have no experience in photoresist copying process.
Thanks,
Laszlo
Hi Laszlo
I am not familiar with the Technics phones.
Do you have the correct spec diaphragm material to make your replacement from?
Are the coil traces very thin and closely spaced?
Could be pretty difficult to get match with the original.
I designed mine using pcb design software and sent the the gerber file and my flexible copper clad laminate sample off to a professional to do the etching.
Though for my first attempt I actually drew the traces with a needle pen filled with etch resist ink.
That worked well for the first model but was too difficult for finer traces on very thin film for the second model.
Mark
I am not familiar with the Technics phones.
Do you have the correct spec diaphragm material to make your replacement from?
Are the coil traces very thin and closely spaced?
Could be pretty difficult to get match with the original.
I designed mine using pcb design software and sent the the gerber file and my flexible copper clad laminate sample off to a professional to do the etching.
Though for my first attempt I actually drew the traces with a needle pen filled with etch resist ink.
That worked well for the first model but was too difficult for finer traces on very thin film for the second model.
Mark
Hi Mark,
Yes, I have correct diaphragm material (I think). It is a household pvc foil aluminized on one side. It is very thin, it seems suitable for the purpose. The traces are very thin and closely spaced, indeed. There are about 10 traces in 5 mm.
I do not need to make a film/file, because the good diaphragm can be used as a photomask. My problem is to find a company who can do the photographic and etching procedure in small quantity. Maybe I will try with a PCB photoresist lacquer (Positiv 20), but I am not confident in the success.
Laszlo
Yes, I have correct diaphragm material (I think). It is a household pvc foil aluminized on one side. It is very thin, it seems suitable for the purpose. The traces are very thin and closely spaced, indeed. There are about 10 traces in 5 mm.
I do not need to make a film/file, because the good diaphragm can be used as a photomask. My problem is to find a company who can do the photographic and etching procedure in small quantity. Maybe I will try with a PCB photoresist lacquer (Positiv 20), but I am not confident in the success.
Laszlo
oshifis said:
Even if you manage to find someone to make the copy for you, chances of it matching the mass, tension, and performance of the original are nil. I think it would make much better sense to look for another pair of those headphones on Ebay and then do some surgery if necessary. You'll get exactly what you need and it will probably cost less in the end.
I_F
You can likely do a credible job using the original diaphragm as a 1:1 mask for photoresist. I'd test the process using something else first, to minimize the handling of the original, to be sure you have good, high resolution photoresist, and you have figured out how to apply it properly and expose & develop it properly.
But the problem is likely to be elsewhere.
Commercially metalized plastic film has the metalization in the thinest possible thicknesses for color only. That means it will be insufficient to handle the power required by a diaphragm.
(PVC is also low temp stuff - maybe you mean polyester/mylar??)
You need a thicker trace on ur new diaphragm than most metalized films will have.
No harm in trying the experiment.
The flex PCB material is an interesting idea, but their thinest is likely too thick (too much mass) for a good diaphragm.
That's why these are usually done by large companies who have the resources to put together the combination of diaphragm material, thickness and trace accuracy and thickness plus the right bonding agent for the foil trace vs. heat.
_-_-bear
But the problem is likely to be elsewhere.
Commercially metalized plastic film has the metalization in the thinest possible thicknesses for color only. That means it will be insufficient to handle the power required by a diaphragm.
(PVC is also low temp stuff - maybe you mean polyester/mylar??)
You need a thicker trace on ur new diaphragm than most metalized films will have.
No harm in trying the experiment.
The flex PCB material is an interesting idea, but their thinest is likely too thick (too much mass) for a good diaphragm.
That's why these are usually done by large companies who have the resources to put together the combination of diaphragm material, thickness and trace accuracy and thickness plus the right bonding agent for the foil trace vs. heat.
_-_-bear
bear,
I see what you mean. The commonly available foil is vacuum metalized indeed, used for flower etc wrapping. Thas has infinite resistance, when measured between any close points. Mine is different, the aluminium layer is relatively thick and it has low resistance at distant points.
BTW, is there any formula to calculate the resistance between two points on an infinite surface? From such measurement one could calculate the alu layer thickness, if the formula were known.
Laszlo
I see what you mean. The commonly available foil is vacuum metalized indeed, used for flower etc wrapping. Thas has infinite resistance, when measured between any close points. Mine is different, the aluminium layer is relatively thick and it has low resistance at distant points.
BTW, is there any formula to calculate the resistance between two points on an infinite surface? From such measurement one could calculate the alu layer thickness, if the formula were known.
Laszlo
I have tried using aluminized film myself.
It was from some packaging.
It was giving a low resistance between points and when tested did work.
But the thinness of the film meant very low power handling.
couple this with the relative inefficiency of the driver and the film
failed quite quickly when asked to do any work.
The aluminium definitely needs to be in the order of microns rather Angstroms in thickness!
My target range for copper would have been in the region 3-6 microns depending on trace width etc.
I have only managed to source 9 micron thus on 12 of polymide [adhesive-less] thus far.
Aluminium laminates are a different ball game, had not luck in sourcing anything that was lighter than the copper combo.
It was from some packaging.
It was giving a low resistance between points and when tested did work.
But the thinness of the film meant very low power handling.
couple this with the relative inefficiency of the driver and the film
failed quite quickly when asked to do any work.
The aluminium definitely needs to be in the order of microns rather Angstroms in thickness!
My target range for copper would have been in the region 3-6 microns depending on trace width etc.
I have only managed to source 9 micron thus on 12 of polymide [adhesive-less] thus far.
Aluminium laminates are a different ball game, had not luck in sourcing anything that was lighter than the copper combo.
Etching wires make sense for speakers IMHO because you need some gap between them and have a space.
http://www.diyaudio.com/forums/showthread.php?postid=1788584#post1788584
Capacitor foil isn't bad if you have a right transformer. Otherwise try to ask for double metallization - easy to find locally. Only one layer has ca. 1kOhm (good for a microphone). I had Chinese address for 2-3 micrometer aluminium foil but I don't like Chinese people - they says yes yes yes and nothing happens then.
http://www.diyaudio.com/forums/showthread.php?postid=1788584#post1788584
Capacitor foil isn't bad if you have a right transformer. Otherwise try to ask for double metallization - easy to find locally. Only one layer has ca. 1kOhm (good for a microphone). I had Chinese address for 2-3 micrometer aluminium foil but I don't like Chinese people - they says yes yes yes and nothing happens then.
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