Hello Wachara,
Here is the method I made up for testing the conductive surface of my diaphragms :
"Mousse conductrice" is a piece of conductive foam (used to package CMOS chips)
"Luciole néon" is a miniature 60 to 80 volts neon light
"Alim H.T." is a high voltage source (my Fluke model 407, 550 VDC power supply)
+ 2 crocodiles clips and a high value resistor (10 M) for security
Connect the crocodile clip to the copper surface of the diaphragm frame and touch the diaphragm conductive surface with the piece of conductive foam. If the neon lights on with constant intensity at anyplace on the diaphragm surface, then the diaphragm is OK.
Philippe
Here is the method I made up for testing the conductive surface of my diaphragms :
An externally hosted image should be here but it was not working when we last tested it.
"Mousse conductrice" is a piece of conductive foam (used to package CMOS chips)
"Luciole néon" is a miniature 60 to 80 volts neon light
"Alim H.T." is a high voltage source (my Fluke model 407, 550 VDC power supply)
+ 2 crocodiles clips and a high value resistor (10 M) for security
Connect the crocodile clip to the copper surface of the diaphragm frame and touch the diaphragm conductive surface with the piece of conductive foam. If the neon lights on with constant intensity at anyplace on the diaphragm surface, then the diaphragm is OK.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Philippe
3 pages in and this thread is already turning in to quite a resource.
Wachara, can I ask where you sourced your mylar from?
Wachara, can I ask where you sourced your mylar from?
fwiw I found a supplier of Aquadag in the UK;
http://www.abbey-chemicals.co.uk/index.php?main_page=product_info&cPath=1_2&products_id=43
http://www.abbey-chemicals.co.uk/index.php?main_page=product_info&cPath=1_2&products_id=43
Hi Philippe,
Thanks so much for sharing your techniques.
I use only a multimeter to measure the resistance of 2 points around 1 inch apart. If it shows any value higher than 1 mega ohm, it's good.
Wachara C.
Thanks so much for sharing your techniques.
I use only a multimeter to measure the resistance of 2 points around 1 inch apart. If it shows any value higher than 1 mega ohm, it's good.
Wachara C.
Hi Vaughn,
Do you mean where I get my 1.4 and 0.9 micron mylar from? The link is here: www.indoorspecialties.com . The 1.4 is called Ultrafilm and the 0.9 is SuperUltrafilm.
And thanks for your link.
Wachara C.
Do you mean where I get my 1.4 and 0.9 micron mylar from? The link is here: www.indoorspecialties.com . The 1.4 is called Ultrafilm and the 0.9 is SuperUltrafilm.
And thanks for your link.
Wachara C.
Philippe,
Could you tell us what material you use to coat the diaphragm? I don't see any color. I guess it's not graphite powder.
I use graphite powder.
Wachara C.
Could you tell us what material you use to coat the diaphragm? I don't see any color. I guess it's not graphite powder.
I use graphite powder.
Wachara C.
Thanks for the mylar link Wachara. I'm not sure of the company I linked to for the Aquadag will ship outside the U.K. or not, but it might be worth a try.
Did you use a second non-stretched diaphragm as Philippe did to protect the diaphragm from moisture? Also, did you use a common two part epoxy to attach the diaphragm?
Matt
Did you use a second non-stretched diaphragm as Philippe did to protect the diaphragm from moisture? Also, did you use a common two part epoxy to attach the diaphragm?
Matt
Hi Matt,
Yes, I did make two outer rings with 11 micron film on them to protect outer sides of the stators from moisture. Without them, my sweat would go through the stator holes and shot circuit with the diaphragm. Thailand is hot.
I use 11 micron film on the outside because I feel that I get too much bass out of the 6 micron mylar diaphragm in the middle. It helps reduce the bass a little. But I might change that in the future.
Wachara C.
Yes, I did make two outer rings with 11 micron film on them to protect outer sides of the stators from moisture. Without them, my sweat would go through the stator holes and shot circuit with the diaphragm. Thailand is hot.
I use 11 micron film on the outside because I feel that I get too much bass out of the 6 micron mylar diaphragm in the middle. It helps reduce the bass a little. But I might change that in the future.
Wachara C.
Hello Wachara,
I don't use graphite powder, I know graphite powder, Aquadag (graphite colloïdal), for me it's not reliable. The conductive coating may be sticked strongly to the surface of the diaphragm because the diaphragm vibrates and is submitted to a high electrostatic field.
I use a solution of water with water-soluble acrylic varnish and carbon obtained by pyrolysis of white sugar (like caramel). Carbon may also obtained from white sugar with sulfuric acid. The coating is very thin (< 0.1 µm) and transparent.
Philippe
I don't use graphite powder, I know graphite powder, Aquadag (graphite colloïdal), for me it's not reliable. The conductive coating may be sticked strongly to the surface of the diaphragm because the diaphragm vibrates and is submitted to a high electrostatic field.
I use a solution of water with water-soluble acrylic varnish and carbon obtained by pyrolysis of white sugar (like caramel). Carbon may also obtained from white sugar with sulfuric acid. The coating is very thin (< 0.1 µm) and transparent.
Philippe
Hi Philippe,
Wow, you are very good at everything. Chemistry is something that I would raise a white flag.
Thank you for sharing.
Wachara C.
Wow, you are very good at everything. Chemistry is something that I would raise a white flag.
Thank you for sharing.
Wachara C.
Try to use my method : acrylic water-soluble varnish + antistatic liquid. The slightly conductive coating obtained is dry and have a high electrical efficiency.
My article in "L'Audiophile" february/march 1989, sorry it's in french ! but maybe it can be interesting : http://www.amfoat.org/download/audiophile/n3casque.pdf
My electrostatic headphones with copper rods electrodes. The rods have a diameter of 1.5 mm and are spaced with 1 mm.
Philippe
My article in "L'Audiophile" february/march 1989, sorry it's in french ! but maybe it can be interesting : http://www.amfoat.org/download/audiophile/n3casque.pdf
My electrostatic headphones with copper rods electrodes. The rods have a diameter of 1.5 mm and are spaced with 1 mm.
An externally hosted image should be here but it was not working when we last tested it.
Philippe
Hi Philippe,
I want to know just how many versions of ES headphone have you made? This one with copper rod looks very interesting. How do you like it compare to the other one?
I will try to find the water soluble acrylic vanish. Have you tried to measure how much resistance you can get out of this solution? I mean how many ohm does it measure?
I'm very interested in all your works. Please show us more. 🙂
Wachara C.
I want to know just how many versions of ES headphone have you made? This one with copper rod looks very interesting. How do you like it compare to the other one?
I will try to find the water soluble acrylic vanish. Have you tried to measure how much resistance you can get out of this solution? I mean how many ohm does it measure?
I'm very interested in all your works. Please show us more. 🙂
Wachara C.
Hi Philippe,
Your article is terrific! It's too bad that I can't understand French. I also write an article. It will be publish in the next 2-3 months. I'll show you later. It'll be in Thai, though. 🙂
Wachara C.
Your article is terrific! It's too bad that I can't understand French. I also write an article. It will be publish in the next 2-3 months. I'll show you later. It'll be in Thai, though. 🙂
Wachara C.
Hello MJ Dijkstra,
Measurement was made on samples by the MTO company with optical interferometry. This company made for me vacuum metal plating on electrodes and diaphragms for testings.
Philippe
Measurement was made on samples by the MTO company with optical interferometry. This company made for me vacuum metal plating on electrodes and diaphragms for testings.
Philippe
Philippe,
Beautiful and very inspiring work! If you post any more I will be forced to get to work on a pair myself! Like Wachara I would love to learn more about the conductive solution you applied to your diaphragms.
Beautiful and very inspiring work! If you post any more I will be forced to get to work on a pair myself! Like Wachara I would love to learn more about the conductive solution you applied to your diaphragms.
Phil47 said:
Hello Philippe
Thats sounds nice.
Could you say something about the absolute resistance and its reproducibility, cause that's where problems of carbon based stuff usually are. At a thickness of less than 0,1 micron (which is 100 nanometer) you will be 'close' to the theoretical limits regarding particle size.