Has anybody made an ELS headphone?

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I tested a 0.4 mm spacer with food wrap plastic as diaphragm. I have to say that I am now very confused. I can't get any sound at all at 600V, 900V or even 1200V. I check and check for any mistake that I might have done and I couldn't find any.

My configuration now is 1mm stator, 0.4mm spacer, diaphragm, 0.4mm spacer, and 1mm stator. I coated the diaphragm with graphite powder this time.

Is it possible that the diaphragm was suck to one side? How can you tell if that is the case?

:bawling:

Wachara C.
 
Atarashi,

It's all my own fault. My conductive material doesn't contact with the diaphragm very well and therefore no electricity goes to the diaphragm. I also have a problem with my 0.4 mm and 0.5 mm spacer. I have tried a few type of glues and they don't stick to the diaphragm well. I now go back to my original spacer which is 1 mm thick and I am using around 1200V as bias voltage.

I've just found out also that I had a mismatch of impedances between the output of my amplifier and the input of my headphone. I now use 4 ohm output tap from my 2A3SE to drive the headphone and it is now singing beautifully.

I am still searching for a thinner material to use as spacer and also a thinner mylar. But as for now, I'm happy.

Wachara C. :)
 
Well, good to hear that you make progress!

try to find a thinner diaphragm, and spacers in the 0.5 - 0.6 mm region, and with around 600V bias and either a nice step-up or (better?) a direct drive amp you will see what is really possible with electrostatic headphones...
(hint: a lot!)

so, good luck and enjoy your headphones!
 
Atarashi,

Thanks for all your help. I have just tried the headphone with my 6528SE amp and my pre amp, and it sounds even better. I can't wait to build a headphone amp for it.

Yes, I will try to source the spacer and diaphragm material. Now that I know what I am doing, I might build a pair of speakers.

:D
 
Well, I few months have passed, and I have finished making two models of ES headphone. I just want to post some pictures here and to thank you all for helping me making this project a success.

Wachara C
 

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Here it is with the cushions on. The diaphragm that I am using now is 6 microns mylar. The bass goes down a lot lower than 11 microns food wrap. I wonder if I change to something even thinner, will the low frequency response be even better?
 

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Hi,

beautiful work man ;)
I´m going to get my coated stator sheets today. I´ll try 1.2µm film.
The improved bass response could be a matter of ´creating´ a small closed chamber between membrane and head by using the cushions.
Measured freely a lot of HPs have a falling response below ~100Hz.
Its the chamber formed by the cushions, the membrane and the head that ´improves´ the bass response.

jauu
Calvin
 
Hi Calvin,

The thickness of the diaphragm really does make a difference in the low frequencies response. I started my 2nd version with 11 microns diaphragm. Only later that I was given the 6 micron mylar by a friend. With everything else stays the same, the difference in low frequencies is just too much to go unnoticed.

Where do you get the 1.5 microns material from? I really like to try.
 
I haven't read all the posts so somebody may have mentioned this already but a good coating is "Aquadag". This was used in earlier Wireless World (Electronics World) DIY headphones designs and is a graphite based liquid. I owned some 20 yrs ago. Used in cathode ray tubes. Might be worth following up. Good luck.
 
Hi SM7UYJ,

Yes, I machined the frame using my CNC as well. It is only difficult when I first design it. After that, the machine does all the work for me. The material is plastic. I use 5 mm for the back cover and 10 mm for the front cover. I got the plastic sheets for free from my friend who uses it for making sign board and advertising stuffs.

I really like your ESL, and I'm going to make a pair similar to yours.

Wachara C.
 
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