My DIY electrostatic headphones

Many people have been sending me PMs to ask me about how to fix their dust covers.  Let me post some pictures here to show you how easy it is to replace them.
 
Suppose you have a broken dust cover as shown:
 

 
First you clean up the spacer ring holding the dust cover.  Then take a piece of 1 - 3 micron Mylar and crumple it.  Tape the Mylar on a table.
 

 
Since the Mylar isn't tension, I find 3M 77 spray glue to be very good.  Spray it on the rings and put the rings on the Mylar to glue them down.
 

 
Cut out the ring using the tip of a soldering iron.  Also, you can use the soldering iron tip to melt away the mylar on those screw holes.
 
That's it.
 
Don't be afraid to do it yourself.  

I thought I would have a go at making some large panel On-Ear ESHS.
I decided to make some innovative changes,.....
These have 0.5mm thick FR4 stators instead if 1mm and rather than 2mm holes in the FR4 stator I've used 1.3mm holes allowing the same hole space to copper ratio but more than double the number of holes! Because the FR4 is only 0.5mm thick, I can get away with smaller holes.
Rigidity is my only concern and I may need to add the Stax style "Electrodes" to stiffen the stators.
 





Still constructing the left panel..... I may make some design changes before building it to do more experimenting...
 
David.
 
.

Your driver looks really nice. How big is your active area?
If I were to do a new set of stators, I would try double sided PCB with the thickness of around 0.6 mm. This is what Stax uses for making its stators too.

Your driver looks really nice. How big is your active area?
 
The active area is 70mm. 1.3mm holes.
When using 2mm holes there are 595 holes in an active area of 70mm. when using 1.3mm holes there are 1369 holes for the same 'open' area.
Using 0.5mm spacers.
 
I'm thinking of using a hole in the middle of the stators, as in the SR009....?
That (I believe) uses holes smaller than 0.8mm on a VERY thin sheet of aluminium re-inforced with 'Stax ElectRodes', (3253 holes if you don't subtract the holes under the ElectRodes and the big hole in the middle). I produced the G code this afternoon to cut one. I'm thinking of cutting it out of sheet aluminium. The thinest alumnium I can get at the moment is 0.75mm thick.... a bit too thick.
 
David.

You can find aluminium film down to 0.05 mm on ebay.
 
How good of an amp is the eXSatA compared to other amps you own?

Thanks for that. I will check eBay lists tomorrow.
Mmmm,... Unfortunately I do not have an exStatA, and never had a chance to listen to one either.
I own a Stax SRM252s which even though it is basic and cheap, I love it.
I also have home made Transformer energiser and TubeCAD valve energiser, both ok...., But,
Even though I am a valve fanatic - I prefer solid state energisers, regardless of make or model!
I could go into the modern advancements in valve circuits which I hate,.... CCS's for load resistors,... please, if you want valve - even order (2nd order) harmonic sound, why try to make it sound like a transistor.
Anyway, windge over, if I were to buy one, I would now consider Stax 252s or 323x, even better, I have not heard one yet, but consider Mjolnir KGSSHV (Carbon...).
Kevin Gilmore's designs seem to be ever more popular.

David.

Hi David,
 
The SR007 stator that I investigated was made of probably 3 oz copper clad double sided PCB.  The thickness is around 0.6 mm.  It seems to be very strong and is much stiffer than my 1 mm stator. 
 
It will be interesting to see your aluminum stators.  0.75 mm aluminum should be study enough.  However, I doubt if you will hear better sound than PCB stators though.  
 
Wachara C.

Yes, I accept that the aluminium stator might not sound better after all the extra work, But, If I wish to emulate the SR009 as closely as possible, I might have to try it?
I do not have SR009s, my design comes purrely from Google images, which are pretty good images of the panels out of the cases.
It appears that the stator is very thin aluminium, not foil, with a re-inforcing frame, Stax call 'ElectRodes'. It also has a large hole in the centre.
I could just use 0.5mm double sided FR4, small holes, and a large centre hole.
I can understand how the second layer of copper stiffens the stator. I guess that the outer layer is not electrically connencted.
 
David.

I have both SR007 and SR009.  To me, the thin stators with back reinforcement don't make them better than little thicker and more sturdy stators.  I've often compared my DIY phones with SR009 and SR007.  I really feel that my headphones sound as good.  
 
The SR007 stators are double sided PCB with plate through holes.  So both sides are electrically connected.
 
Wachara C.

Mmmm,.. plated through holes, I didn't expect that.
This may sound like a daft question, are you sure it is not solid copper sheet instead of FR4?
Can you see the edge of the panel and see the fibre glass edging?
 
David.

Oh, yes.  I'm 100% sure.  I've taken apart and fixed a few pairs already.  I even have their exact measurements.  
 
One interesting thing that I can't prove is that I think Stax's diaphragm isn't Mylar.  It's tension is much greater than mine, but the bass is terrific.  I don't know what material that is.  Or is it the tensioning technique?
 
 
Wachara C.

Here is a picture of a stator and spacer which I took a few years ago.
 


Stax uses very thin plastic (Mylar?) spacers to adjust its diaphragm and stator distance.

Thanks for the info'.
I have recently been testing out lower tension on the diaphragm. What you said makes sense, my LT diapragms have not been as good.
I might get some 0.5mm FR4 double sided and work with that instead, using small holes, big centre hole and test it with HT 2u Mylar.
I can't do plated through holes though.....
 
David.

Greetings to all!
 
I'm new to this forum, joining after getting much interest in electrostatic headphones. Recently, I tried the KingSound ES headphones and I really liked them, but the price is beyond affordable.
 
Being a DIY guy and having built several solid state and tube stuff, I decided to search for a DIY ES headphones tube amplifier. In the course of searching, I found out that there is a lot of interesting material on building DIY ES headphones. So, I ended to this thread, which is the most extended and detailed on this subject. Although the, so far, 152 pages of posts seems a little intimidating, I decided to start from page 1 and read thoroughly throughout the entire thread.
 
But, early enough, from page 3, I find that a lot of photos posted by the original thread starter are missing. Probably, going further on this thread, these are not really important, but I'm trying to understand in deep the whole process.
 
My question is whether there is way to have a look at those images that the text refers to.
 
Thank you,
 
Evangelos

Hi Evangelos,
 
I just went to see the 3rd page and yes, for some strange reasons, the old images are gone.  I really can't remember which pictures those are.  However, much have changed since those early days.  The later designs of mine are much more efficient than before.   So, if you want to build something similar, please follow my later designs.
 
I'm still very active here.  So, if you have any questions, feel free to ask.
 
Good luck.
 
Wachara C.