[chinsettawong]

Hi,

I've just joined this site today. I just want to say hi to everybody and show you my version of electrostatic headphones and amplifier. I've successfully made the phones and the amp for about a year now. I just love them.

I hope my work might inspire somebody here.

Wachara C.

 

[dBel84]

That is fantastic , would you mind sharing more details with us. 
 
What stator material you used, what film are you using and how are you charging it .... the usual etc etc
 
welcome to HeadFi ..dB

 

[sachu]

Indeed..that is quite an achievement..congrats!!
 
And yes, please do share some details if you are willing. The builds of both look very nice too.

 

[Uncle Erik]

That is really interesting and I'm very interested in what you did. Would you mind posting some more information about the headphones and can we talk you into sharing the schematics for your amp?

 

[chinsettawong]

Hi,
 
I'm more than willing to share with you my project.
 
First of all let me tell you that I own a DIY CNC router.  It makes my work a lot easier.
 
I use 1 mm PCB for making the stators and spacers.  Everything is cut by my CNC machine.  I have tried many different thicknesses of material for diaphragm - 11, 6, 3, 1.5, and 0.8 micron. They all sound quite nice.  With exception to 11 micron which is a food wrap material, all 6,3,1.5,and 0.8 microns have enough highs and bass for me.  I'm now using 3 microns Mylar and just love it.
 

 

[chinsettawong]

At the very beginning, I didn't know what I was doing and I biased the headphones upto 1200V and the sound was still too soft.  Today, I bias the headphones with 600V.  As for amplifier, I got the design from http://www.tubecad.com/november99/page8.html .  The design is very good and I highly recommend it to anybody who wants to build an amp for his headphones.
 
My headphones design is open back, and I like it better this way.  However, you need a quiet room to listen to good music with this kind of headphones. 
 
Wachara C.

 

[chinsettawong]

Based on the design from www.tubecad.com, I draw up a more detail schematic for the amp:
 

 
Frankly speaking, I have no way to compare this amp to any other direct drive amp for electrostatic headphones as I don't have any other.  Oh,I just noticed that we have an eXStata DIY electrostatic amp in this forum, can someone point me to its schematic diagram, please?
 
Wachara C.

 

[dBel84]

comprehensive information on Alex's web page , there is a link to the HF thread there too. 
 
edit - he is running a group buy now, so if you are interested, I would suggest signing up. 
 
edit again 

 , I see you had already found the GB
 
What coating did you use for the mylar? 
 
..dB

 

[chinsettawong]

Hi dBel84,
 
Thanks a lot for the link.
 
About the coating material for the diaphragm, I use my own formula.  It consists of 2 parts of PVA glue, 5 parts of water and 2 drops of balck poster ink.  Instead of black ink, 1/10 of a part of graphite powder works well too.  What I mean "part" can be a tea spoon.
 
I use a wet sponge to apply the coating material lightly onto the diaphram.  After the coating, the diaphragm should still be very transparent.  The formula works well for me. 
 
Wachara C.

 

[spritzer]

Welcome to HF Wachara. 

 
I have a similar amp to yours (as in it uses the same basic topology, basic phase splitter) but it has ECC83 inputs and a quad of 6S4A's for the output.  It runs on a fully regulated PSU with +/-350V rails and I added some feedback to stabilze it.  Certainly not a bad little amp for the tiny amount it costs to build one, plenty of grunt but a bit limited in ultimate output. 

 

[dBel84]

Thank you Wachara C
 
I am sure I will have many more questions as I try and think through this all, but for now, only one. 
 
Do you have a special trick for tensioning the diaphragm evenly and how do you fix the diaphragm to the holding ring. 
 
..dB

 

[chinsettawong]

Hi Spritzer,
 
I really enjoy being on this forum.  It's my first time to see so many people using electrostatic headphones.  I'm really excited and looking forward to building more amps for my headphones.
 
I am not familiar with 6S4A.  I'll study about the tube and hopefully try what you suggested.
 
Here is another amp of mine - same schematic but in different housing.
 

 
Wachara C.

 

[gurubhai]

Wow! very interesting.
Do you mind posting more pictures & some listening impressions as well ?

 

[vapman]

those headphones look super cool, and i'd love to hear how they sound in general (or against a pair of Stax, maybe). if you ever get a chance to hear a pair of Stax, compare the two! i'd love to build a pair of electrostats one day.
 
i couldn't help but notice, is that just straight up foam you're using as pads? that's insane.

 

[chinsettawong]

Hi dBel84,
 
I use tape to glue and tension the mylar.  For ES speakers, I use a digital weight scale to help me tension every piece of tape to the same tension.  But for headphones, there is no need to do that.  I glue the diaphragm directly to the stators.  After gluing the diaphragms for both side, I knock the diaphragm against a table to check that the sound from both diaphragm is similar.  If they are not, I use hot air to help tension the one with more loose sound.  I hope you can understand what I mean. 
 
Wachara C.