[chinsettawong]

@bui501-tech came to see me today at my office. I showed him all my 3 versions of headphones, KGSS Carbon, and KGST. He seemed to like my Omega clone and KGST a lot. He did a very good job on his electrostatic headphones drivers. They sounded really nice. He also CNC his own Stax jack and cast the exact duplication of Stax plug. One of these days I'll need him to come to teach me how to cast the plug.

 

[bui501-tech]

@bui501-tech came to see me today at my office. I showed him all my 3 versions of headphones, KGSS Carbon, and KGST. He seemed to like my Omega clone and KGST a lot. He did a very good job on his electrostatic headphones drivers. They sounded really nice. He also CNC his own Stax jack and cast the exact duplication of Stax plug. One of these days I'll need him to come to teach me how to cast the plug.

Thank you for an amazing afternoon, Chinsettawong! I want more than ever to build my own headphones after hearing your headphones, especially the Omega clone. Those were the best sounding headphones I've ever heard. And of course, I now want my own tube amp after seeing your KGST in the wooden case.

We can make some plugs after I get back from vacation -- I've already ordered the teflon for the cores.

 

[Whitigir]

Hey DIY folk, are you interested in our Stax Pro compatible amplifier plugs for your projects? We'd be happy to make them available if the answer is yes.

They're solid machined Teflon with machined OFC gold plated pins and a solid AL casing. Works best with round cables, though with some craftiness flat cables can transition to the hole...

I will be interested in this for sure ! Waiting on the pricing and availability

 

[chinsettawong]

Thank you for an amazing afternoon, Chinsettawong! I want more than ever to build my own headphones after hearing your headphones, especially the Omega clone. Those were the best sounding headphones I've ever heard. And of course, I now want my own tube amp after seeing your KGST in the wooden case.

We can make some plugs after I get back from vacation -- I've already ordered the teflon for the cores.

Let's get together again. I'm really looking forward to listening to your headphones and KGST.

Since this afternoon, thanks to you, I've been researching on how to mold and cast things. I think I get some ideas now. I'll try to make something before you come back from vacation.

By the way, I did notice that my Stax SR007 didn't get much of your ear times at all. Did my phones sound better?

 

[bui501-tech]

By the way, I did notice that my Stax SR007 didn't get much of your ear times at all.

The omega clone sounds a lot better than the stax. I was seriously considering purchasing an Sr007based on its reputation, but hearing the side-by-side comparison of it with your headphones showed me it is possible to make DIY electrostatic headphones that are even better sounding.

I didn’t listen to your larger rectangular headphones as much because it was too large for my head, but I thought it sounded fuller than both the SR007 and your omega clone—you described it as having a wider sound stage, I think? I really, really like that sound.

I’m going to increase the size of my drivers. I’m also going to try the 3μ mylar that I have as you had suggested. What do you recommend as the max active area? (I’m using .054mm FR4 as spacers.). So many things to try, so little time...

 

[chinsettawong]

Everything is relative. With the standard Stax bias voltage of around 580V, for a round shape driver, a 80 mm diameter active area and 0.5 mm thick spacer is ideal.

When we meet next time, please spend more time with my Orpheus clone and JF clone. I'm sure that you'll come to like them better too.

 

[statfi]

Newbie to this thread...
Can anyone point me to an electromechanical equivalent circuit of electrostatic headphones? I.e., something like the Thiele-Small model for loudspeakers applied to electrostatic headphones.
At what frequency is the fundamental drum-mode resonance of the diaphragm? Pointing me to URL would be as good as a typed answer !-)

 

[MrSlim]

Newbie to this thread...
Can anyone point me to an electromechanical equivalent circuit of electrostatic headphones? I.e., something like the Thiele-Small model for loudspeakers applied to electrostatic headphones.
At what frequency is the fundamental drum-mode resonance of the diaphragm? Pointing me to URL would be as good as a typed answer !-)

Good luck with that...
Some of the variables that would have to be taken into account would be driver size, film thickness and tension, if you are looking at the resonant frequency of the driver. A manufacturer of who is producing a consistent product may be able to tell you that, but it's difficult to imagine that they would divulge that kind of info.
Maybe mylar film mfrs provide those kind of details?

 

[quintile]

I will bite

I have repaired some Micro Seiki MS2 headphones, replacing the diaphragms.
I have found the best LF response comes from a diaphragm resonance of 270hz
witch seems very high I agree but thats my experience.

I use 2micron mylar and the diaphragm are about 50mm in diameter.

I would say that the LF response of electrostatic headphones is a mystery to me,
I have a set of parameters which seem to work but when I adjust any of the parameters
I cannot consistently improve the LF performance.

-Steve

 

[chinsettawong]

Newbie to this thread...
Can anyone point me to an electromechanical equivalent circuit of electrostatic headphones? I.e., something like the Thiele-Small model for loudspeakers applied to electrostatic headphones.
At what frequency is the fundamental drum-mode resonance of the diaphragm? Pointing me to URL would be as good as a typed answer !-)

I do not understand your question. But if you want to see some frequencies response curves of some of my DIY headphones, here is the link https://www.innerfidelity.com/content/extraordinary-diy-electrostatic-headphones-chinsettawong

 

[Muamp]

Hi Statfi,

An electrostatic panel can be considered as a capacitor, and behaves as if an equivalent capacitor of the same capacitance where to replace the panel.
The panel capacitance can be measured or calculated, Eo.Er.A/D
A = panel area, D = distance between plates (D = 2 * d, which is the distance from panel to diaphragm).
Normally the area would be multiplied by 2/3 or 3/8... depending on the panel to hole ratio.
All this and MUCH more is in the free book, by Frank Verwaal, the URL has been mentioned many times in this thread, but I cannot remember what it is without looking back.....

The resonant frequency can also be measured or calculated, the measurement method can give a wide spectrum of results but gives a ball park figure. Using a microphone, tap the diaphragm lightly and record the sound, even ‘Audacity’ can be used to see the frequency response and show the peak frequency. The resonant frequency will be dependant on the wavelength (2* shortest distance of panel surface), tension of diaphragm and mass of diaphragm. The resonant frequency will be the ‘peak’ in the response, not the LF cut off.

David.

 

[jgazal]

(...)
Can anyone point me to an electromechanical equivalent circuit of electrostatic headphones?
(...)
Pointing me to URL would be as good as a typed answer !-)

Try this:

https://web.archive.org/web/20150103093849/http://headwize.com:80/?page_id=722

Not sure if it is 100% accurate, but I guess it might be a good place to start.

 

[statfi]

Thanks so much for the references! Forums work.
I need to do a lot of reading here and there, but, for building loudspeakers the fundamental resonance is like the first thing you decide on. With DIY 'stat's I imagine you have to control the tension on the diaphragm when you mount it to a ring. Is the tension of primary concern, or is it sort of a secondary consideration?
(In another life I built a lot of loudspeaker systems. In a future life I hope to build ES cans !-)

 

[Muamp]

Hi jgazal,

Interesting link! especially the J.P. Wilson panel part.
It is the first time I’ve seen that electrical/mechanical equivalent circuit.
Also interesting, the spacer thicknesses he used 0.04” (1mm) and 0.025” (0.635mm) and assosiated comments.

David.

 

[inuponken]

Hi Chinsettawong,

Thank you for sending me the new double-sided stators and spacers for the Orpheus clone.
I made extra spacers with 0.8 mm PCB in case the 0.5 mm spacer is unstable with my diagram tension.

I need protect very thin moisture/dust cover film on the front, however sound clarity decreases if place a speaker grill to the front. It looks ugly, but I end up with a fiberglass window screen.

For the headband, I am modifying Sony MDR7506 Head Band that purchased at e-bay.
This is not genuine replacement part from Sony and quality is inferior to original, but it is good for the price.

Wood frames, the first one failed at drilling so I’m making another pair… painting now.