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?
Wachara C.
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?
Wachara C.
or, there was no contact between your bias supply and the diaphragm?
you could try holding it up against a light bulb. if you have the correct angle you can see the diaphragm, maybe this works?
you could try holding it up against a light bulb. if you have the correct angle you can see the diaphragm, maybe this works?
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. 🙂
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. 🙂
I tried with lower volatges. At 900V, using a 2A3SE amp and a preamp, the headphone sounds OK. But with 600V, the sound is a little too soft.
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!
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.
😀
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.
😀
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
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.
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.
Your stators and everything look really professional, well done! Do you have more information on that DIY CNC machine? I'd be interested to know how you build it.
You can look for very thin films for model airplanes, they often use values close to 1u film for the wings.
You can look for very thin films for model airplanes, they often use values close to 1u film for the wings.
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.
wow, I'm impressed, they really look very nice!
i hope you have the time to enjoy your "new" headphones.
now that the headphones are working, what about the amp, direct drive or with output transformers?
Michael
i hope you have the time to enjoy your "new" headphones.
now that the headphones are working, what about the amp, direct drive or with output transformers?
Michael
Hi Arend-jan,
I have been playing with my CNC machine for the past few years. I learned a great deal from www.cnczone.com. There is a few open source plans that you show you how to build the machine yourself. If you need more info, please let me know.
Wachara C.
I have been playing with my CNC machine for the past few years. I learned a great deal from www.cnczone.com. There is a few open source plans that you show you how to build the machine yourself. If you need more info, please let me know.
Wachara C.
Hi Atarashi,
The amp directly drives the headphones. I got the circuit drawing from http://www.tubecad.com/november99/page8.html . It sounds really wonderful.
I hardwired the amp, since there are not so many components.
Wachara C.
The amp directly drives the headphones. I got the circuit drawing from http://www.tubecad.com/november99/page8.html . It sounds really wonderful.
I hardwired the amp, since there are not so many components.
Wachara C.
Attachments
Hi Jonathan,
I used graphite powder, and it worked very well. I also have got a can of graphite spray. It seemed to stick to mylar quite well. I haven't really given it a try though.
Wachara C.
I used graphite powder, and it worked very well. I also have got a can of graphite spray. It seemed to stick to mylar quite well. I haven't really given it a try though.
Wachara C.
Nice work!
Have you machined the "frames" for the head phones with your CNC as well ?
What material did you use?
/R
Have you machined the "frames" for the head phones with your CNC as well ?
What material did you use?
/R
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.
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.