[Brapp]

that's awsome!!
im' kinda new in diy so im easily impressed but those are awsome!!!

 

[koikoi]

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.

The design of the amp is just amazing.

 

[koikoi]

Hi 12517,

Can you at least let us know a little about yourself? Do you have a CNC mill?

As you can see, I have built so many different versions. Which version would you like to build?

Wachara C.

Dear chinsettawong,
This is a really long post and I have not finish reading the whole post yet.

I did not see any scheme design of the earphone. According to the information I have learnt from the first 22 pages of this post (this is so far I have read), I draw this picture. Did I understand correctly to your design?


Thanks.
koikoi

 

[chinsettawong]

Hi koikoi,
 
Your understanding is correct.  The only thing that I will add to your drawing is that I glue the dust cover on a 1mm spacer.
 
I coat only one side of the diaphragm that is the one facing the ear.  The bias voltage now is at 570V which is similar to what Stax is using.
 
Wachara C.

 

[koikoi]

Hi koikoi,

Your understanding is correct.  The only thing that I will add to your drawing is that I glue the dust cover on a 1mm spacer.

I coat only one side of the diaphragm that is the one facing the ear.  The bias voltage now is at 570V which is similar to what Stax is using.

Wachara C.

Hi Wachara C,
Thank you very much for the reply! I never expected to get your reply so fast. Everything you shared on the forum helps DIYers like me to save a lot of time and money.

You coat on the facing-ear side of the diaphragm only, so the 570V bias voltage is only connected to the PCB spacer that contacts the coating side of the diaphragm?

Do you put glue on the other side at where it contacts the spacer or you glue on both sides? Have you tried to coat on both sides? I guess this may increase the sensitivity of the speaker. Just a guess, I have forgotten everything learnt from electronics courses in school.

I have some more questions, please forgive me, while reading the post, I have got lots of questions. How do you apply the staticide to the diaphragm? Do you spray or use a tool like a brush? How much staticide should be applied on to the diaphragm?

You mentioned previously, the size of diaphragm is important. I am planning to make some pairs portable headphones with smaller diaphragm, eg. Φ=40mm or even smaller like the Stax SR-001. While I reducing size of the diaphragm, what other elements do you think I need to change in order to maintain the SQ in a good level? At least you can give me some directions I can do experiments with.

These are a lot of questions. I will thank you for your time to reading my post first.

Best wishes,

Koikoi

 

[koikoi]

Following my last post, I have read only about half of the post(22 pages). If you have answered my questions somewhere in the post already, please just tell me to go back to read. I know to keep answering everyone's questions in a long time is a hard work.

Thanks again for sharing everything.

Koikoi

 

[chinsettawong]

Hi koikoi,
 
There have been some experiments done by other DIYers that show no noticable difference between coating one side versus 2 sides.  I didn't bother to try it.
 
I always glue the diaphragm to only one of the spacers.  The other spacer is used as a charge ring for the diaphragm. 
 
About the diaphragm size, if you are going to make a pair of full size, over the ears headphones, go for the biggest diaphragm size you can make.  To achieve good low frequency response, you need a large diaphragm area.   Diaphragm diameter of 40 mm won't give you good bass.
 
I don't know anything about SR-001 type headphones.  I've never listen to them. 

 
Please feel free to ask anything you like.  I don't mind at all.
 
Wachara C.

 

[koikoi]

Hi Wachara,

Thanks for your good advises. I think it is a safe way to just follow your steps while building my first pair of ESL headphones.

And, how do you apply the staticide to the diaphragm? Do you spray or use a brush? How much staticide do you apply on to the diaphragm?

Best regards,
Koikoi

 

[chinsettawong]

I put a small drop of Staticide on the diaphragm and wipe it with a sponge.  You only need a very thin coating on the surface. 
 
Wachara C.

 

[koikoi]

Thanks Wachara. It is very kind of you. I think now I am able to make my own ESL headphones.
Best wishes,
Koikoi

 

[chinsettawong]

Go for it! 

 
Wachara C.
 

 

[koikoi]

Is there anyone has an idea that can I use a 5-pin XLR connector and 2 x 3-pin mini XLR connectors (on the headphone side) to make a custom ESL headphones cable? I am not sure about the breakdown strength between the pins of XLR connectors. They are not designed to carry the 570V high voltage.

Thanks
Koikoi

 

[bidoux]

I have been using a 3 pins XLR connector for my mono prototype. Although this is not respecting the XLR's datasheet I am not sure it is an actual issue. On a related thought, as anyone found male stax plug ? I still have the female sockets Franck Cooter gave away but can't match it yet ...

 

[spritzer]

Allied Electronics have the male plugs. 
 
http://www.alliedelec.com/search/productdetail.aspx?SKU=70144660

 

[bidoux]

Thanks Spritzer
Though it seems that this connector needs to be inserted in some sort of housing to make it usable. Maybe a XLR shell ?