[coinmaster]

You get addicted to trying, testing and experimenting with different ideas.

That's my problem, I'm already spending most of my time with amplifier prototypes, I can't afford the time or money to do complete R&D into another subject. I was hoping the people of this thread have worked out all the quirks enough to the point where I could build a high end pair of headphones without spending 2 years on R&D.
Not that I wouldn't go into full R&D mode at a later point, but right now I have everything invested into amplifier design.

 

[janosch simon]

hey gang as my first headphones work i want to get no into detail work :
if i remember correct one member from this thread said that he uses creased mylar foil as sweat and dirt stop but how do you guys fix that on the stator next to the ear? glued loosly on anther spacer?
cheers janosch

 

[chinsettawong]

Hi janosch,

You simply make 2 more spacers and glue the same Mylar on the spacers to make the protective covers. But make sure you don't stretch the Mylar when you glue. Actually you want to crumple it before you glue.

You put these two dust covers on the front and the back of the driver and now you have an air-tight driver that will not be affected by the surrounded dust and moisture.

 

[janosch simon]

nice will give it a try thx

 

[janosch simon]

Hi Luc,

...Also, all my ESHS designs use fleece ear cups which are 'breathable' and allow the listener to use for extended periods without any sweat build up that you would get with leatherette / leather / suede ear cups....

David.

hey David do you produce the fleece ear cups on your own or do you buy them? would love to made the ear cups custom to the size i want
cheers janosch

 

[coinmaster]

.

 

[Muamp]

Hi janosch,

I make the ear cushions by using fleece material cut in to two 'doughnut' shapes, slightly larger than the surrounds.
I sow the two pieces together and fill with wadding. It is time consuming.
You could buy from a Chinese ebay seller (even AliExpress). There are many available in round, oval and eclipse shapes of various sizes.
I am currently working on Muamp#6 which will be......, different from my normal designs.

David.

 

[janosch simon]

hmmmm when i get my new cnc mill perhabs i will stick with pads that i can buy

OHHH david is teasing what are you building? Muamp #6 cant wait to see hope you share something

Janosch

 

[janosch simon]

hey there i just finished my second eshp a with new 3d printed case and when it works its amazingly good but with some problem
here are the build details:
-pcb stator 1mm
-pcb spacer 0.5mm
-mylar 2um foil glued with 3M 4693 glue which is more fluid then uhu por but also the moment it touches the copper of the pcb it gets more sticky and the coating is not even. the mylar is coated with RS-components ESD spray (the cheap one but i also ordered the techspray crystal to test)

compared to my first design where i used plastic screws and plastic washer to put everything together the new 3d printed case is made of 2 parts and fixed very good with 4x M4 screws and 4xM4 nuts.
it seems that because of the better and tighter fixing the mylar now comes to close to the stator and the sound is gone or distorted.
at the moment distance is 0.5mm mylar to the stator.

the questions:
a) how hard do you fix your assembly? i can imagine when i loose my assembly it could work but thats no solution for me
b) put the stators the other way around and a higher the bias voltage. is there a negative effect when you put the stator electrodes facing outwards and not inwards? except the higher bias voltage?

cheers janosch

 

[chinsettawong]

Hi Janosch,

As I have told you before, using 0.5mm spacers isn't easy. Everything has to be perfect. When you have the problem with the unstable Mylar, your diaphragm tension is not enough. You need to put more strength into pulling your diaphragms.

If you flip the stators and use the insulated sides to face each other, you increase the gap between the stator and diaphragm by the same thickness of the insulation. I don't think that is good. If you really want to increase the air gap, you want to try it a little by little. A very easy way is to cut a sheet of paper into the spacer shape and put it in between the spacer and the stator. Now you increase the airgap by only the thickness of that sheet of paper spacer. If that's still not enough, you can further add more paper spacers as you want.

Wachara C.

 

[janosch simon]

hey wachara the flipping is not possible with my latest case hmmmm so you think the tension of the mylar is not enough thats highly possible cause i make this now by hand without any consistency

will try to build this tire stretcher thing and report back so much fun and btw my bigger cnc 3020t mill is on the way so there will be a lot of different designs

cheers janosch

 

[ts8051]

Hello,
I use epoxy glue with two components in order to glue the membrane with spacers Please, what glue do you use?

 

[janosch simon]

hey ts8051 first i used uhu por just like wachara recomended and now im trying 3m 4693 which is a little bit more fluid then the uhu por but first i need my strecher will report back

 

[100VoltTube]

When milling FR4, how do you hold it down, and what do you put under it? I currently have a piece of 0.5" thick MDF to put under it, and screws with washers to clamp it down from the edges. Is there a better way?

 

[janosch simon]

i just use very strong double sidded tape on a 1"mdf plate works very good but with my new cnc mill which is much faster (240mm/sec vs 2000mm/sec) i cant mill a fullspeedbecause then the endmill breaks
350mm/sec with an 1.4mm endmill is max and the tape is strong enough to hold it with that speed in place.

cheers janosch