[chinsettawong]

That's way too much tension!

 

[ondesx]

Just a few pics to show the evolution of the project ! We can see the drilling of the stators with the outer rings in place. This method allows perfect alignment of the 4 pieces. Then, the gluing of each half-cell.
 

 

 

 
Stay tuned !

 

[chinsettawong]

Looking good!  

 

[ondesx]

Thank you Wachara !
 
I already did some "calibrated" masses in order to determine the best tension for Mylar and be able then to reproduce it.
 
Here is a pic...
 
 

 

[chinsettawong]

  Thank you Wachara !
 
I already did some "calibrated" masses in order to determine the best tension for Mylar and be able then to reproduce it.
 
Here is a pic...
 
 

 
So, you're going to use weight to tension your diaphragms?  How much weight is it for each of them?
 
Please let us know how you like this method.
 
Wachara C.

 

[ondesx]

   
So, you're going to use weight to tension your diaphragms?  How much weight is it for each of them?
 
Please let us know how you like this method.
 
Wachara C.

Oh yes ! Definitely...
The whites are about 600 g and the blues about 400 g (more or less, I don't think that the needed precision is so high...).
 
The first try had shown that it's not so easy indeed... The more thin the PET the more difficult the procedure. Two main issues, first the pinch of the plastic is not tight enough, thus the film easily escapes, secondly the round form of the jig induces a lot of wrinkles even after attaching a high weight.
 
Afterwards, it isn't easy to coat the diaphragm without a support under it and, of course, to glue the spacers on each side of it...

 My first tries were made using a 12 µ Mylar, I wonder what will happen with a more thinner film (like 1 to 3µ...).
 
OndesX

 

[Congo5]

still here and still trying things...
 
  I use an innertube stretcher but have an digital HVAC pressure gauge,(reads in 1/10th LBS)
Still its easy to over do it.
But also easy to build extras and slide them in to try. Yes I tend to make them too tight.
 
 One of the problems I have is with coatings, of all the antistatic screen cleaners I have ( none are gel),
they sound great but only last for hours. Want to try the floor cleaners next.
 
also have some Staticide 6300 and it has to be baked or dry for 24 hrs at 70F.
Yesterday I cleaned and applied it and let it dry then sorta baked it on top of a tube amp  (125F).
 
one side came up fine but the other had really low volume.  What fixed it was cleaning it with alchohol and rubbing
with dry cotton????
 
 I found a better paint for the stators at Grangers called Sprayon EL609 insulating varnish. 2,850 volts/ml.
It solved some problems I was having with bias migration/noises.
 
 Using double sided 1mm staters, .5mm spacers, 2um mylar, yellow contact cement.
been listening for two hours and there is not volume loss or imbalance ........yet...
getting closer inch by inch. after they are proven stable I will try to make better looking ones.
for now here is the state of my prototypethose are the largest earpads I have)

 
Thanks Wachara!!!

 

[ondesx]

 
 One of the problems I have is with coatings, of all the antistatic screen cleaners I have ( none are gel),
they sound great but only last for hours. Want to try the floor cleaners next.
 
also have some Staticide 6300 and it has to be baked or dry for 24 hrs at 70F.
 

 
From ACL I have "Reztore Staticide" and will try it, but I'm afraid it'll last, like your own attempts, only few minutes or a couple of hours... 
 
Unfortunately, it seems that graphite also escapes from the diaphragm in a few hours, even after hard rub !
 
My other concern with all the sprays is the weight added to the membrane...
 
I don't see a robust method for coating the Mylar for ages at the correct resistivity !
 
Yet QUAD used a coating that was known to last more than 25 years !...
 
Any other advice welcome...

 

[ayaflo]

I remember anti-static spray/gel helps ...the ones you get in PC stores. Also floor cleaners do help.
 
Go through the gallery here and you will be able to find a pic of 2 white bottles.
 
Regards,

 

[ondesx]

Sorry for this perhaps trivial question, but how did you guys use these static sprays ?
 
Either you spray it on the film and you wait it dry, or you rub it on the diaphragm with a microfiber cloth ? Intuitively, the rubbing might improve the adherence of the coating...
 
But, simultaneously some of the coating will be removed. 
 
Thank you for your opinions.
 
OndesX

 

[chinsettawong]

It could be my luck, but the antistatic gel and floor cleaner that I use seem to work very well.  I have at least two pairs of headphones here that have been performing well using either one.
 
For applying, I put just a little drop of gel or cleaner on a piece of microfiber cloth and wipe it on the diaphragm.  The coating is extremely thin that you can't really see the trace of coating.
 
Wachara C.

 

[ondesx]

Thanks Wachara,
 
What are the floor cleaner and the static gel ?
 
I read that you also use these products :
 
http://www.head-fi.org/g/i/1025405/default/sort/display_order/
 
And you also gave a recipe with 2 parts of PVA, 5 parts of water, and ink or 1/10 part of graphite...
 
What is the best approach for you ?...
 
OndesX

 

[chinsettawong]

 I've certainly posted about this product here before. 
 

 
Please don't use my PVA formula.  It's not so good in high humidity weather.
 
Wachara C.
 
 
 

 

[chinsettawong]

  still here and still trying things...
 
  I use an innertube stretcher but have an digital HVAC pressure gauge,(reads in 1/10th LBS)
Still its easy to over do it.
But also easy to build extras and slide them in to try. Yes I tend to make them too tight.
 
 One of the problems I have is with coatings, of all the antistatic screen cleaners I have ( none are gel),
they sound great but only last for hours. Want to try the floor cleaners next.
 
also have some Staticide 6300 and it has to be baked or dry for 24 hrs at 70F.
Yesterday I cleaned and applied it and let it dry then sorta baked it on top of a tube amp  (125F).
 
one side came up fine but the other had really low volume.  What fixed it was cleaning it with alchohol and rubbing
with dry cotton????
 
 I found a better paint for the stators at Grangers called Sprayon EL609 insulating varnish. 2,850 volts/ml.
It solved some problems I was having with bias migration/noises.
 
 Using double sided 1mm staters, .5mm spacers, 2um mylar, yellow contact cement.
been listening for two hours and there is not volume loss or imbalance ........yet...
getting closer inch by inch. after they are proven stable I will try to make better looking ones.
for now here is the state of my prototypethose are the largest earpads I have)

 
Thanks Wachara!!!

 
 
Nice work!  How do you like your Megatron?
 
Yes, using the inner tube stretcher, you can easily over stretch your diaphragm.  You have to be extremely patient and gentle when applying the air into the tire.  
 
Wachara C.

 

[ondesx]

Thanks again Wachara,
 
I discover that you had some exchanges with Calvin on DIY Audio. He provided this formula :
 
my recipe for 100mL of coating is:
1 volume part glue (Tesa brand)
4 volume parts destilled, deionized water
2 tiny drops of black writing ink
 
I think I'll do a first try with my Reztore Staticide sample...