[spritzer]

I still think this is just a connection issue, all the data from Stax certainly supports that.  If the diaphragm could move enough to touch the stators (which it can't) then it would be burned to a crisp, even with the output current limiters of the modern Stax designs (and the KG units). 

 

[chinsettawong]

Quote:

I still think this is just a connection issue, all the data from Stax certainly supports that.  If the diaphragm could move enough to touch the stators (which it can't) then it would be burned to a crisp, even with the output current limiters of the modern Stax designs (and the KG units). 

That could be the case too.  However, if the stators are insulated, then the diaphragm would never burn up when it touches the stators.
 

 

[3210]

Even the diaphragm don't move like a piston,
if the diaphragm looses tension, this would allow more excursion
and thereby increase the sound pressure level (if not electrically damaged), or  ?
 
Did the failure also occurs with the SRM323 ?
I saw Kevin Gilmours SRM323 psu schematics,
and the bias circuit is connected before the main rectifier,
probably to get enough bias voltage before the main voltage increases.
 
Maybe Spritzer is right, and it's just a bad bonding/connecting issue. 
 

 

[spritzer]

The diaphragm can't loose its tension unless some environmental effects do serious harm to the molecular structure of the plastic.  Direct sunlight over an extended period of time will do that but it takes years and years. 
 
Quote:

That could be the case too.  However, if the stators are insulated, then the diaphragm would never burn up when it touches the stators.
 

I've never seen insulated Stax stators and these don't appear to be insulated. 
 

 

[Currawong]

With the voltages involved and the thinness of the diaphragm, no insulation would be thick enough to prevent arcing IMO.
 
I haven't done a side-by-side comparison yet, but I listen to the 009s at 9-10pm on the 007t whereas I used to listen with the 02s at 11 or 12pm.

 

[3210]

Quote:

I had the exact same thoughts but wouldn't you expect the diaphragm to get back to default position as soon as the stator it is stuck too changes polarity (i.e. push mode)? If not an ES force, what is making it adhere so well to the stator that only applying a large pressurization to the chamber makes it go back to default position?
 
 

 


Quote:

For some reasons that I also don't understand, that isn't the case.  The diaphragm would normally sticks to the stator and wouldn't go back to its default position. 

 
 
Probably, if the diaphragm bounces the electrode,
the high impedance bias can't dominate against the low impedance output (at least at the bouncing spot) and it'll be over with the bias loads.
But then polarisation of the diaphragm (in the opposite direction of the outer field) could occur and the diaphragm sticks. 
 

 

[chinsettawong]

Quote:

With the voltages involved and the thinness of the diaphragm, no insulation would be thick enough to prevent arcing IMO.
 
I haven't done a side-by-side comparison yet, but I listen to the 009s at 9-10pm on the 007t whereas I used to listen with the 02s at 11 or 12pm.

 
I always put 2 layers of insulation paint on my DIY electrostatic stators, and yes, I've experienced diaphragm being sucked by the stators before.  My thinnest diaphragm is less than 1 micron.   My normal bias voltage is 650V and spacer thickness is 0.5 millimeter.  When the diaphragm is sucked to the stator, even when I play music through it, there is no arching. 
 
Wachara C.
 

 
 

 

[Currawong]

Interesting. Were any commercial 'stat drivers painted?

 

[spritzer]

The HE60 drivers are painted plastic. 
 
Quote:

With the voltages involved and the thinness of the diaphragm, no insulation would be thick enough to prevent arcing IMO.
 
I haven't done a side-by-side comparison yet, but I listen to the 009s at 9-10pm on the 007t whereas I used to listen with the 02s at 11 or 12pm.

Which O2 is that since they aren't all the same.  Mk2.5 is more sensitive than the other versions...
 

 

 

[chinsettawong]

It seems that the new 507 stators are painted. 
 

 

[Gu Sensei]

The second replacement pair I received #93 has been going strong for two weeks now while the first two exhibited troubles within a couple of days of use. I did get the sense from the clerk, who indicated that he had called Stax, that there had been some sort of delay in production between the time of the first shipment (with the first two I had 62 & 14) and a second shipment with my current pair. There definitely was a bit of a language barrier so I would not swear to the complete accuracy of that last bit of information though. I do know for sure that there was a waiting period that had to do with getting another pair from the manufacturer and not from waiting for additional stock to be sent from the store's headquarters.
 
Just to add another clue for the investigators on the Case of the Imbalanced Stax 009 Drivers:
 
The second pair (#14) worked fine for a few days and then started to go in an out of balance with the right driver losing volume. However, while I was waiting for the replacement pair, it actually stabilized and went for a week with no issues. Whereas I could previously affect the issue by pressing the cups down uniformly or alternating pushing side to side, during the stable period, that kind of manipulation had no effect. This actually caused me troubles when I went in to exchange them because they worked fine for the clerk when he tested them in the store and I had to argue my case that they had in fact malfunctioned when I first got them.
 
No doubt dealing with this has been a hassle and consumed a fair amount of time and energy, but the whole time that all has been secondary to the fact that these phones are a significant step up above any pair of headphones that I have owned or heard. It was always in my mind that it was just a matter of when the problem would be resolved, not 'if'. For a lesser pair of phones, I would have given up, but for these, it has been completely worth it.
 
I am really looking forward to other members getting their pairs. Stock does seem a bit more plentiful in Japan and with a few more new owners from Europe chiming in, hopefully it will not be much longer.
 
 

 

[Currawong]

Quote:

The HE60 drivers are painted plastic. 
 

Which O2 is that since they aren't all the same.  Mk2.5 is more sensitive than the other versions...
 

Sorry, I should have stated they were the MK1. I've never tried the MK2 in any form.
 

 

[spritzer]

Quote:

It seems that the new 507 stators are painted. 
 

Not sure what they use on those stators but it certainly isn't paint.  Probably some sort of powdercoating and it's not for any insulation purpose but to dampen those large brass stators.  
 

 

[Currawong]

My bad if I was wrong about the 009 diaphragm being multi-layer.  I'll have to check why I thought that.

 

[jgazal]

Quote:

It seems that the new 507 stators are painted. 
 

 
[size=10.0pt]If the diaphragm is made with Mylar (the one in the middle), which material is used to avoid dust reaching the diaphragm (the two covers at both sides)? Is it also Mylar?[/size]