Some interesting findings about Stax electrostatic stators

chinsettawong · 24th September 2011, 03:07 AM

I opened up a pair of broken Stax 507 drivers a while ago. I found something unusual about the stators. On the surface of the stators, there are many small spikes. What do you think they are for?

Wachara C.

Calvin · 24th September 2011, 07:00 AM

Hi,

A: spacers

jauu
Calvin

chinsettawong · 24th September 2011, 08:28 AM

Hi Calvin,

That's what I thought so too. How do you think Stax made those spikes? I really like to try making them on my headphone stators too.

Wachara C.

oublie · 24th September 2011, 08:53 AM

I'm guessing here as I've never had a broken pair to examine but there are a few ways that could possibly work.

1. punched from the other side
2. some sort of hot glue or other dry set material formed onto the stator with a mould prior to painting
3. solder? - although I don't know how they would get the size right.

chinsettawong · 24th September 2011, 10:47 AM

Hi Oublie,

I think they are epoxy or some kinds of plastic material, because you don't want to create any sharp edges on the stators. These spikes are actually quite stiff and they stuck to the stators quite well.

I always thought that by having spacers in the middle of the stators would somehow affect low frequencies. But even with these many spacers, the low frequencies are still very good in these drivers. Perhaps these spacers do not actually touch the diaphragm. They might just put them there to protect the diaphragm from ever touching the stators. What do you think?

geraldfryjr · 24th September 2011, 04:33 PM

Hi,Wachara,

What would the D/S be?

They could be too not let the diagphram stick to the stator as was suggested and can happen very easily with a very light tension.

When I pushed my little panels to the onset of stator clipping it was barely noticeable until I got passed about 5% clipping distortion.

I was not even aware that this was happening until I saw the signal on a scope from a microphone.
The little bit of distortion that I was hearing I wrote off as the amp clipping,But it was not the amp at all.

It was quite livable at that volume but I did not dare too get my ear that close like a headphone driver would be with that test.

At lower levels my little panels are wonderful for headphone drivers but they are 3 times the length that is needed.
The D/S on those is around 1.5 mm.

There were a few times in various tests that got the diagphrams to stick to the stators (mainly with low tensions),and, Just a little knudge with a toothpick through a stator hole was enough to get it to snap back even though the were still energized.

jer

chinsettawong · 25th September 2011, 08:47 AM

Hi Jer,

The D/S is only 0.35 mm and the stator width is 50 mm. The bias voltage is 580v.

It really is a wonderful, little driver. The bass goes down very deep and the treble is lovely.

Wachara C.

DaveG · 25th September 2011, 09:18 AM

Could the whole surface have been photo etched leaving the spikes?

Kontra · 25th September 2011, 03:46 PM

Quote:

Originally Posted by chinsettawong

Hi Jer,

The D/S is only 0.35 mm and the stator width is 50 mm. The bias voltage is 580v.

It really is a wonderful, little driver. The bass goes down very deep and the treble is lovely.

Wachara C.

can u *.jpg full range?

SY · 25th September 2011, 04:07 PM

Quote:

Originally Posted by DaveG

Could the whole surface have been photo etched leaving the spikes?

Why not injection or compression molded? Seems the easiest way.

24th September 2011, 03:07 AM	#1
chinsettawong diyAudio Member Join Date: Jun 2006	Some interesting findings about Stax electrostatic stators I opened up a pair of broken Stax 507 drivers a while ago. I found something unusual about the stators. On the surface of the stators, there are many small spikes. What do you think they are for? Wachara C.

24th September 2011, 08:53 AM	#4
oublie diyAudio Member Join Date: May 2009 Location: Northern Ireland	I'm guessing here as I've never had a broken pair to examine but there are a few ways that could possibly work. 1. punched from the other side 2. some sort of hot glue or other dry set material formed onto the stator with a mould prior to painting 3. solder? - although I don't know how they would get the size right. __________________ There are 10 types of people in the world: Those who understand binary, and those who don't...

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Attenuation circuit findings Fe208e sigma	adamt	Full Range	0	22nd June 2010 02:20 AM
Interesting old Philco electrostatic tweeter	peace brainerd	Multi-Way	0	8th March 2010 10:56 PM
UltraLinear in toroidal parafeed, my findings.	Shoog	Tubes / Valves	2	4th February 2006 07:58 PM
Stators	MrPin	Planars & Exotics	10	12th January 2006 03:06 AM
Stax electrostatic headphones	npdang	Swap Meet	0	21st October 2004 07:33 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

24th September 2011, 07:00 AM	#2
Calvin diyAudio Member Join Date: Nov 2004 Location: close to Basel	Hi, A: spacers jauu Calvin

24th September 2011, 08:28 AM	#3
chinsettawong diyAudio Member Join Date: Jun 2006	Hi Calvin, That's what I thought so too. How do you think Stax made those spikes? I really like to try making them on my headphone stators too. Wachara C.

24th September 2011, 10:47 AM	#5
chinsettawong diyAudio Member Join Date: Jun 2006	Hi Oublie, I think they are epoxy or some kinds of plastic material, because you don't want to create any sharp edges on the stators. These spikes are actually quite stiff and they stuck to the stators quite well. I always thought that by having spacers in the middle of the stators would somehow affect low frequencies. But even with these many spacers, the low frequencies are still very good in these drivers. Perhaps these spacers do not actually touch the diaphragm. They might just put them there to protect the diaphragm from ever touching the stators. What do you think?

24th September 2011, 04:33 PM	#6
geraldfryjr diyAudio Member Join Date: Feb 2008 Location: Jackson,michigan	Hi,Wachara, What would the D/S be? They could be too not let the diagphram stick to the stator as was suggested and can happen very easily with a very light tension. When I pushed my little panels to the onset of stator clipping it was barely noticeable until I got passed about 5% clipping distortion. I was not even aware that this was happening until I saw the signal on a scope from a microphone. The little bit of distortion that I was hearing I wrote off as the amp clipping,But it was not the amp at all. It was quite livable at that volume but I did not dare too get my ear that close like a headphone driver would be with that test. At lower levels my little panels are wonderful for headphone drivers but they are 3 times the length that is needed. The D/S on those is around 1.5 mm. There were a few times in various tests that got the diagphrams to stick to the stators (mainly with low tensions),and, Just a little knudge with a toothpick through a stator hole was enough to get it to snap back even though the were still energized. jer

25th September 2011, 08:47 AM	#7
chinsettawong diyAudio Member Join Date: Jun 2006	Hi Jer, The D/S is only 0.35 mm and the stator width is 50 mm. The bias voltage is 580v. It really is a wonderful, little driver. The bass goes down very deep and the treble is lovely. Wachara C.

25th September 2011, 09:18 AM	#8
DaveG diyAudio Member Join Date: Feb 2007 Location: Grease	Could the whole surface have been photo etched leaving the spikes?