[legopart]

Finish to restore Sr-202, the old signature back even with 2micron membrane, and I hate it!!!
glue it little bent, not 1:1 on the stators holes
I just so clumsy and unprofessional.

Life less sound! bad and dry ear-pads.
some said it because the low quality cable that having high capacitance on purpose, to make the sound less warm.
(some said that this is the same drivers that installed in sr404 and sr-sigma-404 )
this is the most low level of Stax I ever heard!

I have the Stax Lambda Pro, that having life full sound.
This is my reference headphones (and untouchable for any mods)

I can't do nothing to fix the Sr-202.
Still preper to fix my first electrostatic headphones that broken after I tried to clean them.
The Sr-Lambda Normal.
I carved before gluing it together 0.5mm hole for the stators.
Don't know how it capable and safe (1mm or less air distance between the stator and the bias), but after I will install/glue the membrane and hop to restore,
I still not have any specific Pro cable for them and the price for new one is too high.
can dissasamble the Sr-202 cable for any experiment.

 

[afgmjkl]

Try to re-screw little bit and tight again (don't break the screws) the connectors maybe you created some dis-balance or glue the corners with regular thin selotape only to see if it helps.

do the screchie noises comes after several time of listening or immediately ?

I bought defective unit so I hear noises immediately.

 

[legopart]

I bought defective unit so I hear noises immediately.

Used?

but, really this headphones built from 2 metal plates and nylon layer
what could be the difficult one from another?

electrical distortion? Yes its a great problem with build and insulation.
Dynamic drivers may have even more distortion, dust could be the reason too.

maybe the burned holes made some material parts wider ... so it touching the plates.

I don't want to recommend you to disassemble it, but if you going to do so take some picture of it.
again, disassemble the electrostatic headphones/speaker for the first times most can cause to dysfunction of the headphone .


Look I really don't aspect from 30Hz squire wave to change something...
http://onlinetonegenerator.com/

 

[legopart]

Found the sr-202 now having some electrical noises/distortion after I tap on/hit it a bit from the side.
at this point I cant even open or change anything with them after they glued.

with Normal bias its works without randomal distortions.
think to dissasamble it again, this time to paint the the stators.
the same thing with the other lambda.
the squicking noise on Pro mode (580v) making me really angry and dissapointed

Additional problem: I need some new pads for sr-202, and Stax pads cost too much so I don't want to buy it. what to do?

 

[Tjj226 Angel]

Quick question for you guys.

I would like to make some completely inverted electrostatic headphones like Ikos98 did here https://www.head-fi.org/threads/my-diy-electrostatic-headphones.498292/page-212

I was looking on ebay for mylar, and I found a listing for both 2um mylar and some Elvamide. https://www.ebay.com/itm/Electrosta...191878?hash=item2a69f37f06:g:gR0AAOSw6EhUQNa9

I know Elvamide can be used for restoring electrostatic speakers, but does it work just as well for headphones? There seems to be a ton of options for chemically treating membranes, but is there any particular one that the community seems to favor that might be better than elvamide?

 

[Torac]

Quick question for you guys.

I would like to make some completely inverted electrostatic headphones like Ikos98 did here https://www.head-fi.org/threads/my-diy-electrostatic-headphones.498292/page-212

I was looking on ebay for mylar, and I found a listing for both 2um mylar and some Elvamide. https://www.ebay.com/itm/Electrosta...191878?hash=item2a69f37f06:g:gR0AAOSw6EhUQNa9

I know Elvamide can be used for restoring electrostatic speakers, but does it work just as well for headphones? There seems to be a ton of options for chemically treating membranes, but is there any particular one that the community seems to favor that might be better than elvamide?

Elvamide is difficult to coat equally and well, most people seem to use antistatic screen cleaner as it is cheap and easy to coat with.

 

[legopart]

Elvamide is difficult to coat equally and well, most people seem to use antistatic screen cleaner as it is cheap and easy to coat with.

The seller on ebay promised to send me some guide to my email, and do so.
I ordered the 2um+Elvamide and don't know what to do with it.
the 2um from ebay actually good, and worth the price.
do someone know where can I get some less thickness?

Important message about anti-static spray that sold, it contains acetone (acetyl) that destroying the previous coating totaly, the electret coating too, destroying the glue connections that holding the membrane and destroying any color insulation.
this spray destroyed my sr-202 because the stators was covered by insulation color that just melted and touch the membrane.

 

[qu1en]

The seller on ebay promised to send me some guide to my email, and do so.
I ordered the 2um+Elvamide and don't know what to do with it.
the 2um from ebay actually good, and worth the price.
do someone know where can I get some less thickness?

Important message about anti-static spray that sold, it contains acetone (acetyl) that destroying the previous coating totaly, the electret coating too, destroying the glue connections that holding the membrane and destroying any color insulation.
this spray destroyed my sr-202 because the stators was covered by insulation color that just melted and touch the membrane.

You should try Lycron. It's just a permanent spray. It does not contain acetone and won't melt your headphones.
Elvamide is more work, for no additional benefit. Also be careful when working with all these chemicals. Wear a respirator when using it.
2um is very thin. I can't imagine any thinner than 2um would be difficult to handle it easily. I use 3um.

On a completely different note: Earlier I saw a comment to the effect that there was a rumor that additional capacitance is added to the harness to make it more warm. This cannot be true. Additional capacitance will introduce of slew and distortion to the high frequencies and will sound extremely harsh. This is kind of a rediculous claim. If a warmer sound is required, there are many other methods to achieve this (equalizers, circuit LPF, tension changes etc..)

 

[Tjj226 Angel]

Elvamide is difficult to coat equally and well, most people seem to use antistatic screen cleaner as it is cheap and easy to coat with.

Awesome, thanks for the quick reply. Now its time to go mock up the design in cad : )

 

[legopart]

What will happened if I will put twice the amount of coating on the membrane from seller recommendation (for quad esl 57)?
do the sound will become dipper or the headphones will be more sensitive?

although I think at this point that almost all of the distortion is gone, I still think that the regular coating is not enough or the tension it too high or the membrane too thick (have to use some wider) or not quality enough.

I still cant understand how to work with this program + the fact that I not use it long time.
but this two headphones tested on the same setting, environment and time:
Red - stax sr-202 that I fixed
Green - Stax sr-lambda pro original (from 80s ?)

Its really not easy part to disassemble all the glued parts
(yes, I put too much strong glue again)

 

[wrinex]

What will happened if I will put twice the amount of coating on the membrane from seller recommendation (for quad esl 57)?
do the sound will become dipper or the headphones will be more sensitive?

although I think at this point that almost all of the distortion is gone, I still think that the regular coating is not enough or the tension it too high or the membrane too thick (have to use some wider) or not quality enough.

I still cant understand how to work with this program + the fact that I not use it long time.
but this two headphones tested on the same setting, environment and time:
Red - stax sr-202 that I fixed
Green - Stax sr-lambda pro original (from 80s ?)

Its really not easy part to disassemble all the glued parts
(yes, I put too much strong glue again)

you need a method to replicate, either use the weight method (placing a weight onto the original until you hit the stator and use that as reference for your new foil) or the method i used with a speaker and REW in this video.

but for such small things i think the weight might be the easiest way to go

 

[lkos98]

Quick question for you guys.

I would like to make some completely inverted electrostatic headphones like Ikos98 did here https://www.head-fi.org/threads/my-diy-electrostatic-headphones.498292/page-212

I was looking on ebay for mylar, and I found a listing for both 2um mylar and some Elvamide. https://www.ebay.com/itm/Electrosta...191878?hash=item2a69f37f06:g:gR0AAOSw6EhUQNa9

I know Elvamide can be used for restoring electrostatic speakers, but does it work just as well for headphones? There seems to be a ton of options for chemically treating membranes, but is there any particular one that the community seems to favor that might be better than elvamide?

Thanks for trying my design. I hope you will find it good. I'm still trying to improve mine, tested with different tension, different amps, etc. I still think this design have 2 big advantages - extremely low capacitance and no need for dust cover. I also want to try now to blow some air between membranes in order to keep them a bit bulge, hence away from the stator. In such case the spacers can be made thinner - may be 0.3-0.2 mm, which should increase the sensitivity as well. Problem is how to put the air (could be also some inert gas), between membranes and then keep the pressure there infinitely. Must create some kind of a valve - any ideas would be appreciated.
I'm using 2u mylar, and antistatic 100, have no idea about Elvamide, but there were a lot of discussions on it on this thread, I have tried floor cleaner as well - works fine, but I guess it's with a higher resistance, because the phones are less sensitive and you need to increase the volume, where it starts clipping.
I was busy lately with building amps - created 3 of them - class A and class AB, and spent too much time on trying a class D, Unfortunately, it appeared class d is very efficient for 50 - 100W amp with supply voltage up to 100V, but not for electrostats with 600V rail, because with this voltage and SW frequency of 200kHz, the switching losses are about 2-3 W, which makes it very inefficient for 1-2 W headphone amp.

 

[lkos98]

The seller on ebay promised to send me some guide to my email, and do so.
I ordered the 2um+Elvamide and don't know what to do with it.
the 2um from ebay actually good, and worth the price.
do someone know where can I get some less thickness?

Important message about anti-static spray that sold, it contains acetone (acetyl) that destroying the previous coating totaly, the electret coating too, destroying the glue connections that holding the membrane and destroying any color insulation.
this spray destroyed my sr-202 because the stators was covered by insulation color that just melted and touch the membrane.

I don't know what antistatic spray you have, I have never had any issues with antistatic 100. It definitely contains alcohol, but not acetone. I have never seen any effect on the glue or any plastic part.
What I don't like is that it is a spray - it makes it difficult to apply evenly to the membrane, and it doesn't feel cheap to me, actually it's quite expensive (comparing it to a floor cleaner for example )

 

[legopart]

Thanks for trying my design. I hope you will find it good. I'm still trying to improve mine, tested with different tension, different amps, etc. I still think this design have 2 big advantages - extremely low capacitance and no need for dust cover. I also want to try now to blow some air between membranes in order to keep them a bit bulge, hence away from the stator. In such case the spacers can be made thinner - may be 0.3-0.2 mm, which should increase the sensitivity as well. Problem is how to put the air (could be also some inert gas), between membranes and then keep the pressure there infinitely. Must create some kind of a valve - any ideas would be appreciated.
I'm using 2u mylar, and antistatic 100, have no idea about Elvamide, but there were a lot of discussions on it on this thread, I have tried floor cleaner as well - works fine, but I guess it's with a higher resistance, because the phones are less sensitive and you need to increase the volume, where it starts clipping.
I was busy lately with building amps - created 3 of them - class A and class AB, and spent too much time on trying a class D, Unfortunately, it appeared class d is very efficient for 50 - 100W amp with supply voltage up to 100V, but not for electrostats with 600V rail, because with this voltage and SW frequency of 200kHz, the switching losses are about 2-3 W, which makes it very inefficient for 1-2 W headphone amp.

0.3 space is too small for 580v, any mistake or high volume will lead to shorts and distortion.

Some trying looser membrane and 1.0mm with 1000v bias.
dont know about it safetiness. electricity could make arcing.


about my sr-202, Its sounds good but with air-conditioner function in my room its stops to function! (the dust filters not helped)

 

[lkos98]

0.3 space is too small for 580v, any mistake or high volume will lead to shorts and distortion.

Some trying looser membrane and 1.0mm with 1000v bias.
dont know about it safetiness. electricity could make arcing.


about my sr-202, Its sounds good but with air-conditioner function in my room its stops to function! (the dust filters not helped)

Well if you have read about my design it's different. First of all I dont use 580, but +-360V on 2 membranes. Secondly, if there is trapped air between membranes under slight pressure it would not allow them to slap to the stator. And third ( I was also very surprised):
"The electric field needed to arc across the minimal-voltage gap is much greater than what is necessary to arc a gap of one metre. For a 7.5 μm gap the arc voltage is 327 V, which is 43 MV/m. This is about 13 times greater than the field strength for the 1-metre gap. The phenomenon is well verified experimentally and is referred to as the Paschen minimum."
So even if we consider the "normal" 3.4MV per meter, for 0.3mm it will require about 1000V to arc.