[chinsettawong]

Hi Dude_500,
 
Different people might have different technics.  As for me, I only heat treat Mylar when I feel that the tension isn't enough. 
 
Most of the times, if the Mylar loses its tension, it's because of the glue.  Mylar normally wouldn't elongate by itself.
 
Wachara C.

 

[chinsettawong]

I've finally drilled a couple of holes on the side of the cups and put the headband on.  
 

 
This concludes the making of my 2nd pair of Omega clone.  My next one will be a revisit of my very first version of oval shape headphones.  From time to time, I still go back to listen to them, and I still really like them.  I'm going to redesign a new enclosure, etch out the unneeded copper, and improve the way I'll hold the drivers together.  

 

 

[spritzer]

I've always done heat treatment as that's what the pro's do and according to Dupont, it's the only way to get a stable film over any period of time.  It fixes the tension in place by annealing the membrane. 

 

[chinsettawong]

Quote:

I've always done heat treatment as that's what the pro's do and according to Dupont, it's the only way to get a stable film over any period of time.  It fixes the tension in place by annealing the membrane. 

Hi Birgir,
 
How do you do the heat treatment?
 
Wachara C.

 

[Maverickmonk]

Any thought on using a sputter coater to coat the mylar? I know it might be hard to keep the mylar stable on the vacume chuck, but it would be possible to get very thin coatings with nanometers of accuracy

 

[spritzer]

Quote:

Hi Birgir,
 
How do you do the heat treatment?
 
Wachara C.

 
I use the large stone oven in my bakery at its lowest setting which is about 140°C.  Leave it there for a few minutes (depends on the size of the frame) but I put them in a box due to what's normally in those ovens.  Quad used an oven as well to cook their panels. 

 

[dude_500]

Quote:

Any thought on using a sputter coater to coat the mylar? I know it might be hard to keep the mylar stable on the vacume chuck, but it would be possible to get very thin coatings with nanometers of accuracy

I may some day try this. Unfortunately all my vacuum equipment is at home and not with me at college. I'll probably sputter some when I'm back home for winter break, or maybe get around to setting up a high vac station in my dorm room (been meaning to for a while).
 
I'm not sure what you mean by getting it stable on the vacuum chuck. I would put the entire thing within a vacuum chamber then pump down and turn on an ion source, so there would be equal pressure on both sides of the film and it would feel no forces.
 
I believe the Sennheiser Orpheus is sputtered gold.

 

[Maverickmonk]

Quote:

I may some day try this. Unfortunately all my vacuum equipment is at home and not with me at college. I'll probably sputter some when I'm back home for winter break, or maybe get around to setting up a high vac station in my dorm room (been meaning to for a while).
 
I'm not sure what you mean by getting it stable on the vacuum chuck. I would put the entire thing within a vacuum chamber then pump down and turn on an ion source, so there would be equal pressure on both sides of the film and it would feel no forces.
 
I believe the Sennheiser Orpheus is sputtered gold.

That makes a lot more sense, procedure wise.... Man, now I want to try this in the schools nano lab.

 

[chinsettawong]

While you guys are busy discussing what you're discussing, I'm busy making more headphones.  

 
A friend of mine fried his HE-6 drivers, and he asked me to utilize his HE-6 cups and make them into electrostatic headphones.  Fortunately, the inside of HE-6 has the dimension close to that of the drivers of my Omega clone.  So, I'll modify the design of my drivers a little, cut them, and put them in his headphones.  Stay tune.  

 

 
 

 

[jcx]

doesn't the membrane coating want to be highly resistive so the charge "stays put" at audio frequency http://www.audiocircuit.com/DIY/Electrostatic-Speakers/Material:Coatings
 
sputtering gold would have to be very carefully monitored to hit the GigaOhm/sq decade of sheet resistance
 

http://www.nanoscalereslett.com/content/6/1/96

 

[Arfan]

I'm going to be trying my hand at creating electrostatic transducers very soon too, I'm not sure yet whether to create a loudspeaker or a pair of headphones yet though. But I have a few quick questions, I know pretty much exactly how to assemble the transducers but I'm pretty clueless on how to drive them properly.
 
I only have a highschool level knowledge of the electronic side of things*, although I could follow guides to assemble materials. I was wondering exactly how difficult it was to actually create the amplifiers, the step up transformers and any circuits I'll need. I had a look around I've found some schematics but I think they might be too complex to create in the time frame I have. And I thought if I'd find anyone could help me with this i'd find them here considering all the success you guys have had with your electrostatic transducers. 
 
I thought I could work around this problem however by just using an ordinary solid state amp and using the RCA output to step up the voltages using a toroidal transformer, maybe one for each channel, to make it suitable for the electrostatic transducer's stators, and use another circuit to supply the bias to the diaphragm which shouldn't be too hard to do. I was wondering if this would sufficient to drive the small speakers/ headphones. Does anyone have anything to say on the easiest and most cost effective method to drive these transducers? I don't mind using mid-fi here and there too. 
 
Any help would be greatly appreciated, I can't wait to get started on these too.  
 
* although I have access to one of my physics teachers who is an oxford graduate who could help me through some of the electronics, although he's very busy all the time so I don't have much time with him so I thought I'd find out as much as I could myself before consulting him. 

 

[dude_500]

Quote:

I'm going to be trying my hand at creating electrostatic transducers very soon too, I'm not sure yet whether to create a loudspeaker or a pair of headphones yet though. But I have a few quick questions, I know pretty much exactly how to assemble the transducers but I'm pretty clueless on how to drive them properly.
 
I only have a highschool level knowledge of the electronic side of things*, although I could follow guides to assemble materials. I was wondering exactly how difficult it was to actually create the amplifiers, the step up transformers and any circuits I'll need. I had a look around I've found some schematics but I think they might be too complex to create in the time frame I have. And I thought if I'd find anyone could help me with this i'd find them here considering all the success you guys have had with your electrostatic transducers. 
 
I thought I could work around this problem however by just using an ordinary solid state amp and using the RCA output to step up the voltages using a toroidal transformer, maybe one for each channel, to make it suitable for the electrostatic transducer's stators, and use another circuit to supply the bias to the diaphragm which shouldn't be too hard to do. I was wondering if this would sufficient to drive the small speakers/ headphones. Does anyone have anything to say on the easiest and most cost effective method to drive these transducers? I don't mind using mid-fi here and there too. 
 
Any help would be greatly appreciated, I can't wait to get started on these too.  
 
* although I have access to one of my physics teachers who is an oxford graduate who could help me through some of the electronics, although he's very busy all the time so I don't have much time with him so I thought I'd find out as much as I could myself before consulting him. 

 
A pair of audio step up transformers is indeed the easiest way. In fact, this has been used in numerous retail products. Just connect it to a standard speaker amp and it makes it higher voltage. All you need in addition is a bias supply which is trivial to make. Transformers aren't necessarily the best for audio quality, though. There are several diy designs for amps if you want to take it to a higher level. Electrostatic amplifiers tend to be difficult to build given the high voltages, though. I have hundreds of hours invested in my Blue Hawaii. Unless you actually want an amplifier to be a project in itself, transformers definitely might be the way to go.

 

[Nixon]

I can't find any 0.5mm pcb board, but would 0.4mm work instead or would that be too narrow?
 
http://uk.rs-online.com/web/p/prototype-development-boards/2926932/

 

[chinsettawong]

Try Ebay:  http://www.ebay.com/itm/FR4-Copper-Clad-Laminate-PCB-Printed-Circuit-Board-Material-FREE-SHIPPING-USA-/120802756087?pt=LH_DefaultDomain_0&var=420050924083&hash=item1c2067c5f7

 

[bidoux]

Could these work too ? (shipping is really expensive with amt33461 )
http://www.ebay.com/itm/360377165165?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648 and http://www.ebay.com/itm/360377165921?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
 
And as for the stators, how important is their thickness ? I thought that it wouldn't matter as much as with the spacers.