[coinmaster]

You tried it with both diaphragms in between the stators? Echoing seems like it may be result of non synchronous operation of the diaphragms or some sort of resonant or geometrical problem. Maybe the axis offset of either diaphragm relative both polarities caused issues or there was some sort of reflective geometry or resonance in the material.
I would try with a single stator and and diaphragm on either side of it.

 

[chinsettawong]

I tried it many years ago. And didn't like it. But if I have the time, I will try it again.

Anyway, here is a picture of my Omega clone VS Stax O2 MKI.

Driving them with my KGST, my DIY phones have better mids and highs. The bass is about the same.

 

[wppk]

Wonderful !

 

[Kerry]

Impressive as always

 

[100VoltTube]

Very nice. The casework on the KGST is amazing.

 

[JoaMat]

Indeed very nice.

 

[chinsettawong]

Thank you guys.

 

[100VoltTube]

What voltage rating do the koss/stax cables have? I ask because I'm putting together an order for a trafo box with a varaible bias supply. In its current state, it can put out a bias of 0V to 1.5kV or so. I understand that a bias that high can cause arcing in headphones with 0.5mm spacers, but I want to play around with spacers and bias at some point. If the cables are rated for voltages like that, I'll continue as planned, but if they're only rated at 600V or 1kV, I'll drop a few stages from the voltage multiplier.

BTW, this is the trafo I'm using. It will need resistors to create a fake center tap.
Edit: that trafo will not work. It's only rated at 5mW

 

[Muamp]

Hi 100VoltTube,

That is an expensive audio transformer. Two of them for stereo is very expensive.
Why not use the audio transformer I recommended on the DIYers Electrostatic headphone thread. They are much cheaper and very good, and have centre tap.
I use these in a transformer energiser I have on my test bench.
As for the bias voltage, unless you will be making panels as big as Jecklin Floats, surely 580v - 600v is adequate?

David.

 

[100VoltTube]

That is an expensive audio transformer

Not really. In the big picture, it's quite cheap. Look at the $130 lundahl trafos spritzer is using. I can't get the trafos from rs components, as they don't ship outside of the UK. They do look quite nice.
I''m doing some more research into determining transformer performance based on numbers to see if I can find a better deal.

As for the bias voltage, unless you will be making panels as big as Jecklin Floats, surely 580v - 600v is adequate?

I was under the impression the spacer thickness controls affected necessary bias more than diaphragm area. Anyway, I want flexibility for playing with odd designs, or maybe even making some very-near-field speakers.

 

[janosch simon]

Hey there what an amazing thread my background is that i was actualy looking for a good dac and somehow ended on a stax forum and there a guy was listening to the meridian explorer 2 with his Stax sr007 and i though hmm whats that and thats how i got intrigued to electrostatic headphones
i already got alot out of the thread and some pm´s with Wachara and now i feel confident to start my journey but not in the dark
i own a little cnc mill which has at the moment some problems another problem is that the working area is tiny with only 160x80mm so i cant make very big phones :-/ if i cant fix it i might upgrade to another cnc mill but the whole hifi project already costs alot
my raspberry music streamer is still missing its dac ( will go with the soekris dam1021-12) and the amp desing im not sure either
but first i will try to make the stator, spacer and how to strech the membrane until now i cant find 3 mircon mylar in europe and ordinging it form taiwan hmm meh perhabs i will try ordinary houshold foil and report back how it goes

ah one question is gilmore.chem.northwestern.edu only for me down? i read i all over the place in regards to amp design but the pages wont open for me :-/

and one last question for now why most of you try to imitate the stax conector with 5pins? i mean you need per phone 3 pins so why you only use 1 pin for the bias? for me it would be more convenient to use a connector with 6 pins just a thought

cheers janosch

 

[100VoltTube]

I can't access gilmore.chem.northwestern.edu either. I'll PM Gilmore about that.

You can buy stax plugs like this. You can also buy it with the 6th pin in the middle, like on the old normal bias stax. Other places also sell it. You can buy a replacement chord assembly from stax here. Sockets, like plugs can be bought from all over the place, like here. You can also CNC or 3D print plastic parts and use pins from XLR connectors.

will go with the soekris dam1021-12

Lucky European. I was planning on making one, but then they stopped shipping to the US.

I think that mylar can only be ordered from Taiwan. That's where mine came from

 

[chinsettawong]

Hi janosch,

Welcome aboard. I'm excited to see what you are going to achieve. Please don't be shy to ask any questions that you have. I and many of us here are here to help.

About Dr. Gilmore's link, I think he has retired from the university. Therefore, everything that was there was moved to the other site. Please ask him about it.

Wachara C.

 

[janosch simon]

yeah exciting times and it SEEMS my cnc mill is back to live i already ordered 1mm and 0.5mm pcb but the controll board of my mill gets sooooo hot i just opened the case and installed a bigger fan

at work ( i work for a small laser company) i might be able to cut some glass stators but the scanner we use have only a scan field of 60x60mm hmmm perhabs my boss buys a biggerscanner

cheers janosch

 

[janosch simon]

as my cnc mill can only do 160x70mm i might start with in ears did you finish them? who did they work? yesterday watching videos about shure kse 1500 and their bias voltage seems to be 200v hmmmm
best janosch

For me, the drivers are no problem to be made, but to make good housings for them could be challenging. Here is what I have made right now.

Fitting in the ear isn't that good yet.

Wachara C.