[MikaFoxx]

Thought I should read all the posts before I asked any dumb questions. A few days and over 3800 messages later, here I am.

Congrats and thank you, Chinsettawong, on sticking around and continuing to innovate and educate about these homemade Endgames.

I'm just an audio and electronics hobbiest that's mostly worked on and made some vacuum tube equipment. The best I've got - and heard of headphones, is only the Hifiman 400i, so hopefully I'm in for a good surprise if things work out.
So far, I've been just doing small experiments using graphite rubbed cling wrap and 0.5mm card spacers with metal speaker grille mesh as the the stators. It sounds pretty decent (for what it is) running off a pair of 70v to 8ohm transformers in reverse, for a 90:1 step up ratio. Being lazy, I sacrificed a disused bug zapper for 500v bias, with an extra 22meg in series for some semblance of safety.

I attempted a design using metal mesh like was recently suggested after seeing the the Stax and Hifiman Shangri-la, by gluing the mesh to a sturdier backing to keep it mostly parallel, but it was fairly quiet due to slight warping away from the diaphragm, and the larger 80mm active size made the card spacers even more lacking in stiffness and insulation.

So far, it seems that I need to make a deal with someone local with CNC and 3D printing capability, and to suck it up and build a proper version of the KGSS amp.
You most recent float design looks great, Chinsettawong, and if I can find some help, I'd love to provide a second opinion on how it sounds.

 

[chinsettawong]

Thought I should read all the posts before I asked any dumb questions. A few days and over 3800 messages later, here I am.

Congrats and thank you, Chinsettawong, on sticking around and continuing to innovate and educate about these homemade Endgames.

I'm just an audio and electronics hobbiest that's mostly worked on and made some vacuum tube equipment. The best I've got - and heard of headphones, is only the Hifiman 400i, so hopefully I'm in for a good surprise if things work out.
So far, I've been just doing small experiments using graphite rubbed cling wrap and 0.5mm card spacers with metal speaker grille mesh as the the stators. It sounds pretty decent (for what it is) running off a pair of 70v to 8ohm transformers in reverse, for a 90:1 step up ratio. Being lazy, I sacrificed a disused bug zapper for 500v bias, with an extra 22meg in series for some semblance of safety.

I attempted a design using metal mesh like was recently suggested after seeing the the Stax and Hifiman Shangri-la, by gluing the mesh to a sturdier backing to keep it mostly parallel, but it was fairly quiet due to slight warping away from the diaphragm, and the larger 80mm active size made the card spacers even more lacking in stiffness and insulation.

So far, it seems that I need to make a deal with someone local with CNC and 3D printing capability, and to suck it up and build a proper version of the KGSS amp.
You most recent float design looks great, Chinsettawong, and if I can find some help, I'd love to provide a second opinion on how it sounds.

Nice! I would love to hear what you think. Please share your work here so that we all can enjoy together.

 

[MikaFoxx]

Nice! I would love to hear what you think. Please share your work here so that we all can enjoy together.

It's going to be a bit of a slow process to make a proper version of your floats, but once I get past the 5 messages or so I'd be happy to show off a few pics of the initial concept experiments, as bad as they are. I have a friend that has leftover 6 micron mylar from some quad ESL63's, how does it compare to your preferred 3 micron? I know the original Stax models of the 60's used it, so it can't be too bad.
The KGSS is quite a radical design - no coupling capacitors anywhere - unlike any other audio gear I've made or worked on. Might try to make a dynalo amp first, the KGSS low impedance equivalent, to see how it Stax up.

 

[chinsettawong]

6 microns Mylar is nice too. I’ve tried it before and really liked it.

I would really love to see your work.

Yes, most of KG’s amp designs are direct coupling. There is no need for the expensive coupling capacitors. KGSSHV Carbon is very, very nice. I highly recommend it.

 

[MikaFoxx]

Just a few more questions or ideas.
Have you thought about attempting a closed back electrostat like the Koss ESP 6-10?
I've got an old pair of crappy headphones with a similar build I could give a go with.
Speaking of Koss, I heard that the ESP 95x doesn't have dust covers? Not sure if that's true or not, but considering issues people have on this thread, it would seem like quite the oversight. Might be neat to investigate their driver make-up as nobody here seems to have talked about it yet.

As for the KGSSHV Carbon, I would be building it myself, and I can't find too much for schematics or details for the HV or Carbon, and the KGSS would still be miles and leagues above the repurposed transformers I'm using now. Plus I've most likely got silicon that's suitable for it but not the upgraded versions; I'm on a fair budget. My first few are probably going to look a lot more like the person's in the YouTube clips you've shared than your latest works.
Someone previously mentioned microwave oven mesh as a material for stators and I may jump on that if I can source some before someone with a CNC. I'll be sure to share any progress, and I'll be making rectangular float sized drivers as that's a lot easier to cut.

One more thing. I've been using contact cement and it doesn't have a very good bond against the film if I coat only the spacer and press it against the film, even still wet. Once it dries, it doesn't have much holding power. Coating both holds far better, but then you most likely get some glue into the active membrane area. Any suggestions?

 

[chinsettawong]

The electrostatic headphones sound far better with open back. You can try coving the back side with your hand and you'll know. I really don't recommend a closed back design.

Any amp that can drive the headphones is fine. Even simple step up transformers can sound very nice too. I don't really care about the look of your headphones, I just like to see and appreciate your works.

I'm not sure if we are using the same kind of glue. The contact cement that works great for me is the yellow rubber type. It smells rather bad and it's solvent base. In my country, it's known as the glue for gluing shoe soles.

 

[lkos98]

I support everything Chensettawong said above. Any closed back even simple damping foam affects the sound badly. Once covered with hands it becomes like a mono phones.
For the glue - yes contact cement glue is the best for me as well. In my latest design I made thin 0.8 mm channels (with CNC) in the frame (spacer) and press out the contact cement glue with a syringe in the channel, so it just covers it. It works great, the membrane sticks perfectly and there are no bumps, glue-less spots, etc.

 

[ts8051]

According to the seller, it's 80 mesh. About the back support, I will go with acrylic just like what Stax uses with its original Omega. I have a laser cutter and so cutting acrylic isn't a problem at all.

Hello, Please do you know a seller who sells the membrane 2micron or 3 micron for the electrostatic headphones ? The seller in Taiwan via ebay stoped selling this material. I live in Greece and here does not exist such material. I checked on the whole Europe and i found it in Germany before corona virus era, as i remember, with astronomical price per meter.

 

[chinsettawong]

Hello, Please do you know a seller who sells the membrane 2micron or 3 micron for the electrostatic headphones ? The seller in Taiwan via ebay stoped selling this material. I live in Greece and here does not exist such material. I checked on the whole Europe and i found it in Germany before corona virus era, as i remember, with astronomical price per meter.

I just checked Ebay and the Taiwanese seller is still selling it: https://www.ebay.com/itm/Electrosta...2349624.m46890.l49286&mkrid=711-127632-2357-0

 

[ts8051]

Thanks!!!!

 

[c12Windfury]

Now that Koss no longer sales the extension cable what's a good one to use now that's affordable?

 

[defaultchi]

Thanks for sharing!

 

[Roukii]

I encountered a problem. After listening my SR-007mk1 for 10 minutes or so, the sound pressure level will gradually decrease. Put it aside and wait for a while, and it will recover again. Has someone met the similar situation?

 

[KDS315]

Sounds like a Biss voltage issue;

 

[ts8051]

Very nice work Congo5. I really like the way you make your headband.

By the way, on my side, I've upgraded my headphones with professionally made stators and spacer rings. The stators are made from double sided PCB with plate through holes. Now it's very easy to solder the wires on either side and the copper trace doesn't get in the way of the spacer rings anymore.

For some unclear reasons, after the upgrades, my Orpheus clone and Omega clone are quite a bit more efficient. They sound as loud as my Stax SR009 now. I have to remake the diaphragms since using the old ones and they are not able to keep stable. The dynamic and bass also get much better. You guys should try.

Hello again,
In all cases when my diy electrostatic headphones, even with best frequency responce, sticks to one stator because of a accidental vibration (small). It sticks only with non conductive coating. How can i avoid this problem? After many years of development i cant find the solution.