Welcome to all,
I am Joseph from Debrecen, Hungary.
I have been interested in old electrostatic headphones for a long time.
I'm mainly interested in vintage Stax models (SR-3, SR-5, SR-X Mk3 etc.) and clones from the 70's like Marantz SE-1, Magnavox 1A9217, Realistic HP-100, NAD Model 20E etc.
I am happy to repair and refurbish them. I believe that we should keep these classic headphones alive as long as possible. They are worth the care. They are relatively cheap to buy. Besides, these headphones still have a much nicer sound than most of today's dynamic headphones.
I've been trying new things lately. I converted my SR-5 Gold NB headphones from normal bias (230 V DC) to pro bias (580 V DC). The result is impressive! The SR-5 Gold retains the same sonic character, but now reproduces the sound with much better quality. More power handling, more volume, wider frequency response, more bass, more detail, etc. In short, it's worth converting old Stax models like the SR-5, SR-5 Gold, or SR-X Mk 3 to pro. I use 1 or 2 micron Mylar film for the conversion. But I'll talk about those in another thread later.
In this post, I would like to show you my refurbishment of the 1976 NAD Model 20E electrostatic headphones with photos. I hope that this will help others who are interested in this subject.
The NAD Model 20E headphones are one of the Stax clones. The construction of the clones is similar, so the other clones can be improved in a similar way.
The headphones are easy to disassemble, the base plate is fixed by 3 screws under the ear cushion.
It is a good idea to take a photo before disconnecting the wires.
The stator contact on the ear side should be unscrewed.
The cup is fixed by 4 rivets, these need to be removed. I use a sharp knife and my fingernails for this.
When the 4 rivets are removed, the cup opens.
The diaphragm is loosely glued between two metal rings.
The diaphragm is tensioned by 4 springs on a plastic flange.
Caution: 3 springs can easily roll away. I glue these in place.
I use antistatic foam to rebuild the diaphragm.
Usually it is enough to coat the diaphragms once with the antistatic foam. If the channel symmetry is not the same, I repeat the coating once more on the quieter diaphragm.
The result: like new headphones. I have found that the use of antistatic foam shortens the charging time of the diaphragms. You don't have to wait hours for a full charge, the headphones sound at full volume immediately.
The assembly is done in reverse order.
Hope I could help!
Best regards,
Joseph
I am Joseph from Debrecen, Hungary.
I have been interested in old electrostatic headphones for a long time.
I'm mainly interested in vintage Stax models (SR-3, SR-5, SR-X Mk3 etc.) and clones from the 70's like Marantz SE-1, Magnavox 1A9217, Realistic HP-100, NAD Model 20E etc.
I am happy to repair and refurbish them. I believe that we should keep these classic headphones alive as long as possible. They are worth the care. They are relatively cheap to buy. Besides, these headphones still have a much nicer sound than most of today's dynamic headphones.
I've been trying new things lately. I converted my SR-5 Gold NB headphones from normal bias (230 V DC) to pro bias (580 V DC). The result is impressive! The SR-5 Gold retains the same sonic character, but now reproduces the sound with much better quality. More power handling, more volume, wider frequency response, more bass, more detail, etc. In short, it's worth converting old Stax models like the SR-5, SR-5 Gold, or SR-X Mk 3 to pro. I use 1 or 2 micron Mylar film for the conversion. But I'll talk about those in another thread later.
In this post, I would like to show you my refurbishment of the 1976 NAD Model 20E electrostatic headphones with photos. I hope that this will help others who are interested in this subject.
The NAD Model 20E headphones are one of the Stax clones. The construction of the clones is similar, so the other clones can be improved in a similar way.
The headphones are easy to disassemble, the base plate is fixed by 3 screws under the ear cushion.
It is a good idea to take a photo before disconnecting the wires.
The stator contact on the ear side should be unscrewed.
The cup is fixed by 4 rivets, these need to be removed. I use a sharp knife and my fingernails for this.
When the 4 rivets are removed, the cup opens.
The diaphragm is loosely glued between two metal rings.
The diaphragm is tensioned by 4 springs on a plastic flange.
Caution: 3 springs can easily roll away. I glue these in place.
I use antistatic foam to rebuild the diaphragm.
Usually it is enough to coat the diaphragms once with the antistatic foam. If the channel symmetry is not the same, I repeat the coating once more on the quieter diaphragm.
The result: like new headphones. I have found that the use of antistatic foam shortens the charging time of the diaphragms. You don't have to wait hours for a full charge, the headphones sound at full volume immediately.
The assembly is done in reverse order.
Hope I could help!
Best regards,
Joseph
