Dear all,
I'm rather new in this community so I cannot ask the standing experts directly yet. Here's my conundrum: I'm currently making a new pair of diaphragms for my Stax SR-007 Mk1 electrostatic headphone as one of the stock diaphragms tore up and Stax refused to receive the unit for a repair quote (long story). I've already geared up with the needed materials and tools, including new custom-made pcb stators, 1.4 um Mylar film (the stock SR-007 diaphragm is 1.35 um thick) and a Mylar stretching device to tune the diaphragms in matched quads (good to have spares), thanks largely to the generous advice from Head Case user chinsettawong who has been helping me remotely with this task.
My current choice for the coating material is a silicone-based graphene spray used for car detailing, but my previous experience with using it for recoating did not yield great results at all regarding durability (channel imbalance returned after a couple of days at the longest), even with some buffing. I was considering trying to "enhance" the spray with reduced graphene oxide (RGO) powder, but I'm skeptical this will improve durability of the coating at all. That's one of the reasons why I haven't started making the new diaphragms yet (other reason is lack of time, but that's another matter...) - I'm currently looking for more promising, longer-lasting alternatives for the coating material. I don't want to keep reopening my SR-007 every couple of months to recoat the diaphragms.
My assessment of some of the alternatives around:
I'm rather new in this community so I cannot ask the standing experts directly yet. Here's my conundrum: I'm currently making a new pair of diaphragms for my Stax SR-007 Mk1 electrostatic headphone as one of the stock diaphragms tore up and Stax refused to receive the unit for a repair quote (long story). I've already geared up with the needed materials and tools, including new custom-made pcb stators, 1.4 um Mylar film (the stock SR-007 diaphragm is 1.35 um thick) and a Mylar stretching device to tune the diaphragms in matched quads (good to have spares), thanks largely to the generous advice from Head Case user chinsettawong who has been helping me remotely with this task.
My current choice for the coating material is a silicone-based graphene spray used for car detailing, but my previous experience with using it for recoating did not yield great results at all regarding durability (channel imbalance returned after a couple of days at the longest), even with some buffing. I was considering trying to "enhance" the spray with reduced graphene oxide (RGO) powder, but I'm skeptical this will improve durability of the coating at all. That's one of the reasons why I haven't started making the new diaphragms yet (other reason is lack of time, but that's another matter...) - I'm currently looking for more promising, longer-lasting alternatives for the coating material. I don't want to keep reopening my SR-007 every couple of months to recoat the diaphragms.
My assessment of some of the alternatives around:
- Antistatic sprays such as Licron Crystal and Staticide are unobtanium for me here in Brazil, these are usually not shipped abroad for being hazardous goods. Thus, not really an option. Besides, mileage seems to vary regarding their durability as a coating material.
- Antimonium-doped tin oxide (ATO) seems promising. diyAudio user neil5m used the ATO antistatic coating solution RB-048 by Shanghai Huzheng to restore his pair of MartinLogan Clarity ESL's, but he also reported on this coating being rather humidity-sensitive. Head Case user Kung also used an ATO alcohol solution to "repair" (more like rebuild...) a pair of Hifiman Shangri-La Jr. e-stat diaphragms. Despite Shanghai Huzheng claiming a duration of 5 to 8 years for the coating, I'm still curious about actual long-term longevity in my scenario.
- Finally, there is the HTEC coating solution by diyAudio user Martin-Jan Dijkstra. Have just learned about it, so not much to say on my behalf. I'm currently unable to PM him directly to know more due to my being a diyAudio newcomer. Edit: Mr. Dijkstra has just answered to a query of mine and informed that HTEC has been discontinued, so this is no longer an option either.
- The ideal solution would be to do as Audeze did with the CRBN e-stat and have an appropriate conducting material embedded into an appropriately thin polymer matrix (they use carbon nanotubes, hence the name), no longevity problems at all with that. However, only Audeze seems to be able to get something like a 1.4 um thick, carbon nanotube-infused Mylar film with an appropriate surface resistivity (my SR-007 measurements point to 4 x 10^8 Ohms/sq. as a reference point).
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A couple other alternatives that seem worth trying:
- Statclear A50 antistatic spray from Edson Electronics. Unlike Licron Crystal and Staticide, this is claimed to be water-based and thus can be shipped anywhere. However, as it happens with other antistatic sprays, mileage also seem to vary regarding durability of the coating, even though the manufacturing company itself advertises success of the product to that end. I asked for a sample, let's see how it goes.
- The ER coating material from Australian ESL manufacturer ER Audio. Like Dijkstra's EC and HTEC coatings, ER coating is provided for non-commercial DIY projects. These are special purpose-made and thus seem to be the most promising alternatives short of industrial CVD coatings used by major ESL manufacturers and specialized conductive films such as the one used by the Audeze on the CRBN.