A couple of weeks ago I received an email from an old friend and bandmate regarding his Stax headphones. He contacted me because I was the "expert" who recommended he purchase a pair of Stax earspeakers for his home recording studio.
While my friend loved the sound of the two pairs of Stax he had, they were both no longer functional. His Stax SR-407 had a broken yoke while his pair of original Lambda Signatures had a broken headband. He had looked into getting replacement parts but had come upon a series of dead ends and he was, to use his words, "Had it" with the Stax's physical delicacy. He wanted to be rid of both of these earspeakers along with the SRM-3 headphone amplifier.
I used to own quite a few Stax earspeakers, but I sold off all the oldest ones. Currently I only have a pair of SR-X, a pair of Nova Signatures, and an SRM-007t headphone amplifier.
After talking on the phone we agreed to a trade - I would take his Stax gear in exchange for two pairs of headphones and a headphone amplifier. I traded two recently discontinued and extremely well-built and comfortable headphones that I knew would stand up to whatever rigors he could subject them to as well as a tube-based headphone amp to drive them. And then I began my own search for parts to make at least one pair of earspeakers usable.
Finding parts for the newer SR-407 earspeakers wasn't hard, but it was not inexpensive. Woo Audio, who sell Stax earspeakers on their website, also stock some Stax parts, including earpads and headband/yoke assemblies. A new headband assembly for the SR-407 set me back $120US. Yes, that does seem pricy for such an insignificant assemblage of plastic parts, but that's the cost. At least I was able to "add value..."
I mentioned that I already owned a pair of Nova Signature Pro earspeakers. I had them so long and used them so much that the headband had gotten to the point where the friction sliders for adjustment needed to be wired into place since the friction was nil and the leather headband part had to be modified with a handknitted "headband cozy" that I wrote about back in 2016. While this has worked, it is a bit too Grandma Moses for my tastes.
Since I only needed one of the yokes from the new headband part from Woo, I replaced the headband and leather slider assemblies on my Nova Signatures with new ones from the SR-407. Now I had TWO working Stax headphones for the price of one new headband part.
If only replacing the headband for the older Lambda Signature Pros were as easy...
Neither Woo nor any of my other sources for parts had any headbands for earlier Stax Lambda pros. Unfortunately, the headbands for the SR-407/Nova Pros will not fit the older Stax because the yoke mounting holes on the older Stax is only half the diameter of the later Stax. The Earspeaker capsules themselves are identical looking, so you could resort to enlarging the older Pros' holes with a hand drill, which is not without risk. If I can't find the parts after a couple of months of searching on EBAY I may resort to the hand drill route.
During this whole project I kept wondering if there wasn't, perhaps, a ready market for some enterprising audio firm to make replacement Stax headbands for older models. I'm not advocating clones of the originals, but better headbands, perhaps employing metal rather than plastic? Given the high cost of the originals, there could be enough margin for a "better" aftermarket headband that could even be priced at or above the cost of the current plastic ones. Heck, even a Grado headband could be adapted with newly-fabricated replacement yokes for Stax use...and the final result would be much more rugged than the originals...