$5.99can for STAX headphones

[seangoesbonk]

Well, I was routing through the local thrift store when I came across some headphones.

Well, turned out to be STAX SR-40 for $5.99can. But the SDR-4 transformer was missing.

Anyways, what should I do with them? I could build some sort of amp driver if I knew some specs.

I don't want to spend any money on them if they don't work. Anybody know how I can test them?

Anybody know anything? Thanks in advance.

[fdegrove]

Hi,

The 40,60 and 80 are electret headphones and as such use a permanent magnet principle.

From what I read about them a PSU is not required, the magnets getting polarised by passing the AC ( music) signal through them.

UNFORTUNATELY IN GERMAN...

Cheers,

[mrfeedback]

The pair that I have in a box somewhere use a step-up transformer box.
I do not know the step-up ratio required, but you could probably try a small 240-15 transformer wired in reverse and see what you get.
These use a permanent electret capsule, and as I understand it these can lose their polarization, and go low audio output level.
I have replaced these capsules in a pair of Yamaha electret headphones in the past, and these looked like they could have been Stax oem.

Eric.