Vintage Stax repair and maintenance

The problem with stax comes down to decaying foam and driver problems. If the dust gets into the drivers- expect bad things to happen.

High humidity is an issue too. But a lot of units last a long time with some care. I've got a pair of sr-40's (35 years old) that work fine.

As far as the electronics go, cap replacement and cleaning controls seem to be common. A used srm-1 mkII that's been re-capped and cleaned

should run for years more. An adapter like a srd-7 seems to run forever without any real problems.

I recapped my srm1 mkII myself. Not too hard to do with some basic skills. I'm old and half blind, so it came down to wearing those

flip down head visors with lenses to see what I was doing. You young guys shouldn't have any problems.

Hi

Ive just received my 1st venture into Stax and electret/electrostatic  Stax sr-80 pro and an SRD 4 adapter.

This combo is refered to an sr84 (1984)  I hope I have collected that info correctly

My 'earspeakers' have a huge imbalance 85% left and 15% right.  Im pretty sure its not the adapter at fault having tested both left and right outputs with the good left channel and vice verser.  SO definatley the right earspeaker at fault.

I have learned so far that this is not an un-usual fault over time (30 years or so) as the micro measurments of these devices are suseptible to dust. 

Like you I am not an expert at all but thought I might let you know what I have learned in the last week or so. 

Inside my earcups it appears that componets have been removed from the wiring, and then cut and shut back together,  either Ive been ripped off or this is a common modification, with a view to regaining the balance.  Im not sure but I have viewed around 8 different photos online and they all have 2 components per ear hidden in the earcup.  Diodes I think? 

Im putting off doing a continuity test as I dont have access to exposed wires at the earspeaker end and would rather not start hacking away at the insulation until someone can offer a miracle cure..(I can hope) 

I did a continuity check with the pins after reading an article and they are all open circuit as they should be.

Many thanks and good luck with research

I haven't tried to open a set of sr-40. They work great, and all I would do is cause a problem. The real trick is to find a good set, then take care of them.

Quote:

Originally Posted by Headdie 

Buntudor,

 

I have an opportunity on a SR-84 system : sr-80 / srd-4.

 

The guy ask 250$ telling me that it's mint.

 

I'll meet him and listen to his Stax system.

 

Is there something that I should check to make sure everything's perfect ?

 

Thanks,

WOW - way overpriced.  Last set I bought was well under $100.00 (closer to $75.00)

Let them charge for a few days.

The diaphragm coating on these sets doesn't age well and contacts corrode which adds considerable resistance to the system. 

The coating on the diaphragm deteriorates over time.  And the resistance on the diaphragm surface becomes much higher than what it used to be.  Therefore, it takes a lot longer time to charge up.  If you can, just keep it charged at all time.

Wachara C.