[Scottsmrnyc]

or can anyone show me how to repair it myself and where to get the parts.  I should also say that I have an old but working pair of Stax Lambda Pros five pin headphones.  Could I use the Lambdas pros to repair the Sigma Pros?  I e mailed Yama in California to see if he would repair them but he says they are now too old and there are no parts for it. 
 
Any help would be great. 

 

[n3rdling]

What's wrong with it?

 

[Scottsmrnyc]

There is no sound coming out from the right ear speaker. 

 

[NamelessPFG]

Hmmm...no sound on the right channel? This could be a few things...
 
-Cable fault. Maybe a solder joint to one of the driver's contacts broke, particularly the diaphragm bias wire. Perhaps there's a fault within the cable itself. If this is the case, it should be relatively easy and affordable to fix if you can get a hold of a new cable.
 
-The actual driver itself is damaged, perhaps by the stators arcing through the diaphragm and burning a hole in it. I don't know if that would cause it to fall totally silent, but that would be very bad and require a very expensive replacement driver (or finding someone that can rebuild the driver; unfortunately, I don't know who rebuilt the drivers in my Lambda). Should it come to that, you could transplant the Lambda Pro drivers into the Sigma if you wanted to...or you could do what some other people do and make it a Sigma/404, that is, a Sigma with SR-404 drivers, to improve the sound quality even further from stock.

 

[Scottsmrnyc]

Thanks NamelessPFG.  I think I will investigate a new cable for it.

 

[Scottsmrnyc]

My problem has now been resolved.  I almost feel embarrassed to say what the problem was; but since a number of my fellow headfiers were kind enough to offer their help, I will state that I had the left channel volume control on my SRM007ta deactivated to a point in which the left channel wasn't producing any sound. Once I turned the volume knob up, it worked perfectly.  I am very happy that my sigma pros are now working just fine and I do admit I am feeling a little foolish. 

 

[n3rdling]

Haha, that's a rookie mistake!

 

[NamelessPFG]

I'm certainly glad to hear that it's not a problem with the Sigmas after all.
 
I didn't even know the SRM-007ta even had any form of balance control; I haven't paid too much attention to Stax amps yet since they're out of my budget, though it would be nice to line up an SRM-1/Mk2 Pro down the road so as to open up a Pro bias upgrade path (and get this huge receiver off my desk).

 

[Scottsmrnyc]

Well Yes, The SRM 007t and SRM007ta amps have a large dial knob that is really two knobs-one behind the other.  They are for balancing left and right channels.  I am also sad to say that I think my problem isn't resolved. When I play that Sigma Pro headphones, If I fool around with the SRM007t or Ta balance control the left channel will work faintly at times and then when I move the balance control to a different setting it fades out completely.  I tested a second set of Sigma Pros and the sound was way fuller and louder at lower volumes needed for my broken Sigma Pros.  So I am back to saying that one of my pair of Sigmas is broken. Ebay or Audiogon await for another replacement pair. 

 

[NamelessPFG]

Aw, just when we thought you were in the clear...I had no idea you even had a second Sigma Pro to use. At least you have one working set.
 
Now might be time to give the defective pair the Lambda SR-404 driver overhaul, if you can afford it, and send the defective drivers off to someone who can rebuild them. (That's assuming that the drivers are defective and not the cable, anyway.)

 

[Scottsmrnyc]

Well, I don't mean to be selfish but I have been a little bit of a hoarder.  I have three pair of Sigma Pros, three pair of Sigma Non Pros, three pair of 4070s, three pair of Lambda pros and one SR007.  I collected these over a six year people specifically with the idea that I would need back up just in case something like this would happen.  I like twos and threes of all my audio equipment.  I might just wait for another pair of Sigma pros to hit an internet auction site or I might try a little exploratory surgery myself.  Thanks for all your help.

 

[Scottsmrnyc]

In regard to affording a overhall; did you look at my avatar photo???  Nothing more needs to be said. 

 

[Scottsmrnyc]

Sucessful Headphone Surgery without a Medical Headphone Surgery License!!!!!  Okay I took a chance and opened up the right earspeaker on my broken Stax Sigma Pros.  Once opened I noticed two unusual things that as a layman didn't look right to me.  Firstly, there seemed to be a lot of dust and or particles around the transducer.  The second thing that I noticed was that there was one piece of black electrical tape around all three of the inner prongs that connect to the transducer.  I removed the tape and then with a tissue paper, I slowly removed all the dust/particles from on the transducer and around the plastic.  I am no expert but I just the dust was inhibiting the electrostatic charge from taking place properly.  Once clean, I took three small pieces of electrical tape and rapped each transducer prong with a seperate piece of tape.  Then I put the whole thing back together and plugged it in to my SRM007ta.  WELL IT IS NOW WORKING GREAT AND IS WORKING CONTINUOUSLY AND SOUNDS GREAT ETC ETC ETC.  IT HAS BEEN RUNNING FINE FOR ALMOST AN HOUR.  I suggest to anyone with this type of problem to do the same kind of surgery.  Thanks for all you help and comments.

 

[NamelessPFG]

Well, that's a relief. The drivers and cable are fine after all, and you know it this time. Sigma/404 can wait if you're fine with the sound as is.
 
(In terms of affording things, I'm used to thinking frugally, even here.)

 

[Scottsmrnyc]

i am now tempted to do a cleaning and retaping on all my Sigmas.  It will be interesting to see what it looks like inside.  I will keep you posted.