[ericohgb]

Dear friends,
 
[size=medium]I've been listening to my SR-007A for a couple of weeks now and have noticed that the right channel outputs lower volume (about 5-7db) than the left channel.[/size]
[size=medium]It happens when listening with both my GES and 727A amplifiers. [/size]
[size=medium]I also have a 404LE and that issue doesn't happen.[/size]
[size=medium]Could you possibly know what is the problem?[/size]
[size=medium]Dou you know how I can fix it? or[/size]
[size=medium]Do you know where I can send it for service in the US?[/size]
 
[size=medium]Thanks in advance,[/size]
 
[size=medium]Erik[/size]

 

[edstrelow]

Quote:

Dear friends,
 
[size=medium]I've been listening to my SR-007A for a couple of weeks now and have noticed that the right channel outputs lower volume (about 5-7db) than the left channel.[/size]
[size=medium]It happens when listening with both my GES and 727A amplifiers. [/size]
[size=medium]I also have a 404LE and that issue doesn't happen.[/size]
[size=medium]Could you possibly know what is the problem?[/size]
[size=medium]Dou you know how I can fix it? or[/size]
[size=medium]Do you know where I can send it for service in the US?[/size]
 
[size=medium]Thanks in advance,[/size]
 
[size=medium]Erik[/size]

  My first guess would be a bad connection to one stator. You might be able to check this out by opening the ear cup with the problem.  The wire there may be broken or there could be a break in the cable. I have partly opened my 007A but I didn't get to the wires.  I  also repaired a broken cable in my 404 which uses the same cable as the 007. I located the break by visual inspection, stripped around the broken wire, soldered a connecting wire and sealed the cable with an epoxy plastic.  
 
You don't say how old this unit is,  or if it was damaged somehow. 
 
Yamasinc is the distributer/repair facility in the US.  I would say send them an e-mail about cost of repair.  I would guess a couple if hundred unless you need drivers replaced.  Yamas has a bad reputation for not responding to communications but I have always been able to get things done with them. If your unit is grey market they may refuse it.
 

 

[ericohgb]

Dear Edstrelow,
 
Thanks for your reply.
 
My SR-007A is quite new, around 2-month use. I had already a 404LE, which plays perfectly, that's why I suspected that something was odd about it.
 
By the way, Yamasinc does not answer my e-mails.
 
Best regards,
 
Erik.

 

[edstrelow]

Quote:

Dear Edstrelow,
 
Thanks for your reply.
 
My SR-007A is quite new, around 2-month use. I had already a 404LE, which plays perfectly, that's why I suspected that something was odd about it.
 
By the way, Yamasinc does not answer my e-mails.
 
Best regards,
 
Erik.

In that case it sounds like warranty time.

 

[ericohgb]

Quote:

In that case it sounds like warranty time.

The problem is that I bought in Japan...
I guess I'll have to try to fix it as you did with your 404.
Thanks,
Erik

 

[Solude]

That is definitely the cable connection at one stator.  Mine is on route to the UK for service since yes, Yama isn't interested in revenue  Course mine is 4 years old and has had its cable rolled over yanked and otherwise been heavily used so not surprising.  Pads were also done so the shipping hurts a little less... little.

 

[XXII]

It's unlikely to be a cable issue if you're still getting sound.
 
I had the same problem with both(!) of my O2s when the weather was very humid, I would get channel imbalance. The solution was to put the O2 in it's box for a few days and then it should go back to normal. If you live somewhere humid this is probably the problem.
 
On the other hand, it could be a parasitic charge issue. 

 

[Solude]

No its a cable thing.  The cable, being flat, gets pulled on one side more than the other.  If the loaded side comes off its solder joint that stator drops.  Once unloaded it returns because the harness is held in place.  Basically, pull cable on one side, volume drops, push up... back on.  Given how the O2 cable sits I'm surprised it doesn't happen VERY often.  Essentially zero offloading of weight on the solder points, bad design.

 

[XXII]

Quote:

No its a cable thing.  The cable, being flat, gets pulled on one side more than the other.  If the loaded side comes off its solder joint that stator drops.  Once unloaded it returns because the harness is held in place.  Basically, pull cable on one side, volume drops, push up... back on.  Given how the O2 cable sits I'm surprised it doesn't happen VERY often.  Essentially zero offloading of weight on the solder points, bad design.

I (respectfully) disagree. If the cable were damaged you would get drop-outs.
 
Also, the OP has a sr-007A which has a much better strain relief than the SR-007 mk1.

 

[Deadneddz]

Quote:

Given how the O2 cable sits I'm surprised it doesn't happen VERY often.  Essentially zero offloading of weight on the solder points, bad design.

This is incorrect. If you open up the O2, you will see that there is no way there would be any weight on the solder points as that portion is clamped off with some extra slack. The reason for bad cables(in the MKI version at least) is the utter piece of crap that is supposed to be a strain relief. It breaks at that point, not the solder joint. But the MK2 does fix this issue so....

 

[Solude]

Say what you will, mine is broken, mine is the cable.  Its a balanced system, one stator is pull the other push, if one drops... you still get a push or pull but not the other so a drop in volume.  Whether the tear is at the solder point or the junction where the cable reaches the R or L plastic doesn't change that a cable replacement is in order.
 
That or Stax service is blowing smoke up my arse and my O2 is coming back just as broken minus the couple hundred the service cost.  But how its cabled is pretty clear, search for the photo, its the cable into the R and L pieces pops out and gets soldered directly to the stator above, no turns, no slack, straight up and down.
 
http://wiki.faust3d.com/wiki//index.php?title=Image:Stax_SR-007_driver.jpg
 
The only thing I couldn't tell because I didn't want to destroy it, was if the cable and the L/R pieces are molded together.  So to review... details aside, I'm saying the problem is caused by the cable not feeding one stator.

 

[spritzer]

Late reply but if you loose one stator you get basically nothing out of the drivers.  If one channel is a few dB down then it is the dreaded electret effect which should go away with use. 
 

 

[jgazal]

 
[size=10.0pt]Hello, Erico! [/size]
 
[size=10.0pt]It is nice to see you here.[/size]
 
[size=10.0pt]Do you have your audio system properly grounded (earth-earth)? [/size]
 
[size=10.0pt]I mean the third pin in the wall AC plug/receptacle really connected to the ground with an arrange of copper rods (usually three rods in a triangle arrange, separated from the neutral/cold that has already been done by the energy distributor in the entrance of your house, which you can reinforce anyway).[/size]
 
[size=10.0pt]It has been really dry here (except for last week). For instance, 20% to 30%, 7/17/2010. [/size]
 
[size=10.0pt]The low humidity might be keeping the transducers statically charged more time than usual. I think someone at the Stax thread explains how to discharge the earspeakers after use. [/size]
 
[size=10.0pt]Technically speaking Stax earspeakers are designed to be used in a vast humidity range: less than 90% (without condensation).[/size]
 
[size=10.0pt]I hope you find the solution.[/size]
 
[size=10.0pt]Best regards,[/size]
 
[size=10.0pt]Jose[/size]

 

[jgazal]

Second thought.
 
GES comes from USA (110V, okay).
 
But 727A is designed to work with 100V primaries.
 
Your wall is given you 120V.
 
Are you using a step down transformer?
 
If not, you might be supplying a little more than the regular 580V pro bias to the mylar.
 
Do not know the consequences. But they are not specified to work under those conditions...
 
Best regards,
 
Jose  

 

[Scottsmrnyc]

here is a possiblity that you might not have tried.  Did you know that the volume knob on the srm007t and srm 007ta as two parts to it; so that the outer part of the knob controls one channel and the inner part of the knob controls the other.  You might be using this knob not knowing that this is the case.  Scottsmrnyc