Stax SR-009 Channel Imbalance Trouble / Driver Problem?

[Ali-Pacha]

I'll get another pro-bias source soon (SRD-7/SB mk2)...and will see (hear) 

 
Ali

 

[shipsupt]

So for those interested in the process of warranty work with PriceJapan the front end of the process looks like this. 
 
I ship my 009's back to PriceJapan directly, at my cost.  They will initiate the claim with STAX directly, so all of the work will be covered by warranty.  When they receive the repaired headphones or replacements (repair is likely) they will ship them back to me at my cost.
 
They did warn me that with the current back order wait time my repair could take a long time, possibly 2 months. 
 
And the wait begins.

 

[KingStyles]

Bummer on the wait. Now that i have a set of 009, not having them would be annoying.

 

[Shep]

I believe that returns are prioritised because I waited just as long as it took Stax Japan to send a pair to Stax USA repair center (Accutech).   They kept me informed all the way (Stax US service was exemplary which came as shock after reading so many bad experiences).
 
Sure, Stax distributors are going to get preferential service from Stax Japan but it's entirely possible that the long wait list for the 009 is affected by returns, some of which we know about but there are surely many more.  Anyhow, I hope you'll get it sorted through PJ just as fast.

 

[eric65]

Quote:

I finally took some time to measure my Omega 2mk1 yesterday and also re-measured the 009 to check for consistency / repeatibility. While I didn't notice anything last time, it would appear the right channel of the 009 is 1-2dB down from the left side. The omega 2 seems just fine and I could reproduce the imbalance using different measurement method (on urethane backed plate or using in ear microphones).

So, while I haven't processed the data yet (just was looking at the time traces / peak meter in audacity), it would seem my 009 has also gone south a little. Will report back after I get done with the number crunching.

 
Arnaud, the problem of imbalance in the Stax headphones seems to be increasing, at least in France.
On the French HCFR Stax forum at least two SR 009 (that of Peter and Ali Pacha), two 507 SR (mine and that of Arnoparigo), an SR 007mk2 (that of Karim) and one SR 207 (that of a client of Peter) were affected more or less recently.

 

[athenaesword]

Had to send mine in 2 Months ago as well cus 1 side basically went super soft. I got mine back in a month but the local distributor took care of me so I didn't have to pay for shipping

 

[rgs9200m]

Just to note, my SR009 that I bought new from Stax USA (#1550) about 18 months ago has perfect balance, no problems, and seems to sound better month after month.
They do seem to break in, and where sibilance bothered me early on now they are awesome.
I use my trusty 007t/ii amp and really see no need to trade up.
 
They are so compelling I feel like I can't stop listening (I know that's a cliche, but it's true.) They have a combination of detail and musicality  that usually don't go together.
 
I had the 007t/SR007 combo for years, and the SR009 has the similar goodness of this combo with much deeper insight and density that is thrilling. There is lots of tube-y-ness that I like.
 
I really think they need to break in and be given a chance. 
I think there is a huge silent majority of Stax lovers out there who are fans of Stax amp/Stax phone combos that don't post a lot.
But, after years with these combos:
T1W amp / Lambdas;
Original 007t amp / SR007 Mark 1s;
and now the 007t/ii amp / SR009s;
I feel I know the Stax sound well in all its glorious intimacy and speed and sweetness and I think it's a myth that you can't find happiness with a Stax amp.
 
I can hear the evolutionary progress from these 3 combos and I just appreciate it's unique goodness.
It's not a bass or soundstage monster sound, but that's not what I think the Stax signature is. It's bass and staging that's just there, with fantastic insight,
and it sounds complete to me, and un-duplicated by any other phones.

 

[MacedonianHero]

Quote:

 
Arnaud, the problem of imbalance in the Stax headphones seems to be increasing, at least in France.
On the French HCFR Stax forum at least two SR 009 (that of Peter and Ali Pacha), two 507 SR (mine and that of Arnoparigo), an SR 007mk2 (that of Karim) and one SR 207 (that of a client of Peter) were affected more or less recently.

 
Did you happen to miss his very next post:
 

False alarm... No channel imbalance with my 009 after all. I double checked the RMS levels with Audacity, no issue.
 
- Here's a new measurement of the 009, repeted 3 times, could be cleaner but not terrible:
 

 
- On the other hand, the miniature in-ear mics are a real letdown, what a pair matching and SNR below 50Hz... This post is going to be forwarded to tech support soon...

 

 
- Here is a comparison of SR009 measurement (on a urethane lined plane baffle using EMC8000 mic): yesterday vs. last august. I believe the differences at high frequency is more due to mic placement (else the amplifier has totally different transfer characteristics as a function of volume - I do not test at specific SPL - yet):
 

 
Arnaud
 

 

[eric65]

Quote:

 
Did you happen to miss his very next post:
 

Not.
 
For the default balance of both SR 507 and SR 007mk2, it was total, not immediately, but a few hours to a few tens of hours after purchasing the headphone. Same for the SR 009 Peter. For the SR 009 Ali-Pacha, it was more a question of loss of definition on one of the chanel.
 
All these headphones were returned to Japan or the importer for repair or exchange.
 
Edit : 
You can also read this information at the following links (French Forum HCFR on STAX)
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4455.html
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4365.html
 
For more understanding, use google translator Automatic

 
Eric

 

[eric65]

Here an intervention by Peter (Pierre) on HCFR Stax Forum, translated from French into English, about the problem umbalance chanel some Stax headphones.
 
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4365.html
 
" Yes, Herve, as Eric said, and it's just the production of headphone Stax having some small problems in the balance for some time.
This does not include only the SR 009, but the entire production of headphone.
I sold a 207 and last month introduced an imbalance after ten days ..
Stax decided to stop production for a few days this July, to try to resolve the problem.
Headphones ordered earlier this month will arrive next week so very late.
The problem is finally solved, I do not know.
Anyway, as stated by Eric defective headphones are found throughout the world and not only in France ...
Approximately 10% of the production, from what I know, would be affected ...
In case a SR009 bought in the French distribution network has a fault, it is quickly changed by the importer.
I made myself the experience with my personal (SR 009) and demo. Or demo and personal ... It's up to you! : D
Pierre (Peter) "

 

[Ali-Pacha]

Quote:

 
Did you happen to miss his very next post:
 

Arnaud <> arnoparigo 

The first one is the well-known head-fier living in Japan, the other one lives in France 

Ali

 

[MacedonianHero]

Quote:

Not.
 
For the default balance of both SR 507 and SR 007mk2, it was total, not immediately, but a few hours to a few tens of hours after purchasing the headphone. Same for the SR 009 Peter. For the SR 009 Ali-Pacha, it was more a question of loss of definition on one of the chanel.
 
All these headphones were returned to Japan or the importer for repair or exchange.
 
Edit : 
You can also read this information at the following links (French Forum HCFR on STAX)
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4455.html
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4365.html
 
For more understanding, use google translator Automatic

 
Eric

 
Quote:

Arnaud <> arnoparigo 

The first one is the well-known head-fier living in Japan, the other one lives in France 

Ali

You guys must be fairly new to stat-headphones. This has been around for years. That's why most stat amps have vol control for both L and R.

 

[eric65]

Quote:

 
You guys must be fairly new to stat-headphones. This has been around for years. That's why most stat amps have vol control for both L and R.

 
Insufficient to correct, for example, a deficit level> 30 dB in the left channel of my SR 507 before I do it refunded.

 

[MacedonianHero]

Quote:

 
Insufficient to correct, for example, a deficit level> 30 dB in the left channel of my SR 507 before I do it refunded.

30dB is a problem. No doubt.

 

[eric65]

 




Hello 
 
The questions are: why these dysfunctions ? (unbalance or loss of definition on a channel)
(NB : partial malfunction or may become total which apparently concerns potentially a part of the production current Stax (10% of headphones?)
What is the mechanism by which these disturbances occur, sometimes several tens of hours after buying the Headphone?.
Is it related to a too thin film too fragile tearing the long run?
Is it a problem of poor contact between the electrodes?
Is it a problem of impurities?
So many questions!
Solutions?
 
Eric
 






(quote) :
Originally Posted by eric65
 
In France, two problems of imbalance L/R (> 15 dB) recently found for Stax headphones : for a 507 (mine : immediate default) and a 009 (one of Pierre (Peter) : default after 30 hours of listening).
 
For now my 009 works well.
 
Eric

Edited by eric65 - 4/20/13



 


(quote) :
Originally Posted by spritzer
 
A brand new set from Japan went bad recently so it hasn't been fixed.  It's definitely a connection issue but where it is, that's the problem. 
 
Edited by spritzer - 4/20/13




 


(quote) :
Originally Posted by eric65
 
Arnaud, the problem of imbalance in the Stax headphones seems to be increasing, at least in France.
On the French HCFR Stax forum at least two SR 009 (that of Peter and Ali Pacha), two 507 SR (mine and that of Arnoparigo), an SR 007mk2 (that of Karim) and one SR 207 (that of a client of Peter) were affected more or less recently.

Edited by eric65 - 8/3/13