The Headcase Stax thread

[Arthrimus]

I've got a problem that I could use some advice on. I just snagged a trio of SR-X Mk IIIs and boy do these sound sweet. This is the first time I've heard one and I honestly think it might be my favorite headphone right now. All is well with two of them, but the last one is quite sick. It's got some channel imbalance and has very little bass at all. I figured that they may need to charge for a while like my SR-5s which don't start sounding good until they've had 30 minutes or more to charge. They've been plugged into my SRM-1 mk2 for three days now with no change in sound whatsoever. The pads are in rough shape, the vinyl is flaking off badly, so I changed them out and and that once again had no effect. I thought there might be something wrong with the aluminum baffles so I swapped them with one of my good pairs and there was still no change. I fear that they have been arced badly but before I deem them a loss, does anyone have any other diagnostic suggestions for me?

Thanks,

Caleb.

Edited November 8, 2015 by Arthrimus

[spritzer]

Massive imbalance and lack of bass can really only point to very badly arced diaphragms.  If these were used with SRD units then that is more probable than not. 

[Ali-Pacha]

Yep, normal bias SR-X were often exposed to that issue (too much volts through SRD boxes => arcing). Curiously, it looks like SR-3/5 aren't as concerned...don't know why.

BTW, you can try to unmount them. If there is no sight of arcing, a re-coating with some antistatic product could work. I did that with rinse aid some months ago ( http://www.head-fi.org/t/498292/my-diy-electrostatic-headphones/1725 ), it stills work perfectly but some say it's not very durable as coating. Generally speaking, check out Wachara (chinsettawong) posts / threads here and out there, there's a ton of knowledge in them.

Ali

[spritzer]

Same exact drivers in the SR-5 so exactly the same problem there. 

[Ali-Pacha]

I've met far more burnt SR-X than burnt SR-5, thus my writing. But I'm not really into statistics, and would be hard in such a niche market.

Speaking of drivers, SR-5 gold and SR-X/mk3 have theoretically the same ones, but they are different from one another on my units : PCB spacers on SR-5 Gold, Inox ones on SR-X. And when using SR-X diaphragm/spacers in SR-5 Gold drivers, there's a strange tickling noise when bias comes in...maybe slightly different stator/diaphragm gaps. I think I'm looking at one of the several production changes made by Stax without saying...the same on amps, right ? 

Aside from drivers, there's something that could explain my impressions with SR-X more easily burnt : vinyl on original pads peels off like bad leprous skin, then more risks to have some particle making its way through the dust cover and entering the driver...I had to remove one of thes particles from a SR-X/mk3 pro driver to get rid of some annoying buzz.

2 cents.

Ali

 

[spritzer]

All of these drivers are the same through the entire product run.  Some have spacers to account for unit to unit variation but they were always the same.  That includes the later Pro versions, just different spacers for the diaphragms. 

[Arthrimus]

I pulled the drivers out of the cups and swapped them to see if the issue was in the cable. Unfortunately the imbalance followed the drivers, but I did notice something strange about the quiet driver. Where the loud driver is shiny the quiet one has a kind of haze on the rear stator. It almost looks like a fungus of some sort. Here are some pictures of what I'm talking about.

EDIT: I pulled the driver apart and found NO ARCING! The diaphragm was glued to the rear stator and  has some hazy residue on it. I suspect this driver may have been exposed to some moisture or something explaining it's problems. Here's a picture of the diaphragm. 

I flipped the diaphragm over and reassembled the driver and now I'm getting full output from both drivers! Bass is present too. I think the perceived lack of bass was due to the channel imbalance. The good driver was working properly the whole time.

Should I do anything to try and clean the diaphragm and stators, or should I just leave well enough alone and enjoy them now that they are working?

Edited November 8, 2015 by Arthrimus

[spritzer]

Just leave them alone. 

[Arthrimus]

Will do. As a side note, now that I've seen how easy these drivers come apart, I'm curious about doing a pro bias mod. Spritzer, I know you have done one. What material did you use for the spacers? How doable is it for the average guy?

[chinsettawong]

Oh, it's good that the coating is still OK. 

Are there dust covers on the front and the back of the driver?  Are they still in good shape?  The dust covers if they are in good condition, should provide a pretty good shield against moisture.

I wonder what that black wire on the drive is for.

 

[Arthrimus]

Oh, it's good that the coating is still OK. 

Are there dust covers on the front and the back of the driver?  Are they still in good shape?  The dust covers if they are in good condition, should provide a pretty good shield against moisture.

I wonder what that black wire on the drive is for.

 

I believe it's a zener diode intended to prevent arcing from SRD boxes. It seems that this solution doesn't really work very well.

And yes the dust covers are intact.

Edited November 9, 2015 by Arthrimus

[chinsettawong]

About adding the thickness to spacers, you can try something as simple as a piece of paper.  Last time when I measured, the 80 GSM A4, photocopy paper was about 100 microns thick.

Edited November 9, 2015 by chinsettawong

[Arthrimus]

Wow, so just 2 pieces of paper cut to size on each side of the diaphragm should do it? Sounds like a piece of cake!

Edited November 9, 2015 by Arthrimus

[4tray]

My friend and I are almost finished building my soon-to-be KGSSHV

I can't decide whether I want to buy some 007 or 009's in anticipation. I sold my last working set of Lambdas to a frenchman.

Damned downsizing, grr....

[grawk]

stop spamming so that you can look like a member when you're trying to sell your headphones

[DefQon]

I pulled the drivers out of the cups and swapped them to see if the issue was in the cable. Unfortunately the imbalance followed the drivers, but I did notice something strange about the quiet driver. Where the loud driver is shiny the quiet one has a kind of haze on the rear stator. It almost looks like a fungus of some sort. Here are some pictures of what I'm talking about.

 

EDIT: I pulled the driver apart and found NO ARCING! The diaphragm was glued to the rear stator and  has some hazy residue on it. I suspect this driver may have been exposed to some moisture or something explaining it's problems. Here's a picture of the diaphragm. 

 

I flipped the diaphragm over and reassembled the driver and now I'm getting full output from both drivers! Bass is present too. I think the perceived lack of bass was due to the channel imbalance. The good driver was working properly the whole time.

Should I do anything to try and clean the diaphragm and stators, or should I just leave well enough alone and enjoy them now that they are working?

That is how I've fixed 4 of each of my SR-X MK1-3 and all of them were purchased from Japan sold as junk. The problem with the diaphragm sticking to the back stator is more common on the MK3 models and few of mine had to have had the diaphragm replaced. Moisture (humid areas), poor storage condition (headphone under the sunlight or heat sources) are all possible culprits to the problem as it will cause the diaphragm to sag and stick to the stator. 

I would re-coat that diaphragm as most of the coating is lost after being peeled off from the back stator and imbalance will settle in again soon enough. This happened to my last MK3 I fixed which I thought was fine and I had it on the test/burn-in bench for 1 week straight and the channel imbalance came in and the driver ended up dying on me completely. Just food for thought in case it does happen.

[PATB]

My SR-009 will probably fit better if I could adjust it to sit just a little lower.  Unfortunately, my slider is already set to the end (topmost setting).  So I am thinking of replacing the head pad with something just a touch longer.  Or use an after market suspension strap like the ones used by Audeze owners.  To do so, I need to remove the existing head pad.

I notice that there is only a single screw fastening each end of the head pad to the frame.  Is there anything else I need to worry about (e.g., is the screw epoxied in)?  Thanks much.

[Voltron]

Hi Pat!

[edstrelow]

On 11/8/2015, 5:55:21, spritzer said:

All of these drivers are the same through the entire product run.  Some have spacers to account for unit to unit variation but they were always the same.  That includes the later Pro versions, just different spacers for the diaphragms. 

Can you turn a low bias  unit into a pro just by increasing the thickness of the spacer (and rewiring the plug?)

[sorenb]

1 hour ago, edstrelow said:

Can you turn a low bias  unit into a pro just by increasing the thickness of the spacer (and rewiring the plug?)

E = V/d

[DefQon]

On 18/11/2015, 04:24:14, edstrelow said:

Can you turn a low bias  unit into a pro just by increasing the thickness of the spacer (and rewiring the plug?)

 

Yes you can. I've done this to SR-3 and Gamma units.

[edstrelow]

Cool.

 

[dripf]

 

Stax product placement leaving the beats world cup ad in the dust.

[spritzer]

Wow.... 

[judo]

I am thinking about buying a "new" SR-007. Have you got experiences buying from PriceJapan in Europe? Any difference in shipping with EMS or FedEx except the cost? I would appreciate any piece of advice.