[chinsettawong]

The two diaphragms can also take a little different amount of time to charge up. So, it’s best to plug them in a minute or two before you listen.

 

[adidas128]

Has anyone bought used Stax 009S, what's a good used price?

 

[Hi-Fi-Apricity]

Can anyone make a video on how to install the SR-009 / SR-009S pads?. One of my 009S pads slipped a bit so I have been trying to put it on for hours now. I cant seem to get it to fit tight enough compared to the other pad and the leather bunches up more when I put it on compared to the left pad. (right pad is the one I tried to reput on)

 

[PointyFox]

Use something flat and plastic, maybe a credit card if it will fit, to poke the pad material into place for about an inch, then pull it into place, working in a circle until it's all tucked in.

 

[Mach3]

Both the 323s and the 353x are solid state drivers. Shouldn't take more than 5-10 to charge up.

 

[chococya96]

Hey guys, I'm having this weird noise issue with my L300 + 252s.

Basically, I'm hearing this constant weird humming/buzzing noise (?) from the left channel of my L300 whenever I turn on the 252s. It's a one note noise where there are no fluctuations. The noise is present all the time regardless of whether the amp is on or off.

I really don't know the correct term for this specific noise but, it sounds like one of those VHS tape playback where you hear humming noise during idle.
Furthermore, I can hear the noise even when I disconnect L300 from 252s! After disconnecting the 5 pin pro bias cable, when I physically touch the 252s, the noise is more prevalent.

The only way to get rid of this noise is by unplugging the power input from the back of 252s. Then the noise is completely gone. Plug it back in, and the noise back again.

I really don't know what's going on with my STAX srs-3100. I'm not even sure if the fault lies on the earspeaker or the amp, or both. It's almost a month since I've purchased this set and I didn't experience this noise issue as it recently happened a few days ago.

I appreciate your help.


UPDATE: According to various threads relating to humming/buzzing noise, it seems like the problem is most likely caused by ground loop issue. Can anyone confirm this?

FYI, the wall outlet that I'm currently using are properly grounded. Also, the humming/buzzing noise is not present on my other amps (Magni 3, JDS the element). It's only my STAX set that is having this noise issue.

I've tried the following to see if the noise goes away though none of them worked:
- Trying different input cables (USB, coax and optical)
- Placing my DAC (JDS EL DAC) away from srm-252s. My original setup was stacking the amp on top of the DAC
- Plugging the power adapter to different outlets on my UPS unit. I use Cyberpower 1500VA
- Plugging the power adapter directly to the wall outlet

Lastly, I'd like to mention that I live in Australia and I've bought Stax srs-3100 from authorized Australian seller which, comes with a power adapter that is rated for aus voltage.
As for the plug, although it comes with Australian plug, it doesn't have grounding pin on the plug. I'm not sure if this is relevant as my other amps also comes with aus plug without grounding pin.

Is the power adapter the culprit? Or is it my STAX amp that is causing this problem? Again, I did not experience this issue before.

Argh, this is driving me nuts...


UPDATE 2: Another weird thing that I've found out is while the noise is present, when I lay my hand on top of SRM-252S, the noise disappears. Then when I remove my hand from it, the noise is back again.

 

[Don Quichotte]

Back in my mother's house where I was living, my Stax SRM-313 energizer also exhibited some noise which disappeared when I touched its chassis. It turned out that the grounding on the electric outlet was actually,,, not grounded. The SRM-313 has a grounding pin on the back of the chassis, so I connected a wire from the chassis to a true ground in the house (a heating pipe) and the noise was gone.

 

[mlxx]

Basically, I'm hearing this constant weird humming/buzzing noise (?) from the left channel of my L300 whenever I turn on the 252s. It's a one note noise where there are no fluctuations. The noise is present all the time regardless of whether the amp is on or off.

You say you hear a hum when you turn on the 252 but also when its on or off. It is weird it will still hum when off.

UPDATE 2: Another weird thing that I've found out is while the noise is present, when I lay my hand on top of SRM-252S, the noise disappears. Then when I remove my hand from it, the noise is back again.

Does the humming also go away if you place something heavy on the case like a heavy book (something non conductive) instead of your hand?

It doesn't seem like an earthing issue as the power adapter has no earth pin and the 252 uses a DC power supply so both these are isolated from earth. The hum is only in one channel so I don't think the power adapter is at fault or it would affect both channels most likely. It could be a "signal" ground issue, does it still hum if you disconnect all the interconnect cables? If you swap the interconnect cables does it still hum in the same channel? Also have you tried different interconnect cables?

 

[chococya96]

You say you hear a hum when you turn on the 252 but also when its on or off. It is weird it will still hum when off.

Yes, it also hums when I turn off the 252 (i.e. turning the knob counter clockwise until it clicks and the led goes out). And while the unit is off, when I place my hand on the amp the hum is more prevalent and audible.
It's only when I unplug the power (either from the adapter or from back of 252) where the hum is no audible from my L300.

Does the humming also go away if you place something heavy on the case like a heavy book (something non conductive) instead of your hand?

It doesn't seem like an earthing issue as the power adapter has no earth pin and the 252 uses a DC power supply so both these are isolated from earth. The hum is only in one channel so I don't think the power adapter is at fault or it would affect both channels most likely. It could be a "signal" ground issue, does it still hum if you disconnect all the interconnect cables? If you swap the interconnect cables does it still hum in the same channel? Also have you tried different interconnect cables?

Yes, any weight on top of the the amp will somehow make the hum go away.

As for RCA interconnect cables, it'll still hum even when I:
- Disconnect both R and L from 252
- Swapping R and L around (it's still audible from left side)
- Trying different RCA cables


Alll in all, I've actually contacted the authorized Australian STAX distributor and they told me to send the whole set (including the earspeaker) for further diagnostics. They told me that this is first time this kind of issue has happened for any STAX lambda earspeakers.
I've packed everything away to its original packaging box and I'll be sending it out today or tomorrow.
Though, if there's any other troubleshooting I could try before posting it away, please let me know.

 

[mlxx]

Though, if there's any other troubleshooting I could try before posting it away, please let me know.

Can't do much more from the outside, seems like an internal fault, better to let them fix it under warranty.

 

[chococya96]

Can't do much more from the outside, seems like an internal fault, better to let them fix it under warranty.

Thanks for the swift reply. I'll send it in and see how it goes.

There's one thing I don't quite get regarding to this issue: why didn't it happen earlier? Like, when I first acquired STAX srs-3100 a month ago?
Did the parts inside the amp or power adapter "degraded" slowly to the point where the hum noise was audible or something?
Strange.

 

[mlxx]

Could be something has just come loose since it goes away when you press on it. Opening it could void your warranty.
Chances are whatever is wrong you won't be able to fix yourself anyway so better to use the warranty.
They will probably just replace it with another one.

 

[hanouk]

Well, i've tried turning on the amp for 30 min then plugging the Lambda and playing music - right driver was still quiet and went to normal level after a few minutes. So this is definitely an earspeakers issue.

Next day I tried both times swapping the RCAs but the Lambda worked perfectly right after I played music. Surpisingly, seems they work fine now.

 

[Grant99]

Has anyone ever replaced the headphone case holder on a SR-404? I'm referring to the black arm that attaches to the headphone case & allows the headphone case to pivot, it is attached to the headband. The black arm is broken, so I am trying to remove it from the headband; it looks like it is locked onto the headband by a either a pin or a rivet of some kind, but I'm not 100% sure if this is what's holding it in place. Is it possible to push this pin/rivet out using a small drift/pin or do I have to get some special tool?

I'm trying to replace just the black arm/case holder instead of the entire headband assembly, there's a website in the UK that sells is separately.
Any suggestions/comments would be greatly appreciated, thanks!!

 

[Doom0]

@Grant99 Do you mean this pin?

If so, I used Torx T6 screwdriver to get it out.

EDIT: Yes, this small pin holds the case holder in a place. When you take it out, case holder will fall out. Here is the image illustrating where the pin is blocking the case holder from falling out (at least for Stax L300 headband, but I guess 404's headband is very similar):