[Decommo]

Hello,
PLEASE HELP....

I just got Stax 2170 direct from Amazon Japan and SRM 252S amplifier is not turning on. I suspect that it is lemon unit or I got wrong power adapter. I got this 3rd party adapter to use here in Australia (http://www.ebay.com.au/itm/322184543844?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT). Is there any way that I know if it is amp issue of power adapter issue? 
I called local Stax dealer and consulted briefly over the phone. They said that they cannot help since I got this from overseas (hard lesson learned). However, they gave me an impression that the adapter may not strong enough.
 
Can anyone give me some advice if it is amp or adapter issue? Not sure any Australian Head-Fiers own Stax SRM 252S amp.
 
Any help would be greatly helpful..... 

 

[miceblue]

Hello,
PLEASE HELP.... I just got Stax 2170 direct from Amazon Japan and SRM 252S amplifier is not turning on. I suspect that it is lemon unit or I got wrong power adapter. I got this 3rd party adapter to use here in Australia (http://www.ebay.com.au/itm/322184543844?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT). Is there any way that I know if it is amp issue of power adapter issue? 
I called local Stax dealer and consulted briefly over the phone. They said that they cannot help since I got this from overseas (hard lesson learned). However, they gave me an impression that the adapter may not strong enough.

Can anyone give me some advice if it is amp or adapter issue? Not sure any Australian Head-Fiers own Stax SRM 252S amp.

Any help would be greatly helpful..... 

Question 1: Did you order the wall wart with a negative center?
The power specifications are just fine: 12V, 1A, 12W.

I use an iFi iPower which has 12V, 1.1A, 13.2 W output and I use the included polarity inverter.


Question 2: If you did order the wall wart with a negative center, what happens if you plug it into the SRM-252S, turn it on, and wait ~20 seconds?

The SRM-252S actually shuts down when I first turn it on with the iPower plugged in, and it turns back on about 15 seconds later and it works perfectly fine.

 

[Decommo]

 

 

Question 1: Did you order the wall wart with a negative center?
The power specifications are just fine: 12V, 1A, 12W.

I use an iFi iPower which has 12V, 1.1A, 13.2 W output and I use the included polarity inverter.


Question 2: If you did order the wall wart with a negative center, what happens if you plug it into the SRM-252S, turn it on, and wait ~20 seconds?

The SRM-252S actually shuts down when I first turn it on with the iPower plugged in, and it turns back on about 15 seconds later and it works perfectly fine.

 
Thank you so much for your feedback.
I turned it on and left it on for 5 minutes but light is not on and does not do anything.
I ordered negative center adapter this is the physical adapter that I got.
 

It does not say anything about center negative.
 
And, I notice this on the tip of adapter. Does this mean that Center is Positive?

 
I just sent a message to seller of this adapter and waiting for his confirmation, too.

 

[brandnewgame]

  Hmm, did you try the "straw mod" on your 207's? That increased bass volume nicely for me (still nowhere near basshead volumes), and I detected none of the ill effects of porting the pads that make others advise against it.....but I'm not a critical listener, either. I just let the music play, man Peace!
 
With the straw mod, my 2170 isn't exactly neutral, but still close enough that I feel HD600 is the closest comparison in my collection; and in short,there is NO comparison LOL. At least for the genres I listen to, Stax bests HD600 cleanly in every metric I could think of, excepting perhaps soundstage size. I'm not a huge Classical fan though, so if that's your thing, others would give better advice.
 
I describe my Stax as a W-shaped HD600....with a +2dB boost across the board, more or less.
 
I'm actually jealous of your collection! I'd love to own some Audeze, but I'm a po' boy LOL. I'm glad I now own a 2170 system...for me it's good enough and I'm stopping in my search.
 
And as a basshead compliment to the Stax, my X00 Purplehearts are also good enough to satisfy and keep me from wistfully eyeing the TOTL crop. These 2 will be my long-term pairing for awhile, I think.

Thanks for suggesting the straw mod - I now enjoy the bass without an EQ. It seems that the mod emphasises mid-bass most, typical of dynamic headphones, so I experimented with the port size for a pleasant hump which didn't compromise linearity too much. I'm not a critical listener by Head-fi standards either and the straw mod colours the sound to match my preferences. If I had bought X00 Purplehearts and the SRS-2170 early on I almost certainly wouldn't have such a large collection 

 Those two compliment each other really well and pretty much cover all the basses. Can't wait to get home and listen to the straw modded 207s now.

 

[Music Alchemist]

Thought I'd share a conversation between myself and @miceblue (hope it's okay!) here, since it might help someone out.
 
me: I had no problems with the 212 driving the 207 aside from not enough volume in rare cases where I would push it to its limit, and at maximum volume it would distort a little.
micey: What DAC were you using with the SRM-212?
me: Just the onboard DAC of my laptop, which sounds the same to me as a Schiit Modi 2.
micey: Wait so you just used the headphone out port of your laptop to connect to the RCA input of the 212? That port must have a really, really low voltage output then compared to any source I've used. Geek Out 450 outputs 2.68 VRMS, Pulse X Infinity 2.25 VRMS and I have the volume knob on the 252S at 11 o'clock maximum. Using a 3.5 mm to RCA cable from my MacBook Pro, I only have a slightly higher volume knob level on the 252S.
me: I don't think it has a low output. I can drive most headphones just fine directly from the headphone outputs of my laptop. In fact, I compared those headphone outputs to a Schiit Magni 2 Uber and Schiit Modi 2 stack and did not hear a difference with many headphones.
micey: The voltage you feed the amp matters. I don't see how it's possible that you listened to the 212 with near maximum values. Even with my quietest music tracks, I never have to turn the volume knob past 1 o'clock with sources that output more than 1 VRMS.
 
So I guess even if the headphone outputs of your computer have plenty of power for more sensitive headphones, it still may not be suitable for connecting to an electrostatic amp. I always used 75-100% of the volume knob! Lesson learned: even if it doesn't sound any better, it can pay to use a dedicated DAC.
 
For the moment, however, with the cheap system I temporarily downgraded to, I actually prefer my laptop's DAC over the DAC in my DAC/amp, so I just use it as an amp, and in this case, I can actually get more volume that way.
 

  If I had bought X00 Purplehearts and the SRS-2170 early on I almost certainly wouldn't have such a large collection 

 Those two compliment each other really well and pretty much cover all the basses. Can't wait to get home and listen to the straw modded 207s now.

 
I feel the same about the SR-207 and Yamaha HPH-MT220. The former is very accurate and transparent while the latter has powerful bass and a more exciting sound. Some people in the MT220 thread are saying the TH-X00 is very similar to the MT220.

 

[brandnewgame]

  I feel the same about the SR-207 and Yamaha HPH-MT220. The former is very accurate and transparent while the latter has powerful bass and a more exciting sound. Some people in the MT220 thread are saying the TH-X00 is very similar to the MT220.

I need to try the HPH-MT220 since I love fun-sounding headphones I've heard great things about the TH-X00 and am fond of the aesthetics, but importing them into the UK is cost-prohibitive.

 

[hardpike]

Thought I'd share a conversation between myself and @miceblue
(hope it's okay!) here, since it might help someone out.

me: I had no problems with the 212 driving the 207 aside from not enough volume in rare cases where I would push it to its limit, and at maximum volume it would distort a little.
micey: What DAC were you using with the SRM-212?
me: Just the onboard DAC of my laptop, which sounds the same to me as a Schiit Modi 2.
micey: Wait so you just used the headphone out port of your laptop to connect to the RCA input of the 212? That port must have a really, really low voltage output then compared to any source I've used. Geek Out 450 outputs 2.68 VRMS, Pulse X Infinity 2.25 VRMS and I have the volume knob on the 252S at 11 o'clock maximum. Using a 3.5 mm to RCA cable from my MacBook Pro, I only have a slightly higher volume knob level on the 252S.
me: I don't think it has a low output. I can drive most headphones just fine directly from the headphone outputs of my laptop. In fact, I compared those headphone outputs to a Schiit Magni 2 Uber and Schiit Modi 2 stack and did not hear a difference with many headphones.
micey: The voltage you feed the amp matters. I don't see how it's possible that you listened to the 212 with near maximum values. Even with my quietest music tracks, I never have to turn the volume knob past 1 o'clock with sources that output more than 1 VRMS.

So I guess even if the headphone outputs of your computer have plenty of power for more sensitive headphones, it still may not be suitable for connecting to an electrostatic amp. I always used 75-100% of the volume knob! Lesson learned: even if it doesn't sound any better, it can pay to use a dedicated DAC.

For the moment, however, with the cheap system I temporarily downgraded to, I actually prefer my laptop's DAC over the DAC in my DAC/amp, so I just use it as an amp, and in this case, I can actually get more volume that way.


I feel the same about the SR-207 and Yamaha HPH-MT220. The former is very accurate and transparent while the latter has powerful bass and a more exciting sound. Some people in the MT220 thread are saying the TH-X00 is very similar to the MT220.

Strange
I have my srd-x pro directly single ended (not even balanced) from a pono player and I am only 10 to 20% of volume
Maybe 30% with some sacd...

 

[Pahani]

  Thanks for suggesting the straw mod - I now enjoy the bass without an EQ. It seems that the mod emphasises mid-bass most, typical of dynamic headphones, so I experimented with the port size for a pleasant hump which didn't compromise linearity too much. I'm not a critical listener by Head-fi standards either and the straw mod colours the sound to match my preferences. If I had bought X00 Purplehearts and the SRS-2170 early on I almost certainly wouldn't have such a large collection 

 Those two compliment each other really well and pretty much cover all the basses. Can't wait to get home and listen to the straw modded 207s now.

Outstanding!! Glad it worked out for you

 

[Music Alchemist]

Strange
I have my srd-x pro directly single ended (not even balanced) from a pono player and I am only 10 to 20% of volume
Maybe 30% with some sacd...

 
Do you know the max output voltage? (It's 280 V RMS for the SRM-212 and SRM-252S.)

 

[hardpike]

Do you know the max output voltage? (It's 280 V RMS for the SRM-212 and SRM-252S.)

Let me investigate...

 

[droebbel]

   
The extra 'computer noise' you're describing is also caused by incorrect grounding. I experienced this exact problem with my USB DAC. Fixing the grounding solved it completely. Also, I recognize that you can influence the hum by touching the case. This is also something I experienced with my Stax amp, and which I solved by fixing the grounding.
Probably, if you were to ground the case directly with a copper wire to earth, your problem would be solved. This helps for me. Unfortunately, the SRM-Xh doesn't have a ground binding post on the back, like the bigger Stax amps (for precisely this issue!), so you would have to improvise here. It would be a shame to scratch some paint of to attach a wire somehow. What you could try, is to ground the source in your system, if it has a screw somewhere on the case under which you could attach a copper wire to earth. I used to use the bindings post on the back of my Stax SRM-717 to ground my whole system, but now I do it via my computer case. It doesn't have to be the source, it just needs to be the next (or 'next to next') case in your system that is connected to the SRM-Xh. The RCA cables from the source to the amp connect both of their cases and hence their ground (unless your source is double insulated), so if you ground the next case, you'll ground the SRM-Xh along with it. Basically this is what you do when you touch the case: you are providing a path for the electricity on the case to escape the system. You must provide this path in a different, permanent, low-resistance way to solve your problem.
How easy this is, depends what kind of outlets they have where you live, and in some cases how old your house is. If you do not have grounded outlets, you can try grounding your system by tying the copper wire to a radiator, water pipe or the ground of the radio/television cable. This is not exactly how it's supposed to be, but it works well in a lot of cases.
The reason it works normally with your other sources, could be that these have grounded power cords to grounded outlets, while your raspberry pi and Stax amp both do not have grounded cords to their cases, leaving you with an ungrounded system.

Thanks A LOT!
Now I found myself a grounded outlet, connected my power amp, set up raspberry and headphone amp. Noise as before in headphone until I connected the raspberrys (inactive) headphone out with one of the power amps inputs, in order to to provied grounding to raspberry and headphone amp. Noise was gone. BUT: it was gone already when the RCA plugs center pin got contact. Normal?
 
Not that it really matters now, but how can one explain the noise to be audible even with the amp switched off?  I'd be grateful for a hint.
 
Now I just have to hire an electrician to install grounded outlets on the second floor...
 
David

 

[Michgelsen]

  Not that it really matters now, but how can one explain the noise to be audible even with the amp switched off?  I'd be grateful for a hint.
 

 
Yes, it's strange. It has to do with the power supply always leaking or generating a tiny bit of electricity towards the case while plugged in, which is enough to move the diaphragm because that's so super light, at least as long as it keeps its charge. I don't know what the cause of this leakage to the case is unfortunately, but a lot of devices with metal cases do this.

 

[miceblue]

So I guess even if the headphone outputs of your computer have plenty of power for more sensitive headphones, it still may not be suitable for connecting to an electrostatic amp. I always used 75-100% of the volume knob! Lesson learned: even if it doesn't sound any better, it can pay to use a dedicated DAC.

Not power, voltage. Line out connections depend on the output voltage, hence why the SRM-252S has an input impedance of 50 kOhms.

Let me investigate...

http://www.stereophile.com/content/pono-ponoplayer-portable-music-player-measurements#7b1RvHqk8Zq0Ak7F.97

The volume control operates on the headphone output only; the output with a 1kHz tone at 0dBFS from the headphone jack with the volume control set to its maximum was the same as from the line output: 961.3mV.

 

[Music Alchemist]

Not power, voltage. Line out connections depend on the output voltage, hence why the SRM-252S has an input impedance of 50 kOhms.
http://www.stereophile.com/content/pono-ponoplayer-portable-music-player-measurements#7b1RvHqk8Zq0Ak7F.97

...Head-Fi is being screwy tonight. Says "The rich text editor is not compatible with your browser."

I was referring to power in a general sense, not a technical sense, just like how people talk about "powerful" electrostatic amps when they mean ones with lots of voltage. Plus "plenty of power for headphones" does specifically refer to output power for driving conventional headphones from the headphone outputs. If it has high power, then it follows that it also has high voltage, relatively speaking.

I was also asking about the maximum output voltage of the STAX amp, not the DAP.

 

[donc55]

I bought a SR-009  from Japan two years ago, and the right channel is bad.
 
I Sent a message to STAX USA on their web site, stating they were out of warranty, and bought in Japan. That was a few days ago, and I have not heard back.
 
I have read on the web that STAX USA will not service them.  Is this true?
 
Do the headphones have a serial number?  Can they tell if they were sold in Japan, and not the USA?
 
What do I do?