[AnakChan]

This debate about 009's and any changes. Can't somebody just ASK THEM! Or are Stax one of these folk who just don't pick up?

I did just now at the e-earphone Headphone Festival. As others have alluded to, Stax official stance is "No change".

 

[Sorrodje]

  Sorrodje has precisely this pitch of yours...except he's from France. You may find him on the HD-800 thread 

 
Ali

 
Damned. i'm Spied

 
So it's time to emerge from the Shadows and subscribe to this famous thread.  New Stax owner here. I bought a SR404 + SRM1/mkII combo indeed.  Firstly , i bought the amp to drive the KOSS ESP950 I'm waiting too and I thought to sell the SR404 quickly in order to fund the a part of the amp and a full service at INEXXON.com  but I'll wait a bit before taking my decision.
 
Have a good day

 

[HemiSam]

 
The SRM-1 is getting quite old and will at least need to have the capacitors replaced and the balance and offset re-adjusted to account for ageing.
 
An alternative is the SRM-323s, this is a current production model and a used model can be had for about $150-$200 more than the SRM-1 based on a quick look on Ebay.
A new SRM-252s for about the same price from places like PriceJapan.
 
The SRM-252s runs at a lower voltage and does not play as loud as the 323s, works well if the 12V wall wart is replaced with a real regulated PSU.
 
I own both of them.

 
Thank you for your post, b0bb.  I have concluded the same about the caps, balance and offset so that is an incremental expense...good point.  It looks as if the SRM-323s is as powerful as the SRM-1/MK-2 on paper unless I'm missing something.  Interesting about the 323s and the 252s, including the need for an upgraded power supply for the 252.  
 
The 323s looks like a good option.  Have you compared the 323 to the SRM-1 and did you have a preference?  Also, how are you powering your 323s if you don't mind sharing?
 
HS

 

[NoPants]

323s has its own built-in power supply, 252 has a wallwart

 

[richard51]

 
The SRM-1 is getting quite old and will at least need to have the capacitors replaced and the balance and offset re-adjusted to account for ageing.
 
An alternative is the SRM-323s, this is a current production model and a used model can be had for about $150-$200 more than the SRM-1 based on a quick look on Ebay.
A new SRM-252s for about the same price from places like PriceJapan.
 
The SRM-252s runs at a lower voltage and does not play as loud as the 323s, works well if the 12V wall wart is replaced with a real regulated PSU.
 
I own both of them.

 What is the site that sell your regulated PSU for stax?  I want to buy one.... but i dont know what nor where.....thanks  I have a srm 252s

 

[b0bb]

 What is the site that sell your regulated PSU for stax?  I want to buy one.... but i dont know what nor where.....thanks  I have a srm 252s

 


The 252s pinout on the power connector is *reversed*
Apart from STAX, there are no ready made PSUs for the 252s that I am aware of.

I bought a basic 12V PSU from Ebay and modified it.

I also installed output protection diodes on my PSU.

 

[b0bb]

 
Thank you for your post, b0bb.  I have concluded the same about the caps, balance and offset so that is an incremental expense...good point.  It looks as if the SRM-323s is as powerful as the SRM-1/MK-2 on paper unless I'm missing something.  Interesting about the 323s and the 252s, including the need for an upgraded power supply for the 252.  
 
The 323s looks like a good option.  Have you compared the 323 to the SRM-1 and did you have a preference?  Also, how are you powering your 323s if you don't mind sharing?
 
HS

 


The 323s comes with the power supply built in.

The comparisons I have done between the 323s and the SRM-1/MK is limited to the history and the evolution of the circuit design.
Schematics are available for both units on HF and elsewhere if you are interested in the details.

The 323s was launched in 2010, the SRM-1 in 1979 and the SRM-1/Mk2 in 1982

Personally I will hold on to stuff as long as parts for maintenance is available, the Achilles heel of these type of amps is the available supplies of the specialized high voltage transistors.
These transistors are even more rare than vacuum tubes.

 

[HemiSam]

 

   
Thank you for your post, b0bb.  I have concluded the same about the caps, balance and offset so that is an incremental expense...good point.  It looks as if the SRM-323s is as powerful as the SRM-1/MK-2 on paper unless I'm missing something.  Interesting about the 323s and the 252s, including the need for an upgraded power supply for the 252.  
 
The 323s looks like a good option.  Have you compared the 323 to the SRM-1 and did you have a preference?  Also, how are you powering your 323s if you don't mind sharing?
 
HS

 


The 323s comes with the power supply built in.

The comparisons I have done between the 323s and the SRM-1/MK is limited to the history and the evolution of the circuit design.
Schematics are available for both units on HF and elsewhere if you are interested in the details.

The 323s was launched in 2010, the SRM-1 in 1979 and the SRM-1/Mk2 in 1982

Personally I will hold on to stuff as long as parts for maintenance is available, the Achilles heel of these type of amps is the available supplies of the specialized high voltage transistors.
These transistors are even more rare than vacuum tubes.

 
 
Thanks again, b0bb.  I'm doing some research to see if there are schools of thought regarding one being better than the other.  All being equal, it's hard to argue with the points you've made.  I think, in terms of reliability, perhaps technology (can't say yet) and servicing.
 
HS

 

[HemiSam]

P.S. - I'm going to need to convert a Koss extention cable to take a Stax plug for the Pro connection.  Does anyone know where I can purchase the plug?
 
HS

 

[gepardcv]

Apart from STAX, there are no ready made PSUs for the 252s that I am aware of.

 
I use this one, and it works perfectly: http://www.digikey.com/product-search/en?pv1376=2&pv48=2&pv2=105&pv2=173&pv52=6&FV=fff40009,fff8004a&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
 
It's regulated, has the Stax-style center negative polarity, and a somewhat higher power rating than the stock one. No idea if it sounds any different, and I wouldn't have bothered with it, but I like brining back Stax gear from Japan, and needed a PSU with a North American voltage.

 

[richard51]

   
I use this one, and it works perfectly: http://www.digikey.com/product-search/en?pv1376=2&pv48=2&pv2=105&pv2=173&pv52=6&FV=fff40009,fff8004a&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
 
It's regulated, has the Stax-style center negative polarity, and a somewhat higher power rating than the stock one. No idea if it sounds any different, and I wouldn't have bothered with it, but I like brining back Stax gear from Japan, and needed a PSU with a North American voltage.

is this one is ok for the srm 252 s ?
 
http://www.ebay.com/itm/NEGATIVE-CENTER-PIN-5-5mm-12V-1A-500mA-200mA-AC-DC-Adapter-Power-Supply-Charger-/400815931957?pt=US_MP3_Player_Chargers_Cradles&hash=item5d527dc235

 

[n3rdling]

  P.S. - I'm going to need to convert a Koss extention cable to take a Stax plug for the Pro connection.  Does anyone know where I can purchase the plug?
 
HS

Search the Koss 950 thread, I know it's been linked to in there a few times.

 

[HemiSam]

  Search the Koss 950 thread, I know it's been linked to in there a few times.

 
Thanks...
 
http://www.moon-audio.com/stax-cable-mount-5-pin-din.html#
 
I'm trying to read through that entire thread....all 102 pages
 
 
HS

 

[gepardcv]

is this one is ok for the srm 252 s ?

http://www.ebay.com/itm/NEGATIVE-CENTER-PIN-5-5mm-12V-1A-500mA-200mA-AC-DC-Adapter-Power-Supply-Charger-/400815931957?pt=US_MP3_Player_Chargers_Cradles&hash=item5d527dc235

The specs looks okay, but I would not trust the pin polarity, or that it's regulated, without double-checking the output voltage with a multimeter. I checked the one from digikey before plugging it into my 252.

 

[yaluen]

 

is this one is ok for the srm 252 s ?

http://www.ebay.com/itm/NEGATIVE-CENTER-PIN-5-5mm-12V-1A-500mA-200mA-AC-DC-Adapter-Power-Supply-Charger-/400815931957?pt=US_MP3_Player_Chargers_Cradles&hash=item5d527dc235

The specs looks okay, but I would not trust the pin polarity, or that it's regulated, without double-checking the output voltage with a multimeter. I checked the one from digikey before plugging it into my 252.

 
Make sure it has a 2.1mm inner diameter barrel plug or it won't make proper contact with the socket.