The Stax Thread III

[milosz]

Quote:

How scarry do you think the water damage on the Stax F83's. To me it looks like it leaked down near the bottom of the speakers into the transformer area quite a bit. I would consider buying them and having them sent to be rebuilt but I would hope they wont turn into a nightmare. Any input on this? Thanks Jay

Beats me.  Send the guy a message, get more info.  Maybe ask Wayne Piquet ( http://quadsunlimited.us/ ) he may be able to rebuild them.
 
Inside the bases are a couple of  transformers, some diodes, capacitors, etc. Probably that could all be cleaned of the water damage / diodes & caps replaced (they're standard parts, cheap)
 
The panels themselves might be OK, or they might need rebuilding.  Now, maybe Stax would do that for you (or maybe not) - and if they would, the international shipping would be very costly and Stax would probably charge an arm and a leg. That's why I suggested Wayne Picquet -  he is an absolute master at rebuilding Quad ESL's, and I would think he could do a decent or possibly great job on  these panels too -  unless they are very exotic.  Certainly I would think he could clean and refurbish the hi-voltage units in the bases.  
 
Wayne is not cheap - but he would still likely be WAY less expensive than sending things off to Japan. [Note:  no connection between me and Wayne, except I had him rebuild some  panels for my Quad ESL-57's.)
 
If you are real lucky, all you'll have to do is clean the innards of the bases, and refinish the wood-  you never know.
 
[Note to moderator, I know these aren't headphones, but they ARE  Stax...  

 ]

 

[spritzer]

I'd speak to Kent about working on these as he's pretty much the only one who will touch the giant Lambdas.  I call them that as the drivers are very similar...
Quote:

What about the 727?

 
Stock it is very rolled off on top and the bass suffers quite a bit.  Stax tried to go all Ayre on the amp  (no feedback in the last stage) but it can't be done at these power levels. For the amp to be linear you need to burn a lot of juice. 
 
The amp modified is quite good and the mods a lot simpler than what I need to do to the 007t to make it behave. 
 
Quote:

Quote:
 
[size=11pt]The trick is with the current in pentode mode – it should be reduced. [/size]

 
Well yes but the tubes are not as linear when run as triodes.  Even when you reduce the current it won't make up for extra grids and how the tubes behave when you push the voltage.
 
I don't think I ever asked for the old tubes but what is the B+ voltage for the AL4's? 

 

[Oingo Boingo]

Quote:

 
Well yes but the tubes are not as linear when run as triodes.  Even when you reduce the current it won't make up for extra grids and how the tubes behave when you push the voltage.
 
I don't think I ever asked for the old tubes but what is the B+ voltage for the AL4's? 

[size=medium]As far as I recall it’s 260-265v between cathode and anode and with reduced anode current the tube does not exceed its max settings on dispersal power on anode.  In this mode the voltage on the anode can safely be higher than nominal.  Also, as a current amp pentode shows better resistance to parasitic capacitances (compared to triode), plus the sound of the pentode can get warmer and richer then triode, but it takes fine tuning to get the right result.  Dmitry while experimenting was also pushing pentodes up to breakdown voltage and getting very interesting results re sound and performance. [/size]

 

[reiserFS]

Did I make a good deal? First time I've used eSnipe and damn, it's awesome. http://www.ebay.de/itm/130972977111?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[eric65]

Hello Oingo Boingo,
 
Your Demograf amplifier is very impresive ; Dmitry did not skimp on the quality of the components used and the importance given to the powerful and sophisticated external power
 
I have a question for you: have you had the opportunity to listen to the amplifier Headamp Blue Hawaii SE (BHSE) with headphones Stax SR-009?
Otherwise, would you like rather have a very clear and detailed sound, or do you prefer, instead, a warmer sound, full, but perhaps less neutral and slightly less detailed?
 
Thank you for your opinion.
 
Eric
 
PS : Ajr, in the French forum HCFR, told of you about the choice of Demograf and Orpheus HE 90 :
 
" The arguments that each "people" would have a different "ear" appear numerous and well argued. It could be that the ear of our distinguished friend "casquophile" Russian is formatted to prefer this type of sound reproduction (ie a warm and full sound). And its system is build ​​accordingly.
While a "French" ear may be would prefer more clarity and detailed sound. "
 
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4725.html

 

[Oingo Boingo]

Quote:
 

Hello Oingo Boingo,
 
Your Demograf amplifier is very impresive ; Dmitry did not skimp on the quality of the components used and the importance given to the powerful and sophisticated external power
 
I have a question for you: have you had the opportunity to listen to the amplifier Headamp Blue Hawaii SE (BHSE) with headphones Stax SR-009?
Otherwise, would you like rather have a very clear and detailed sound, or do you prefer, instead, a warmer sound, full, but perhaps less neutral and slightly less detailed?
 
Thank you for your opinion.
 
Eric
 
PS : Ajr, in the French forum HCFR, told of you about the choice of Demograf and Orpheus HE 90 :
 
" The arguments that each "people" would have a different "ear" appear numerous and well argued. It could be that the ear of our distinguished friend "casquophile" Russian is formatted to prefer this type of sound reproduction (ie a warm and full sound). And its system is build ​​accordingly.
While a "French" ear may be would prefer more clarity and detailed sound. "
 
http://www.homecinema-fr.com/forum/casques-haute-fidelite/club-des-heureux-proprietaires-de-casques-stax-t29819561-4725.html

 
[size=medium]Eric, bonjour!  Yes I have heard BHSE, I have also heard and/or owned few other top electrostatic amps.  BTW, there is a large and active headphones’ community in Russia and former USSR.  Here is our forum:[/size]
[size=medium]http://forum.doctorhead.ru/index.php?act=idx[/size]
 
[size=medium]009 + BHSE are a bit too bright to my taste and not warm and rich enough.  007 get better result imho with BHSE then 009 with this BHSE.  009 have certain advantages over 007 even with BHSE due to overall higher level of 009.  Since I own both 009 and 007 I do realize the need of different approach re amplification of these 2:  007 need more powerful and linear amp, whereas 009 benefit from bass extension and warmer sound.  The resolution of 009 is very high, at some point it may become over the top – we don’t want to turn 009 into an atomic microscope, do we?  In other words, the right amp for 009 may be too warm and bassy for 007; whereas the right amp for 007 may be too bright for 009.  Dmitry made a lot of effort to make the amp sound right for my taste (his own taste is actually close, which helped a lot).  The main approach to the sound was to make it rich & warm with high resolution (but not too much analytical) with high musicality, involvement and dynamics.  The side effect is that it’s hard to force myself to get the e-stats off my head ))  [/size]
 
[size=medium]We were not dealing with “009 vs 007” dilemma that much, since a clear priority were Omegas, HE90 and 009.  In the end of the day 007 now sound too juicy with Demograf to my taste, but it helps when the record itself “lacks the body”.  I like the mid-bass and mids of 007 with Demograf, but the bass is a bit too much for me. I still own HEV90 (with very good tubes) so if I need, I can listen to 007 without bass extension.  Before start working on the amp, Dmitry has considered the KGBH design (along with T2, HEV90 and few other options).  In the end of the day the approach was as you can see.  Sure, the Demograf amp is not very simple to reproduce as a commercial one, the spare parts are not the easiest to find and not the cheapest ones, not even talking the weight, which became 4.5 kg heavier after AL4 upgrade (now it’s 32.5 kg of power unit plus 14 kg of main unit).  The amp also requires extensive fine tuning, but the result imo is definitely worth it.[/size]

 

[complin]

So you would not describe this at all as a neutral amplifier ie a straight wire with gain?
Sounds like you have tried to get a vintage (30's/40's) tubey sound which can sound romantic to some but coloured to others? 
Quote:

Quote:
 
 
[size=medium]Eric, bonjour!  Yes I have heard BHSE, I have also heard and/or owned few other top electrostatic amps.  BTW, there is a large and active headphones’ community in Russia and former USSR.  Here is our forum:[/size]
[size=medium]http://forum.doctorhead.ru/index.php?act=idx[/size]
 
[size=medium]009 + BHSE are a bit too bright to my taste and not warm and rich enough.  007 get better result imho with BHSE then 009 with this BHSE.  009 have certain advantages over 007 even with BHSE due to overall higher level of 009.  Since I own both 009 and 007 I do realize the need of different approach re amplification of these 2:  007 need more powerful and linear amp, whereas 009 benefit from bass extension and warmer sound.  The resolution of 009 is very high, at some point it may become over the top – we don’t want to turn 009 into an atomic microscope, do we?  In other words, the right amp for 009 may be too warm and bassy for 007; whereas the right amp for 007 may be too bright for 009.  Dmitry made a lot of effort to make the amp sound right for my taste (his own taste is actually close, which helped a lot).  The main approach to the sound was to make it rich & warm with high resolution (but not too much analytical) with high musicality, involvement and dynamics.  The side effect is that it’s hard to force myself to get the e-stats off my head ))  [/size]
 
[size=medium]We were not dealing with “009 vs 007” dilemma that much, since a clear priority were Omegas, HE90 and 009.  In the end of the day 007 now sound too juicy with Demograf to my taste, but it helps when the record itself “lacks the body”.  I like the mid-bass and mids of 007 with Demograf, but the bass is a bit too much for me. I still own HEV90 (with very good tubes) so if I need, I can listen to 007 without bass extension.  Before start working on the amp, Dmitry has considered the KGBH design (along with T2, HEV90 and few other options).  In the end of the day the approach was as you can see.  Sure, the Demograf amp is not very simple to reproduce as a commercial one, the spare parts are not the easiest to find and not the cheapest ones, not even talking the weight, which became 4.5 kg heavier after AL4 upgrade (now it’s 32.5 kg of power unit plus 14 kg of main unit).  The amp also requires extensive fine tuning, but the result imo is definitely worth it.[/size]

 

[Oingo Boingo]

Quote:

So you would not describe this at all as a neutral amplifier ie a straight wire with gain?
Sounds like you have tried to get a vintage (30's/40's) tubey sound which can sound romantic to some but coloured to others? 

 
[size=11pt]I don’t like bright sound, but I’m not a basshead either.  So the idea was to make it an old school “rich & warm” sound, but with good details and dynamics.  The bass of the amp is reasonably extended to first of all please HE90 and 009 which imo benefit from solid body (and Omegas too, but Omega’s bass is the best of those 3 anyway).  The instruments and voices sound very realistic, so the sound is warm but not colored – believe it or not.  I do know how colored for example some of AT closed cans may sound, so it’s definitely not the case. [/size]

 

[spritzer]

That amp was clearly designed for a certain sound and let's just say it's more HEV90 than BHSE. 

 
Quote:

Quote:
[size=medium]As far as I recall it’s 260-265v between cathode and anode and with reduced anode current the tube does not exceed its max settings on dispersal power on anode.  In this mode the voltage on the anode can safely be higher than nominal.  Also, as a current amp pentode shows better resistance to parasitic capacitances (compared to triode), plus the sound of the pentode can get warmer and richer then triode, but it takes fine tuning to get the right result.  Dmitry while experimenting was also pushing pentodes up to breakdown voltage and getting very interesting results re sound and performance. [/size]

 
I assume that is the full voltage swing per tube then so 530Vp-p?  That is not a whole lot, less than the small Stax amps (252, 212 etc.).  Triodes have pretty much zero capacitance as they are though, 2-3pF is the norm which only the 2SC4686A can come close to match in transistors.  Sad to see that one go so soon... 

 

[complin]

I really had some doubts about the 009's when I first heard them, but I came to realise they are so resolving they demand a source which is as neutral as possible, analogue like.
 
Having lived with them for several months I realised it was not so much the 009's at fault but my source. Having now changed these the 009's offer true insight into the music in a way that perhaps only the HE90's can equal.
I'm surprised you feel 009's need help from an amplifier in the bass as they are far easier to drive than the Omega or Omega 007's. The entry level SRM 252 does a half decent job driving the 009's. 
The 007's have always provided great natural bass, but the 009's take this even further with much greater extension and with incredible texture I have never experienced before with any headphone, truly amazing. 
 
Personally I dont like audio components which try to present a rose tinted view of the sound, or for that matter hyper detail like many of the so called super resolving DAC's. This is why so much of our recorded music these days does not sound good (too hot in the treble, compressed no dynamics) because engineers impose their own slant on oveaarll sound for whatever reason. Many of the greatest recordings were made very simply, whithout adulteration or high compression. 
 
Quote:

 
[size=11pt]I don’t like bright sound, but I’m not a basshead either.  So the idea was to make it an old school “rich & warm” sound, but with good details and dynamics.  The bass of the amp is reasonably extended to first of all please HE90 and 009 which imo benefit from solid body (and Omegas too, but Omega’s bass is the best of those 3 anyway).  The instruments and voices sound very realistic, so the sound is warm but not colored – believe it or not.  I do know how colored for example some of AT closed cans may sound, so it’s definitely not the case. [/size]

 

[eric65]

Quote:

Quote:
 
 
[size=medium]Eric, bonjour!  Yes I have heard BHSE, I have also heard and/or owned few other top electrostatic amps.  BTW, there is a large and active headphones’ community in Russia and former USSR.  Here is our forum:[/size]
[size=medium]http://forum.doctorhead.ru/index.php?act=idx[/size]
 
[size=medium]009 + BHSE are a bit too bright to my taste and not warm and rich enough.  007 get better result imho with BHSE then 009 with this BHSE.  009 have certain advantages over 007 even with BHSE due to overall higher level of 009.  Since I own both 009 and 007 I do realize the need of different approach re amplification of these 2:  007 need more powerful and linear amp, whereas 009 benefit from bass extension and warmer sound.  The resolution of 009 is very high, at some point it may become over the top – we don’t want to turn 009 into an atomic microscope, do we?  In other words, the right amp for 009 may be too warm and bassy for 007; whereas the right amp for 007 may be too bright for 009.  Dmitry made a lot of effort to make the amp sound right for my taste (his own taste is actually close, which helped a lot).  The main approach to the sound was to make it rich & warm with high resolution (but not too much analytical) with high musicality, involvement and dynamics.  The side effect is that it’s hard to force myself to get the e-stats off my head ))  [/size]
 
[size=medium]We were not dealing with “009 vs 007” dilemma that much, since a clear priority were Omegas, HE90 and 009.  In the end of the day 007 now sound too juicy with Demograf to my taste, but it helps when the record itself “lacks the body”.  I like the mid-bass and mids of 007 with Demograf, but the bass is a bit too much for me. I still own HEV90 (with very good tubes) so if I need, I can listen to 007 without bass extension.  Before start working on the amp, Dmitry has considered the KGBH design (along with T2, HEV90 and few other options).  In the end of the day the approach was as you can see.  Sure, the Demograf amp is not very simple to reproduce as a commercial one, the spare parts are not the easiest to find and not the cheapest ones, not even talking the weight, which became 4.5 kg heavier after AL4 upgrade (now it’s 32.5 kg of power unit plus 14 kg of main unit).  The amp also requires extensive fine tuning, but the result imo is definitely worth it.[/size]

 
Quote:

 
[size=11pt]I don’t like bright sound, but I’m not a basshead either.  So the idea was to make it an old school “rich & warm” sound, but with good details and dynamics.  The bass of the amp is reasonably extended to first of all please HE90 and 009 which imo benefit from solid body (and Omegas too, but Omega’s bass is the best of those 3 anyway).  The instruments and voices sound very realistic, so the sound is warm but not colored – believe it or not.  I do know how colored for example some of AT closed cans may sound, so it’s definitely not the case. [/size]

 
Большое спасибо  for your informations.
 
They are also followed with interest in France  

 

[eric65]

Quote:

I really had some doubts about the 009's when I first heard them, but I came to realise they are so resolving they demand a source which is as neutral as possible, analogue like.
 
Having lived with them for several months I realised it was not so much the 009's at fault but my source. Having now changed these the 009's offer true insight into the music in a way that perhaps only the HE90's can equal.
I'm surprised you feel 009's need help from an amplifier in the bass as they are far easier to drive than the Omega or Omega 007's. The entry level SRM 252 does a half decent job driving the 009's. 
The 007's have always provided great natural bass, but the 009's take this even further with much greater extension and with incredible texture I have never experienced before with any headphone, truly amazing. 
 
Personally I dont like audio components which try to present a rose tinted view of the sound, or for that matter hyper detail like many of the so called super resolving DAC's. This is why so much of our recorded music these days does not sound good (too hot in the treble, compressed no dynamics) because engineers impose their own slant on oveaarll sound for whatever reason. Many of the greatest recordings were made very simply, whithout adulteration or high compression. 
 

Hello,
 
With my combi Audiovalve RKV - Wee + 009, the level of bass is a bit stronger (more realistic) relative to SRM 727, with a little more roundness in the lower midrange while maintaining a good dynamic and a good level details ; In addition, the sound stage is wider. It is not unpleasant to listen to.
My source (dac Audiomat Maestro Reference + D1 Drive, very High-end http://www.highendaudio.fr/convertisseurs/maestro-reference.html ) gives the sound a very analog rendering that is very suitable for very detailed headphone 009.
The audiovalve RKV and adapter (Audio Energizeur Woo Wee) provides the richness and warmth to the sound while being very dynamic.
 
Eric

 

[NamelessPFG]

All right, I've got an SRM-T1 now (had it since Friday), and I've tried to dig up as much info as I can, though search engines are giving me a lot of useless results.
 
Is there anything in particular I'd need to know about it? As far as I can tell, it sounds perfectly fine (no hum or hiss, no imbalance), but this being Head-Fi and all, people like to go the extra mile and mod these Stax amps.
 
-The rebiasing procedure has been posted a few times here and elsewhere. I'll need to refer to this if changing tubes or just want to ensure the amp's working as intended.
-A full electrolytic capacitor replacement for amps that old is commonly advised, but what caps should be used in their place?
-The T1 can be modified to accept ECC99 tubes and basically become an SRM-600 as a result, but what's the benefit of this over the stock 6GC7s? Is it enough of an upgrade that it'll suddenly make this thing SR-007-worthy, or will that simply not happen until getting into KGSSHV and BHSE territory?

 

[milosz]

Quote:

 
-A full electrolytic capacitor replacement for amps that old is commonly advised, but what caps should be used in their place?
 

 
I don't know that just replacing ALL electrolytics is necessary. Just replace the bad ones -  i.e., test them for capacitance, leakage and ESR. 
 
SOME electrolytics can be replaced with film caps, but most can't due to space limits (film caps are much larger than electrolytics for a given value) - I have been able to hear the difference between a film cap and an electrolytic that is directly in the audio path - a coupling capacitor- and I decided the film cap sounded cleaner in the highs (In a double blind test) - but I don't know that there are any electrolytic coupling caps in the SRM-T1 amp, Spritzer would know that.  If there are coupling / DC blocking caps in the signal path, it might well be worth the effort to replace them with film or vintage PIO caps like Sprague Vitamin-Q caps - if you can get the needed values on the NOS market.
 
Certainly there will be filter caps in the power supply; I think using all film caps as filters in a power supply, while heroic, may not actually make anything sound better.  This is just an opinion, I've not done any testing of this.
 
Also there will likely be electrolytic bypass caps here and there. Replacing electrolytic bypass caps with film caps may also be a lot of trouble and expense for not so much gain in sound.
 
If you find any electrolytic caps that are more than 20% off value, are leaking DC through them, or have high ESR, those caps you absolutely should replace. But which brand to use?
 
There's lots of caps on the market, some of which have fans that ascribe to them near magical powers.  The much vaunted Black Gate caps, no longer made, are said by some to "sound best." Probably they sound better and better as they become harder and harder to get.... Sometimes you can find Black Gates in various markets. There are also various other "wonder caps" from Mundorf, Jensen, F&T and others.  These are expensive and maybe they are better, who knows.  
 
Quite a few audio DIY'er seem to like the Elna Silmic, Elna Silmic II and Elna Cerafine capacitors, which are not terribly expensive and are said to be "audio grade" somehow -  you can buy those Elna caps at Digikey, Mouser, Newark and others.  Many DIY-ers  scoff at all this capacitor nonsense and just use a low cost but high quality part, like the Panasonic FM series.  I tend to use Elna Silmic and Cerafine caps in things I build, they are not much more expensive than Panasonic, and one can hope they somehow impart sonic improvements.....

 

[davidsh]

^Very fine post, indeed. I thank you, will save it for later reference.
 
Do you really have to desolder that caps to test them? Seems like a hassle. Also, what is the cheapest multimeter that you can recommend for doing such things as measuring caps, general use, measuring low numbers as the voltage/amperage going through dynamic headphones, and of course being fairly future proof?