SR-009 vs Orpheus/SR-Omega/O2s?

[Mossback]

i've only had the 009's for a few days, and i only have the SRM-717 for a stat amp; but no doubt the O2 Mk1 is veiled in direct comparison to the 009. the O2 Mk1 also has an overall darker view on the music and more fullness in the bass. compared to my speaker system, neither are able to reach that level of information, although the 009 gets closer. these are provisional perceptions as i need more time to get a bit more perspective.
 
it's important to note i like the overall performance of the O2 Mk1 thru the SRM-717 so my comments are not intended as anything but my personal comparitive view of the 2 cans based on limited exposure. and i don't personally consider the O2 Mk1 to be veiled per se, only that the 009 makes it sound as if it is.
 
we'll see what happens when i have more time with the 009 and when my BHSE arrives and i try the metal base Philips EL34's. my mind is open.
 
the SRM-717 sits on Wave Kinetics A10 U8 footers, and is fed by an Equi=tech isolation transformer and Absolute Fidelity power cord, for sources i'm using a set of Transparent Opus MM2 RCA interconnects from the darTZeel NHB-18NS preamp 'record out'. my sources are (1) Playback Designs MPS-5 digital player/server DAC, (2) Wave Kinetics NVS turntable/Talea 2 arm/Ortofon A90 cart, and (3) 1/4" Studer A820 RTR deck into a King Cello repro (and three other RTR decks).

 

[kiertijai]

Dear Arnaud
@ Kiertijai: very interesting findings about the preamp pairing. It begs the question: are you still following up with Craig about his prototype Stax amps? I know they've been a bit criticized by the experts as for the choice of tube (which does have barely enough gain to get sufficient voltage swing) but on the other hand, I believe Craig has the ability to make sweet sounding gear so I am definitely curious about what he may come up with.
     I have changed the interconnects to the Silnote Morpheus XLR and that changed the sound of the SR009 to be darker
it is still brighter than the O2mkI).  I plan to get  ASI liveline interconnects that is more neutral to see how the SR009 will
perform.    Now it seems like I prefer the Marconi B65 more than other driver tubes with the SR009.
     Yes, I have talked to Craig quite frequently .  I just sent the Marconi PX25 balloon and Marconi PX4 for him to test and try
with the Electra SE and BA.  The new electrostatic amplifier will be 2 versions : standard and SE.  The standard has finished and Craig begin testing that and will bring to RMAF too.  The standard version will use 4 6L6GC as power tubes and 2 6SN7's + 26SL7's  and a set of rectifier which I cannot recall.   He said that it can achieve 800 V Voltage swing (or much more than that because of the different topology that he use i.e. the Electra uses dual differential amplifiers for drive, and a split load inductor for output). Please don't ask me what it is  or how it works as I completely have no idea.  
     The Special Edition uses 2 KR PX25's as power tubes, 4 Raytheon 5842q 's or 4 WE417 's  for drivers while using one 274B and one 6X4 for rectifier.    He changed his mind not to use the 300B's .  With the PX25 the voltage swing is 760V .  I asked him whether it is possible or not to use the 300B as power tubes he said that may not be appropriate because the voltage swing is only 360V .   Again after  he  found that he can get the much larger voltage swing with his dual differential amplifiers for drive, and a split load inductor for output,  I asked him again because I got  the impression from this blog that SR009 or HE90 or even SR Omega may not need that high voltage swing and need warm full sound.   He said that he will try to test the 300B (which he thinks will work) if it works he will make a switch that can use both PX25 and 300B.   The PX25  is for O2 and 300B for HE90, SR009, SR Omega.   I really hope that the 300B works so I will use the WE300b + WE417 +WE274 for this amplifier.   I can use all the Stax headphones by switching only the power tube from 300B to PX25
       The standard Electra will be at RMAF , hopefully along with BA and Super 7 amplifier. Those who can go there please enjoy and share the info.

 

[spritzer]

I for one wouldn't be so quick to declare the 727 a good amp for the 009 since the amp is way too colored for that IMHO.  The only good thing about the stock 727 would be the lower gain, that's about it.  Buy some resistors and do the bloody mod, it's not like it isn't 100% reversible... 

 
As for the new Eddie Current amp, I have serious doubts about using inductors at the output of electrostatic amps and it is certainly one of the reasons the WES is so terrible.  There is a reason why Stax never used inductors in the dozens and dozens of designs they drew up.  It's also interesting that the whole bit about using 300B's was chalked up as some misunderstanding on our part and then there are the issues with all EC amps, utterly terrible build quality (they can't even solder them properly) and cheap parts.  I'd be very happy to have a new amp which isn't just a cheap attempt to capitalize on the Stax popularity but I'm not very optimistic. 
 
Quote:

Wow, these latest observations make me almost glad I did not bother messing with my stock 727A yet. I do notice the etch / feeling of projection at higher volumes / with some recordings and I thought it was due to the amp but, based on the recent posts it seems to be even more problematic with higher end amps? Maybe I am lucky to have may system fine tuned for the 009 balance in the sense that my D/A is particularly non-edgy / warm sounding and I'm using some DIY copper interconnects that are supposed to be easy going too (Belden or Neuman mic cable or something like that, I have to admit I can't hear these subtle differences that well...).
Birgir, it looks like you have pretty much found / built the perfect headphone for your needs, I hope to hear it someday as I really have hard time finding anything that my 007A does better than 009 if only be kind to music collection . As you said also, listening volume is likely playing a big part in everyone's impressions, I listen to fairly low volume at home (and did have issues with the 009 at some noisy store).
 

The SR-007Mk1 will remain my top set but a properly setup 007A (SZ2 version) isn't that far off.  The trick with that one is to adjust the arcs so that the earpads close the ports most of the way.  The bass is still a bit bloated at the lowest registers but other than that, not bad at all.  Now mating this sound with an unmodded 727A isn't a very good idea though. 
 

 

[kiertijai]

Dear Birgir,
I for one wouldn't be so quick to declare the 727 a good amp for the 009
   I cannot comment much on that because for the stax amplifiers that I  have  are your modded 727A and SRM300.
With the modded 727 before I acquired SR009 ,  I found that 727A modded improved the sound of O2mkI by a big leap.
At first I  like the SR009 with 727A  less than the SR Omega and SR009 may be equal or a little better than O2mkI.
However that depends also on other factors such as genre of music.  After RSBRVSP blog that mentioned
about the use of tube preamplifier I tried the SR009 with the use of preamplifier function of the Balancing Act and
found that when I used tubes with rich warm mid (Marconi B65, NU 6SN7, KenRad VT231) the performance of SR009
improved.  Now my setup use the Lindemann 820S CD/SACD player ...XLR digital out via Heaven Gates cable....Weiss DAC202....Analysis plus golden oval interconnects.......Balancing Act.......XLR out (via Silnote Morpheus ) to 727A modded and   RCA out (via Stealth Indra) to SRM300.   I use two stax outputs of 727A modded to drive SR009, SR Omega alternating with O2mkI  and SRM 300 to drive the HE90.  Tubes used for the BA preamplifier function are WE 300B original + MWT B65 metal base. With this setup I can listen to 3 different electrostatic headphones at the same time and from the same source.  I can also listen to the dynamic headphones all most at  the same time too  by switching between line/can of the Balancing Act.   On brief listening I found that all 4 phones performed excellently (HE90, SR009, SR Omega, O2mkI).  It is split hair difference and it depends on personal choice.  For the SR009 the sound became fuller, richer, sweet without compromise in the treble extension.  O2mkI was not so dark while the soundstage also improved.   I myself still prefer the SR Omega and HE90 because my music is of more laid back style.  I compared those phones by only listening to the vocal Chinese music and I am now enjoying the music of Michael Franks "Time Together".   Again I agree that SR009 is more suitable with
tube amplifier with warm sound, for me who don't have that I use the SR009 through tube preamplifier and it works excellently for me.  I don't know I have a feeling that SR009 may also be good with the Aristaeus.  It is a guess anyway until Justin begins
building my Aristaeus ( I have been waiting for almost a year and Justin told me that it would be finished in 4 months. No
real complaint here because several has been waiting for almost 2 years for the BHSE)
 
As for the new Eddie Current amp, I have serious doubts about using inductors at the output of electrostatic amps and it is certainly one of the reasons the WES is so terrible
     I think Craig will go to RMAF and compare his standard Electra with the Woo WES as some people believe that the Woo WES perform well with the HE90 and Stax headphone with wider soundstage??  The tubes used in the Woo WES are almost
the same as in the Electra standard  (EL34 vs 6L6GC, 6SL7 vs 6SN7).  We will get better idea after RMAF however Craig mentioned that if the result is not that good  he will go to the SE that use the PX25's .  I am not confident that the 300B will work.

 

[spritzer]

I've never been a fan of dulling things down by deliberately adding loads of distortion to some of the cleanest transducers money can buy.  If that works for you then great but sort of looses the point of striving for better and better amps. 
 
As for the Electra, the tubes used may be similar but the actual circuits are probably far apart.  For instance the rebuilt ES-X uses the exact same tubes as the WES yet the design and specs couldn't be further apart.

 

[kiertijai]

Dear Birgir,
As for the Electra, the tubes used may be similar but the actual circuits are probably far apart
   That's what Craig has said , however he would like to compare with the Woo WES.  The finished amplifier
is the standard version.   Craig has written to me yesterday and he said that he has finished the prototype
of the standard version and will bring to the RMAF.   He also said that the circuit is different from the Woo WES.
On initial impression, he found to his surprise that he can get the voltage swing up to 1500V or more (initially he
thought it to be around 800V while the PX25 configuration of SE is 760 and 300B can have only 360 V voltage swing).
The electra has more depth and range.  The sound was full , rich and warm similar to the sound of the
LCD2 rev 1 driven by the BA and there was excellent treble extension.  The electra goes out at 80Hz so that is plenty
of air.   I would like to know how it performs with more tube rolling experience.  I also informed Craig about the inductor
and he is thinking of this info.
    The electra standard version will be at the RMAF  also with the Balancing Act and Super 7 Amplifier
    It's good to know that the standard version performs well but I will be waiting for the SE version especially when
it can use WE 300B (which Craig now things that it should be possible because he found that his standard Electra
has almost double voltage swing than initially thought)
     I may need more than a week to share the experience with the SR009, SR omega, HE90, O2mkI   and probably with
the R10, Qualia and LCD2 rev1, 2  .  The electrostatic phones will use the tube preamplifier function which I found that
I like their sound passing through that.   My Aristaeus will probably ship at the same time or later than the BHSE.
Our DIYT2 was completed but there is some noises which we know that it may be due to the resistors that we used
we will change that with probably Zicons resistors and will make the second unit at the same time too  because initial
impression showed that the amplifier is very powerful and sounded so nice even with the noises.
 

 

[arnaud]

Dear Kiertijai, 
 
Thank you for the updates. Do you have any rough idea of the cost (including tubes) / weight / dimensions of the standard and special versions? If this is considered off topic, I am happy to receive a PM . I can contact Craig directly though, but he's probably wary of me since I dropped out of BA pre-order listen midway through (when I decided to switch to stats)...

 

[kiertijai]

Dear Arnaud,
   You may contact directly to Craig.  I don't think he remember your info and I think if he
remember he does not care much about that because BA's are back ordered. BA is one heck of the headphone amplifier and you can also use its preamplifier function which is much better than the preamplifier at the same price.
    Craig does not want to release more information at the moment because it is still in the
building process.  He will provide full info. later and he will answer the question of the inductor.
He also said that the use of inductor may not be bad and Stax did not include that probably because of the cost more than other things.
     From Craig's description the sound of the Electra standard version is quite impressive.
If it's true as he mentioned that the sound is more like the LCD2 rev 1 with high extension
of treble and bass, it will be of much interest.

 

[ishumarian]

Quote:

Did you mean 'light side'?
 
 

Hi, Amarphael. No, the reviewer meant bright. If you read my translation, I said the 'tonal quality' of the bass, not the bass itself, which is a meaningful distinction for the reviewer, I believe. I think I know what he's talking about. I've heard a number of megabuck speakers whose bass output was quite stout, but the tonal shade tended toward the brighter side.
 

 

[purrin]

Quote:

...
     From Craig's description the sound of the Electra standard version is quite impressive.
If it's true as he mentioned that the sound is more like the LCD2 rev 1 with high extension
of treble and bass, it will be of much interest.

 
You are making me want to run over to his place and sneak in a listen! I don't want to bug him now though because he is probably busy getting everything together for CanJam. 

 

[Elysian]

Quote:

     From Craig's description the sound of the Electra standard version is quite impressive.
If it's true as he mentioned that the sound is more like the LCD2 rev 1 with high extension
of treble and bass, it will be of much interest.

Thank you for sharing the early impressions of EC's amp!  If there is any other information Craig doesn't mind shared, please continue to post your comments.
 
Out of curiosity, how would Craig characterize his aim for the BA?  I'm wondering, as it'd be interested to know if there are any similarities with the WIP electrostat amp with the BA, with respect to the overall sound signature.

 

[kiertijai]

Out of curiosity, how would Craig characterize his aim for the BA?  I'm wondering, as it'd be interested to know if there are any similarities with the WIP electrostat amp with the BA, with respect to the overall sound signature
      I really don't know this.   I only know that his new version is 2A3/45 BA which is quite good.
      I think  his main concentration now is on the Super 7 which is perfect match for the LCD2 and HD800
however there is still some problem with the treble  extension and the driving power may not be enough for the AKG K1000.
Another main thing that he is concentrating right now is the Electra Standard version  which he already has great
result but he is still concerned about the price that may be too high.  He concerns even 100$ for some minor thing that
increase the performance but the customer has to pay for it.  I said that for those who can buy the SR009 or O2mkI
would not mind that at all.  Those people would not mind purchasing other expensive thing like the Alps RK50 instead of
the Goldpoint step attenuator.
     After RMAF we will know better.

 

[jaycalgary]

I don't get it? Is it just about using the expensive tubes?

 

[kiertijai]

Is it just about using the expensive tubes?
    Not at all,  I don't think Craig like to use expensive tubes.
    I bought some expensive tubes or phones to use and Craig use the word "exotic"
I think he tries to use best buy tubes and I think most of the amplifier builder tends to do that
 but Craig  open the options for us to try the more expensive (probably better in our opinion) 
probably he knows in his heart that we will do that most of the times.  He has this attitude
including the wall outlet, power cable , umbilical cord and interconnects.
 

 

[jaycalgary]

I dont know but it does sound like the most expensive tubes possible