Question about amps for the Stax SR-009
Jan 18, 2012 at 4:15 AM Post #46 of 883


Quote:
To the OP, I would wait for Eddie Current's Electra if you are in no hurry.  Heard the prototype and it's just what the doctor ordered for the 009 IMHO.  



I'll be certainly waiting long enough to hear about comments on and impressions about the Eddie Current's Electra before I get another amp, as I am waiting for someone to commercially build the KGSSHV (which could be a little while or even never happen at all
frown.gif
, although Justin seems to have shown some interest, and who knows, perhaps Kevin Gilmore will allow someone else to build (commercially) the amp sooner than later). 
 
 
 
Jan 18, 2012 at 5:23 AM Post #47 of 883


Quote:
1. The DACT stepper that is found in the "normal" BHSE is also rated above the BHSE's temperatures so the ALPS makes no difference with regards to that silly heat/pot theory.
 
2. Even if there was a brightness issue with the BHSE/009 (which there isn't IMO), this makes no difference when used with the Smyth Realiser you are referring to as that EQ's the frequency response of the headphone and amp to match what was measured.  The issue would only come up when using the headphones/amp alone and not with the Realiser activated.

I am sure that's the case, but when I was looking at amphead's web site there was very little info on what went into the amp. Yes if Justin listed the "DACT stepper" I could have looked it up, I have a Alps RK50 in my WA5LE so I know what it can do, and yes my fairly heavily modded WA5LE does also run hot so I know what to expect from the heat.
 
No you are wrong about how the Realiser works when doing a HPEQ, the Realiser is not really a EQ in the normal world. What it does is measure response's time basically for sound staging and balances the right and left ear cups for the shape of your ears and how you hear these sounds/test tones. Its for this reason why my HPEQ probable would not work for you, just as the PRIR would not work for you. However there is a manual HPEQ setup in the Realiser but mainly it is to better balance the sound-stage R/L/C/Sides/Rears and SW coming from the headphones. The same goes for the PRIR's and it is when you make a PRIR of a sound system is when you would do a manual HPEQ, at least for best results.
The whole Idea of the Realiser is to copy the sound system and room acoustics, not to EQ or change it as a real EQ would do. However yes you can do some manual EQ but imo that really detracts from what the Realiser can and should do.
To put it simply the Realiser developed by Dr. Smyth (the creator of DTS) is to copy and balance a sound-system not change it, and in part using the Binaural type of recording technique but in the Realisers case it uses your body, head and ears not a dummies and then also is able the add a MCH speaker setup so you get the sounds coming from were ever the speakers are placed when you did a PRIR
 
 
 
Jan 18, 2012 at 6:25 AM Post #48 of 883
2 different people have contacted me recently about building commercial kgsshv
and i've told both of them that it is OK to do so.  Whether they follow thru on this
is not up to me.
 
One of these 2 people has bought significant stock of the hard to get semiconductors,
so it is likely that he may follow thru.
 
Jan 18, 2012 at 7:13 AM Post #49 of 883

 
Quote:
Originally Posted by sillysally /img/forum/go_quote.gif
No you are wrong about how the Realiser works when doing a HPEQ, the Realiser is not really a EQ in the normal world. 


Sillysally: I strongly believe n3rdling is correct... The realizer is effectively taking the headphone response out of the equation through a headphone+amp IR measurement. Personnalized data indeed (ear shape and what not), impulse response rather than parametric and other traditional equalizer indeed, but equalized out nonetheless.
 
Only requirement is for the headphone is to be sufficiently fast so as to be able to reproduce the target system and not severely restrained in low frequency extension so as to not create a mess of a compensating filter and put unreasonable strain on the transducer /amplification chain (e.g don't expect to emulate a 30 inch subwoofer from an anemic headphone).
 
 
 
Jan 18, 2012 at 10:42 AM Post #50 of 883


Quote:
Quote:

If you read the thread you would find the answer to your question.
 
@ Spritzer - I know you have said that you are not a fan of equalization, but it seems to me that it would be much simpler to just equalize the treble on the SR009 down a bit rather than chasing the amp that will happen to do that for you. You would also avoid any compromises in those amps like coupling capacitors.
 
 


EQ is the easy way, real men build 10 different amps to solve the same problem. 
tongue.gif
  For me the SR-009 is perfectly useable as it is but it's always worth the try to see if there is a synergistic match to be found for that particular transducer.  It's well established what the SR-007 Mk1 requires from the amp to shine but the SR-009 is new so the legwork has to be done all over again.  Even though I'm a champion for Class A, direct coupled beasts they simply don't work with all transducers.  The He90 probably being the most famous example. 
 
Nothing wrong with coupling caps if there aren't that many of them around.  Not that they have the definitive say on how a circuit sounds but the difference between a WES and the ESX (same tubes used in both amps) is quite startling.  The ESX has only one set of interstage caps so they are small and can be of very high quality for not a whole lot of money.  Very different circuits though and power supplies but one could build one of each from a lot of the same parts.  Now the output caps used in the old Stax amps are tiny (5nf) so I'm able to use vintage silver mica caps which are arguably the best money can buy. 

 
Quote:
Which doesn't mean, I assume, that the KGSSHV or the BHSE with the 007 wouldn't still outperform by a wide margin the 009 with the 727, right?


No, things aren't as cut and dry as that.  Both transducers are excellent, just two different takes on the same "problem" with rather different voicing. 
 
Quote:
 
I also think it's really funny that Alps offers to build the RK50 for automotive applications.


Ok, that is bloody funny,  A quad RK50 is probably half the size of the radio in my car...
 
 
 
Jan 18, 2012 at 11:07 AM Post #51 of 883


Quote:
 

Sillysally: I strongly believe n3rdling is correct... The realizer is effectively taking the headphone response out of the equation through a headphone+amp IR measurement. Personnalized data indeed (ear shape and what not), impulse response rather than parametric and other traditional equalizer indeed, but equalized out nonetheless.
 
Only requirement is for the headphone is to be sufficiently fast so as to be able to reproduce the target system and not severely restrained in low frequency extension so as to not create a mess of a compensating filter and put unreasonable strain on the transducer /amplification chain (e.g don't expect to emulate a 30 inch subwoofer from an anemic headphone).
 
 




Yes you are right when you say impulse response , and yes the headphone must be sufficiently fast so as to be able to reproduce the target system and not severely restrained in low frequency extension along with mids and highs. And it is for that reason why the Smyth folks offer a Stax headphone and amp, but still that system does restrain low frequency when a LFE CH is present. But as far as what was said about taking out "brightness issue" no a HPEQ will not do that. I have done many HPEQ's with many different headphones and combined the HPEQ with the same PRIR and there is always different results with different higher end headphones and amps. What will be similar is the way the headphone projects the sound if you use a different HPEQ not made for the headphone you are using the HPEQ on. I am not saying that there is no EQ going on but not the way a traditional EQ works. As I said the biggest factor in a HPEQ is how the headphone and amp project the soundstage, speaker balance and how you hear that projection. Matter of fact even the placement of the mic's in your ear will have a bearing on the soundstage and tonal quality's of the audio using the same headphones.
Please understand if there was a real EQ going on as is suggested there would be no point of looking at a headphone like the 009, I would just stay with my HE6, HD800 or LCD-3 because I would have the same results using these headphones, but unfortunately that's not the case and that's not how imo Smyth designed the Realiser.
 
Anyway If you guys would like to know more about the Realiser, I think it best to go to the Realiser thread.
 
Jan 18, 2012 at 1:25 PM Post #52 of 883


Quote:
2 different people have contacted me recently about building commercial kgsshv
and i've told both of them that it is OK to do so.  Whether they follow thru on this
is not up to me.
 
One of these 2 people has bought significant stock of the hard to get semiconductors,
so it is likely that he may follow thru.



That is very good news! Thank you very much for letting us know. -- Would it be too indiscreet to ask whether Justin was among those two people?
 
Jan 18, 2012 at 6:17 PM Post #53 of 883


Quote:
Yes you are right when you say impulse response , and yes the headphone must be sufficiently fast so as to be able to reproduce the target system and not severely restrained in low frequency extension along with mids and highs. And it is for that reason why the Smyth folks offer a Stax headphone and amp, but still that system does restrain low frequency when a LFE CH is present. But as far as what was said about taking out "brightness issue" no a HPEQ will not do that. I have done many HPEQ's with many different headphones and combined the HPEQ with the same PRIR and there is always different results with different higher end headphones and amps. What will be similar is the way the headphone projects the sound if you use a different HPEQ not made for the headphone you are using the HPEQ on. I am not saying that there is no EQ going on but not the way a traditional EQ works. As I said the biggest factor in a HPEQ is how the headphone and amp project the soundstage, speaker balance and how you hear that projection. Matter of fact even the placement of the mic's in your ear will have a bearing on the soundstage and tonal quality's of the audio using the same headphones.
Please understand if there was a real EQ going on as is suggested there would be no point of looking at a headphone like the 009, I would just stay with my HE6, HD800 or LCD-3 because I would have the same results using these headphones, but unfortunately that's not the case and that's not how imo Smyth designed the Realiser.
 
Anyway If you guys would like to know more about the Realiser, I think it best to go to the Realiser thread.


Thanks for sharing your experience sillysally, I was actually following the realizer thread for a while but am behind lately :wink:. In regards to what you're noticing, only explanation for me is that the compensating impulse response is somehow smoothed or artificially damped out and thus won't fully compensate for sharper resonances. As discussed in other threads, these 1 mic / 1 headphone position measurements do need some form of smoothing anyway so I guess this is the reason why they're doing it that way. Given that the measurement is bound to vary a bit every time you reseat the headphone, they're probably not exactly using the HPIR as is so I understand your point now...
 
Will try to catch up in the other thread :wink:
 
cheers,
arnaud
 
 
Jan 18, 2012 at 7:20 PM Post #54 of 883
Would there be any potential synergy between a SR009 and an Aristaeus?  I may be borrowing a SR009, so will be deciding whether I want to go with a SR007A or SR009 for the long-run.
 
I'm unfamiliar with the HEV90 and Aristaeus design, and whether they pair well with specific Stax models.
 
Jan 18, 2012 at 8:48 PM Post #55 of 883


Quote:
Would there be any potential synergy between a SR009 and an Aristaeus?  I may be borrowing a SR009, so will be deciding whether I want to go with a SR007A or SR009 for the long-run.
 
I'm unfamiliar with the HEV90 and Aristaeus design, and whether they pair well with specific Stax models.


There would, at least according to some posts here in the Headamp Blue Hawaii Special Edition thread, if I am not mistaken.
 
 
 
Jan 18, 2012 at 10:59 PM Post #56 of 883
There is only speculation about the pairing of the BHSE/Aristaeus, iirc - it is guesswork based on what people read about the perceived warmth of the amp and the supposed (non-existent) brightness of the 009s. 
 
Why anyone would pay BHSE prices for such a crippled amp that is only suitable for the HE90 is beyond me.  It is probably one of the worst options for the 009s, since you are diluting the cans' amazing detail retreival
 
Jan 18, 2012 at 11:10 PM Post #57 of 883


Quote:
Yes that is correct and is why I took the Alps RK50 option when I put a deposit on the BHSE.
All I was ever saying is that the Alps RK50 is a safe bet with a amp that does run hot.
The only reason why I pulled out of the BHSE was because of what others are reporting about the BHSE/009 combo. Maybe true maybe not, but to take a chance on a 11K+ rig didn't seem to be a safe bet.
 
My system is based on Binaural type of recordings and not just for 2Ch but for MCH (5.1/7.1) HQ sound track from Blu Ray movies, duplicating AIX's sound studio's high end audio equipment and room acoustics through headphones.
 
I am sorry if I bore some folks with what they consider to be pointless posts, but in my case not being a amp builder I must take into consideration what others say and post what I have read or experienced. But imo what is pointless is to ridicule someone that is trying to improve on a system that most know nothing about.


 
 


Quote:
There is only speculation about the pairing of the BHSE/Aristaeus, iirc - it is guesswork based on what people read about the perceived warmth of the amp and the supposed (non-existent) brightness of the 009s. 
 
Why anyone would pay BHSE prices for such a crippled amp that is only suitable for the HE90 is beyond me.  It is probably one of the worst options for the 009s, since you are diluting the cans' amazing detail retreival


 
because a guy on the internet who sat at a meet table w/ 80dB ambient noise listening to unknown music from an unknown CD player for 1 minute said so?
 
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Jan 19, 2012 at 1:25 AM Post #58 of 883


Quote:
 
 

 
because a guy on the internet who sat at a meet table w/ 80dB ambient noise listening to unknown music from an unknown CD player for 1 minute said so?


No of-course not, not when you are in this level. You even thought that a Aristaeus may be a better choice for me with the 009's.
I also must correct myself when I said "only reason why I pulled out of the BHSE was because of what others are reporting about the BHSE/009 combo" that is not the only reason. The other factor is heat that is generated by a combination of my gear. As I said I have a fairly heavily modded WA5LE (thanks jamato8 and alabama historical radio society) and if I am not careful that amp gets very warm in the summer because of how warm the ambient temperature can get in my man cave when my gear is turned on.
 
I don't know how much the ambient room temperature would affect your BHSE, so the only thing I have to go by is my WA5LE and other post about the BHSE.
 
Right now I am looking into spritzer suggestion about the 727II for the 009's, paired with the rest of my rig.
 
Please understand what I am saying in no way suggests that your fine BHSE is nothing less than a fine [size=x-small]Electrostatic Amp.[/size]
 
Jan 19, 2012 at 2:08 AM Post #59 of 883


Quote:
I am sure that's the case, but when I was looking at amphead's web site there was very little info on what went into the amp. Yes if Justin listed the "DACT stepper" I could have looked it up, I have a Alps RK50 in my WA5LE so I know what it can do, and yes my fairly heavily modded WA5LE does also run hot so I know what to expect from the heat.
 
No you are wrong about how the Realiser works when doing a HPEQ, the Realiser is not really a EQ in the normal world. What it does is measure response's time basically for sound staging and balances the right and left ear cups for the shape of your ears and how you hear these sounds/test tones. Its for this reason why my HPEQ probable would not work for you, just as the PRIR would not work for you. However there is a manual HPEQ setup in the Realiser but mainly it is to better balance the sound-stage R/L/C/Sides/Rears and SW coming from the headphones. The same goes for the PRIR's and it is when you make a PRIR of a sound system is when you would do a manual HPEQ, at least for best results.
The whole Idea of the Realiser is to copy the sound system and room acoustics, not to EQ or change it as a real EQ would do. However yes you can do some manual EQ but imo that really detracts from what the Realiser can and should do.
To put it simply the Realiser developed by Dr. Smyth (the creator of DTS) is to copy and balance a sound-system not change it, and in part using the Binaural type of recording technique but in the Realisers case it uses your body, head and ears not a dummies and then also is able the add a MCH speaker setup so you get the sounds coming from were ever the speakers are placed when you did a PRIR
 
 



I'm not wrong.  I wasn't going into detail about the whole Realiser process because there wasn't a need in order to make my point: The FR of a headphone does not matter when used with an active and calibrated Realiser system.  That's a HUGE part of why the Realiser even works.  If this wasn't the case, you'd have no chance of making the headphones mimic a specific speaker system.  I'm not saying the Realiser is simply an EQ and I don't know how you inferred that from my post.  I'm well aware of how it works as I've been following it closely since it was announced.
 
Jan 19, 2012 at 3:56 AM Post #60 of 883


Quote:
I'm not wrong.  I wasn't going into detail about the whole Realiser process because there wasn't a need in order to make my point: The FR of a headphone does not matter when used with an active and calibrated Realiser system.  That's a HUGE part of why the Realiser even works.  If this wasn't the case, you'd have no chance of making the headphones mimic a specific speaker system.  I'm not saying the Realiser is simply an EQ and I don't know how you inferred that from my post.  I'm well aware of how it works as I've been following it closely since it was announced.


Please do go into detail.
 
 
The purpose of the Realiser is not to make a silk purse out of a sows ear, that's up to the user. The only real HUGE part of the Realiser is with the PRIR that you make and were you make it from. A crappy sound system and room acoustics like headphones and supporting rig will only yield poor results. Its that simple. The HPEQ is mainly for sound staging and what your headphones can and can't do in that respect, it doesn't use a 32 band graphic equalizer or what ever all, though you can do a manual EQ but then you need a some very high end equipment for, I have tried but without much luck.  I guess that's why some folks do use a real graphic equalizer (i don't) and others have reported great sound quality but poor sound staging using iem that can not be HPEQ'ed. As I said there may be a very small amount EQ going on but I don't think anybody really knows for sure. What I would suggest you do is make a auto HPEQ then you will hear the 5 sec of test tone (yes tone but with the volume level changing) and hear it checking how your headphones present the sound stage.
The Realiser is not about changing any tonal quality's, its about coping the tonal qualities of a external sound source.
wink.gif

 
 

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