[KDS315]

You have the Blue Hawaii (BHSE) already, why are you even asking? Would you like to know the p2p values (peak-to-peak voltages?) or the bias current they are operating with? (Dr.) Kevin Gilmore would be your best address then...

From what I have on file he posted a while ago this (a partial quote of his original posting then):
((quote Dr Kevin Gilmore - with some slight edits for clarity))

500 v power supplies require 15ma of output current at 20khz into 120pf
A T2 can do this. A megatron can do this

450 v power supplies require 14ma of output current.
a kgsshv carbon can easily do 18 to 20 ma
a kgsshv is limited to a max of about 9ma

400v power supplies require 12ma of output current
a Blue Hawaii (BH) will easily do this and more

350v power supplies requires 10.6ma of output current
Most stax amps (t1,717,727,007t...) are 350v power supplies and can only supply about 7ma

300v power supplies require 9ma of output current
some stax amps including the d50 are limited to about 6ma

175v power supplies D10 requires 5.25ma of output current
amplifier is limited to 6ma

((unquote))

PS: the mentioned 120pF is the normal capacitive load of a STAX headphone which a suitable amp has to drive up to at least 20kHz frequency.

 

[ufospls2]

You have the Blue Hawaii (BHSE) already, why are you even asking? Would you like to know the p2p values (peak-to-peak voltages?) or the bias current they are operating with? (Dr.) Kevin Gilmore would be your best address then...

From what I have on file he posted a while ago this (a partial quote of his original posting then):
((quote Dr Kevin Gilmore - with some slight edits for clarity))

500 v power supplies require 15ma of output current at 20khz into 120pf
A T2 can do this. A megatron can do this

450 v power supplies require 14ma of output current.
a kgsshv carbon can easily do 18 to 20 ma
a kgsshv is limited to a max of about 9ma

400v power supplies require 12ma of output current
a Blue Hawaii (BH) will easily do this and more

350v power supplies requires 10.6ma of output current
Most stax amps (t1,717,727,007t...) are 350v power supplies and can only supply about 7ma

300v power supplies require 9ma of output current
some stax amps including the d50 are limited to about 0.6ma

175v power supplies D10 requires 5.25ma of output current
amplifier is limited to 6ma

((unquote))

PS: the mentioned 120pF is the normal capacitive load of a STAX headphone which a suitable amp has to drive up to at least 20kHz frequency.

Thanks for the info, very helpful.

 

[martin778]

https://www.trilogyaudio.com/spd-h1
Anyone familiar with this model?

 

[kevin gilmore]

300v power supplies require 9ma of output current
some stax amps including the d50 are limited to about 0.6ma

that should be 6ma

 

[Zoide]

Is the current output in mA the main metric for determining the ability of an amp to drive a demanding electrostatic earspeaker (e.g., Stax 007)?

Or do we also have to take into account the voltage and multiply it by the current to get power?

Thanks

 

[KDS315]

300v power supplies require 9ma of output current
some stax amps including the d50 are limited to about 0.6ma

that should be 6ma

Yep, I should have seen and corrected this. Done now! Thanks!!

 

[KDS315]

Is the current output in mA the main metric for determining the ability of an amp to drive a demanding electrostatic earspeaker (e.g., Stax 007)?

Or do we also have to take into account the voltage and multiply it by the current to get power?

Thanks

No, not this way. It is a bit more complicated than that, as it is about the precise reproduction of transients, which need rather high du/dt and di/dt values (these are measures of the speed of a voltage resp. current change values) in volts and amps per microsecond.

I’m sure Kevin Gilmore might explain that better than me. My Phd is in power electronics (kiloamps / kilovolts) only…

 

[Aspirant Audiophile]

Question for seasoned experts: in what ways can an underpowered amp paired with power-hungry earspeakers affect listening experience?

Context for my question: I recently got a pair of x9000s and, after much trial and error and trading in purchases in order to upgrade, I made a plan: start with the x9000s as the strongest link in my chain, and build a setup from there.

Current setup: Node 2i, RME ADI-2 DAC, SRM-353x, x9000s

I think I need the Node, for now at least--I get different sound out of my PC when connecting via USB, all my music is streaming, I don't need a Roon for mobility etc., and I don't know enough about streamers to make a different decision. I know I need the RME--it solves so many potential problems that go beyond just being a good DAC.

The 353x is an affordable placeholder while I try out various amps and make a more long-term decision. What I want to better understand is what happens to a pair of 'highest end' earspeakers when they're used with lesser-grade amps. I have no frame of reference to answer this question. I hear a lot of distortion at high volumes with the current setup, and not as much clarity or separation as I hoped for, but I have no idea whether this is a result of the 353x. I will personally test out several 'top' amps over the coming months, but it would help a lot to know what I should be listening for, besides 'more power.'

 

[slazhx]

Hi, Stax die-hard head-fier.

I currently own Hifiman HE6 OG and Shure KSE1500 e-stat iem. What I love from HE6 is bass punch and slam. For KSE1500, it is always that high resolution and details. My music tastes are heavy metal with many instruments and notes going on like Dream Theater, and OST by Hans Zimmer such as Interstellar. Can you guys recommend any model of Stax fitting my type?

My friend is lending Mjolnir KGSS Klassik for me, so now I'm on the hunt for Stax headphones fitting this amp and my taste.

AFAIK, SR-007 would better fit than 009 as It has more attack and bass region, right? (Had tried 009 w/ Woo WES but didn't like it)

Which sub-model code should I try? It seems there are SR-007 MKI, SR-007 MKII, SR-007A, etc. I know nothing about the differences in sounding. Can you guys please enlighten me?

Sorry for my ignorance, I believe there might be many same questions on this thread, but now we are on 14xx pages ...

Thank you

 

[BenF]

Question for seasoned experts: in what ways can an underpowered amp paired with power-hungry earspeakers affect listening experience?

Context for my question: I recently got a pair of x9000s and, after much trial and error and trading in purchases in order to upgrade, I made a plan: start with the x9000s as the strongest link in my chain, and build a setup from there.

Current setup: Node 2i, RME ADI-2 DAC, SRM-353x, x9000s

I think I need the Node, for now at least--I get different sound out of my PC when connecting via USB, all my music is streaming, I don't need a Roon for mobility etc., and I don't know enough about streamers to make a different decision. I know I need the RME--it solves so many potential problems that go beyond just being a good DAC.

The 353x is an affordable placeholder while I try out various amps and make a more long-term decision. What I want to better understand is what happens to a pair of 'highest end' earspeakers when they're used with lesser-grade amps. I have no frame of reference to answer this question. I hear a lot of distortion at high volumes with the current setup, and not as much clarity or separation as I hoped for, but I have no idea whether this is a result of the 353x. I will personally test out several 'top' amps over the coming months, but it would help a lot to know what I should be listening for, besides 'more power.'

Underpowered amps would result in a less dynamic sound (even if they can get your earspeakers loud enough), and the bass punch suffers most.
However, when it comes to "highest end" vs "lesser-grade" (which has nothing to do with power), the effects can be practically anything.

 

[padam]

Which sub-model code should I try? It seems there are SR-007 MKI, SR-007 MKII, SR-007A, etc. I know nothing about the differences in sounding. Can you guys please enlighten me?

Sorry for my ignorance, I believe there might be many same questions on this thread, but now we are on 14xx pages ...

Thank you

SR-007A = SR-007 Mk2 https://www.head-fi.org/threads/the-stax-thread-iii.677809/post-16625118

The cable entry has an open port on the Mk2, after sealing it Blu Tack, the sound becomes closer to the Mk1. But there are different revisions of each.
But many people still seem to be looking for the Mk1 version in the Classifieds section. So you can guess, which one is regarded as the most thought after version in general. (at least in stock form).
I only had several copies of the Mk1 so far, and they seemed to sound somewhat different, although I did not have two at the same time. And making it perfectly fit for your head is important (bending the assembly, making sure the elastic on the headpad is tight) so there are a handful of factors that will affect the sound just as much as the version you get.

So I wouldn't sweat too much about it and get a new (or nearly new) Mk2 (or A) that should be the Mk2.9 and it is regarded as very good (After port-modding).

 

[hifixman]

Any ideas of how to drive stax via speaker amplifiers?

 

[BenF]

Any ideas of how to drive stax via speaker amplifiers?

You need an energizer, like the Pro-bias SRD-1 here: https://mjolnir-audio.com/products/ or Wee here: https://wooaudio.com/amplifiers/wee

 

[KDS315]

Any ideas of how to drive stax via speaker amplifiers?

Get a (used) SRD-7 PRO and be happy with it (if your amp is good enough that is...)

 

[slazhx]

SR-007A = SR-007 Mk2 https://www.head-fi.org/threads/the-stax-thread-iii.677809/post-16625118

The cable entry has an open port on the Mk2, after sealing it Blu Tack, the sound becomes closer to the Mk1. But there are different revisions of each.
But many people still seem to be looking for the Mk1 version in the Classifieds section. So you can guess, which one is regarded as the most thought after version in general. (at least in stock form).
I only had several copies of the Mk1 so far, and they seemed to sound somewhat different, although I did not have two at the same time. And making it perfectly fit for your head is important (bending the assembly, making sure the elastic on the headpad is tight) so there are a handful of factors that will affect the sound just as much as the version you get.

So I wouldn't sweat too much about it and get a new (or nearly new) Mk2 (or A) that should be the Mk2.9 and it is regarded as very good (After port-modding).

Thank you for your advice.

Too bad, I have no skill about modding with Blu Tack. Accoding to my music taste, do you recommend me to get standard updated 007A/MKII or try getting MK I? Any S/N I should pay attention to?