[milosz]

   
Did you mean http://www.princeton.edu/3D3A/Publications/Pure_Stereo.pdf
This is impressive. Especially #20.

That also  which is the theoretical paper
 
 
http://www.princeton.edu/3D3A/PureStereo/Pure_Stereose4.html   links to http://masisaudio.com/   the Asia distributor for this system, also a US / Europe distributor as well http://www.theoretica.us/

 

[djonny]

  How do you like the 307 in general?

407 (404) much better than 307. The cable in 407 have much less capacity and much better quality of made and copper.

 

[JayM481]

Thanks for the answers and info so far. 
 
One question I'm pondering is whether the adapter/energizers are neutral? In other words, do they reveal the character of the amp, or impart their own signature? Also, what sort of load do they present to valve/tube amps? 
 
As I mentioned in my first post, I'm considering an energizer as a budget solution to using my earspeakers in a second system.

 

[allets]

I'm joining the Stax Mafia with the SRS-3170 system. I can't wait! 

 

[gepardcv]

So is the SR-307 different from the 507, other than the $100 leather earpads? The Stax USA site says it has the same driver.

 

[allets]

  So is the SR-307 different from the 507, other than the $100 leather earpads? The Stax USA site says it has the same driver.

SR-307 = 340 g, 132 Ohms, 101 dB/mW
SR-507 = 388 g, 145 Ohms, 118 dB/mW
 

 

[Jones Bob]

SR-307 = 132k Ohms, 101dB/100Vrms@1kHz

SR-507 = 145k Ohms, 100dB/100Vrms@1kHz

FIFY

 

[gepardcv]

Thanks, got it. In other news, someone told me that the 323S 240V version works if you just plug it into a North American power outlet. How is this at all possible?! Does it do any harm? I found instructions on an earlier Stax thread for resoldering a 323S for 120V, but I'm not 100% confident mucking around in a high-voltage device like an electrostatic amplifier. (Or I'd just jump into building a KGSSHV.)

 

[kevin gilmore]

nope. However if its the 240v version then none of the wires on the transformer have been cut like
the 100v only versions, and then you re-wire it for 120v which is easy.

 

[dripf]

Hi Kevin,
 
How do we quantify the performance of an electrostat amplifier? What unit of measurement should be used?
 
Also, as it is a seeming consensus that the SR-007 has greater amplification requirements, how do we measure this? It specifies the same 100dB / 100V r.m.s. 1 kHz and a lower capacitance relative to other models.
 
Regards.

 

[gepardcv]

nope. However if its the 240v version then none of the wires on the transformer have been cut like
the 100v only versions, and then you re-wire it for 120v which is easy.

Thank you for your comment, Kevin, but I don't understand — do you mean "no, plugging the 240 V version into an American outlet won't work", or "no, it won't do any harm to plug the 240 V version into an American outlet"? If it's the latter, then I just don't understand how the amp could possibly work at all, as I have been assured (on another forum) it does.

 

[kevin gilmore]

The + and -350 supplies will end up at +/-175  so it will make some music.
but the bias will be off, the voltage range will be off etc. Person obviously
has no clue.

 

[milosz]

  Thanks for the answers and info so far. 
 
One question I'm pondering is whether the adapter/energizers are neutral? In other words, do they reveal the character of the amp, or impart their own signature? Also, what sort of load do they present to valve/tube amps? 
 
As I mentioned in my first post, I'm considering an energizer as a budget solution to using my earspeakers in a second system.

I tried an SRD-7 adapter on a number of different amps - tube and solid state- using SR-007 and Lambda Signature 'phones.  I did hear differences between the amplifiers. Kind of the same differences I heard from those amplifiers when driving speakers. 
 
Is the SRD-7 ALSO imparting a sonic character, in addition to what the amplifier brings to the party?  Yes, I would guess it does add some contribution to the sound.  Is an SRD-7 "more netural" than a Stax amp?  I don't know that you could really ever answer that. When I used the SRD-7 with a good amp, it sounded great.  That's all I could conclude.  My SRM-T1 sounds great too.  I think the T1 sounds a bit more "refined" than any of the amp-and-SRD-7 combos I tried, but I didn't do any blind A/B tests.

 

[astrostar59]

  Hi Kevin,
 
How do we quantify the performance of an electrostat amplifier? What unit of measurement should be used?
 
Also, as it is a seeming consensus that the SR-007 has greater amplification requirements, how do we measure this? It specifies the same 100dB / 100V r.m.s. 1 kHz and a lower capacitance relative to other models.
 
Regards.

You don't need to measure it to be convinced, us your ears. Anyone who has heard the 007s against the 009s and even the 507s will hear it needs more current to sing. The design of the drivers in the 007 was the first real attempt IMHO where Stax addressed the 'rest of the world' taste for some real bass, as apposed to transparency only. Maybe this was partly why it needed more current? The 007s is a great headphone, it was possibly a problem for Stax that none of their amplifiers available to the real public (no T2) was really capable of doing it any justice. 

 

[kothganesh]

  You don't need to measure it to be convinced, us your ears. Anyone who has heard the 007s against the 009s and even the 507s will hear it needs more current to sing. The design of the drivers in the 007 was the first real attempt IMHO where Stax addressed the 'rest of the world' taste for some real bass, as apposed to transparency only. Maybe this was partly why it needed more current? The 007s is a great headphone, it was possibly a problem for Stax that none of their amplifiers available to the real public (no T2) was really capable of doing it any justice. 

+1. Which is when Geoff stepped in.......