The Stax Thread III

[thinker]

L-700 vs.SR-009 very short review because my new laptop sucks and i have listened only 1hour and the L-700
should be break more in
 
The presentation between these phones is different.
Resolution and transparency is better on SR-009, the 009 has almost microscopic like resolution thats why the source is important when driving 009 and the reason why so many different opinions about 009 some call it too neutral or cold i can only imagine how good it sounds for instance with Frank Cooters amp.
First thing i noticed that the L-700 sounds warmer and fuller especially on midrange , the bass is also fuller and somehow tighter with L-700 and it has more layerings.The upper midrange peak wich 009 sometimes has is gone .The presentation of 009 is although much airier than l-700 and you hear more subtle articulation and air between instruments with SR-009.The l-700 background is somehow very dark and i get the feeling that the presentation could be livelier like 009 is wich makes the music more alive.Soundstage or headstage on 700 is as wide as 009 to LR direction but as a whole the soundstage appear smaller with L- 700.It's easier or more relaxing to listen with l-700 because there is nothing wich pop on you face.The highs are articulated and somehow "seemless" because you don't make attention to them i think it's because the whole presentation is very balanced
When comparing to older Lambdas the l-700 is not as euphonic as the old but definitely better than Lambda pro
Comparing to Lambda signature i find the signature to be more musical but the sig.is far from to be as balanced as 700.
Comparing to Omega i quess Omega has now tough times because the 700 is very close to Omega and might be better.The sound is quite similar what you hear from Omegas warm and articulated.I think you can't really compare it to SR-009 they are different in many ways the same analogy between HD-800 and HD-650.
If the L-700 get's more air when breaking in it will be the second after 009

 

[Ali-Pacha]

Comparison through a Verto ?
 
Ali

 

[thinker]

  Comparison through a Verto ?
 
Ali

Transistoramp v4 and verto and ​323

 

[thinker]

  When you say you are charging up the drivers, what do you mean exactly? Is it necessary to plug in new stax headphones and power up the amp to charge them before the first time you use them, out of the box? 

yes

 

[potkettleblack]

Great update thanks. Any comparisons on detail retrieval?

 

[ufospls2]

  yes

For how long?

 

[thinker]

Great update thanks. Any comparisons on detail retrieval?

Detail articulation is excellent when comparing to 009 i miss nothing, the ground for details is warmer so you don't make too much attention in them

 

[thinker]

  For how long?

i don't know exactly some hours i guess

 

[ufospls2]

  i don't know exactly some hours i guess

Cool, Thanks!

 

[bearFNF]

Still breaking in my lambda normal bias ~28 years and counting...

 

[joseph69]

  For how long?

This is the first time I've heard of "charging" the HP's, so I looked in my 009 user manual but can't read Japanese and there was only a description in English pointing out the construction of the HP itself e.g. ARC/headband/adjusters/cups/pads and thats it. I'm curious to know about this "charging" also, being the first time I used the 009 I just plugged them into the amp and listened to them at low volumes, So does anyone know if they NEED to "charge" initially when "new" or before listening each time?
Thanks.

 

[joseph69]

  i don't know exactly some hours i guess

Did you read this somewhere/know for a fact, or are you just guessing?
Thanks.

 

[ufospls2]

  This is the first time I've heard of "charging" the HP's, so I looked in my 009 user manual but can't read Japanese and there was only a description in English pointing out the construction of the HP itself e.g. ARC/headband/adjusters/cups/pads and thats it. I'm curious to know about this "charging" also, being the first time I used the 009 I just plugged them into the amp and listened to them at low volumes, So does anyone know if they NEED to "charge" initially when "new" or before listening each time?
Thanks.

I think I read a Kevin Gilmore  post that mentioned burn in not existing but the headphones needing 1-2 days charge time. I'm not sure what that entails. I have some guesses about it but I don't want to post them as I don't know for sure. I will let someone more experienced chime in. 

 

[joseph69]

  I think I read a Kevin Gilmore  post that mentioned burn in not existing but the headphones needing 1-2 days charge time. I'm not sure what that entails. I have some guesses about it but I don't want to post them as I don't know for sure. I will let someone more experienced chime in. 

(HERE) is what I found with a quick search.
Apparently the Stax are charged (at least mine were) enough to hear them right out of the box, but may still ned more charging, I don't know? According to this link there would be no sound or a distorted sound coming from them without a charge.  

 

[edstrelow]

Electrostatics  need to charge up their bias before they can operate.  That's why each driver has three contacts   In that respect they are unlike dynamics which just need a signal and ground to operate and just have two contacts. It could take some time for the stats  to charge up properly.  I recall getting both an SR007 and SR003 from Japan which sounded terrible on first use but settled down after a few hours. 
 
As far as run-in or breakin, I find nothing implausible about a mechanical system such as a speaker or diaphragm needing at least some flexing before it loses some stiffness. Also the mechanical flexibility of a driver  may very well change after  long use.  But that doesn't mean that this is true of every phone or that it's always a big deal.   It's one of those things you consider if you do not like what you are hearing with a new phone.  Before you send it back,  let it run at least a few hours.
 
However, I think the greater issue with stats is bias problems. One issue is that If the electrostatic forces that drive the diaphragm are not at their full capacity or evenly spread across the diaphragm and/or the outer plates, then the phones will not run up to spec. So longer use of the phones could settle this. I haven't seen any measurements to back this up however but it seems possible.
 
The problem which is better established is what some people call a "parasitic charge," or the "electret effect."  Some materials can hold static charges for very long times, and that is the basis of the electret phone and microphone, which is a near relative of electrostatics.  These phones are more or less permanently biased and don't need the third contact.   The problem is that a true electrostatic   may also end up holding a charge which in some situations, like an electret,  which could be detrimental to its correct operation.  I worked in an EE department years ago which made electrostatic drivers for ultrasonic research and I recall the senior technician discussing the problem.  He found that sometimes the diaphragm of a newly made driver  unit held a charge of opposite polarity to its intended charge and that the driver  accordingly did not measure up to spec in use.  He was able to measure this charge, which he called the electret effect, with a high impedance probe. He  was concerned that he would have to remake the  entire driver units since they weren't fit for the job.  
 
I  personally find that the Stax phones can sometimes sound "off" if not used for a long time and it may take  a few hours use, possibly over some days before they get back to their best sound.  I recall that Gilmore suggested shorting the pins of the phones after they were removed from the amp, to alleviate this problem.  I generally leave my stats plugged in when not in use and this seems to help avoid the issue too. 
 
And of course the amp may also need to warm up and charge its capacitors.  Stat amps are generally class A and run very hot. If they are cold, I suspect they run off spec.  From my earliest days of listening to Stax, I have been hearing that the systems sound best after 45 or more minutes of use. I find that if the amp has been used throughout the day, it doesn't seem to need as much warm- up, even if it has cooled down. I wouldn't demonstrate them to show their advantages, if the system was stone cold and hadn't been used that day.