[Rossliew]

All this talk of the Lambda NB makes me anxious for my Carbon that's being built with a normal bias socket as well Hope it does the NB justice as much as the BHSE does.

 

[Ampeezy]

As discussed elsewhere, the current controls brightness. 18ma is what the majority votes. 400V is gd enough.

From KG:
Calculations of the current needed to drive the headphones at full power at 20khz. That number is something like 18ma or so, the T2 is 16ma, a lot of the other amps are much less. at 20ma, the carbon has both a faster rise time and wider frequency response than anything else out there. So for a while it seems bright, then it seems more natural.

​Did anyone call the sr-007 (modded) dark? With the carbon at 20ma it is very neutral with excellent extension both ends, with a good weight to the sound. I don't feel that the amp is bright itself though, but rather that the sr-007 is being driven with a good kick in the behind.
 
I can see though how a brighter headphone, like the sr-009 has been purported to be, might not fair so well at this current

 

[deuter]

Don't knock the Lambdas, dude. I love the L700 out of my BHSE, and would've bought Purk's Lambda Pro if he'd sell it. Haven't heard the Lambda NB but I trust it's awesome too.

Understand, never heard one so probably should've kept quiet.

 

[Ampeezy]

Don't knock the Lambdas, dude. I love the L700 out of my BHSE, and would've bought Purk's Lambda Pro if he'd sell it. Haven't heard the Lambda NB but I trust it's awesome too.

I assume you have the 009 as well. Quck comparison with the L700?

 

[Ali-Pacha]

Understand, never heard one so probably should've kept quiet.

Throwing $6K in a BHSE for only one pair of Lambdas looks like a whole new level of stupidity...but we are on head-fi, so your reaction is not that illegitimate. Sorry for the easy sarcasm 

 
BTW, Lambdas are all around not up to Omega level (technicality), but they have their particular sound, and among those Lambdas, normal bias / signature are my favourite. I find SR-X0X too shouty and somehow gritty in the upper mids, and Nova signature a bit boring, even out of a BHSE.
L700 is kinda different beast, with some of 009 technicalities...see some of my posts from here : http://www.head-fi.org/t/785949/the-stax-sr-l500-and-sr-l700-impressions-thread/510#post_13340045
You may also look at another posts about some of my Staxen's on another site 

 
Ali

 

[JimL11]

As discussed elsewhere, the current controls brightness. 18ma is what the majority votes. 400V is gd enough.

From KG:
Calculations of the current needed to drive the headphones at full power at 20khz. That number is something like 18ma or so, the T2 is 16ma, a lot of the other amps are much less. at 20ma, the carbon has both a faster rise time and wider frequency response than anything else out there. So for a while it seems bright, then it seems more natural.

Let me point out that KG's post has mostly to do with engineering decisions.
 
1)  the slew rate needed for a signal is directly level and frequency dependent - i.e. if you double the signal level you double the slew rate.  Also, if you double the frequency reproduced, you double the slew rate.
 
2)  the maximum level which can be produced by most electrostatic headphone amps is very high.  With a typical Stax headphone producing 100 dB levels at 100 VRMS, most headphone amps can produce at least 110 db average levels - a live rock concert produces 110-120 dB levels.  Per OSHA standards, the maximum work exposure levels are 8 hr/day at 90 dB, 2 hr/day at 100 dB and 30 min/day at 110 db.  Furthermore, exposure to 100 dB for 15 min can cause permanent hearing damage in some people.   In other words, playing music at peak levels sufficient to clip your amplifier for a significant period of time WILL cause permanent hearing loss.  We know that many long time rockers have hearing damage, but even classical musicians, where average levels are significantly lower, can have permeant hearing loss.  Here is a website that lists comparative sound levels:
http://www.industrialnoisecontrol.com/comparative-noise-examples.htm
 
3)  to reproduce 99+% of music signals, the maximum slew rate required is that required to reproduce a 6 kHz sine wave at full volume - this was shown a number of years ago by both Nelson Pass and Peter Baxandall.  Note that the required slew rate for 6 kHz is 1/3 the rate required to reproduce a 20 kHz sine wave at full volume.
 
When you combine all these considerations together, the requirement for reproducing 20 kHz sine waves at full volume is well in excess of what is required for music reproduction at safe hearing levels.  Of course, there is nothing wrong with overkill - if you can afford it.

 

[Whitigir]

Let me point out that KG's post has mostly to do with engineering decisions.

1)  the slew rate needed for a signal is directly level and frequency dependent - i.e. if you double the signal level you double the slew rate.  Also, if you double the frequency reproduced, you double the slew rate.

2)  the maximum level which can be produced by most electrostatic headphone amps is very high.  With a typical Stax headphone producing 100 dB levels at 100 VRMS, most headphone amps can produce at least 110 db average levels - a live rock concert produces 110-120 dB levels.  Per OSHA standards, the maximum work exposure levels are 8 hr/day at 90 dB, 2 hr/day at 100 dB and 30 min/day at 110 db.  Furthermore, exposure to 100 dB for 15 min can cause permanent hearing damage in some people.   In other words, playing music at peak levels sufficient to clip your amplifier for a significant period of time WILL cause permanent hearing loss.  We know that many long time rockers have hearing damage, but even classical musicians, where average levels are significantly lower, can have permeant hearing loss.

3)  to reproduce 99+% of music signals, the maximum slew rate required is that required to reproduce a 6 kHz sine wave at full volume - this was shown a number of years ago by both Nelson Pass and Peter Baxandall.  Note that the required slew rate for 6 kHz is 1/3 the rate required to reproduce a 20 kHz sine wave at full volume.

When you combine all these considerations together, the requirement for reproducing 20 kHz sine waves at full volume is well in excess of what is required for music reproduction at safe hearing levels.  Of course, while there is nothing wrong with overkill - if you can afford it.

What does this have to do with the way how ES work in related to Current setting and tonality ? I don't know all that, but I can tell you that from my Carbon and 009 , 16.5mA have more organic sound than 17.5mA and above

 

[JimL11]

My point was that it probably doesn't have a lot to do with what the "proper" current setting is for your amplifier.  From a strictly engineering perspective, 16.5 mA or 20 mA are both are more than adequate.  Now, perhaps there might be a measurable difference in distortion at near clipping levels, but its relevance to the sound at lower levels would be conjectural.  20 mA is MORE overkill than 16.5 mA, but in terms of sound, who knows [shrugs shoulders]. The overall point is that it is difficult to tie in the sound to a particular measured parameter, which is something that needs restating from time to time.

 

[astrostar59]

  My point was that it probably doesn't have a lot to do with what the "proper" current setting is for your amplifier.  From a strictly engineering perspective, 16.5 mA or 20 mA are both are more than adequate.  Now, perhaps there might be a measurable difference in distortion at near clipping levels, but its relevance to the sound at lower levels would be conjectural.  20 mA is MORE overkill than 16.5 mA, but in terms of sound, who knows [shrugs shoulders]. The overall point is that it is difficult to tie in the sound to a particular measured parameter, which is something that needs restating from time to time.

Good information JimL11
 
I haven't heard my Carbon at different mA levels, it is at 18 now I believe. But I read some posts at the other place of folk who tried lowering the mA and they stated it 'calmed' the treble a bit, but crucially reduced the soundstage a bit. I have no brightness issues on my Carbon and 009, so won't try it. I would say, it is better to 'tune' the rest of the gear if is is a bit bright, or change the DAC for example. It is worth the hassle IMO.

 

[Whitigir]

Good information JimL11

I haven't heard my Carbon at different mA levels, it is at 18 now I believe. But I read some posts at the other place of folk who tried lowering the mA and they stated it 'calmed' the treble a bit, but crucially reduced the soundstage a bit. I have no brightness issues on my Carbon and 009, so won't try it. I would say, it is better to 'tune' the rest of the gear if is is a bit bright, or change the DAC for example. It is worth the hassle IMO.

Yes, great info indeed. I have now returned to my 16.5mA and I am happy again.

For my experiences, the lower-end spectrum and the tonality body are different from 16-17mA. Neither treble nor soundstage sacrifice the whole lot to my observations. Also, it is very true that the treble extensions and the edges are smoother in the lower range than higher range. This result stands true from either my Walkman as a source or my DAC.

This has got to be heavily personal preferences.

 

[ductrung3993]

Any Stax guy in SF? I got a 007 mk1 coming but got no electrostat amp to try it on. Would be great i can have a session with your amp. Thanks!

 

[Sianlaser]

I am looking to get a set of the new Stax L300 and I was wondering if I should just get the package SRS 3100 or get the L300 and an aftermarket amp.  So is there an amp that is under $500 that would be a noticeable improvement over the amp that comes in the SRS 3100 set?
 
Thanks!

 

[JimL11]

  I am looking to get a set of the new Stax L300 and I was wondering if I should just get the package SRS 3100 or get the L300 and an aftermarket amp.  So is there an amp that is under $500 that would be a noticeable improvement over the amp that comes in the SRS 3100 set?
 
Thanks!

The only way you could get a better amp under $500 are 1) build it yourself or 2) buy used.  However, most of the used Stax amps that sell for under $500 are older models like the SRM1 Mk II Pro (solid state) or SRM-T1 (hybrid with tube output) that will need, at a minimum, replacement of all the electrolytic caps, since 20 or 30 year old electrolytic caps tend to go bad.  With the SRM1, you also need to make sure it has a pro output socket as some of them pre-date the onset of pro bias Stax headphones. Sometimes you can get a used SRM323 for $500 or less. This is a newer model and would be a better bet if you don't want to deal with replacing electrolytic caps.   
 
OTOH, the advantage of DIY is that building something like a KGSS Carbon, or even an SRX Plus, will allow you to upgrade your headphones in the future without having to change amps.  I built my SRX Plus for about $500, a KGSS Carbon will cost significantly more.

 

[Razornova]

Anyone tried adding a tube preamp before a stax solid state amp for some tube flavor? Would love it know if anyone has managed to get good results doing so.

 

[dubharmonic]

Anyone tried adding a tube preamp before a stax solid state amp for some tube flavor? Would love it know if anyone has managed to get good results doing so.

I tried using the output from a Vali 2 a while back. It was interesting but not fun enough to stick with.