[statfi]

... I currently have a DAC with volume control (Berkeley Alpha) directly connected to my main amps and I was planning on adding the BHSE to this set up via an XLR switch like the Goldpoint SW2X.  Has any one used this (I'm hoping others had to deal with a similar situation).  Also, since I don't have a preamp, I control volume using the Alpha; is it okay to put the BHSE volume at max in this configuration? ...

I just looked at the Berkeley site and, for "an" Alpha, they say "Digital attenuation and balance control: 0.1dB/step with .05dB/step trim, 60dB range".  I would never consider using a digital gain control and loosing bits.  I.e., I do not use the gain in Amarra: I use my (current, Stax) amp's analog control.   However, it would be good if someone who knows the Alpha more intimately could comment.

 

[jcx]

the "loosing bits" heuristic is overdone, audio  DAC tech has improved since mid 1980's barely 14 bit linear ADC/DAC at the beginning of the consumer digital audio era
 
now flagship audio DAC have >120 dB weighted S/N - you have to have your music peaks hitting 120 dB SPL for the DAC noise to even reach the human hearing threshold in quiet after minutes of accommodation - not a limitation while listening to music peaking at 120 dB SPL
 
so if your system's gain structure is reasonable for your headphone's sensitivity the DAC electronic noise is already as low as humans can hear, better than any of microphone, studio, listening room or just the microphonics you get wearing headphones (muscle tremor, blood flow/pulse, "seashell " effect raises headphone listening noise floor ~10 dB over free field listening in  a anechoic chamber)
 
even 16 bit source is almost always played back in 24 bit DAC in audio today - good attenuation software should redither but the much higher electronic noise is in fact good dither at the 24 bit lsb level

 

[nickif]

setting the BHSE volume to max is the same as if it had no volume control

But would that introduce unwanted noise? I have a pre amp in my chain and I always end up with the volume knob at 12 a clock, esp for GSX-Mk II

 

[jcx]

poor system gain structure is the usual issue when audible hiss is encountered - with ES headphones and their dedicated amps things aren't so bad as people using amps with too much gain to drive too sensitive headphones
 
Stax ES "earspeakers" have ~ 100 dB/100V sensitivity, the amps typically 500x (SR727, Justin's BHSE) or 1000x (original Blue Hawaii) gain
 
I don't have enough of the history at hand - but likely dropping ES amp gain to 500 is a recognition of the reality of consumer digital audio source  often having 2 Vrms full scale level
 
older analog audio reproduction systems had variable peak output levels generally lower than today

 

[wsilvio]

Does anyone know if the loop output only works with the selected input?  For example, in RCA out RCA loop, or is it possible to have RCA in but loop out through the XLR loop out?  

 

[statfi]

Sometimes, when I plop down into my listening chair wearing the 009s, I hear what sounds like a diaphragm deforming, a sort of "pop".  Has anyone experienced anything similar to this?  Does anyone know it is not an issue ?-)

 

[dude_500]

  Sometimes, when I plop down into my listening chair wearing the 009s, I hear what sounds like a diaphragm deforming, a sort of "pop".  Has anyone experienced anything similar to this?  Does anyone know it is not an issue ?-)

 
A distinct sharp pop with electrostatic headphones is not a good sign at all, generally indicates either arcing or extreme diaphragm instabilities.
 
But a "woosh" or gentle slap is very normal and not at all a problem.

 

[Ali-Pacha]

Stax fart.

Ali

 

[Phil95]

   
A distinct sharp pop with electrostatic headphones is not a good sign at all, generally indicates either arcing or extreme diaphragm instabilities.
 
But a "woosh" or gentle slap is very normal and not at all a problem.

Stax 009 User's notice warns about this, stating that it's no problem.

 

[greggf]

Ali x2.  STAX fart.  Benign.

 

[statfi]

Originally Posted by greggf /img/forum/go_quote.gif

Ali x2.  STAX fart.  Benign.

Thanks, guys!

 

[justin w.]

Testing continues, 2:59AM

 

[Ali-Pacha]

Hi Justin,
 
are jacks still white ( http://www.head-fi.org/t/621279/teflon-stax-headphone-jack-from-headamp-now-available-our-first-part#post_8585846 ) with dark front plates ?

Ali

 

[Meng-609]

Hi Justin,
 
May I ask how many BHSE you would ship next time?
And what is the date for the first order you would ship this time?


Regards,
Meng

 

[wink]

You're joking, right?