[kevin gilmore]

you could just buy 64 x 9 volt batteries and wire them in series.
would last forever. (shelf life of alkaline about 15 years)

 

[rx79ez08]

64 x 9 volt battery is going to cost a fortune....

 

[NoPants]

but it's the cleanest supply for the cleanest headphones

 

[kevin gilmore]

about $70 for 64 batteries
not so bad.

 

[tdogzthmn]

My SRD-7 SB only has a single grey cord coming our the back with terminates into four banana plugs in addition to the four binding posts on the rear of the unit.  I agree with the others about the unit scaling very well.  The background is perfectly black and the sound from both my speaker amps is lovely.  I have no desire to try the other STAX amps.

 

[rx79ez08]

Where do you get your battery?
9v battery are like a few bucks each down under.
Finally understand what signal is being fed into the headphones....
It is 580vdc for bias, then small signal audio signal on top of it right?

 

[davidsh]

Where do you get your battery?
9v battery are like a few bucks each down under.
Finally understand what signal is being fed into the headphones....
It is 580vdc for bias, then small signal audio signal on top of it right?

Just some variable signal between 0 and some 300-700 volts depending on the amp... Much like normal amps, yet higher voltage.

 

[milosz]

Care to explain how the energiser/adapter units work without a bias supply? Takes speaker signal, ramp up the voltage with a transformer and then... What?

The stax adaptor plugs into the wall.  It converts AC current from the wall to DC 580 volts for the bias. So it does not work without a bias supply.  It IS a bias supply.
 
The stax adaptor also connects to a speaker amplifier.  The audio voltage from the amplifier is put through a step-up transformer that increases the voltage of the audio signal enough to drive the electrostatic headphones.
 
Also, the transformer roughly presents an 8 ohm load to your amplifier and matches it's output to the proper impedance to drive the headphones.
 
In the old days, Koss made some energizers which could convert some of the audio power fed into them into bias, in addition to coupling the audio from the amplifier to the electrostatic headphones, but this is not an ideal way to go.  It's better to convert AC from the power line into the DC bias-  it is more stable, etc.  Maybe some early Stax energizers developed bias from the audio input too, I do not know.  The most commonly seen Stax adapter-  SRD-7 - uses the power line to produce the bias voltage.

 

[milosz]

  about $70 for 64 batteries
not so bad.

Yeah, but where do I buy the teflon-jacketed, oxygen-free silver 9 volt battery clips?  

 

[SquireC]

  My SRD-7 SB only has a single grey cord coming our the back with terminates into four banana plugs in addition to the four binding posts on the rear of the unit.  I agree with the others about the unit scaling very well.  The background is perfectly black and the sound from both my speaker amps is lovely.  I have no desire to try the other STAX amps.

I'm with tdogzthmn on this.7-SB with a good power amp sounds as good, sometimes better, than a Stax amp like the T1. Pity I can't get a new 7-SB anywhere.

 

[kevin gilmore]

  Yeah, but where do I buy the teflon-jacketed, oxygen-free silver 9 volt battery clips?  

silly person...
 
you make them.
 
preferably on a 3 axis NC mill. you have one right?
 
oxygen free silver... not for long.

 

[wink]

Wallmart or Amazon may have them on special soon with NiMH batteries thrown in for free.
 
Happy waiting................
 
Actually, I like phosphor bronze battery clips more than silver.

 

[milosz]

 
silly person...
 
you make them.
 
preferably on a 3 axis NC mill. you have one right?
 
oxygen free silver... not for long.

I do, but it's currently being rewired with Cardas cable and re-capped with Black Gates....
 
The oxygen free silver is no problem, I use high resolution oxygen free air in my listening room.

 

[DefQon]

I'm with tdogzthmn on this.7-SB with a good power amp sounds as good, sometimes better, than a Stax amp like the T1. Pity I can't get a new 7-SB anywhere.

+1 I have the last gen of the adaptor lineup the srd-7sb mk2 and from a select few integrated amps I preferred it over the Stax amps.

 

[wink]

  Quote:milosz

 
silly person...
 
you make them.
 
preferably on a 3 axis NC mill. you have one right?
 
oxygen free silver... not for long.

I do, but it's currently being rewired with Cardas cable and re-capped with Black Gates....
 
The oxygen free silver is no problem, I use high resolution oxygen free air in my listening room.

 
I see 2 major problems here:-
1/ You should be using Zu cables instead of Cardas, and Auricaps instead of Black Gates.
2/ You need titanium instead of silver cables. Beryllium is better still. The high resolution oxygen free air is problematic for continuance of life. It is strongly suggested that sulfur dioxide is substituted.
Listening to headphones is preferably conducted in a small intimate cubicle where you are not distracted form the sonic experience, and do not offend others with your insular behaviour.