What DIY Amps are available for Stax?

[EUVL]

He is using the output from the Mu-follower directly, with a large DC offset.
I am not sure I want to do that myself, as your ear is close to one of the stators.
And normal listening is not much more than 70V above Gnd.
The membrane is at 580V, but the boas supply cannot supply any current, as opposed to the stator.

So I would still use output caps.
But of course you can ssk him directly.


Patrick

 

[Marco audio]

I prefer output capacitors too with a 10 Mohm résistor behind for each tube.It's safer.
Regards

 

[robbo1802]

There is a simple reason to use DC coupled output, or rather dual (symmetrical) voltage power supply.
If you wish to have say +/-350V output per phase, you would need a +/-380V PSU, or a bit higher.
But for a single voltage PSU and hence capacitor coupled output, you would need to go to +700V or more.
PSU for such high voltage is not trivial, and it is also getting dangerous and hazardous.

Electrostatic Headphone Amplifier & IMC for 300B


Patrick

While all true, there is no difference if you connect yourself across a single ended 700V supply or from rail to rail on a +- 350V supply. In any case, the danger comes with the current. If the supply can only deliver microamps, you are usually safe, but many milliamps...



Bob