Help from the DIY gurus

[heady 0]

Hi all,

I am casing my PPA in a metal enclosure. The enclosure is connected to the earth of the mains power for safety reason. My input is via isolated RCA sockets. But I am concerned re: my headphone output. Do I need to have an isolated output socket as well? Is it ok to connect the output signal ground to earth?

 

Thanks for any comments/help.

 

 

[Kippei 0]

You need to have a isolated output. If i remember PPA use TLE to as a voltage splitter thus creating a virtual ground. The earth ground is different from the virtual ground.

[Firefox 0]

Hi all,

I am casing my PPA in a metal enclosure. The enclosure is connected to the earth of the mains power for safety reason. My input is via isolated RCA sockets. But I am concerned re: my headphone output. Do I need to have an isolated output socket as well? Is it ok to connect the output signal ground to earth?

 

Thanks for any comments/help.

 

Yes, you should isolate the headphone ground from mains earth.

[Firefox 0]

You need to have a isolated output. If i remember PPA use TLE to as a voltage splitter thus creating a virtual ground. The earth ground is different from the virtual ground.

 

That is only half-correct.

 

If it's just a virtual-ground, you can choose to connect it to mains earth.

 

The problem is that the ground channel output of a PPA is not the same as the input ground from the RCA's. It's an actual active channel.

If you have devices in the chain that tie the signal ground to mains earth, you're going to cause the ground channel to oscillate were it's output connected to mains earth as well.

[heady 0]

Thanks guys.