question regarding hypex ucd wiring

[Putzeudel]

Hi,

i found this pdf explaining the wiring: http://www.hypex.nl/docs/wiring.pdf.
I do not understand why the chassis (figure for balanced input) is connected to the signal ground. One benefit of balanced connection is that you can keep the stuff that the shield on the cable has caught out of the signal ground. The figure for unbalanced input mentions ground loops and suggests not connecting safety earth to the chassis, yet for balanced input the chassis is connected to signal ground as well

I thought i just leave the XLR-shield at the chassis and connect hot/cold to the amp, will that work?

Kind regards!

 

[nigelwright7557]

You should always connect chassis to safety earth.

Connecting zero volts to chassis is used for stopping hum if there is no other earth connected to zero volts i.e. ipod
On the other hand if you have multiple connections to earth this can cause hum.
It alll depends on your setup.

 

[Putzeudel]

Maybe i did not understand what you mean, but where should the hum come from in a power amp? Why should i connect a possible "dirty" XLR-shield to my clean signal ground?

 

[nigelwright7557]

I am talking about the amplifier wiring.

 

[Putzeudel]

Sorry, i dont understand .. i always thought that you get hum when you connect signal ground with safety ground - do you tell me it's just the other way around?