G9 - Almost finished

Soeren_DK

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Jun 7, 2004
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Denmark
Hallo everybody.

So i have build the unit.... Jubii.... But how should the XLR terminal be wired... In the discription on jakobs site is there something about a wire from 0v/Ground to the input?????

And the Outbut only have + and -? Where should the shield be taken from?

http://www.niehans.dk/billede/g9.jpg
 

gyraf

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As a rule-of-thumb, you should always connect your circuit ground/0V to the chassis at - and ONLY at - the input XLR(s).
Use the ground tab found on most XLR's, or if it hasn't such one, mount a solder tag with the screws that hold the XLR.

This is also where you connect the ground of your power inlet.

Connect all pin1's (grounds) of the XLR's together - maybe use a piece of rigid copper wire for this.

This explains why the outout does not have a ground: You will have to use the one going to the input.

All this to prevent ground loops..

Jakob E.
 

Kev

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Melbourne, Australia
[quote author="gyraf"] Use the ground tab found on most XLR's, or if it hasn't such one, mount a solder tag with the screws that hold the XLR.
This is also where you connect the ground of your power inlet.[/quote]

This is where Jakob and I differ every so slightly. ( no offence mean to Jakob )

The earth/ground coming in from the mains IEC connector, in my opinion should go to a solid part of the chassis.
It is there for safety and regulations and other rules that may be particular to your country. Audio quality is not part of the this issue.

It is a subtle difference but I'd go straight to a very solid connection point on the chassis and then up to the XLRs. Then you can break the XLs and pull them out of the chassis and abuse the box as many people might do out there in the Live and Broadcast Audio world ... the box should still remain safe.

head down
 

gyraf

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Kev,

You're right.

Grounding power ground to chassis at the XLR's is only done as described if you're sure to have a cood chassis connection at that point - that is, if you use decent metal XLR's.

When using nylon XLR's, make sure that your power ground is securely attached to the chassis some other way.

Jakob E.
 
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