Balanced cable and RCA connector: how to wire them?

[Bricolo]

Hi all,


I've foune a nice audio cable, but it's intended for balanced connections (2 wires and a shield). All my audio rig uses RCA connections.

What would be the proper way to connect the cable to the RCA?
-both wires at the signal, and the shield as ground
-one wire as signal, the shield and the other wire to the ground?


Thanks
Alex

[electroaudio]

The best way to connect it is by connecting the sheild to ground on only one side (The recieving end is theoretically the best) and then connect the signal and ground thru the inner two cables.

[Bricolo]

That's also a question I wanted to ask: this technique has also been adviced in some application note (don't remember wich one).

But, can't this long (1 or 2m) shield connected at only one end act like an antenna?

[Thunau]

See Rane reference at the link
http://rane.com/note110.html

[pooge]

Originally posted by electroaudio
The best way to connect it is by connecting the sheild to ground on only one side (The recieving end is theoretically the best) and then connect the signal and ground thru the inner two cables.

Grounding the receiving end is not "theoretically the best". There are advantages and disadvantages to each way. Experts in the field usually recommend grounding the shield at the source end.
In any event, you should mark the cable to know which end has the shield grounded. See the attached link for the reasons for grounding the source end.
Whitlock paper on grounding

[electroaudio]

But, can't this long (1 or 2m) shield connected at only one end act like an antenna?

They say so. thats why it should be connected at the recieving end and not at the senders end.
But you can probably shortcurcuit the "antenna" with a small capacitor at the senders end.

more about grounding and antennas here..
http://www.prosoundweb.com/studyhall...ing/ground.php

[electroaudio]

Grounding the receiving end is not "theoretically the best".

Read his signature, thats why i choosed that phrase.

Just remember: in theory there's no difference between theory and practice.
But in practice it usually is quite a bit difference...

[pooge]

Originally posted by electroaudio


But you can probably shortcurcuit the "antenna" with a small capacitor at the senders end.

Yes. You can use a capacitor at the receiving end to eliminate the possible disadvantage of the antenna problem, while maintaining the advantage of having the shield connected to ground at the source end, which connecting at the receiving end only doesn't provide.