Making RCA line level cables with balanced conductor

[disorder]

Yeah I am making a few cables for my turntable, headphone amplifier, etc. Simple RCA to RCA for line level use. I have a good amount of quality balanced audio cable around that I would like to use. It has two 26AWG conductors inside a standard copper shield. I was wondering the proper/best way is to wire these up. An obvious way would be to connect both internal conductors as the "tip" of the RCA plug and then simply use the shield as the "sleeve" connection of the RCA. I feel like I read about a better way to do it where you use one conductor as the “tip” and one conductor as the “sleeve”, and then connect the shield to the sleeve at one end only. I'm wondering what purpose this serves and if I'm remembering it correctly. Any suggestions appreciated it!

 

[JonSnell Electronic]

RCA or Phono cables are unbalanced and as such have two conductors; Earth or Shield and signal.
The other strand of cable will be unused.

 

[rayma]

use both internal conductors as the "tip" of the RCA plug and the shield as the "sleeve" connection
of the RCA. I feel like I read about a better way to do it where you use one conductor as the tip and
one conductor as the sleeve, and then connect the shield to the sleeve at one end only. it!

I would suggest making up one pair in each configuration, and try them out. The pair with the shield
connected at only one end should have that end at the source. A shield works best when only one
connection is made to it, so current cannot flow in the shield, which creates voltage differentials.
A shield should be an equipotential surcface.

 

[scottjoplin]

The other strand of cable will be unused.

Best not to leave it floating though, use it as signal too

 

[scottjoplin]

I feel like I read about a better way to do it where you use one conductor as the tip and one conductor as the sleeve, and then connect the shield to the sleeve at one end only. I'm wondering what purpose this serves and if I'm remembering it correctly. Any suggestions appreciated it!

To delve into all the options you may find this thread interesting, lots of good links and discussion Cable shield as a Faraday cage

 

[DF96]

For a turntable to phono preamp connection you can use a pseudo-balanced cable: inners for signal and return, shield grounded at preamp end.

For all other unbalanced connections it is important that the signal return has low impedance, so use the two inners for the signal and the shield for return. This will not be as good at rejecting interference as a proper coaxial cable but it will probably be good enough for most purposes.

 

[Speedskater]

When using a 2 conductor shielded cable for a RCA unbalanced interconnect. I would:
use one conductor, center pin to center pin.
connect the shield shell to shell.
the other conductor may also be connected shell to shell, or just lest unconnected.