What's better, one conductor or two conductors for an RCA interconnect?

When shield is used as return any electrical noise current induced in the shield will create voltage difference along it  - between source/output and destination/input.  Input will "see" the difference between output signal wire and output GND, plus noise voltage between both ends of the shield.

The best is to use two wires (signal and return) with shield connected only at one side.  

 

@jumia 

But I see higher end RCA cables with two conductors and ground wire. Which is better?

How would one know?  Wouldn’t one have to try both first before answering this question?  If two conductors happens to sound better, wouldn’t every cable manufacturer use this configuration?  What brand of higher end RCA cables are made with 2 conductors and a ground? So many questions…

@spenav

hey so don’t get all philosophical on us now!!... 😂

Let me please clarify my statement from my earlier response.

Your coaxial cable can also be used for digital signals. Such as from a transport or music server to your DAC. A good coaxial cable is important to have.

Once you get into the analog world having a 2 wire RCA/SE or 3 wire XLR/Balanced cable is needed. Such as from a TT or DAC to your pre-amp.
This could change in the future as our equipment gets more digitized.

Joe Nies

Interconnects can be a very important components in a system. The better the boxes in your system the more important the interconnects are. With cheap interconnects the actually materials are important and maybe the configuration. But as the cost goes up… as does the effort in getting better sound the less the specific materials and configurations determine the output. It is the effort put in to choosing materials and configuration. There are lots of ways to accomplish great sounding interconnects.

In most cases one parameter will not determine the sound. It will be highly dependent on your system and the specific interconnects.