Good morning,

I've got a curiosity.

My hifi system has all sources (CD player, DAC, phono preamp) without the earth connection.

The amplifier, on the other hand, has the earth connection to which the chassis is connected (and there is electrical continuity also with the ground of the RCA sockets.

I use unbalanced (RCA) directional signal cables, where the shielding is connected to the ground only on the source side (microphone cable type: two wire plus shield).

My question is this: with the amplifier being the only piece of equipment connected to earth, does it make sense to place the cables with the shield connected from the amplifier side, rather than from the source?

I didn't try to reverse the direction.

I wondered if there was an electrical explanation that favored one direction over another.

If I connected the shield at both ends, wouldn't there be a risk of forming an antenna? Because the ground runs through both the internal wire and the shielding... or not?

Unless the shield is connected to ground at both ends it is as good as useless in actually providing RF shielding, but it might make a good antenna. Directionality, however, is a widely accepted characteristic of cables. You may hear a difference on reversing the cable direction.

It's worth reading Grahams' blog and comments at the foot of the cables page, both can be found on the Tabs at the top of this page.

Happy Listening (and reading)

Ian

Thanks for your answers.

I thought that some difference could be generated due to the shielding connected only on one side; therefore it would appear that the directionality is at a level of electrical transmission at the level of the individual conductor, rather than the type of construction of the complete cable. This is very interesting.

If the sources in your system are not connected to ground then you're unlikely to have ground loop issues, so it shouldn't matter if your cables are grounded at both ends or only one.  However, I'd suggest connecting the grounded end to the (grounded) amplifier to provide a ground path for the shield.   If it's connected the other way around, in best case, the shield won't be doing very much and, in the worst case, could act as a parasitic element.  I have no idea if this is something that you will hear.  As for directionality, I've tried swapping cables around but have yet to notice a difference.

- james

*I assumed the cable manufacturer did this in order to use two identical wires offering the same high conductivity or they thought running the signal through the shield risked interference being added, or they just wanted to be distinctive.

Lucas is right to surmise the directionality is usually associated with the wires inside rather than floating one end of the cable's shield.

Hello Jon,

My comments were only meant to apply to the 2W+shield 'microphone'  cable construction mentioned in the original post and obviously wouldn't work on a coax construction where the shield forms the return path.

I can't comment on the directionality of cable as any blind testing that I done hasn't shown up any difference so have just used the van den Hul cables I have with the grounded end connected to the equipment with a decent ground.

- james