Shielded wire: which end should be grounded?

[rtarbell]

I am running shielded wire for the audio signal between a volume control pot and the power amp through shielded signal wire. Which end should be connected to the stud ground: the end closer to the volume control or the end closer to the power amp?

[Algar_emi]

I think it is always the source that must be grounded.

Bye...

[AMV8]

Hi
If it is a shield - and the shield is not carrying a signal - it is probably best to connect to the pre amp case which will be connected to the mains ground.

If the shield is carying a signal it is probably best to connect to the pre amp negative signal output.

I am separating the 0V from the ground as they may ( and if possible should ) be different. The )v is usually best connected to the mains ground by a 10ohm 5w resistor at one point only.

The Doug Self book has a chapter on this point and is very good.

Generally he makes the point that a system should only have one 0v point - preferably at the pre amp with the ground connected to the 0v in the pre amp. In theory the power amp is therefore floating. The power amp is therefore not the best point to connect the shield to.

Don

[AndrewT]

Hi,
is this Co-ax or shielded twin core?

Wiring up will be different. Have a look at Rane and Jensen sites.

You need a flow and return from pre-amp/source to volume pot.
You also need a flow and return from volume pot to power amp.

You must provide the flow AND return. Otherwise current will not flow=no signal.

Try, not to connect any part of the audio signal (flow and return) to the chassis.

The 0V reference inside the power amp and inside the pre-amp/source should be isolated from the chassis of each. Some manufacturers do not adhere to this practice.

Two pieces of equipment with the same fault will give an earth loop and will hum.