All three lines to your audio system should have one common ground.
On my system I achieved "preferential" grounding for the stereo. This is achieved by driving a copper ground rod deep in the earth, or using an existing copper cold water pipe. Keep these dedicated ground runs as short as possible.
Then run another wire ( I used 6 gauge ) from that same copper ground rod or copper water pipe, BACK to the ground for the house.
The stereo gets preferential ground by way of extremely short ground run, without ground potential and ground loop problems.
It is possible to experiment with the two grounds. You may listen with the grounds TOTALLY separate OR with the 6 gauge run between the dedicated run and whole house ground. The electrical code will favor tying the two together but I doubt your facing personal safety issues either way. The equipment could suffer from a catastrophic event, but the possibilities are so endless that it could fill another thread.
A word of advice if you are on a pier and beam foundation. Purchase a bus bar like those found in a breaker panel. Attach it to a copper ground clamp and attach the whole rig to the dedicated ground.
If you add additional dedicated runs to the stereo, their dedicated grounds attach to an open slot in the bus bar.
Last, saturate the copper wire connections, the screws and clamp at the bus bar with Oxguard, Cramalin or other oxidation retardant material.
Wrap the entire thing HEAVY with Scotch 2228 rubber mastic. This is a thick stretchy rubber seal (adhesive one side) that remains pliable and is pretty much water and insect proof. The connections should maintain their conductivity for many years before needing attention.
On my system I achieved "preferential" grounding for the stereo. This is achieved by driving a copper ground rod deep in the earth, or using an existing copper cold water pipe. Keep these dedicated ground runs as short as possible.
Then run another wire ( I used 6 gauge ) from that same copper ground rod or copper water pipe, BACK to the ground for the house.
The stereo gets preferential ground by way of extremely short ground run, without ground potential and ground loop problems.
It is possible to experiment with the two grounds. You may listen with the grounds TOTALLY separate OR with the 6 gauge run between the dedicated run and whole house ground. The electrical code will favor tying the two together but I doubt your facing personal safety issues either way. The equipment could suffer from a catastrophic event, but the possibilities are so endless that it could fill another thread.
A word of advice if you are on a pier and beam foundation. Purchase a bus bar like those found in a breaker panel. Attach it to a copper ground clamp and attach the whole rig to the dedicated ground.
If you add additional dedicated runs to the stereo, their dedicated grounds attach to an open slot in the bus bar.
Last, saturate the copper wire connections, the screws and clamp at the bus bar with Oxguard, Cramalin or other oxidation retardant material.
Wrap the entire thing HEAVY with Scotch 2228 rubber mastic. This is a thick stretchy rubber seal (adhesive one side) that remains pliable and is pretty much water and insect proof. The connections should maintain their conductivity for many years before needing attention.