I finally got around to a job that has been on my to-do list for far too many month. A couple of years ago I installed a separate ground, or earthing circuit for my listening room. The earthing spike I used at the time was a 50 cm. piece of copper pipe. Not ideal, but it was at hand at the time. The intention had always been to replace this this a proper copper spike, and to up-rate the cable into the listening room to a heavier gauge. I managed to get an earthing spike, clamp while at the electrical suppliers last week, and yesterday afternoon I finally got the job done. One word of advice here, don´t install your earthing spike in the center of a rose bush like I did. Ouch! I used a 1.5 m copper spike to get get the best earth contact. Here the soil is VERY dry for most of the year, and the more copper in the ground the better. I also chose to put this in an area with a large bush that gets watered regularly which should improve the chance of the soil retaining moisture throughout the summer months.
Once the spike had been hammered into the ground the 6 square mm (9 AWG) cable was attached with a copper clamp and the assembly coated with silicone grease to stop corrosion/oxidation. It was then wrapped in electrical tape.
The cable was run through the wall, in conduit, in to my listening room. The white box on the exterior wall
houses the air pump for my MG-1 air-bearing tonearm so I was lucky to have the conduit there from this previous installation. The cable is terminated in the listening room on a bus bar, mounted on my equipment rack, which allows multiple cables to be connected at a central point.
The bus bar is then used as a central earthing point for all my phono equipment (SUT´s, phono stages and turntables). This is a star-grounding layout, and allows me to keep my signal ground and electrical ground completely separate. It is much easier to eliminate earth/ground loops with this setup, and in my system it has helped lower the overall noise floor considerably.