Affordable Grounding

A'gon user @mahgister has written here previously about devices such as this, IIRC.

Yes.  Best results(for me) was installing a ground rod just outside the wall, running CU cable through wall to my dedicated AC outlet(hospital Grade) ground connection,  then ALL AC power to my system plugged in to that receptacle.

Write Synergistic Research on it in crayon, charge $600 for it and whole-heartedly recommend at least 3 for best results, and the cable sniffers will follow you to the ends of the earth.

Gents,

Grounding circuits perform several functions and each has its requirements in terms of design. Safety is a number one requirements, and for this the ability to pass a fault current to a ground reference (earth) instead of through your body is the primary design goal. This "design" however effective for safety does not mean it's a good RF (radio frequency) ground. Safety grounds require a good low resistance path to ground; RF grounds require a good low impedance path to ground. As the RF frequency rises, your reactance (impedance) of the ground circuit rises. For your "black" background, you want to ensure the best low impedance ground for your equipment, i.e. very large gauge ground conductor or flat copper strap to a ground rod, shortest path possible from equipment, and use a termination ground (single point) from all your gear. No special stuff here, my studio grounding system is less than $200 worth of materials. Noise mitigation from your power line is a whole other science I'm sure has been discussed in length - I use brute force L/C filters and isolation transformers, but the grounding considerations are the same. (In the "old days" we used motor-generators for clean AC). 

The "signal ground" tactic to a DIY "signal grounding box" worked very well on my system. The ground leads buried in the grounding box material (fine quartz sand mixed with fine graphite powder) are soldered to RCA connectors which are then plugged into unused RCA connections on the back of the CD transport and the DAC. Each component had its own dedicated grounding box.As per a suggestion I heard from Caelin Gabriel of Shunyata in an old interview I grounded only two source components. This instantly sucked noise out of my system - not subtle. The system was already on a dedicated line, so there was still enough noise left in the system that grounding boxes made an audible difference.