Grounding with a Earth box?

It is snake oil.

There is something called a ground lifter, which in a few bucks achieve exactly the same purpose and grounds your system as well as eliminating any possibility of hum arising from ground loops.

It is probably trying to simulate that, but at a price tag suitable for audiophools.

@cakyol,
Incorrect.
Ground lifting and grounding boxes are two different things.

Though I am not versed as to how the other manufacturers connect their equipment, I do know that the CAD unit uses an unused input to connect to the grounding box. This essentially grounds the equipment's circuit, not just the chassis.
B

The Nordost grounding box makes a huge difference, really & I mean VERY noticeably cleaning up the sound (the extent of which surprised me, I didn’t go in open-minded) - but they make no claims to stuffing it full of minerals etc. Used can be had for biggish discounts. There are 3 units in 2 ads on AG at this moment. I wouldn’t buy anything stuffed with minerals unless I heard it, especially side by side with a Nordost. I trust my aural memory enough that unless I heard a huge improvement w/o a comparison, it’s (very) unlikely to be as good.

Best ground box you can get, package of dillies and a 6 pack.

I require Hallographs (pair behind speakers and pair at rear of room) despite my high end custom listening room. My speakers are not SOTA or close to it (Legacy Focus) and require help in focusing imaging, soundstaging and frequency eveness. The Hallographs tune the acoustics making these speakers adequate for my use without purchasing big bucks speakers I’m looking at ($35K to $60K). My future speakers may not require Hallographs and probably won’t need speakers' SR HFTs either (the speakers I’m entertaining have multiple bass and treble controls built-in). I haven’t tried grounding boxes. It won’t hurt to try.

@millercarbon Nice explanation of RFI and grounding conditions affecting equipment/cabling.