Groundhog+

Groundhog+ creates an earth/ground link for audio equipment that lacks one. A missing ground removes the shielding that normally drains away interference, and the result can be audible hum or buzz. The maker also says that adding the ground can bring more resolution, bass and musicality. A simple touch test helps diagnose the problem: if touching the device lowers the noise, a missing ground is the likely cause. If touching does not change the noise, a ground loop from multiple earths is more likely, and the maker points to its iDefender3.0 for that case.

The unit comes with a set of cables that adapt it to different systems. An RCA base cable suits any audio system with a spare RCA socket. A USB converter serves computer audio systems. A spade converter is for power supplies with a DC barrel connector. A 3.5mm Y-converter is for portable devices with a free 3.5mm connection.

It can also be used with the AC iPurifier. A banana to RCA male cable is supplied: the banana end connects to the AC iPurifier and the RCA end to the amplifier. This combines grounding with the iPurifier's reduction of electromagnetic and radio-frequency interference.