Reamping ground loop eliminated!
I'm using a Line 6 Helix as both my USB audio interface and as a reamp box to record guitar and bass DI tracks directly into my DAW and then have the option to reamp those tracks either digitally all within the Helix or through my collection of real amps and cabs mic'd up. This setup works brilliantly but whenever I used it for my real amps there was a nasty ground loop noise coming through that made high gain reamping unusable. I tried everything I could to solve the issue without buying additional equipment (isolating all equipment into one power conditioned UPS, separating non grounded (2 prong) plugs from the grounded plugs, etc.) and nothing worked. I put the HE-2 in line between the output of the Helix and the input of the amps...problem instantly solved! The passive design that doesn't require any power is a definite bonus as well.