I had a specific issue with some introduced noise from a digital source that wasn't resolved by a number of standard troubleshooting solutions. Likely I would have gone to some isolation devices for hdmi/coax, but thought I'd try the 8D. I picked it up when it finally went on a sale that hit my 'try it' price point.
End result- in this case, the digital separation circuit used in the 8D works. With the source plugged into the standard bank, the background noise was present. When using the digital receptacle, sound floor was lowered immensely. As a benefit, the Furman 8d is a decent surge protector too, so it's got that going for it too. Prewarning as you'll note in several reviews, it's bigger than you might think, so have a good place to locate it.