I notice many iso box reviewers mistake these devices for noise suppressors. They are not; they're meant to fix ground loops, so please make sure you understand the difference between noise and a ground loop before considering this device.
It does exactly what it is supposed to do with absolutely zero audible loss, and I'm quite picky on that.
My use case was:
- Guitar to dual-channel EQ pedal (Source Audio EQ2), to Amp input
- Amp FX loop to second channel of that EQ pedal
- Now you have two different chains connected to the same pedal, which is only grounded once; THAT is a ground loop, lots of unwanted noise.
I placed this device between the FX send and the EQ second channel input: boom, problem solved elegantly! The money you pay here is for the high quality transformer they put in this enclosure; well worth the investment. Don't go cheap on transformers if you care about your sound.