Sometimes you just need isolation without level attenuation - just easy interfacing between equipment that is suffering from ground loop issues due to being on separate ring mains. I've solved issues with humming monitors, FOH speakers and guitar amps with this. It now lives on my pedalboard, to help run balanced lines from a guitar rig to a rack processor and back, TS->TRS->TS, which reduces unbalanced line interference considerably. I also use it at numerous venues, where lighting desks, dimmer controls and even dishwashers are all spewing noise onto the mains. Some of this is cleared up by RF filters, but used in tandem with the Stagebug, you can eliminate just about anything (excl. single coil noise - nothing can save you from this, except humbuckers!). Another use was to put this between an active acoustic preamp and an A&H desk's Inst input, as I had run out of DI channels but still wanted isolation from the desk. Useful PAD and polarity etc. should you need it. Managed to fit this beneath my pedaltrain so it is out of the way. Very solid and well made, and well worth the money, even if you just keep it in your toolkit until it's needed.