@lugia : checked it out, but for the same price you can get two Isolators, which would suit me better. I only have mono things in my rack, and it goes into a mixing desk which already does all the other stuff. The only "feature" I need is to stop worrying that I plug something in wrong, or forgot about some normalling somewhere, and accidentally cook the speaker coils with DC!

The closest contender is the Menu Qi Please Exist, but that's more expensive, discontinued, and only has unbalanced outputs.