No, there's no special setting for using it in front of an amp. It should just work. You might want to take the Boss sd-1 out to simplify the set-up and go straight from the Core into your amp. Then, double check the connections (I'm sure you already have.) If they're right, I'd probably restore the Core to its factory defaults to make sure that it's not a problem with its settings. If you have any presets you don't want to lose, back them up with H9 Control, and then, to restore it to its factory defaults, turn it off and then turn it on again with the right footswitch and big, black wheel pressed.
