At the end of the set, I plug in the tuner to the headphones jack which acts as a mute. Coming back to play again it's ready to tune quietly, then you just pull the plug and you're ready to rock! It does pop but it's not terribly loud.I would love to use it as a tuner out but it kills the main speakers on mine.
My MB212 is fully broken in now and if it were possible, I would have halted the break in a few weeks ago. I'm dialing back the lows ever so slightly but it just sounded better to me when it was newer. This is a very subtle thing, not a big deal at all...most players will like it better after it's broken in but I don't like big lows as much as most folks. Hard to believe a little 38 pound combo could put out sound like this.