Multi effects lvl into the amp

[tseegert]

Is there a universal medium for the master lvl from a guitar processor into an amplifier? I would like to try my ME33 into my amp, as I've tried before, but I was afraid at what might happen if I turn the output of the ME33 up too far. ie, not sure if I could blow something, basically.
Or am I basically ok to turn it all the way up, so long as it pleases the ears?

Thank yas