the mix from the soundboard main outs to the PA amps is dependent on the room(or at least it should be).. if the whole band is mic'ed (drum kit, guit cabs etc) and the venue is small, then obviously the drum kit is going to have to be less in the mix because the drum kit is the loudest instru. on stage.. usually you would like the vocals to be up front, well, this means that the vocal track going out to the pa's is going to be the loudest(hence loud vocals on a sbd tape)... guitar is another story.. If the cab. is mic'ed, then there would be some stage guitar going straight out into the crowd, which means the pa level of the guit. track would be less.. that is unless the guitar is running straight into the board, then I could see the guit. being real loud in the mix..
understand rubber band?