so today was the first time i used my amp while playing with people. drummer guitarist, 4 trumpets 4 trombones tube sax section, the works. My amp worked great with my upright, got nice and loud, but with a passive p bass and a passive j i felt like i shouldnt have to be turning up the 350 3/4 of full volume to get a nice volume that works well. what do i need to balance this out, a signal booster of some sort? i want the levels to be equal, id like to boost my passive bass to the save volume level as my upright or an active bass that i plugged into it. what do i do?