I'm in a concert situation where I need to make quick switches between upright and electric. I'm using a rented bass amp wherever the gig is and would benefit from a stereo/2 channel preamp or some sort of rig I can plug both basses in the amp and would like to have 2 DI's coming out. One DI would work if that's not possible. I don't like having to rely on a monitor guy to mute my upright while making the switch, it just doesn't work the majority of the time. A preamp with a good EQ that's not too ridiculous to figure would be nice. How about a small acoustic amp like a Clarus, would that work as a doubling preamp?