MOTM

is there any quick way to get motm levels down to instrument levels? i'm
playing with a guy next week who wants me to run through 4 mesa 400+
bass amps,  i want to make sure i'm not going to blow the preamps out on
his amps and i don't feel like lugging my PA over either. I don't have
the mixer yet and my smallest mixing board is 36 channels (it doesn't
travel all that well) would tying a resistor between hot and ground on
the final output do any damage to my modules? let me know if anyone has
any ideas. -nate