Thanks for the help on the impedance issue....my rig sounds great! Now...there's the polarity switch on the back which seems to have three positions....is it okay to leave it in the neutral. center spot? I get no hum regardless of which spot but just thought I'd ask if there is a preferred setting if there are no hum issues. I'm going to be playing through a huge generator at an outdoor show today ...I know I should have a conditioner but don't yet...any advice?