[ninja636]

I think two sets are for the channels, and two sets are for the preamps. I read a bunch of reviews on this thing, and have yet to find a bad one. There's a dealer down in Enterprise AL, I'm going there next week to try one out. He said he has the Vector cab as well as the 412 and he'd hook them both up for me. I hope it sounds as good as everyone says it does, if so I'm opening a savings account just for this.