I don't think the korg ax3000b can be used as a preamp since it has no xlr outputs. it as midi outputs, but that could be use for a different purpose. however, you can hook up the korg ax3000b to a d.i box by connecting the instrument cable output from the d.i box to the korg ax3000b. I did that once at a gig from a band I use to play in mainly because my brother and I were just too lazy to bring an amp that night. so we bought our d.i boxes and hook up our multi-effects processors and everything sounded pretty cool. give that a try and see if that works out for you.
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