as I told you in my PM I don't think you need XLR's that is the problem with the gain you are having. If you go into a Korg MR-1000 via the xlr you are going through the mic pre and the gain on the line level will kill the input to the mic pre.. The Line level in is the TRS 1/4"
If you are going out of a Nak you need a rca to TRS where sleeve and Ring are tied together to go unbalanced in. The combo neutrik female on the korg does not like vanilla low end 1/4 inch.. Make sure you get a high quality Neutrik TRS and wire as described...
A