really bad distortion??

ive finally got all my midi workin so it works with cubase. When i play the notes in with my midi keybord from the akai it records fine.When i switch the midi channel selector on 1-16a 1-16b i hit the pads or keybord but there is a terriable feedback and distortion and the meter bar in cubase goes crazy any help appreciated

try turniing down the gain on your sound card, keyboard or even on cubase input, it sounds like the output of something is to loud.