i would use a 1/4 instrument cable to plug the korg TR from the keyboard into channel one on the mixer at the the top. over near the top right of the mixer you should see inputs that say headphones, main out or control room out, i would run another 1/4 cable from the main out into the input on the amp, and should have sound assuming you have a built in speaker in your amp, if you just have a regular amp you can run a 1/4 cable from the amp into a big speaker. if you need more help let us know