sp-404 stereo sampling problem

[fausuto]

Hey guys, here is what happened - I was sampling like a happy ol man when all of the sudden I was only able to hear the very high-shelf frequencies. Once I unplugged the red rca going into the output, sound was clear as day. When I only had the white plugged in, sound was clear as well. When I programmed ableton to be only going to the right or left ear, sound works fine. What is wrong with the rca inputs? Why is it that they work fine alone but not with stereo? I can take a video if you guys don't get what I'm saying