Symptom Solution Ensure that the instrument is connected from the headphone output to instrument input L/Stereo jack on instrument box. Check to see if LC4 Hub is set to “Split Mode.” If so, turn off and see if symptom persists. Sound only heard on one side (left or right) Change cables or headphones with ones that are known to work to see if symptom persists. If not, then you might have a failed part. Contact customer support for information about replacement or repair.