issues with q-link slider in mixing mode

if anyone could provide any advise on the issue im having with my samples being distorted upon manipulting the q-link slider to adjust the volume of a track in the mixing window. its seems that only bass-drum samples become distorted when adjusting these samples from there highest possible volumes to there lowest possible volumes. my ultimate goal is to eventually automate the volume of certain tracks in a sequence.

this might need further explination. but if you have an idea how to trouble shoot or think that my mpc is faulty let me know thanks.