First thing you may want to try is in the amp section and adjust the “definition” parameter.. different guitars sound different on different profiles ( sorry too many differents!). Profiles are snapshots of the whole signal chain so it depends on the type of guitar/pickups were used at the time.
Try looking at the vid in this playlist (the others are very useful also)
http://www.youtube.com/playlis…dN8lDXFKMFAD2tDyC1Q_o7wDp
Secondly try different guitars/ pickup combinations and thirdly try adjusting the clean and distortion sense in the input section (I think there is a vid in the playlist above). If nothing else try all the tips and tricks in the TJ playlist it will get you navigating the KPA pretty quick.
If you are nervous about messing things up do a complete backup in rig magager first. Actually there is no excuse to backing up the KPA regularly .