Nuguy, very likely you are right. I suspected the volumn and balance potentiameter malfunction. Usualy damage items under guarantee will be repaired by the manufacturer/dealer, in this case the pre-amp is so new, barely 2 hours, do you think it is fair to ask for replacement? You know, psychologically it is difficult to accept a "repaired brand new item"! Especialy for high end equipment.To be fair, sonically there is no problem.Anyway if I use the item for awhile (say ,weeks,)it is a different story.TQ