I have a B&K pre amp and the other day it started to increase in volume by it's self. I had it set to -24dB and when I stopped it, it was at -8. I ask on another forum the question and they said turn off pre amp disconnect AC and turn the volume dial back and forth a couple time. Did that and played it for about 90 minutes and no problem. I live in Albuquerque, New Mexico where it's extremely dusty and dry so it's difficult to dust because you just build up more of a static charge. So I clean the top of my components with a damp paper towel. I hesitate to take appear the pre amp because I'm not that confident in myself as to not do more damage.