I noticed at band practice last night that the volume of the amp was cutting out. If i touched the master volum knob it would cut out and in depending on if I moved it much. I'm thinking that at some point in transit something may have hit the knob. Is there a specific pot that I should use to replace it? Has anyone else had to go through and replace a pot in the JMD? I have a show coming up so I'll end up renting another amp so that I don't fear the thing crapping out on me during hte show but was hoping I might get some guidance from some of you fine folks as the roadhouse. Thanks!