I picked up a new-to-me-bass, and I noticed some nasty humming going on. I did some experiements, moved to a new outlet, used different basses and I determined a few things. 1.) The bass was humming. 2.) The amp was humming too! The closer I get to the amp, and especially if I face the amp, it starts buzzing and humming, pretty loud too. The further away I get, it goes away or at least it is soft enough where I can't hear it at that distance. It's an EBS HD-350. This isn't normal right? Time to send the amp for repairs?? Any ideas on what I might be able to check myself?