Okay, I'll admit it - I am a total numpty. I had hemmed and hawed about posting this, but I figure it's better to just swallow my pride in the service of getting my issue resolved. I recently bought a new black pickguard and truss rod cover for my ruby red Rickenbacker 4003s. I *thought* I took care when installing them - but after I finished, I plugged the bass in to give it a play and lo and behold, I was greeted by a VERY noticeable hum or buzz. I swear it wasn't there before. As it goes away when I touch the bridge or strings, I assume this is a shielding issue. What flummoxes me is that if it IS a shielding issue, it should've existed prior to the pickguard change. The old pickguard was not shielded or anything special. Can anyone shed any light on this? Might I have moved something inadvertently that could cause this? If anyone cares, the bass looks great with the new pickguard/trc. Almost makes it worth the buzz.