I'm using the Realist along with the Golden Trinity mic. Everything's peachy except one little thing - every time I hit a low C or Db on the A string, I get an annoying little buzzing sound. The prime suspect is the rats nest of cables, pickup jacks, and pickups between the bridge and the tailpiece.

I had somebody dampen various parts of the bass and pickups whilst I pedaled a loud but buzzing C. The culprit seems to be around the strings below the bridge... I'm not sure if its the output jack or what, but when the A and D string were dampened the problem seemed to go away. I didn't have the problem before installing the Trinity upgrade, and I didn't initially have any buzzing, either.

Does anyone have any suggestions for a way to dampen just the jack or even that entire area of the bass without impacting the sound?

You can use pliers to crimp the jack plate to make it narrower and it will fit more tightly on the strings. I also use the Trinity and I use a piece of felt wrapped around all four strings right above the pickup jack. I put the felt there to cut back on "wolf tones" (which it does), but it also dampens a lot of the wire vibration in that area. Another thing I do is bind all of those wires together with plastic tie strips, so they can't buzz up against each other or wilt down and vibrate against the top. It also looks cleaner that way - less like a spiderweb.

My bass developed a similar sympathetic buzz on open G which turned out to be the G string rattling against the tailpiece on the area between the notched hole where the ball end is anchored and the front plane of the tailpiece under the strings. A small doubled square of felt wedged between string and tailpiece completely fixed the problem.

As mentioned (in fact it is written in my included tips), using a pair of longnose pliers to more severely angle the jack can help, if that is what is making the sound.

An inexpensive stethoscope is a great diagnostic tool for narrowing down exactly where those odd rattles and buzzes are.