buzzing with Realist

The feet of any bass bridge are smaller than the entire area of the Realist, so this is not the problem. Actually, by changing the position of the pickup under the foot (even very slightly) you change the sound coming from the pickup. Sometimes you can improve it this way quite significantly.
So, I don't know about the buzz - how about the wire touching something? Or, maybe it's coming from the bass itself... (Of course, I hope not!)

 

What does it sound like? Is it a tikitikitiki sound on a particular string?

 

I used to use the Realist and sometimes it would do the same thing. The cause was that the jack was not snug. I hope this helps. Cheers...

 

Are you sure it's the Realist? Did you take the Realist off and see if the sound is gone?

I have a tikitikitiki sound coming from my A string -- a Spirocore Weich -- for just a second or two when I pluck with some force. I thought it was the Realist for the same reason you describe, but when I removed the Realist and even changed the bridge, it was still there. Still haven't got it figured out...

 

I had the same problem with my realist. It was the edges of the pickup that didn't fit under the bridge. The foil that the pickup is covered in will bend up and vibrate against the body. I taped it down to make it stop. I eventually solved the problem by not using the realist anymore. For that kind of money I don't want to have to fool around with foil and tape.