If anyone else puts a GK pickup on, do it this way. Put it as close to the bridge as you can get it. I originally had it, center between bridge and pickup. The edge of pickup, has to be, between 15 and 25 mm, to the center of your bridge saddle.
My B string saddle is 25mm. My C string is now 15mm.
The polyphonics track MUCH better now.

I had to mave the pickup, away from the bridge on the other bass. Saddles were right on the edge, of the bridge on that one.
Man, would you look at the marks on that front pickup, and the top of the fingerboard ?

That bass has been rode hard and put up wet.
