I have a Kramer Pioneer series bass guitar that I bought new and years ago I had customized with a JB player neck (more like a Fender Jazz neck then the one that came attached to the Kramer) and I filed the nut down to make the action close. Stupid move on my part. Thought I was going to increase my speed, just gave me hella fret buzz. Well I put the bass away and played my fretless for about the last twenty years. Recently I thought I would like to play the bass again, so I tried something a bassist showed me once, I put paper match sticks in the grooves of the brass nut (worked on his bass),to raise the action,(so high the strings is almost out of the nut groove), and still had the buzz. Then I raised the action on the bridge (Kramer) with an hex wrench, I raised it as high as it would go, still have fret buzz. I guess I have two questions, do I need to replace the nut? Or is this what I've been missing playing a fretless bass all these years. Rich