I noticed that i have a buzzing sound when i pluck my 3rd (D) string open. Also...i play thru a SWR750 head and SWR Golaith III and i dont notice any distortion. Recently i went to record at a studio. I was plugged in directly and i noticed that the sound was very distorted. How can i fixed this problem. ( i havent changed my strings in a yr. i play an avg of twice a week).
change strings... if it remains, go to luthier to get it set-up ( double trussrod.. don't try it at home, kids )
It could be one of many set up problems. Your nut slot could be too low, your action on your D could be too low, you might not have enough string winds on the machine head for your D, your neck might have too little relief. Take your bass to a luthier and have it set up. Make sure you tell him about the nut. If hes a good luthier, he can cut you a new nut. If hes just a guy working at Guitar Center, forget about it. He'll ruin your nut.