My drop zone was making a buzzing noise too and I found it to be the springs. Some how it went away without any adjustments and makes very little noise otherwise. I am happy with the rest. The string leech trick is so you dont hear the rest hit the bottom of the housing. A small dot of silicone would work here too and would probably stay better. Glue may come loose after time silicone sticks very well.

Good Luck!!!

My drop zone was making a vibrating, or chatering sound as I drew, recently. Turned out that the little wheel that the string roles over as I draw was no longer turning, so the string was vibrating as it went over the wheel. I put a drop of oil on both sides of the wheel, and worked it with my finger until I got the wheel turing freely again, and the noise went away. I also put a small drop of oil on the post that the arm goes up and down on, under the spring, and also put a small piece of felt under the arm, where it lands. It's as good as knew again!