If you have a microphone and some place to plug it in and a pair of headphones, you have the makings for a great rumble/noise detector for finding and eliminating the source of noise on your table. I taped a 6" steel ruler to the side of my microphone with about 4 1/2" of the ruler extending past the front of the microphone from my mini-disc recorder. I put on the headphones and put the recorder in record mode. With the volume turned up I touched various points on the table with the free end of the 6" ruler. The noise I heard was incredable! The motor mounts made gobs of noise but when I move to the subchassis, it was reduced to a faint trickle. I then proceded to other parts of the table. I put a record on and could hear the music fairly well just from the stylus in the groove. I have found a source of noise I'm trying to eliminate now.
W