Noise at Bridge?

[flpete1uw]

Alembicans,
  When playing the E sometimes A strings I sometimes hear a mechanical buzzing / rattle when played somewhat aggressively. I put my finger on the bridge or just behind of the offending string and it stops. Also when messing around the bridge to string contact I can get it to stop for awhile.
This buzzing sounds like it's being amplified?  
 
1975 Series 1 shortscale with LaBella nickel rounds E 105.
Note the Bass has the old style bridge. (Original)  
Any ideas or short sightedness on my part?
Peace,
Pete

[5a_quilt_top]

Check your brass cavity covers.
 
I thought I had a bridge rattle once and couldn't track it down for several days.
 
Finally it occurred to me to check the contact between the brass cavity covers and the body - yup, a slight gap.
 
Added a little padding at the edges and tightened the screws - presto - no more rattle.
 
These basses are so resonant that the vibrations transfer to the brass covers.

[bigredbass]

In Jimmy Johnson's thread(s), he remarks that occasionally he gets a rattling E string at the bridge.  Not anywhere else, but rattling at the saddle.  I had this myself, and thought I'd never track it down, until I just happened to touch the string at the saddle, and that snuffed it.  JJ advises to detune down to loose, twist the ball-end a half-turn in the tailpiece and tune back up.
 
He thinks it's caused by the multiple windings in BG strings, and the way strings can actually twist as they're tuned up.
 
This may not be what you're hearing, but easy and quick to try.
 
J o e y

[sonicus]

The mystics and anomalies occurring within the natural material  handmade instruments that we love  are subject to 1st, 2nd and third  order harmonics and who knows how much further. That may friends shows us their personalities . They are alive and living  in our hands while we play them !     They all have their own voice and we learn in practice  how to bring them to their maximum performance . I love that ____ !

[mica]

You swap out a new style bridge and keep the old one for posterity. The new style has a stabilizing pin and intonation screw for each saddle. On the channel bridge, the stabilizer is the channel, so if the string isn't pushing the saddle to the channel, you can get some strange noises. It's possible to insert a shim under the saddle if it's not making contact, but you can make it worse too.  
 
There shouldn't be a question if the sound is amplified - if you don't hear it through the amplifier, than I would just tolerate it and leave it be. If you can hear it through the amp, then you need to remedy it.  
 
And Jimmy is right (of course!).