- In the front of a PRS bridge, the six leading edge screw holes are counter-sunk from underneath, providing six brass knife-edge fulcrums. These rest against the six notched brass body mounting screws. This knife-edge set-up ensures that the bridge will return to pitch after use.
- The pocket in the tremolo bridge keeps the six individually adjustable saddles from moving sideways, thereby eliminating another traditional cause of tuning instability.
- The tremolo block is drilled out so the ball ends rest right up under the bridge base plate. This leaves less string behind the bridge saddle so there is less chance of detuning, via proper string stretching.
- There are no rough edges.
- All adjustment screws are inset and made of brass.
- The unthreaded tremolo arm fits into a hard plastic sleeve staying where you put it, via a small set screw on the side of the bridge that faces the tail end of the guitar (where the intonation adjustment screws are located) therefore it will not wobble or break off in the block.
If the guitar is returning sharp after using the tremolo arm, put a little lightweight machine oil under the head of each screw (do not loosen the screws). This will effectively oil the knife-edge of the tremolo.
The correct adjustment of the six brass screws, which act as a pivot and anchor the tremolo system, is level with each other so the bridge floats 1/16" off the body. These 6 screws are factory adjusted and you really should not have to adjust them at all. If it becomes necessary to adjust the 6 notched screws, make sure the guitar is detuned or you will ruin the knife-edge. Adjust the screws incrementally so the notches under the screw heads are fitted with the corresponding hole in the bridge. These holes serve as the knife-edge on which the tremolo unit rocks. Again, this is a very tricky adjustment and could ruin the knife-edge if done improperly.
The Bridge saddles should be low in the range of adjustment to keep the action low and leverage of the bridge in good working order. They should be adjusted so that the height of the string at the top of the 12th fret to the bottom of the string is 2/32".
If the tremolo bridge is not floating 1/16" off the body, remove the tremolo back plate. Adjust the claw screws about 1/4 turn at a time until the bridge floats perpendicular to and about 1/16th off the body. Tune to pitch and check, re-adjust until the bridge sits properly. When the tremolo is adjusted properly and the guitar is in tune, the tremolo arm will raise the low E string pitch to F#: no more, no less.
The intonation may be adjusted by moving the 6 phillips head screws facing the tail end of the guitar in and out with a phillips head screwdriver. Match the octave (fretted) note of all six strings with their corresponding 12th fret open harmonics by shortening or lengthening the strings with the adjusting screws.
Remember to tune and retune until the process is complete.
Source : http://www.prsguitars.com/csc/bridges.html
