PRS Trem setup

What's Hot

I've read the PRS guidance on setting up the trem and I know I need to detune the guitar before messing with the pivot screws but how much do I need to slacken the strings off to avoid doing any damage?

Normally I wouldn't want to mess with it too much but the screws are all different heights and the trem is quite low.  Just trying to set it back to PRS factory 1/16th specs.

Thanks

 

0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
«1

Comments

  • guitarfishbayguitarfishbay Frets: 7953
    edited September 2015
    Edit: ICBM's answer has more info and more detail - read his.

    FWIW when I adjust the PRS stop tails I fully slacken strings to no tension, and capo first fret so the strings stay in the nut.  Otherwise the tension causes the bridge to pull towards the studs and you mark the studs.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • ICBMICBM Frets: 71959
    edited September 2015
    Slacken nearly all the way off but not quite - you don't want the springs to pull the bridge up off the grooves. Set the screws to the same height by sighting across them, making sure you keep the back edge of the bridge horizontal to the body - it will be touching, with not much string tension on, so it will be easy to see.

    Once you've got it as right as you can, tune up the guitar again and very carefully turn the four inner screws back and forth a tiny amount until you can feel they're at the 'slack' point when the knife edge is not pushing upward or downward on the groove.

    Sometimes PRS bridges are very slightly 'dished' due to the way they're cast, so you may find the screws have to follow that slightly. This should show what I mean (my old Standard 22) - if you look closely you should be able to see that the bridge is slightly curved:

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

    0reaction image LOL 0reaction image Wow! 2reaction image Wisdom
  • ADPADP Frets: 184

    Here's a video made by John Mann, who made the original PRS bridge, that walks you through the whole process of installing a PRS-style tremolo and setting it up:


    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
  • This is something I'd get a tech to do - read horror stories about tinkering with the screws on PRS bridges
    1reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • [quote="thomasross20;773276"]This is something I'd get a tech to do - read horror stories about tinkering with the screws on PRS bridges[/quote

    I thought you were some kind of engineer?!

    1reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • I am but I leave that to the workplace. I'm not a guitar tech!
    2reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • Thanks for all your help.

    That's a good video although no mention of knife edges.  Does make me wonder whether a safer bet would be to take the strings off, take the springs off and basically refit the bridge the way in the video using a 2.5mm allen key to set the height.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • richardhomerrichardhomer Frets: 24793
    edited September 2015
    PRS recommend slackening the strings off to avoid damage to the knife edge:

    http://prsguitars.com/csc/bridges.html

    The only 'safe' way to do it in my opinion is to slacken the strings right off and remove the springs. Because each screw forms a knife-edge with the bridge, it is vital that each is set at the perfect height.

    I adjusted a Custom 24 I used to own, without any dramas - but if you are uncertain how to do it, I'd suggest paying a tech who understands how the assembly works would be money well spent.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • ICBMICBM Frets: 71959
    With all respect to John Mann for making such a good bridge, I really don't like seeing people use power screwdrivers for stuff like that on a guitar, even undoing screws - it's quite easy to chew up the screw heads.

    Not impressed by cutting the strings behind the nut at full tension either. Or using a screwdriver as a punch to drive the spring into the block - too much potential for slipping and damaging the guitar with both these… he nearly does with the screwdriver.

    I would strongly recommend not to do any of this!

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • I guess it wasn't his guitar!

    I think I am going to slacken the strings fully and remove the springs so I can basically start again with it and avoid damage to the knife edge.  Will the knife edges find their way into the grooves once i put the springs back on?  In the video John didn't seem to line them up or anything, just chucked the springs back on.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • ICBMICBM Frets: 71959
    CHrisP86 said:w
    I think I am going to slacken the strings fully and remove the springs so I can basically start again with it and avoid damage to the knife edge.  Will the knife edges find their way into the grooves once i put the springs back on?  In the video John didn't seem to line them up or anything, just chucked the springs back on.
    They usually do, but make sure you check once you've got a small amount of string tension on.

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
  • Thanks IC.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • CHrisP86;773828" said:
    Will the knife edges find their way into the grooves once i put the springs back on?  In the video John didn't seem to line them up or anything, just chucked the springs back on.
    The key thing is to make sure the grooves in the six screws are perfectly in line. Putting one spring in and (gently) helping the bridge 'lock' into the grooves should do no harm. You should put a cloth between the back of the bridge and the top of the guitar, to avoid marking it.

    You can then add a the rest of the springs and string up.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • Wow!

    Tonight I have learned how much a bit of time spent on set up can improve a guitar.  Having got all the pivot screws level and set the bridge up a bit higher the guitar sounds fantastic!!

    For anyone wanting to attempt similar, I:

    1 - slackened the strings all the way (no strings would have been a bit easier)
    2 - removed all the springs
    3 - unscrewed the pivot screws a bit to give more height to the tremolo
    4 - used a 2.5mm allen key between the trem and screw heads to set the height of the screws
    5 - springs back on (knife edges found their way into the grooves themselves)
    6 - tightened the strings back up
    7 - adjusted the claw screws to get the trem level

    Actually fairly easy and leaves the trem floating the PRS standard 1/16th from the body.  
    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
  • So it's made a big difference?
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • Yeah.  It sounded kinda dull, really buzzy because the action was so low and didn't sound quite in tune.  Really fuzzy through an amp as well.

    Now it has a nice chime and no buzzing.  Even now sounds more clear through an amp and exactly how I'd hoped it would sound.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • richardhomerrichardhomer Frets: 24793
    edited September 2015
    CHrisP86;774934" said:
    Yeah.  It sounded kinda dull, really buzzy because the action was so low and didn't sound quite in tune.  Really fuzzy through an amp as well.

    Now it has a nice chime and no buzzing.  Even now sounds more clear through an amp and exactly how I'd hoped it would sound.
    My experience of PRSs is that there is a considerable tonal compromise if the action is too low - there's a definite 'sweet-spot' where they suddenly sound massively better - it sounds like you've found it!

    Glad it's worked out well for you.
    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
  • RaymondLinRaymondLin Frets: 11811
    CHrisP86 said:
    Wow!

    Tonight I have learned how much a bit of time spent on set up can improve a guitar.  Having got all the pivot screws level and set the bridge up a bit higher the guitar sounds fantastic!!

    For anyone wanting to attempt similar, I:

    1 - slackened the strings all the way (no strings would have been a bit easier)
    2 - removed all the springs
    3 - unscrewed the pivot screws a bit to give more height to the tremolo
    4 - used a 2.5mm allen key between the trem and screw heads to set the height of the screws
    5 - springs back on (knife edges found their way into the grooves themselves)
    6 - tightened the strings back up
    7 - adjusted the claw screws to get the trem level

    Actually fairly easy and leaves the trem floating the PRS standard 1/16th from the body.  
    I need to do this, My CU24's trem isn't level to the body back to front.  It's higher toward the neck than the back.


    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • John_PJohn_P Frets: 2744
    I need to do this, My CU24's trem isn't level to the body back to front.  It's higher toward the neck than the back.


    That sounds like you just need to adjust the spring claw - if I change gauge of strings on a guitar it needs adjusting.   I'd only look at the trem screws if they aren't even or there's a tuning issue.        It's a two minute job to detune, unscrew the claw a bit then check it's level when you return. 
    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
Sign In or Register to comment.