PRS Trem Set up Tips
When BAM was around, I did a lot of research there about how to properly set up a PRS with trem. I found a lot of good advice and saved some of the information for later use, which gave me my own confidence/ability to do my own setups. With BAM now gone, I thought I'd share if it's helpful to anyone. Disclaimer: I did not write the below instructions, but have found they help as a general guide to setting up PRS trems. Thanks to the original BAM members (whoever you are) who shared this helpful info!
Buy a capo and a feeler guage that goes down to .005". You shouldn't need a straight edge unless you have fret problems.
Clamp the capo on the 1st fret and hold the string down at the top fret. Measure the relief at the 8th fret. Some people like the relief as high as .010" and some as low as almost .000". I like .005". Tighten or losen the truss rod to get your relief. Keep in mind the truss rod may take a full day to fully adjust to its new setting, so check it after 24 hours. A little adjustment goes a long way. Keep retuning during this process.
Do not adjust the six screws on the bridge unless all other options have been done. Remove the cover plate on the back. Visually look at the flat area between the pickups and the flat bottom of the bridge. These should be very close to parallel (not lined up), with maybe a VERY slight tilt up at the back of the bridge. You adjust this by tightening or loosening the claw screws equally in the back. Each time you move these screws you retune. Move the trem arm up and down each time you adjust the claw screws also.
After the relief and bridge have been set, then adjust the saddles to the desired string height. Everyone has their own height, and mine is very low. Keep in mind that the strings should follow the radius of the fretboard, so the saddles in the middle will be higher than those at the ends. Each time you adjust ... retune.
If you bottom out the saddles and can't get the strings as low as you would like, then repost here and we can go into the 6 bridge screws. Once this is all done, check the intonation.
Another good test is check each string by playing the open string and proceeding up the neck one fret at a time. If you hit a note and there is buzzing, the next fret up might be high. Use a credit card and rock it on the suspected high fret and the frets on either side. If the card doesn't lay flat on the frets, then you will probably want to have a luthier look at it.
Check the nut like this:
Fret each string, one at a time, at the third fret and pluck between the nut and the third. If you don't hear a clear ping then the nut is too low. If the problem appeared (or worsened) over time then the neck relief is likely the culprit (assuming the bridge hasn't been moved).
Adjusting the action is simply a matter of adjusting the height of each individual saddle (there are two allen screws for each saddle). Saddles should be kept parallel to the bridge plate and height adjusted accordingly. I usually like my action around 1/16" on the higher strings and about 5/64" on the bass side (measured at the 12th fret). Playing is as important as measuring, so you should make small adjustments and play the guitar in between to make sure it feels right, doesn't buzz, and doesn't fret out when bending strings. Invest in a 6" machinist scale.
In general, you should adjust the truss rod first (if necessary), then the action, and finally the intonation. Remember that every adjustment you make has an effect on everything else. Use the fretted 12th fret note and compare it to the 12th fret harmonic and use a digital tuner. If the fretted note is higher than the harmonic, then the string length needs to be increased, which means you would turn the saddle screw clockwise which will compress the spring and pull the saddle towards the bottom of the guitar. Vice versa if the fretted note is lower than the harmonic.
Setup step by step - another perspective:
1. Whether you change the strings one at a time or all in one go is up to you. The advantages to "all in one go" are you can clean the fingerboard, headstock face, bridge, pickups and the area around the pickups more easily. If you do this, you may want to put a couple of business cards under the rear of the bridge to protect the top as you release the tension on the strings. The only real advantage to doing one string at a time is you don't have to worry about that step.
2. String up with your chosen gauge. With locking tuners, I tune up, stretch each string by pulling it firmly away from the fingerboard at several points along its length. This will make the tuning more stable while working, as otherwise the string will keep stretching until it reaches the same point. I then detune each individual string completely, loosen the locking mechanism on the tuner and pull the string as tight as I can before locking it in place again. This will result in the smallest amount of wrap around the tuner post and the best tuning stability when using the trem.
3. Once all strings are up to pitch, check the relief of the neck. Hold each string (often 1st and 6th are enough) down at the 1st fret (or use a capo) and at the top fret (although any fret between where the heel gets to its thickest point to the highest fret will do). Check halfway along this section of string around the 9th/10th fret to see how much distance there is between the bottom of the string and the top of the fret. Many people will use a feeler gauge to check this although I tend to do it by sight and feel. Some players like very little relief (often those that have a lighter right hand picking action) while others prefer more (generally those who really like to "dig in"). About the width of a "D" or "G" string is typical. If there's too much relief you need to tighten the truss rod by turning the nut towards the bass strings, too little relief and you need to loosen the truss rod by turning the nut towards the treble strings. As it's a newish PRS there should be no problems with the nut being stiff. Only turn the nut about a quarter turn at a time (or less). PRS necks usually respond very quickly and predictably to these adjustments, so keep checking as you go. If you have time it's often worth letting the neck settle for a while at this point and rechecking before continuing. Also make all these measurements and adjustments with the guitar in playing position - putting the guitar on its back on the bench will change things.
4. Now check the nut to ensure the slots are the right depth. Again some people measure this exactly with a feeler gauge but I just hold down each string at the 3rd fret position. There should be a very small gap between the bottom of the string and the top of the 1st fret (about a high "E" string width), again I do this by sight and feel.
5. Once you're happy with the nut, you need to set the action. If the trem bridge is still set to factory specs, DO NOT adjust the six pivot/mounting screws. That's a whole other topic so I'll not cover that here. At this stage I would adjust the trem claw springs around the back to get the base of the bridge parallel to the flat body area between the pickups. Get it close now and check it again after saddle heights have been adjusted.
6. Now adjust the six bridge saddles to your desired height. Either a finely scaled small ruler or a radius gauge to match the fingerboard (10" radius) really help here. There are many different ways to accurately measure the action, I tend to hold the string down at the 1st fret (to remove the nut from the equation) and measure at the 14th fret. On a PRS with good condition frets, for a lighter player and very little neck relief, an action of 3/64" on the bass side and 2/64" on the treble side (bottom of string to top of fret) is usually possible without any buzzing. Something that low can be a problem on extreme bends even with the 10" radius fingerboard. Factory specs are 6/64" and 4/64" so anything less than that should seem an improvement to you. Almost always you'll need a slightly higher action on the bass side and I always play every note on every string to make sure there is no unwanted buzzing. To avoid damaging the saddle, grub screws or baseplate it's best practice to detune the string before making any adjustments, obviously retuning to check if the desired change has been made.
7. Now's time to check the intonation. You'll need a good tuner or a very good ear. Working one string at a time, play a 12th fret harmonic and ensure this is perfectly in tune. Then play the fretted note at the 12th fret and check the tuning. If the fretted note is sharp, you need to move the bridge saddle away from the nut (tighten the adjustment screw), if it's flat, move the saddle towards the nut (loosen the screw). It's a bit of a pain but again it's best to detune the string before moving the saddle.
8. At any stage, feel free to recheck the neck relief and trem claw adjustment as they can change slightly as the angle of pull on the neck changes (as the action is raised or lowered), but definitely check these and the action/buzzing when you're done with the intonation.
9. There are specs for the factory pickup heights, but the best advice is to use your ears. The general advice is that the polepieces should follow the radius of the strings/fingerboard. Start with the pickups low and raise each side a little until it sounds the best TO YOU. If you use the bridge pickup more, do that first and set the neck height for the best matching (or non-matching) volume level and tone. If you use both pickups together a lot, then the relative heights can make a huge difference to the sound in that position.