PRS custom 24 tuning issues

dannelsonbass

Hi

I’ve been having some problems with keeping my PRS Custom 24 in tune. I’ve ruled out all the usual suspects (sticky nut, proper string stretching etc) and I’m pretty certain the trem is the culprit. Does anyone know any techs out there who have a particular expertise working on PRS? I know the trems can be a little fiddly to say the least. Happy to post anywhere so location isn’t an issue.
Thanks

imalrightjack

Pics of the tremolo angle, etc. will maybe help - and of the six screws on the bridge.  @ICBM will know anyway

guitars4you

Try and isolate a few options first

So assume it is all in tune in the first place

Is the issue when you raise the trem and/or lower the trem
Do the strings go sharp or flat
Is it all the strings or just one or two going out
What gauge strings do you use
Assume the trem is slightly floating - one pic will be handy to see so we can see the gap between the trem assembly and the body
Is it a full blown USA model, S2 or SE
Is it going out after just a slight tweak on the arm for light vibrato - Or heavy de-tune (dive bomb approach)

Age of the guitar - the knife edge fulcrum points can wear out - Or indeed if adjusted incorrectly can cause issues - Yet hard to actually see the fault - But some of your answers above might help identify such issues

dannelsonbass

Thanks for the responses. I'll try and get some pics posted

The trem is floating and I'm using 9-46 gauge D'addarrios. I swapped strings out to rule out the NYXLs I'd recently converted to, and gone back to normal XLs. Still no joy...

Going out of tune randomly and by small amounts - sometimes flat, sometimes sharp, and regardless of whether its a gentle shimmer or flat out dive bomb. I never expect to return to perfect tuning from any trem equipped guitar, but this one is so sensitive it leads me to think something is wrong (perhaps with the knife edge points as being suggested).

It's a core USA model, from 2008 I believe. 

dannelsonbass

https://imgur.com/Q5Vkzd7
https://imgur.com/A6klMys
https://imgur.com/mnt1aXD
https://imgur.com/q9KHQko

Funkfingers

dannelsonbass said:

https://imgur.com/mnt1aXD

In this photograph, it is evident that the vibrato is not sitting properly. Its baseplate should be parallel to the line off the strings.

Yours looks as if EITHER somebody had changed from 009-042 to 010-048 without resetting the spring tension to counterbalance the additional string tension OR the guitar had been set up for dropped tuning then, returned to Standard tuning without resetting the spring tension to counterbalance the additional string tension.

Either way, you first port of call is the vibrato tension springs and "claw" adjuster.

guitars4you

dannelsonbass said:

https://imgur.com/mnt1aXD

agree with @Funkfingers - On that pic the trem is set wrong - Might be other issues that we can't tell - But for now the trem needs to be adjusted - Should be simple enough - Remove the back trem plate and adjust the 2 screws holding the trem claw in place - Need to tighten each screw, so turn clockwise - Should be equal amount on each screw - Probably a turn on each screw - Then re-tune and check - If more adjustment required, then 1/2 turn on each screw this time etc etc - Base of the trem should be running on a line parallel to the strings - On your pic you can see the back of the trem is listed to more of a wedge profile - If anything I run the trem plate parallel to the body

Try this and then re-evaluate

Can't deduct any other issues on the other 3 pics 

Not sure how old your PRS is and what changes to the set-up have being undertaken over time - PRS use to set-up with 9-42 but now it is 10-46

Funkfingers

Another factor is the number of tension springs acting on the vibrato. It may be one short of the number it really needs to balance out.

guitars4you

Funkfingers said:

Another factor is the number of tension springs acting on the vibrato. It may be one short of the number it really needs to balance out.

Valid point - By typing the info, you can forget what you do by nature, at your own work bench all the time - In short it is easier to do it than explain it sometimes

3 springs should be fine on a PRS

dannelsonbass

Do you mean the angle of the bridge? I've always set my bridges so I have around a tone and half uplift. Never had any issues with this before, although all my other trems have 2 pivots. I think lots of other players do this too (those who like a bit of uplift that is!)

dannelsonbass

Regarding the springs, I'm using 4

ICBM

The bridge is too steep really, although that by itself won't cause it. When you say it goes randomly out by small amounts, is it all six strings at once? If so, it probably is the bridge sticking on the pivot screws slightly. If you haven't adjusted them - so the grooves could be out of line - it may just be that they're a little worn. Getting some grease into the pivot points will help - fully slacken the strings and take the springs off, then work it into the gaps using a toothpick or similar.

If you have adjusted them, you may need to make certain that they're lined up correctly. You can do this by first setting the out two screws to the height you want, and then very carefully turning the middle four back and forth gently - you should be able to feel the 'free' point. Do this with the strings detuned but not fully off.

If you have three springs on, make sure they're on straight and not in a 'fan'. PRSs tend to set up better with four springs than three though, even with only 9s or 10s - the trem cavity is slightly shorter than a Fender.

You should be able to fix this yourself whatever the cause is - don't even consider couriering a guitar of this value anywhere unless there's no alternative.

dannelsonbass

Thanks guys

It's difficult to find time at the moment to fix the problem myself, to be honest. I'm happy to courier it anywhere because as it is stands it isn't of any use to me and I wouldn't sell it on if it has a known issue. 

Funkfingers

How old is the guitar under examination? What "phase" of machineheads does it have? The original "wing collar" modified Schaller M6 type eventually wears out and exhibits gear lash. 

dannelsonbass

Should have mentioned that I recently had phase 3 tuners installed. The old tuners were pretty worn and I suspected that they were the cause of the issue.

Guitar dates from 2008, and I have little idea of its history as I bought it from a mate who'd bought it from a mate etc

dannelsonbass

ICBM said:

The bridge is too steep really, although that by itself won't cause it. When you say it goes randomly out by small amounts, is it all six strings at once? If so, it probably is the bridge sticking on the pivot screws slightly. If you haven't adjusted them - so the grooves could be out of line - it may just be that they're a little worn. Getting some grease into the pivot points will help - fully slacken the strings and take the springs off, then work it into the gaps using a toothpick or similar.

If you have adjusted them, you may need to make certain that they're lined up correctly. You can do this by first setting the out two screws to the height you want, and then very carefully turning the middle four back and forth gently - you should be able to feel the 'free' point. Do this with the strings detuned but not fully off.

If you have three springs on, make sure they're on straight and not in a 'fan'. PRSs tend to set up better with four springs than three though, even with only 9s or 10s - the trem cavity is slightly shorter than a Fender.

You should be able to fix this yourself whatever the cause is - don't even consider couriering a guitar of this value anywhere unless there's no alternative.

Not all strings are going at of tune at once. Sometimes I think its confined to the D string, sometimes the G, and sometimes to B. But I guess that's the nature of floating trems: each string affects the other so its difficult to pinpoint a culprit. 

guitars4you

dannelsonbass said:

Do you mean the angle of the bridge? I've always set my bridges so I have around a tone and half uplift. Never had any issues with this before, although all my other trems have 2 pivots. I think lots of other players do this too (those who like a bit of uplift that is!)

dannelsonbass said:

Regarding the springs, I'm using 4

@ICBM suggests 4 springs - I generally use 3 springs but both will work - Especially with 9-42 gauge strings - 3 or 4 springs alone should not be the cause of tuning issues - But as it is set with 4 springs then stay with that 

Yes the angle of the bridge - On a PRS they are designed so the base plate of the trem assembly runs on the same parallel line of the strings - So imagine the strings run past the actual trem towards the strap button  - So look side on to see this - I actually set them up more with the trem plate running parallel to the body - Either way, you won't get a tone + half up pitch - One reason on the PRS Tremonti Mk2 they offered a recess around the trem for more uplift - But on a DGT, Custom 22/24 you won't get one + half up pitch - Sorry, I said on an earlier post to 'undo' the 2 big wood screws on the trem claw - I meant to say tighten, so clockwise turn - 1 turn should be enough - re-tune + check how the trem base plate now runs to that parallel string line - If still out a touch then a 1/2 turn should be fine next time

As @ICBM states - make no change to the 6 fulcrum points when the strings are at pitch - detune by a big margin, to no tension, before making such adjustments to those fulcrum point screws - Okay to adjust the 2 wood screws in the trem cavity when strings are at pitch

dannelsonbass

Well, I reset the trem angle but the issue remains. I've little confidence in my abilities anyway, so that's not to say your recommendations weren't valid. It might well be that the knife edges are worn. 

Can you recommend a tech who could likely solve this issue?

ICBM

dannelsonbass said:

Not all strings are going at of tune at once. Sometimes I think its confined to the D string, sometimes the G, and sometimes to B. But I guess that's the nature of floating trems: each string affects the other so its difficult to pinpoint a culprit. 

That sounds like it's the nut. If the bridge was sticking all the strings would be out at the same time, the G and low E most noticeably.

guitars4you

dannelsonbass said:

Well, I reset the trem angle but the issue remains. I've little confidence in my abilities anyway, so that's not to say your recommendations weren't valid. It might well be that the knife edges are worn. 

Can you recommend a tech who could likely solve this issue?

Okay - try something new

Tune up as normal and leave the trem alone for now - Press gently on the string behind the top nut - Only needs to be enough to raise the pitch a touch - Now check the tuning - Do this on all strings one by one - If it goes out, on one, more or all strings it will hi-light the top nut as the issue

Rob Williams is somewhere in your neck of the woods for guitar repairs - https://robwilliamsguitars.co.uk/contact/