guitar tremolo setup

GUITAR SETUP: WASHBURN N2P

So, after a loooooooooooooooooong time out, here is a promised post on a guitar setup!

A customer of mine and all round nice-guy Nick dropped by with his Washburn N2P….

N2-1

 

The guitar in question is pretty special to Nick, he’s had it since the 90’s and was one of his very first guitars…i’m sure a lot of you will appreciate the importance that would hold for a musician!

Any how, this thing hasn’t been touched for a looooong time and is looking a little worse for wear. I had recently done some work for Nick on his number 1 gigging guitar so, impressed by the results, he wanted me to return this, once fabulous, N2 back to her best.

Now, the first thing we want to do with a guitar that needs work, before breaking out any pointy tools, is to take a good look!

We look at the guitar and try to establish any problems with it before we fiddle with ANYTHING. We give it a good look over from all angles and give it a little play too if string condition allows. We are looking for things that look “odd”, that don’t look quite right. We do this to try to ascertain the cause of any irregularities in the guitars playability. From first inspection of the guitar the main areas of concern seem to be fret wear, an un-balanced Floyd Rose tremolo and, partly as a result of the previous problem, a high playing action:

N2-11

N2-7

N2-8

 

Once we have had a good look at the overall physical condition of the guitar it’s then time to bust out the measuring tools and take some of her vital stats!

This step is UBER important!  It’s important for two main reasons; 1) measuring the guitar’s vital areas of performance gives us a great indication of what is likely to need doing and where it’s likely to need doing to remedy its poor playability and 2) When you have finished setting up the guitar you have a great reference for how much you have done, not so you can show off but so you can calculate exactly how much adjustment was needed and how much disparity there was in key areas between pre and post setup.

So, the critical areas i ALWAYS take note of before i touch ANYTHING are:

PLAYING ACTION- The distance between the underside of the outer E strings and the top of the 12th or 17th frets.

NUT ACTION- The distance between the underside of the outer E strings and the top of the first fret.

NECK RELIEF- The distance between the underside of the strings and the top of the 7-9th frets when the string is depressed at the first and body/last fret (see WTF section on relief!)

FRETBOARD/BRIDGE RADIUS- Checking the curvature of the fretboard and if it matches the curvature across the string spread at the bridge.

TREM FLOAT- Checking for correct bridge pitch for optimal tremolo operation where applicable.

Looking at the photos above gives us a pretty good indication that the playing action and trem float are going to be…well… epic!

So here are Nick’s N2’s vital stats pre-setup:

PLAYING ACTION- 7/64th” on the bass side and 6/64th” on the treble side when measured at the 17th fret…..that is high, even for a more traditional country-style Les Paul action that is on the high side so for a super-Strat guitar that is way out of the park!

NUT ACTION- 0.022″ on the bass side and 0.0015″ on the treble side…not rediculously high, in fact this probably isn’t far off factory settings for most guitars but a little higher than i like to see on “shredder” style guitars.

NECK RELIEF- 0.020″ measured at the 9th fret…again this isn’t far away from factory spec but way higher than i want to see, especially since it’s going to get lovely level frets!

FRETBOARD/BRIDGE RADIUS- The N2’s fretboard measures an expected 12″…unfortunately the bridge does not correspond to this at all….this is a key area for player comfort. If you imagine lightly laying a finger across the fretboard as in a barre shape, if the string radius is “out” then some strings will not contact the fret at the same time making the barre you have made feel horrible and buzz like crazy……eeeerghhh!!!

TREM FLOAT- 4/16th”…..bad! With the bridge pitched up like this the tremolo system will not return the bridge to the correct position for stable tuning as the system is not in equilibrium.

OK, so now we know what the stats are we have an idea which areas we will need to make critical ajustments to a make this baby play right! BUT…before we rip the strings off and start poking about the last test we need to carry out is an electrical check.

On plugging in the N2 it became obvious that we have a problem! This guitar has 2 humbucking pickups sharing one master volume push/pull volume pot which splits the coils at the bridge pickup switching between a single coil and humbucker sound. The neck pickup works fine but the bridge pickup works in the “split” position only…not good! Time to “pop the hood” and check out the wiring!

Once the back plate  was removed i was presented with this:

N2-42

N2-38

N2-48

This is NOT what you want to see when embarking on an electrical fault-finding mission!

For those of you unfamiliar with how guitar wiring should look…this is not it! Solder joints are messy, blobby and dry/cold, wires are under strain, shielding is messy and likely to short, insulation is stripped too far back leaving too much exposed signal conductor, again, likely to short. When wiring is this bad your only option, if you want to do a good job, is to re-wire the whole thing as at some point, even if you fix the main fault, another one is just around the corner!!

So, after taking off the strings and removing the wiring loom, switch and pot it’s time to test! The pickup selector tests ok, the pot is functional but the shaft continually spins round so the pot’s wiper goes from fully open to dead short and round again…operational but, clearly, not right! We know the neck pickup works so we need to test the bridge pickup.

A humbucking pickup that is wired for coil splitting will be of four-conductor construction, here is a wiring schematic to explain the function of each conductor:

billlawrence

From this schematic we can see the normal humbucker connections for this style of pickup would be between the ground/north start and hot/south start. Under normal humbucker conditions the south and north coils are wired together in series but in a coil split situation we can take a signal “tap” from the white/green conductor(s) which will give us either the north coil only (ground to green/white) or the south coil only (green/white to hot)

So let’s test this pup and see what we have:

N2-45

As the photo above shows, when measuring (using the DC resistance setting on the multimeter) between the green/white and hot conductors ( south coil) we read a healthy 6.16 ohms ( most single coil pickups will measure between 4.5 and 7.5 ohms….ish!)

So this will be the single coil we are hearing when the pot was in the “split” position. Now it’s time to test the rest of the pickup:

N2-51

Now we connect the ground and hot wire to the multimeter ( normal humbucker/coils in series wiring) and…oh dear! As you can see from the photo the meter is reading infinite resistance or open line which is telling us that somewhere between the ground and north coil finish (green) we have an open-circuit. Unfortunately, due to the construction of this Bill Lawrence pickup, we can’t inspect the coil to check for possible repair so I’m afraid this pickup is toast!

After some discussion with Nick regarding a replacement pickup for this guitar we came to the conclusion that a Seymour Duncan Custom Trembucker would be just the thing! Obviously a like-for-like Bill Lawrence would have been better but, after some research, it would appear that modern BL pickups are..how should i say this..not what they used to be ( this opinion is based only on what i have read from others experience!)

Fast forward to the arrival of the new pickup and it’s time to get re-wiring! At least i thought it was before discovering that the pickup ring for the BL pickup is too small for the chubby bobbins on the new Duncan pup….modification required!….

N2-31

…after filing the excess material from the pickup ring and smoothing with sandpaper the new pickup is mounted, new push/pull pot is mounted and selector switch is fitted… re-wiring begins!

N2-52

Now, the secret to good wiring is not just soldering technique….don’t get me wrong soldering the correct way is of HUGE importance but the real key is….PLANNING!

Before firing up the old melting stick we sit down and figure out things like; where all conductors will run in the shortest lengths with the least strain, where all our grounding points will be i.e all common to one pot, shared between pots or common to a ground plate and what our heat requirement is for each part of the circuit i.e lots of heat for attaching grounds to the rear of pots and not so much for pot/switch tabs.

When i wire guitar electrics i want the entire system to be functional, neat and able to withstand shock/movement:

N2-44

N2-43

As you can see from the photos, all connections have relief loops which are little loops of excess wire immediately before the connection. These then act as little springs to prevent strain on the connection. All grounding points are neat with no “splayed” screening, insulation is cut neatly to where it is needed and protected from peeling with heat shrink tubing where necessary, solder connections are neat, without excess solder and finished with heat shrink tubing, where necessary, to reduce the possibility of shorts. Excluding component failure, this electrical system should last forever!

Now that the wiring is complete and the system tests ok it’s on to the setup…

Right, we know from our initial inspection of the guitar that the frets on the N2 have seen some action, as such, little “divots” have been worn into the fret surface by the strings causing buzzing, inaccurate intonation and uneven pitch when bending. When this is the case we need to work out if all frets need replacing, some frets need replacing, all frets need levelling or all frets just need polishing. In this guitar’s case the frets are evenly worn the entire length of the neck so partial fret replacement is out of the question and although the frets are pretty low there is enough fret left to level and re-crown. So this job will require levelling,dressing, crowning and polishing. If the wear spots were really pronounced and deep we would be leveling with a course-cut leveling file but here the wear spots are fairly shallow so we can leave the super-butch file out of it and go ahead and level frets with the fret beam.

First things first it’s waaaay easier to perform fret work with the neck removed from the body so some decapitation is in order…

N2-18

…nothing out of the ordinary in here….nice!

N2-20

…and here’s the business end of the neck! Once we pop the cap off of the heel end we reveal the truss rod recess so we can access the truss rod nut.

Since we want the frets to be level WITH the fretboard we need to get the neck as straight as possible before leveling can begin. We do this using an appropriate truss rod key and a notched straight-edge (this useful tool is and engineers straight-edge with notches cut into it at the fret intervals so the edge can sit on the fret board NOT the frets!) and the truss rod is adjusted until the neck is arrow straight ( for reference see WTF Neck Relief )

Once we are happy the neck is dead straight we need to support it as we level so as to not introduce flex in the neck as we apply pressure, if this was to happen we would end up grinding more material away from the centre of the neck than the ends….not good!

We then apply masking tape to protect hardware and surfaces and mark the tops of all frets with machinists ink so we can see where and how much material is being removed.

N2-25

N2-17

My leveling beam is a length of  steel box-section which has two opposing machine-straight surfaces. It is filled with rice so it will take material away under its own weight, when we apply pressure to an object it is very difficult to maintain consistent pressure throughout a stroke so we see inconsistencies in material removal. With the neck firmly supported we make gentle, full length strokes, in-line with the neck perfectly perpendicular to the frets and we check our progress with every group of passes from one side of the neck to the other…

N2-26

…as you can see,after a few passes with the beam we see the material being removed from the high spots of the frets ( shiny spots ) and the low spots ( still marked with ink ) yet to be leveled. The low spots seen here are typical of a guitar played in all positions so there is wear all over the fretboard, here we see some low spots in the central “solo” area of the fretboard. We continue with lateral passes, moving from one side of the neck to the other and back again, each time checking progress, until we see no more inked low spots. Just as i break through the last low spot i usually switch to a radius block with 240 grit paper attached just to sure up any radius imperfections on the outer edges of the frets.

N2-21

Once we have evened out the wear spots we go through and check each fret with a fret rocker to catch any low or high buggers, we check the whole length of each fret starting at the treble side and moving to the bass side at the six string intervals. Once we are happy everything is level we can give the frets a clean.

N2-22

Here you can see a freshly leveled fret. Notice how we are left with a big ugly flat spot right on top of the fret…not very pretty looking and certainly not very good for intonation as the underside of the string will be contacting a huge surface area of fret rather than a nice clean “crown” on the very tip of the fret.

So, now we need to do some crowning. Crowning is basically rounding these flat spots over into a gentle curve. I do this using a three-sided fret dressing file, working one side then the other gently rolling over the flat edges to a smooth “crown”. This technique takes time…lots of time but the end result is a super smooth, gorgeous looking fret with pin-point intonation.

Once a crown is established on every fret we can really start to clean em up! I have a big wad of very dense foam in my workshop that i wrap with varying grades of wet/dry paper to slowly polish frets back to a high sheen. I start with 400 grit and concentrate on each fret making sure i rub out any scratches left by the beam or dressing file then i move through 600, 800, 1000, 1200, 1500 and 2000 grit papers, each time taking out the scratches left by the previous grade. By the time we hit the 2000 grit the frets are perfectly smooth but matt and dull. At this point i move to super fine wire-wool, polishing each fret for 30-60 seconds to bring up a sheen. After this stage the frets are looking pretty good but to add super-sheen i dab on a little chrome polishing compound and really work up some heat on them til they shine like hot-rod chrome!

N2-33

N2-32

…and we have frets again! From worn out looking, dull and pitted frets we have produced super smooth, slick, shiny frets with accurate crowns….lovely!

So, now that’s out-of-the-way we can turn our attention to doing some setup work! After CAREFULLY removing the masking tape (even masking tape can pull finish off of a guitar neck so pull diagonally and wiggle rather than rip!) we clean any remaining polishing compound and goo off with some mineral spirit on a rag and then rub in a DROP of linseed oil to seal the open grain of the rosewood ( only a drop here people, you don’t want to let excess oil penetrate the fret slots. Loose frets with fret slots saturated with oil are almost impossible to treat!).

Once we are happy that the frets and board are nice and healthy we can re-attach the neck.

N2-23

When re-attaching the neck i use Fender’s old trick of rubbing paraffin wax onto the screw threads. This wax not only acts as a thick lubricant it also seals the wood threads against moisture which will reduce the risk of swelling around the neck joint. I do this to any wood screw i remove on a guitar but neck screws are super important!

Once the neck is attached and aligned correctly with the neck pocket we can start looking at the tremolo system. This guitar is fitted with a licensed Floyd Rose system, a very well-engineered unit which is superbly accurate when set correctly and next to useless when not. To get it performing properly we need to remove the entire assembly for cleaning and service.

N2-14

To remove the trem block we first need to carefully remove the springs from sustain block and claw. As you can see above..the correct amount of springs are there but arranged incorrectly! It is extremely common to see three springs arranged like this on a block but i do not like it. Surely, in a finely balanced, sprung-loaded system it makes sense that ALL counterbalance strings are at the same tension at all times?…clearly this can not be the case in this arrangement as the centre spring has less tension due to its shorter travel. Some people will tell me I’m being pedantic and the “splayed” pattern looks better but i like to go with physics here, if you can’t get the springs straight with your chubby fingers then hard luck but that’s how i think they should be!

N2-35

N2-28

Once the trem block is carefully removed from the guitar i can begin taking each intonation piece off one at a time, removing the intonation screw, string clamp screw and clamp block. I then clean every part using WD40 cleaning oil making sure to remove any rust/oxidation with micro mesh polishing paper.

N2-24

When all parts are clean of rust, debris and DNA the unit is reassembled and all intonation pieces are moved BACK as far as they can go so we can sneak-up on our intonation points later.

Before we re-attach the trem block to the guitar this is a good time to inspect the bridge inserts and trem knife-edges for wear. A Floyd Rose system requires that the bridge floats perfectly on a fulcrum set by knife-edges on the bridge base interlocking with complimentary beveled bridge posts. If the knife-edges or post bevels are rusty, worn or chipped in any way then the bridge will not ride correctly and return to the same point. Upon inspection both the post bevels and knife-edges show no sign of wear but a tiny build-up of oxidation… a little rub down with fine grade wet/dry and a small application of vaseline as lubricant does the trick. Now the bridge assembly can be carefully re-located in the bridge posts and the springs can be reattached at the back being careful not to “shunt” the bridge into the posts, chipping the knife-edges!

Now we are ready to attempt what a lot of people get wrong….to balance a Floyd Rose system!

First we need to string-up so the strings are JUST taught, certainly not up to concert pitch. With the strings just taught we need to screw the spring claw out so it’s nearly at its maximum travel. We then use a wooden wedge behind the sustain block to shim the bridge until it is completely level with the plane of the body…

N2-39

 

You can see in this picture that the springs have been arranged in, what i think is, the correct pattern and the claw has been screwed out to just over an inch. My trem blocker is a piece of solid mahogany cut into a wedge that tapers from about an inch to half an inch. It’s imperative that a trem block be of hard wood so no compression can allow the bridge to move. When the bridge is shimmed so that it is level with the plane of the body this is its balanced position and every adjustment can now be made to the guitar (save for final intonation) without changing this balanced position….it is now “locked”!

We now need to look at the playing action and adjust where necessary. Since we know that the nut height needs adjusting but we don’t want to do that yet we need to take this extra height out of the equation for the bridge height, we do this using Fender’s good old-fashioned trick of using a capo at the first fret to give us a “zero” reading from the first position. The neck is still arrow straight from the leveling process which is the perfect starting point here as gradual string tension increase should pull just enough relief into the neck. Using my engineers 6″ rule i set the low E height at the 17th fret to 4/64″ and the treble E to 4/64″…

N2-54

…a good starting point for most strat-style guitars. It is worth pointing out that string action needs to be measured with strings at full tension as this pulling force will kick the neck up a little but. It is also good practice to slacken the strings off before adjusting the bridge height posts so as not to mar the knife-edges or post bevels…it’s a pain in the arse but like i said BEST POSSIBLE PRACTICE! At this point we can check the bridge radius. Unlike Fender style guitars we cannot easily adjust individual saddle height to correct bridge radius, instead low saddles are stepped using thin steel shims. In the case of this guitar one of the centre saddles (G) has been replaced at some point and is much taller than the others. Now in this case we could shim all the other saddles up to the same height but i like to have the fewest amount of shims as possible to maintain good mechanical coupling between saddle and sustain block at all times, so in this case i need to take the saddle off and grind it down to the same height as its corresponding saddle (D) These saddles should be at exactly the same height as they form the crest of the bridge radius. To grind Floyd saddles down a little i use an old fret leveling file upturned in a vice to get a nice dead flat bottom on the saddle…

N2-46

…and then a piece of fine grit sand paper taped to a flat tile to give the bottom a smooth finish…

N2-30

…once the saddle has been ground to the correct height we can then shim the other saddles where necessary to correct the radius. We check the bridge radius using a curved radius gauge underneath the string spread. We can make a second check (as the bridge is set at the same height bass to treble) using the 6″ rule and measuring each string to fret top at the 12th…all readings should be the same at this point.

 

Now we have corrected the string radius to match the fretboard we need to turn our attention to the nut height…

N2-40

…we already know that the nut was too high at the start of this journey and now we have taken a couple of thousands off the top of the frets we know we are going to be even higher. Now, if this was a guitar with a bone or plastic nut we would use nut cutting files to lower each slot to the required height…easy peazy….but this is not that kind of guitar! Guitars equipped with Floyd style trems have locking steel nuts with PRE-CUT NON-ADJUSTABLE string slots so in this case the entire nut has to be moved up or down to compensate. From factory these guitars have a veriaty of shims installed under the nut, these shims are then removed as the frets are dressed over time to compensate for the reduction in fret height. This guitar however has no shims left, the nut is sitting right on the nut shelf which is routed in to the fretboard.

There are arguments for different methods of adjusting the nut in these circumstances. Some will say take some material off the shelf and leave the nut alone but i prefer to modify the nut by grinding its base to make necessary adjustment. This way if you f*** anything up you can replace the nut or shim it, if you f*** the neck up then that’s going to be a tough conversation to have with your customer! In this case the nut shelf on this guitar is very thin and i would run the risk of routing right through the fingerboard and into the neck. So with all this in mind it’s time to grind the bottom of the nut.

The nut itself is machined steel which is chrome plated. In most cases it will only be necessary to knock the plating off and tickle some of the steel so i use the same upturned file i used to grind the saddle to grind the nut. Between strokes on the file i return the nut to the guitar to measure my progress until perfect.

N2-36

 

N2-29

Once the nut is seated at the correct height we are getting closer to where we want to be! Now we can tune up to pitch and check our playing action again as this may have moved slightly and we are measuring without our zero fret capo now. The guitar plays pretty good at this action setting but i feel a guitar like this with a dead level fret job could go lower, plus, i know Nick like a slinky feeling playing action so string height is dropped to 4/64″ and 3/64″ on the bass and treble sides respectively. A quick check of the neck relief shows a nice comfortable 0.004″ almost straight with a hair of breathing room…perfect!

Now we have our string action set we can go ahead and “rough in” the intonation, i say rough-in because remember we are “locked” and not floating yet! Now, when we assembled the saddles before we left them all at their furthest back position, this is a good idea because we want to sneak forward to our intonation spot not back, this way any kinks in the string are left BEHIND the string’s speaking length not within it! I explain the intonation process in detail in the WTF section so wont need to go into it here but for this job we use a strobe tuner, a 2.5mm hex key and a whole lot of patience because we measure, de-tune, reposition saddle, tune up, measure, de-tune, reposition saddle, measure…rinse and repeat until correct!

Once the intonation is set it’s time to float the boat….errrr bridge! With strings tuned to pitch and a quick check to make sure the bridge is still parallel to the body we wind in the spring claw screws bit by bit, 1/8th of a turn at a time SLOWLY until the block just gently slips out and booooom…in theory your bridge should be floating in its correct position!! Be warned though…things WILL have moved slightly so we have to re-check EVERYTHING and adjust where necessary. More than likely your string action wont have changed but you will need to re-check intonation because you can bet that has!

After re-tweaking the intonation and checking and re-checking your other measurements it’s time to play!!

So, as i say in the WTF section setup is about FEEL, you can’t go on measurements alone, a rule and feeler gauges can get you in the ball park but your hands will tell you when your finding the guitar’s “spot”, every guitar has got a “spot” and they’re all different…you just have to find it!

When we are happy with how the guitar feels we set the pickup height. Again much like the guitar’s feel, pickups have their spot, measurements get us close and we use our ears to guide us home. In general i set both pickups to 1/8″ from the string bottom with the strings held down at the last fret then…i listen! I listen for wolf tones from the bridge pickup, these are notes caused by the pickup’s magnetic field interfering with the elliptical vibration pattern of the string, if these wolf tones are present we back the pickup off and balance between bass and treble sides. Then i back off the neck pickup until it is just a touch lower in volume than the neck  adjusting bass to treble balance here also.

When we are done here the guitar is given a final clean, polish and playability check and she’s good to go!!!

 

I’m pleased to say Nick is very happy with the results of this setup and it’s just that kind of feedback that keeps me doing what i do…making guitars better!

If you have any questions regarding this, or any other setup please leave me a comment and i will try to answer you as soon as i can!

 

Thanks for your time,

TFM

 

 

 

 

 

 

 

 

Advertisements