Squire Jagmaster Gets a Total Make-over And Then Some! Part One of Four

Matt has many dreams. One of them was to have an offset-waist guitar with a Tune-O-Matic bridge and a Bigsby. And while we’re at it, a fresh set of pickups. And then, of course, a kill switch, because, why not? And there is Even More after that! This sounds crazy enough for The Unbrokenstring Crew to immediately roll up our sleeves!

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And, yes, Matt is a star!

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We have some added confidence that we can go crazy with this project because this is not the most expensive guitar in the world. But, as we shall see, it is a surprisingly good base for the modifications in mind.

Starting with the pickups, these factory humbuckers will be changed out.

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Each factory pickup measures almost the same resistance, but we labelled them separately for the benefit of future generations.

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A pair of P-94s grace the pickguard.

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The Gibson P-94s look dazzling on this guitar! Matt really hit a home run in the esthetics department. And they sound awesome, as we will later find out.

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A quick test of the wiring is performed by gently tapping each pickup with something metallic while the little Orange amp turns my taps into sound.

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While we’re here, the pickup selector switch is tightened with this serrated nut compression tool.

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Step One is complete. This guitar looks pretty snazzy!

In the next installment of this saga, The Unbrokenstring Crew will take a deep dive into serious Bod Mod and install a Tume-O-Matic bridge and Bigsby tremolo on this instrument. Tune In next week for Episode Two!

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE
281-636-8626

MIJ Fender Precision Bass Gets a New Nut and Setup

Lisa’s marvelous Fender P-Bass needed attention.  Some of the open notes were dead, and the electronics needed some attention.  Could the Unbrokenstring Crew sort it all out?
I just love the pale yellow finish.  Except for a string, everything is here.

 

Yes, it really is Made In Japan.  Back in the day, ‘made in Japan’ was another word for cheap imported junk.  Nowadays, this is some of the better stuff, particularly in guitars.

 

Name, rank, and serial number, please!

 

An electrical test shows that we have no output.

 

A quick look under the hood does not reveal an immediate problem.  Hmmm…

 

Oh, this is it.  The ground point for the whole unit is this potentiometer body.  However, the ground wire to the output lead does not connect to the potentiometer body anywhere.

 

With that fixed, the remaining ground wires are cleaned up a bit.

 

The bridge ground wire made an intermittent connection to the bridge.  We need to remove the green corrosion.

 

OK, the electronics are now all up to snuff, and actually look pretty nice.

 

While we’re here, we’ll tighten the output jack and potentiometers a bit.

 

The knobs go on now.

 

Final test is performed with a signal generator and another bass pickup.  The signal generator excites the windings in a bass pickup from an Aria Pro II bass, which will be featured in a future blog post.  The test pickup is brought near the instrument’s pickups, and the magnetic field carrying a test tone is coupled into the instrument’s electronics.

 

The dead open notes are traced to a cracked nut.  Here, we’re cutting the finish around the old nut so that it can be removed cleanly.  The Exacto knife gets a new blade for this operation.

 

The old nut comes out in two pieces.  The crack expanded until the nut broke in two.  That’s why we’re replacing it.

 

Here is the new nut that the customer wanted installed.  Good stuff!

 

Oops.  Houston, we have a problem  This new nut does not fit the neck.

 

The new nut is just a tiny bit smaller than what is required for this neck.  What gives?

 

We can clearly see the difference in the sizes between the old nut and the new one.  This neck is the width of a five string bass, but it was delivered as a four string bass from the factory.  So, we will make a custom nut for this instrument.

 

A Tusq blank is radiused to match the radius of the fretboard.  I’m using an Exacto knife as a scraper.

 

The Tusq blank is cut to rough length with a fine saw.

 

It doesn’t take long to slice through the Tusq material with this blade.

 

This is a saw blade set that I use for sawing fret slots and general fine work on wood.

 

The blank is now shaped on the disk sander.  A piece of birch plywood serves as a raised table that can be placed very close to the abrasive surface of the disk, necessary when shaping small parts.

 

The blank is now pretty close to the rough shape we need.

 

The first trial fit shows that we haven’t cut it too small, yet.

 

This is a little better.  The ends are flush and smooth with the edges of the fret board.

 

In AutoCAD, a drawing is created showing the cross sections of the four strings and the width of the fret board in actual size.  The distance between the edge of the outside strings and the edge of fret board, established by factory specs, is drawn, and the position of the outside strings fixed.  We then subtract the diameters of the four strings from the width remaining.  This result represents the space between strings, which shall be three equal spaces.  This establishes the center lines of the inner strings.  The spaces between the strings are the same, not the center-to-center distance.

 

But, to cut the string slots, we need to know where the edge of the fret board is, and where the center lines of the strings fall.  These solid lines represent that information.

 

The lines which represent the centers of each string are transferred to the nut.

 

A shallow file cut is made at each string center.  Here, we are checking these cuts against the template.

 

These shallow cuts represent the eventual center of each string.

 

These cuts were made with a triangular mill file.  Nothing special, but accurate enough.

 

Here, we’re polishing up the sides and faces of the nut, in preparation for gluing the new nut in place on the neck.

 

The nut depth is established by the fret height plus a constant which is established by Fender (and can be adjusted a bit by a good luthier, like me, for best play-ability.)  This is the Secret Sauce of making an instrument a great instrument.

 

The slot depth is now established by this stack of feeler gauge shims.  They are held in place with rubber bands wrapped around the back of the neck.  I’ve taped off the head stock so that I don’t scratch it up with the end of a file.

 

When the file touches the stack of feeler gauges, continuity will be detected by this multimeter, and it will beep.  This is another check of slot depth, besides my eyeballs.

 

Here, the slots are cut.  With a little cleanup and polish, this will be a good nut!

 

The nut is all done and polished.  Looks good!

 

The action on this instrument at the twelfth fret is pretty high…

 

We have a metal neck shim between the neck and body, made from a piece of the machinist’s feeler gauge of the proper thickness to reestablish proper neck geometry.  The metal shim is the hardest practical material for this purpose, with an accurate thickness, and better mechanical stability and hardness for greatest vibration transfer between the neck and body than a guitar pick or a piece of business card.  This results in the best tone.  And a set of feeler gauges are less than five bucks.

 

A quick adjustment gives us just the right amount of neck relief.  (Sharp-eyed readers will spot the fact that the strings are off in this picture.  This is the only pic I took of the truss rod adjustment, setting the neck flat while the neck shim was being sized.  Who cares if my pics are out of chronological order?)

 

To set intonation, we needed to work on the bridge.  Here is the underside of the bridge, probably not seen for decades.

 

The intonation screws were dinged.  Here, we are chasing the threads with a die to clean them up.  Yes, they are English/Imperial threads, not metric.

 

The bridge is tightened down and ready to go!

 

The moment we’ve all been waiting for!  Add strings, tune up, intonate, and play!

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

The Korean Squire ‘Blackout Strat’ Build

Matt’s unicorn was to again own a Blackout Strat like the one from his youth.  Could the Unbrokenstring Crew make an equal-or-better unicorn?
The body is a Korean Fender Strat with genuine wear.  The new neck is in superb shape.  This will be the basis for a cool project, particularly since modern parts are available to upgrade this guitar.

 

The neck comes off and will be updated separately.  Say ‘Goodbye’ to the Squire neck plate.

 

The dot inlays in this neck are really spectacular.

 

The pictures do not do justice to the spectacular mother of pearl in this fret board.

 

First, we’ll clean up a couple of handling skuffs that occurred while this project was coming together.

 

Tinted polyurethane, various grades of fine sandpaper, and a buff polish gets us back to where we belong.

 

A set of vintage tuners will be fitted to this head.  Here, we establishing the center line of the tuners.

 

Screws for the tuners will go where the scratches cross.

 

The pin vise is pressed into service to bore the screw holes.

 

This drill bit will be used as a gauge to verify the diameter of the tuner holes in the neck.

 

Sure enough, this neck was pre-drilled for 3/8ths inch bushings.

 

The bushings are fitted tightly into the neck.  This is essential for good tone, as the bushing supports the capstan, which is one end of the support structure that establishes string tension.  If these are loose, your strings won’t work very well.

 

Turning our attention to the body, we find that the ground wire was not properly soldered to the string claw.

 

The interior routes of the body were painted with a conductive paint.  This just won’t do for the Unbrokenstring crew.  This screw ties the conductive paint to the rest of the ground circuit.  We can do better.

 

The output jack is liberated from the stamped ‘football’ socket plate.  We will rework the wiring with heat shrink support in order to support the wires and make it more durable.  And the Unbrokenstring Crew will redo the soldering job, because We Own It if it fails.

 

The neck pocket must be square and clean.  Any debris or finish will interfere with the transfer of mechanical vibrations from the neck.  For maximum sustain, we need to take this pocket down to the bare wood.

 

This side view shows that the corners are square and clean.

 

Copper foil will be used to create the cavity shielding.  We’re starting with the hard stuff, the output jack route.

 

Bottom and sides are done.

 

All of the interior routes are lined with copper.  The seams are tacked together with solder.

 

This is the bottom side of the new pick guard, also made in Korea.  The aluminum foil must go.

 

All of the holes will be de-burred with this tool.

 

We will have a nice flat surface to which the copper foil will adhere without voids.

 

Foiling the pick guard takes just a few minutes!  Again, the seams are tacked together with solder to form a plane.

 

The foil is trimmed away from the edges with an Exacto knife.

 

This build will use these pickups.

 

This set will be a very cool foundation for this instrument.

 

The controls are mounted right to the copper.  True to Fender specs, we are using surgical tubing for pickup springs.

 

The pick guard assembly is done, complete with Orange Drop tone cap.

 

Here is another view.  All that is missing is the output jack wires and the bridge ground wire.

 

Here, the body is going together.  The output jack wiring and bridge ground wire is routed through the body and soldered to the pick guard assembly.

 

This workmanship turned out pretty.  New Old Stuff (NOS) push-back wire insulation is used to complete the vibe.

 

Everything fits!

 

The neck gets a little prep before the strings are installed.

 

Remember the Squire neck plate?  This is the replacement.

 

Meet the strings!

 

This new neck has a new nut, which needs to be slotted and filed.  String spacing is established here.

 

Here, the slots are taken to the proper depth, calculated beforehand.  The stackup of feeler gauge blades establishes the bottom of all of the string slots.  When each file touches the feeler gauge blades, we’re done.

 

The string slot depth is where we want it.  Next is to file off the top of the nut and polish it, which has been shown in other blog posts.  When this is finished, the strings will protrude just above the top of the nut.

 

Now this is beginning to look like a guitar.  This is set up as a ‘hard tail’ so no tremolo bar is needed, but one is supplied.

 

We lost Matt somewhere in the bowels of Guitar Center.

 

This message came into the Unbrokenstring Global Command Center after this guitar made it back to the rehearsal room:

“BTW been meaning to tell you, OUTSTANDING job you did with the recreation of Crow’s Fender Blackout Strat!

     “I think can say, without any hyperbole whatsoever, that just plugged straight into an amp with no tweaking whatsoever, that is the BEST SOUNDING GUITAR I HAVE EVER HEARD IN MY LIFE.

     “Completely outshines even the original Blackout he was trying to unbury.

     “We’re still absolutely dumbstruck by clarity and full tonal range of it. Truly amazing work, sir!

     “Without question, your finest creation to date.”

 

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

Rickenbacker Rick-O-Sound Bass Repair

Craig is a Ric Man.  This beautiful blue bass in only one of his many Rics.  This one has problems with getting both pickups to work.  Could the Unbrokenstring Crew get all this sorted out?

This instrument plays beautifully and has no real discernable setup issues.  However, the wiring seems to be amiss!

 

More than a few of you will have heart palpitations seeing this head stock.

 

Two output jacks allow a mono mix of both pickups as is usually found with most multi-pickup instruments, plus a special “Ric-O-Sound” jack that presents the signals from two pickups as two separated signals, accessible with a stereo cable (TRS.)  This gives the player the ability to run two preamps, two effect loops, two separate amps, etc.

 

Immediately after looking under the pick guard, we find a loose wire.  Poor soldering here.

 

This isn’t even tinned.

 

Here is another broken wire, another ground wire.

 

We have a stack of three inside-tooth lock-washers under each output connector.  Not much spring action available from the teeth of these locking washers, so they don’t really lock.

 

A magnet is the quickest way to clear all this extra hardware out of the control route.

 

This is the stereo jack handling the “Ric-O-Sound” duties.

 

The mono jack handles the single-ended output from this instrument.

 

Soldering workmanship on the switch needs some attention as well.

 

Disconnecting each pickup allows us to do some cleanup in the wiring cavity.  The neck pickup is ohmed-out.  The neck pickup is sometimes called the ‘treble’ pickup.

 

And we do the same with the bridge pickup.  This pickup is also called the ‘bass’ pickup, which seems redundant.

 

Perhaps this soldering was done with plumber’s solder.  It is awfully dull.

 

Another look at the switch.  Not much to brag about here.

 

The ground connection to the control is redone.  Smooth and shiny is the name of the game when soldering.

 

I labelled the controls BV (Bass Volume,) TV (Treble Volume,) BT (Bass Tone,) and TT (Treble Tone.)

 

Now that the controls are identified, we can install the knobs in the Correct location.  Yes, they were in the wrong place.

 

Earlier I pointed out the stack of three inside-tooth lock washers.  Here’s why I mentioned it:

 

When stacked, the teeth have nothing to push against.  The teeth are literally hanging out in space.

 

A flat washer in the middle will provide some ‘resistance’ for all the teeth to press against, thus restoring the action of the lock washers to that of being, er, well, lock washers.

 

The jacks are Imperial measurement and this washer must have been metric.  A little gun-smithing is in order.

 

The output jacks are wired and tightened into their correct locations.

 

Testing shows no output.  It has something to do with this volume pot.  What the hey??

 

This is the hey.  This bit of conductive solder debris was underneath the volume pot, shorting the ‘stapled’ contacts seen in the previous picture to each other, and thus, shorting the output to ground.

 

Together again, and it’s playing in stereo!

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

Warmoth FrankenCaster: It Lives!

This offset-waist project guitar is playable and is actually very cool.  The owner had ‘gotten in over his head’ and broken a few screws and buggered a few others.  Could the Unbrokenstring Crew whip this instrument into shape again?

The easy part is to install gold Gibson speed knobs on the controls.  There are a lot of good parts in this instrument.

 

Looking more closely, the neck pocket will need some serious attention.  What’s going on here?

 

This is what’s going on.  If you look at the high and low strings, you will see that they are not the same distance from the edge of the fret board.  This neck is not lined up with the body of the guitar.

 

It is easy to remove the truss rod cover because these screw heads are already sheared off.

 

The heads of the screws around this pickup were mangled to the point that a regular Phillips screw driver would not engage them anymore.  Here we’re using a pair of cutters to twist the screw out while a magnet serves as a sentinel to keep pieces of metal that will inevitably shave off the screw head away from the magnet in the neck pickup.

 

Wow these are long.  These go most of the way through the body.

 

We are still working on this one.  This is really tough.

 

Note that the head is chewed up pretty badly.  New screws are already in stock.

 

No springs or tubing are underneath this pickup, bur rather a chunk of too-thick too-hard foam.

 

Now we know where this body came from!

 

And the neck is from Guitar Fetish.  Here, I marked where the body ends with a dotted line.  More on this later.

 

So what can we do about these broken screws?

 

No problems removing the tuners…  these screws were busted off as well.

 

To remove the broken screws, we apply heat to the body of the screw.  This dries out the surrounding wood so that it shrinks slightly.

 

I used the same technique with the wire cutters to grasp the body of the broken screw to twist it out easily.

 

Rinse and repeat for the remaining broken screws.

 

Now that everything is apart, I need to fix this neck pocket.  First, we get the bottom flat.

 

Then we get the sides flat.  This body was painted after it left the factory, so we have plenty of over-spray in the neck pocket that we need to clear out with this scraper.

 

I believe that we are down to real wood again.

 

Acoustic coupling occurs best when the neck and body fit tightly, ‘bone on bone,’ if possible.  I really like this wood hardener, which is essentially solid Lexan dissolved in a light solvent.

 

This raw wood will take a few coats to seal and harden.

 

As the old cowboy on the cattle drive once said, “Be sure to look back to see if the herd is still behind you.”  Periodic fit checks are always a good idea.

 

This neck is beautiful because of the thick layer(s) of polyurethane finish.  However, the polyurethane layer may get in the way of acoustically coupling the neck to the body.  Here, I’m hatching the area where I will scrape away finish.

 

Again, the luthiers’ scraper is the perfect tool for removing finish evenly and smoothly, leaving the surface exactly flat.

 

That is much better!  Not shown: the finish on the end and sides of the neck where it meets the body is also removed.

 

A pin vise holds the proper-sized twist drill to resize these holes for the Correct pickup screws.

 

A little canned air clears out the cuttings from the holes.

 

Over-sized screws held the pick guard in place.  The Correct screws are smaller.  Here, a small dowel is glued into each hole, which will be re-drilled with the proper-sized hole.  This is hide glue shown here; just fine for this duty.

 

Once the hide glue is cured, each dowel is trimmed flush.

 

I jumped ahead to show how the Correct screws are nearly flush with the top of the pick guard.  Almost factory.

 

This single-coil pickup reads as an open circuit.  That tiny wire is broken.

 

The tiny wire is broken because these black and white leads can twist around.  Hot-glue now holds them stationary.

 

The pickup is working now.  Here is some new, softer foam in place to hold the pickup in position.  Leo Fender would have used short pieces of vinyl tubing on the screws to act as a spring, but these covers go all the way to the bottom of the cavity route, so the foam is the best option for this setup.  Oh, and you can’t see it, but the copper pulled out when the original foam was replaced, so this guitar has copper in the pickup route and under the pick guard.

 

Here is the actual pickup.

 

And here is the separate cover.

 

The Correct screws are not nearly as hard to drive as the other screws.

 

More Guitar Fetish goodness!  The metal parts of the guitar should be tied to a single point, not at various places along the signal path.  This soldered wire ties the metal body of the pickup to one side of the audio path, and has got to go.

 

That connection is now cut open.

 

A separate layer of foil is wired to the single point ground.  The connection to the bridge and strings is accomplished with another sheet of foil and this outside-star lock washer.  Again, the mechanical ground is not part of the signal path.

 

Everything goes together as it should.  See how the star washer makes the connection between the bridge and foil?

 

The Correct controls are marked T for tone and V for volume.  The switch is ready to wire.

 

The new wiring is accomplished with solid wire in Teflon tubing.  The pickup wiring is the vintage ‘push-back’ wire, which is actually really easy to use and can be very clean-looking as the insulation is cut without resorting to wire strippers.

 

When the control plate is in the correct position, new holes are bored for the screws.

 

The neck plate needs some attention.  This metal polishing paste is also what I use to polish fret wire.

 

These holes are reamed to the proper size for the Correct screws.

 

The tuners are going on!  A bit of red felt is glued to the face of the socket so that the finish is not marred.

 

These new screws going into the correctly-sized holes are very well-behaved now.

 

The truss rod cover screws will now live in properly-sized holes as well.  The pin vise is getting a workout today!

 

The customer uses these strings.  We need the guitar strung so that we can get the neck straight.

 

Note that the outside E strings are equidistant from the edge of the fret board.  The screws attaching the neck to the body are tightened at this point.

 

Now that the neck is properly positioned, we can finish the setup.  The truss rod is adjusted to make the neck perfectly straight.  Do you see the slip of paper next to fret 9?  It is used as a feeler to see that the ruler is in contact with the fret board all along the neck.  A piece of paper is about 0.0015 inch thick or so.  It is used to check for fit between every fret on the fret board.  Yes, that makes a difference!

 

This neck is brand new, and so the frets had never been leveled.  Just a tiny bit of sanding was all it took.

 

Here I am taking a measurement of fret wire height.  I need this shortly to file the nut slots.

 

Frets are polished.

 

Fret board is cleaned and conditioned with oil.

 

Here we are cutting the nut slots to depth (about 0.006 inch plus the fret wire height measurement made earlier.)

 

Once the nut slots are at the right depth, the rest of the nut is sanded away to make the slots shallow.  We need to sand a little bit more away near the high E and B strings, and maybe next to the D string.  We’re getting there!

 

The instrument is back together and sounding good!

 

This is a closeup of the saddle barrels.  These are factory intonated and are VERY close to correct.  How do they do that?

 

Our patient is making her debut at the studio.

 

First Note.

 

I think he likes it!

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626