Guitar tech (again) part one.
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TOPIC: Guitar tech (again) part one.

Guitar tech (again) part one. 3 years, 9 months ago #1

Platinum Boarder
Another field of interest is guitars, mainly solid body electric ones. Over the years, 85 of these axes went through my hands. I have built some from scratch, a few from a kit, but mostly it was repairing, upgrading and/or modifying instruments either from my own collection or from friends who knew that I know about guitars. The history of solid body electric guitars is well known to me, and next to it do play a bit. Sometimes I wish I could play as well as knowing about the instrument itself, but I am happy as it is.

Last week my daughter asked me if I could repair her Stratocaster, there was something wrong with the controls and the thing would not keep in tune properly.

I gave her this guitar some 10 years ago, and the instrument is of mid 80's vintage. It is not a real Fender Stratocaster, it is one of those many clones, in fact this is one they call a law-suit model, meaning they are rather good Fender lookalikes and in this case they even used the same Fender script for the logo on the headstock and they called it a Vester. When I say law suit, I mean that Fender and other musical instrument factories had to take a lot of effort to protect their trade marks by issuing law suits to anyone who came too close to their products. Vester made a lot of very good quality clones. This particular one is from a budget line, but even then some of them are excellent players, like this one. My daughter really loves this guitar

I started to strip the guitar, taking off the strings, tuners, back cover plate, bridge assembly, and finally removed the scratch plate which houses the pick-ups, potentio meters and the switch.

To be continued.
The following user(s) said Thank You: Nobleco, RoutemasterNL

Re: Guitar tech (again) part one. 3 years, 9 months ago #2

Platinum Boarder
I will be watching this thread. Thanks for posting this interesting topic.
The following user(s) said Thank You: Ecclesley

Re: Guitar tech (again) part one. 3 years, 9 months ago #3

Platinum Boarder
Part two:

In the heading it says Guitar tech (again). It has been 4 to 5 years since I last worked on a solid body electric. Guitar collecting, building etc. was on the back foot, one of my other hobbies, a.o. an oldtimer Rolls Royce, took preference. Still I played almost every day, but only on my acoustic. With the exception of one, all my electric guitars were sold. This was also due to my moving house and having much less space to work and play, let alone build a guitar myself. Thanks to my daughter I am more or less back on the tracks of the electric guitar, but no big projects are possible. This Stratocaster is an easy job (for me).

This specific guitar, made in the mid eighties, is a product of cheap labour (South Korea) and as it is a budget model, the hardware; tuners and bridge/tremelo assembly are not very durable. As to the electronics, the potentio meters are quickly spent. The pick ups however are quite good.

The body of the guitar is not made out of what we call solid tone wood, like alder, maple, ash or mahogany, it is plywood, making the guitar a bit heavy. Still plywood has it's own character. With this guitar it sounds just fine. The bolt on neck is rock maple with a rosewood fretboard. Inside the neck there is a metal truss rod. An allen screw, hidden in a small pear shaped cavity on the headstock, attached to this rod, allows you to adjust the neck, if neccesary.

From the pictures of my first contribution you can see that Leo Fender, the man who designed the Stratocaster (with two other people involved) was a very practical thinking man. Everything was bolt on, so if it breaks, just unscrew it and replace it with new parts.

In the body you see the routings for the 3 pick ups, the electronics and the very clever bridge/tremelo unit, which was one of Leo's great innovations at that point in time. I will describe more on this in my further contributions.

For now it was a case of getting the new parts. The guitars badly needed a new set of tuners and all the potentio meters were more or less defunct. I also bought a new bridge/tremelo unit; the old one had seen better days. I got them from my favorite suppliers, living in the town of Landsmeer, close to Amsterdam.

The following user(s) said Thank You: RoutemasterNL

Re: Guitar tech (again) part one. 3 years, 9 months ago #4

Platinum Boarder
Part three.

Having the parts I needed, now comes the moment to put things back together again.

I started with the tuners. The old (cheap) ones removed and a set of 6 inline Kluson type keys to be installed. A tuner, key or machine head, whatever you like to call them, is a rather simple looking item, but it is of the utmost importance to keep your guitar in tune. Basically it is a set of encased gears  that drive a shaft, around which the string is wound. The quality of a tuner is mainly dependent on the bearings of the gears, if those are made of good stuff then the tuner shaft will not move or slip and will have a long life, provided you give them a drop of oil from time to time. The tension of the strings is such that a tuner needs to withstand a lot of strain and when a guitar is played very often they need to perform without fail.

The split shaft tuners I took are very user friendly, and most of all they really hold the strings very tight so they cannot lose tension which would make the guitar get out of tune. But even with the best set of tuners, you always need to re-check the tuning before you start to play. Strings do stretch, especially when they are still quite new, and changes of temperature/humidity will have an effect on the guitar neck.

The shaft has a hole in which you drive the string, next you bend the string through and around the split shaft and then start winding.

The set is fastened with screws at the back of the headstock. The hole in the casing is for applying oil.


To be continued.
Last Edit: 3 years, 9 months ago by Ecclesley.
The following user(s) said Thank You: RoutemasterNL

Re: Guitar tech (again) part one. 3 years, 9 months ago #5

Platinum Boarder
Part four.

With the tuners done now comes the installation of the tremelo bridge. But before I dig into that subject let me first tell you a bit of Fender guitar history, to put this Stratocaster guitar into perspective.

Clarence Leonidas (Leo) Fender (1909-1991) was not the inventor of the solid body electric guitar, but he certainly was the first to make it commercially successful. Fender was more like Henry Ford. Electric guitars already existed before WWII but those were hollow body instruments which played no leading role on the bandstand. Also amplifiers were still in need of development. In order to make a guitar cut through the mix, it needed better amplification and a solid body that would cast the sound into the public and make it heard. During the '40's several people were experimenting with solid body electric guitars like Leo Fender. Men like Paul Bigsby, Les Paul and Orbra Appleton. But it was Fender who conquered the market first in 1950, followed by Gibson in 1952.

The funny thing of it all is, Leo Fender was not a guitar player, but he sure knew how to make excellent amplifiers and electric guitars. His first electric guitar was the model we now know as the Telecaster, followed by probably his greatest innovation, the solid body electric bass guitar (Precision Bass). On the basis of feedback he got from artists in the field he designed the Stratocaster in 1953, an instrument so way ahead of its time it was considered something out of space. One of the innovative features of this guitar was its tremelo bridge.

The solid body electric guitar created new sounds and styles of music and Stratocaster legends were born: for instance Buddy Holly, Jimmy Hendrix, Eric Clapton, Mark Knopfler, David Gilmour, Hank Marvin, Ry Cooder and of course my daughter Roza.

The bridge assembly consists of a base plate, six adjustable (height and length) saddles, a metal block screwed tight onto the underside of the plate, having six channels  through which the strings are anchored, and a maximum of 5 springs which are connected (hooked) to the block  and next to the body claw. Without this inertia block the guitar would have very little sustain and sound flimsy. Then there is the tremelo arm, also called the whammy bar, screwed through a hole in the base plate into the block as well.

The body is routed to house the bridge/block/spring assembly.

The base plate with the block attached is screwed onto the upper body with six heavy screws. The underside of this plate is not totally flat. At the front where the 6 screws are sitting, it becomes pointed; a kind of knife edge, so the bridge can tilt. See arrow:

This where the springs come into play. Without counteracting this tilting, the bridge would lean forward because of this knife edge by about 30 degrees and the whammy bar would be useless. It would be an unplayable static construction.

The next picture shows they way the springs are attached to the block and body claw. Note: the inertia block of a Vester is different in shape than the real Fender ones.

As my daughter does not use the whammy bar I attached all five springs and screwed the claw completely onto the body. The more springs, the heavier the tremelo arm and the deeper the claw is attached the more tension there is on the springs. In this way the bridge becomes what they call a hard tail and will not tilt. One advantage, it stays better in tune, as using the whammy bar stretches the strings a bit. Another advantage is that it is less difficult to set up the guitar for playing. String tension and spring tension is something which normally acquire a lot of work to get it right so that the guitar is well balanced. Players who do use the tremelo arm normally have 3 springs attached and the claw is partly unscrewed like this:

So the bridge is done, next will be stringing the instrument and the intonation of the guitar by adjusting the length and height of the bridge saddles (not an easy job).

To be continued.
Last Edit: 3 years, 9 months ago by Ecclesley.

Re: Guitar tech (again) part one. 3 years, 9 months ago #6

Gold Boarder
Wow . Nice guitar article for sure. I have been playing around with them since 1965 . Mostly just my own. I rebuilt my orginal Kalamazoo 3 times over the years.

Re: Guitar tech (again) part one. 3 years, 9 months ago #7

Platinum Boarder
Rixtoys wrote:
Wow . Nice guitar article for sure. I have been playing around with them since 1965 . Mostly just my own. I rebuilt my orginal Kalamazoo 3 times over the years.



Is that Kalamazoo (Gibson) an SG type of body, or??

Re: Guitar tech (again) part five. 3 years, 9 months ago #8

Platinum Boarder
Part four ended saying that the next step would be stringing the guitar. Wrong!

Next comes the scratch plate/pick guard with the inbuilt electronics. This goes under the strings so better do that first. The Stratocaster pick guard is a plastic plate which forms the basis for the mounting of the tone (2) and volume (1) pots, the pick up selector switch and the three pick-ups. Next it is screwed onto the top of the guitar to cover all the routings, another very clever way of guitar construction.

The wiring scheme is a standard procedure, unless you want to have extra switching facilities to get more kinds of sound. The three pick-ups are basically exactly the same, but as they are placed in different spots on the guitar it affects the sounds they produce. The neck pick-up has a darker, jazzy sound, the middle one is more mellow and the one close to the bridge is clean or twangy as they say. The first Stratocasters had a three way switch so you could choose between one of the three single pick-ups only. But then somebody found out that if you fiddle the switch between the first and second position, you get a mix of the bridge/middle pick-up or in between the second and third position a mix of middle/neck pick-up. That is the way the five position selector switch was born. This guitar of my daughter has the standard wiring scheme with a 5 way switch.

What I had to do is install three new 250 k Ohm potentiometers (pots). One for master volume, which is logarithmic and two lineair pots for tone control.

Soldering everything according to the scheme and hopefully it works, which can only be fully tested when the strings are mounted. So if you make a mistake you must un-string the guitar again, do the trouble shooting and then start all over again. Sometimes on a bad day.........

Another important thing is the ground wiring and shielding. If that is not perfect, your guitar will start making uncontrollable noises when it comes close to other electrical devices/magnetic fields, for instance the amplifier, which is a real misery. This guitar is amply grounded/shielded and it is without any buzz.

Here is how it looks after my soldering efforts:

My daughter had a special request, she wanted a pick guard with a different color/pattern. Well the easy option is to buy one as they can be found in all kinds of colors etc. But I use my own (much cheaper and more individual) way of changing the pick guard. I take adhesive foil, which can also be bought in all kinds of liveries and put it over the guard. It looks like this:

The standard guard:

Adhesive marble pattern foil applied:

Having cut away the excess it now looks like this:

And here is how it looks with everything (new knobs and switch tip) installed.

In this picture the guitar has its strings on, I will address that subject in the next part.


Extra: here a few other examples of pick guards with adhesive foil which did:

This P Bass, made from a kit,  with carbon foil:

Or this Squire '51 with snake skin foil (also on the headstock)

Or maybe a panther:

It does make a lot of difference
Last Edit: 3 years, 9 months ago by Ecclesley.

Re: Guitar tech (again) part five. 3 years, 9 months ago #9

Very very interesting. My son Lars loves this topic!

Re: Guitar tech (again) part one. 3 years, 9 months ago #10

Platinum Boarder
We are now close to the finalization of the guitar. Putting on the strings and next the intonation of the guitar.

My daughter uses very thin/light strings which I personally do not like. Although it gives a lot of clarity, almost acoustic, and plays very light, it misses the depth and strength which is part of playing a solid body guitar. But if that is what she wants, I'll follow. My preference of strings does not go lower than 0.011 inch for the thinnest E string, my daughter wants 0.009.

Note: the late Rick Parfitt from Status Quo used 0.014 for the thinnest string; you need strong fingers to play that one.

Okay lets start stringing this guitar. As shown before, the strings go through the inertia block of the bridge and when pushed through they come to the surface at the relevant saddle. This saddle guides the string over the neck to the nut which is sitting at the end near the headstock and then they are wound up to pitch tension by the tuners. The saddles can be adjusted for string height and - length. The distance between the saddle and the nut is the (individual) scale length of each string.

The nut, see arrow:

The standard open tuning (first octave) of a guitar is E A D G B E, (Eat All Day Green Bananas Eric) seen from the thickest string (0.046 inch on a 0.009 set).

Having put on the strings I start tuning them to pitch one by one, by using an electric piezo tuner. This tuner is set at a 440 Hz frequency, equal to the A key (next to the middle C) on a piano. This is an international standard.

Okay when tuned to exact pitch I start looking at how high or low the strings are sitting above the fretboard of the neck. Too low and they will touch the metal frets; the strings will buzz and sound horrible. Too high and the guitar becomes difficult to play. My daughter wants them as low as possible. By adjusting the screws of the saddle (see pic below) I can achieve this one by one. I never use any kind of gauge, I do it by eye sight and by playing each string fret by fret over the whole of the neck. I keep on lowering the strings until they buzz, which means I went too far and have to screw upward a little. That is my way of doing it.

Now comes the task of intonation. 

For simplicity's sake, intonation is the tune or pitch of your collective guitar strings as you move up the fretboard or scale length. Although it is impossible to perfectly intonate your guitar because of its equal temperament tuning, it is possible to come to a compromise with a proper set up. The intonation can be set on your electric guitar to make the second octave, the 12th fret and above, stay closely in tune with the first octave.

The way to adjust guitar intonation is to shorten or lengthen the scale length of each individual string, which can be done by moving the bridge saddles forward or rearward.

If moved forward, the scale length of the string becomes shorter. If moved rearward, the scale length become longer.

An example: I tune the D string (first octave) to pitch (as on my electronic tuner) next I fret the same string at the 12th position, which is also a D but one octave higher. If it is perfectly intonated it must show the same pitch result, the needle stands in the middle of the tuner. If it is to the left of the pitch (called flat) the string is too long and the saddle must be moved forward, if it is to the right of the pitch the string is too short (called sharp) and the saddle must be moved backwards.

So I move the saddles one by one, bit by bit until I reach the best possible pitch at the 12th fret position for each string. Sometimes it takes a couple of hours to get it as perfect as possible.

Okay finished now, time to start playing this axe.

Last Edit: 3 years, 9 months ago by Ecclesley.
The following user(s) said Thank You: Nobleco, RoutemasterNL
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