The slots for the thinner strings can be cut with a saw although sawing will not give round-bottom slots. But that's OK. Wider slots can be made by rolling the saw side-to-side.

Saw or file the slots until they are just a little higher than you want them to be. Make them the right height later when the guitar is finished and ready to be set up. Finish work on the nut for the time being by sanding and/or polishing it with a small buffing wheel in a drill press.

Wiring the electronics

Now heat the soldering iron and place the body on a piece of carpet and cover as much of the body surface as possible to prevent doing damage to it.

When you do the wiring it is advisable to use differentlycolored wires to avoid unnecessary confusion and to facilitate keeping track of all the wires. Use cold colors such as black or blue for ground wires and warm ones such as red, orange or yellow for signal-carrying (hot) wires.

Braided wire is ideal because it consists of numerous very thin strands of wire and because it is very flexible. Use shielded wire whenever the wire length is greater than about 4 inches. With shorter wires it is not worth bothering since the braided shield will have to be removed on both ends to lay open the conductor wire. Shielded wire consists of an insulated conducting wire surrounded by a braided wire which, when connected to ground, acts as a protective shield against unwanted hum and noise that would spoil the sound coming from the amp. If you want to solder, say, the pickup wire to the pot, you first have to strip a short piece of the end of the wire of its insulation. This can be done with special wire strippers but equally well with a knife. Cut up the insulation very carefully to not damage the thin strands of wire inside, and remove the plastic insulation with the nails of your thumb and index finger. On insulated wires remove about an inch of the insulation before disentangling the braided wire. Start pulling out the individual strands of wire not at the end but at the point where the insulation starts again (i.e. about an inch from the end). A fine sewing needle is ideal for this. After that twist the individual strands together to form a thin wire and apply solder on its end. Then also strip the inner wire of its insulation over a length of about 1/5 " (5mm) and again apply solder on its end and also on the pot lug. For soldering, hold the wire to the point to which it is to be soldered or, if possible, put it through an eyelet, and then hold the soldering iron so that it heats both parts that are to be joined. The solder will soon begin to flow and connect both parts. You will get an even better joint by adding a bit of solder (not too much, though!) after a few seconds. This can, however, only be done with the help of another person - your two hands aren't enough for this purpose.

Soldering

The standard method of forming electrical connections between building components and wires in electronic circuits is soldering. This type of soldering by which two metals are connected with solder is called soft soldering. Use an electrical soldering iron with a power of about 30 to 45 watts. Solder is available at all electronics stores. It is typically 1mm in diameter and consists of a flux core surrounded by a tin-lead alloy. Rosin is often used as a flux to make the solder flow more easily. Because they contain lead, the fumes developing during soldering are toxic and should, if at all possible, not be breathed in.This can, however, never be completely avoided - after all, you have to hold your head over the soldered joint to be able to see what's going on.

The tip of the soldering iron ought to be tinned and kept clean. Clean the tip by moistening it with water and then wiping it in a sponge. Always pre-tin both parts of a soldered joint by holding the hot soldering iron against the wire and by applying solder between the tip of the iron and the wire. When the temperature is right, the solder will spread evenly. A vise might be useful in place of a “third hand” (which is frequently needed for soldering).

Good

Bad

When carrying out soldering work on heat-sensitive semiconductor components such as diodes or integrated circuits (ICs) the soldering time must not exceed five seconds.

Equipment for wiring your guitar

The picture on the left shows the equipment needed for wiring. A 30 to 45-watt soldering iron (1) and rosin-core solder (2) are recommended for soldering. Wire cutters (3) for cutting and special wire strippers (4) for removing the insulation from wire are quite useful, too, although a knife (5) will also do. A pair of tweezers (6) or small pliers can be useful for holding the wire. An unsoldering pump (7) or special unsoldering wire (8) are needed for removing solder. With an ohmmeter (9) badly-made connections and other problems can be traced. Faulty contacts, however, are also easy to identify by connecting an electric light bulb and a battery in series. But digital multimeters have meanwhile become so cheap that everyone can afford them anyway. Most multimeters have a beep tone that can be switched on so that a signal is given off when two points of a circuit are connected.

If, however, you manage to somehow hold the wire in place, as for example in an lug hole or in a small vise, you will have both hands free for soldering. Leave the solder joint to cool without moving any of the parts just joined.

A good soldered joint will never resemble a drop or a lump or look dull. If, however, this is the case, too little heat may have been used for soldering and you will have to reheat the joint, adding a bit of solder until it flows properly. Badly-soldered joints are the reason behind loose contacts - which almost inevitably lead to unpleasant noises - or behind completely interrupted connections. The illustrations on the right show the cross-sections of a good and a bad soldered joint. In the bottom drawing the solder looks dull and has the shape of a lump. Such a “cold” soldered joint is produced when the solder is not hot enough. A bad connection is the result.

It is unfortunately often the case that soldered joints have to be unsoldered to make changes to the wiring. Removing solder from the hole of an eyelet is always a problem. If you try to push a new, tinned wire through hot solder, the twisted-together wire strands often come apart again. Special pumps or wires for removing solder are commercially available. A simple trick that will also do is to heat the solder and to force the tip of a pencil through it. The graphite of the pencil will then remove the solder and open up the eyelet.

If through lack of care the tip of the soldering iron should get in touch with a neighboring contact an unwanted connection may be produced. Such joints can only be “broken” with an unsoldering pump.

To provide better shielding the casing of all potentiometers has to be grounded. Heat the casing with the soldering iron (1) before applying a small lump of solder, making sure that the solder melts on the casing, i.e. that it is hot enough. This is the case if it is of a silvery color and flows nicely and by itself over the casing. If it hasn't been heated sufficiently, the solder will form a lump. When the solder is hot enough, solder the tinned wire to the casing. If several wires are soldered to one point, it is advisable to twist and solder them together before soldering them on (2). Try to keep wires as short as possible to minimize the likelihood of any hum occurring.

The output jack is last to be wired. Make sure to leave the wires long enough to not unnecessarily complicate the soldering (3). By mounting all control parts on a pickguard or an electronic cover plate wiring and servicing is made easier (4).

Shielding the electronics

The electronics can be shielded by spraying on two coats of conductive shielding paint. Such paint is available from guitarmakers' suppliers such as Stewart-MacDonald. Alternatively, you could also use self-adhesive or non-adhesive copper foil (5). Aluminium foil should be avoided because it is almost useless for this purpose. If you use non-adhesive foil, fasten it with spray glue. What is important is that the areas shielded with paint or foil are all connected to ground. The wires can be soldered to the foil or paint in the same way as to the pot casings (see above). Picture 6 shows a cord plugged into a jack and a probe of an ohmmeter clamped to the rear contact point of the jack. As you can see, I am holding the other lead to the foil in the middle control cavity. The multimeter shows a zero ohms reading, which means that the foil-ground connection is fine. No matter against which part of the foil exactly you hold the probe, there always has to be a connection. The foils are grounded with three wires: one of them connects to the foil in the control cavity, another one to the hole in the jack and the third one to the foil on the

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