Nine years. Nine years of work well done, nine years in the professional field, nine years of learning and teaching, nine years of giving our best. And since we're talking about the best, what better way to celebrate than by learning to improve our skills?
Reviews, installations, events… And now, tutorials. Many of you guitarists have thought of going to luthiers and industry professionals to meet your needs for improving your instruments. And you're right to do so, but how about taking your first steps in guitar electronics yourselves? This month we kick off the first chapter on pickup installation. Enjoy!
Because on our ninth birthday, at ISP we don't expect a gift: WE GIVE ONE.
PHASE 1: PREPARING THE MATERIALS
First of all, you have to arm yourself for battle. The first thing is to get a soldering iron. The recommended option is a soldering station, with a 25 or 30 W "pen-type" iron and a set of tips. A soldering station lets you regulate the temperature by means of a knob that varies the voltage applied to the iron. This is important, since some solders have a higher melting point than others.
The most suitable solder is made from an alloy of 60% tin and 40% lead. You'll usually find it on spools, and it's important that it has a flux-filled core, consisting of a synthetic resin that keeps the solder from oxidizing.
Pen-type irons hold their temperature well while plugged in and are fairly easy to handle. The only drawback of this type of iron shows up when it's used for short periods. Why? Because a film forms on the tip that forces us to clean it constantly, and the tips don't last long with this kind of use.
Got your soldering iron? Good. As you know, soldering irons work at very high temperatures, which means taking care of one important aspect: safety. My advice is to wear a long smock that covers you well, especially your arms and legs, and if you're not very familiar with using a soldering iron, some fireproof gloves would come in handy. What is absolutely essential is a stand for the iron, with a silicone sponge moistened with water.
In addition, the work area needs to be well ventilated, since soldering gives off fumes that are as unpleasant as they are toxic (remember that the recommended solder contains lead). As a support for the guitar, a large table covered with soft, non-abrasive material will do, although a neck rest to support the neck is recommended.
Now we have all the necessary materials, so we'll move on to the next phase.
PHASE 2: THE WORK PLAN
First, before getting down to work, we need to be very clear about what we intend to do. We have to consider the type of pickup we plan to install, the number of wires it has and the wiring configuration we aim to apply.
Before moving on to study the circuitry, we must stress something very important about pickups: shielding, that is, protection against the influence of external electromagnetic fields.
Shielding is exactly what the word says: protection that prevents external electromagnetic fields from inducing currents in the pickup's winding. It basically consists of a metal casing that protects the magnet-coil system, so that only the magnet poles under the strings stick out. In the shielding, electric and electromagnetic fields produce currents that are sent to ground through a conductor and neutralized. In addition, the guitar strings are also sensitive to these external fields, so they too must be connected to ground, via the metal bridge. It should be noted that when a metal object is properly grounded, the object itself is at the same potential as ground, that is, neutral.
Pickups connect to the rest of the components through conductor wires: two in single-coil pickups and two or more in dual-coil pickups. Each conductor wire corresponds to one end of each coil. For example, a single-coil pickup without noise cancellation has two conductors: one corresponds to the coil connection (the so-called hot output), and the other is the shield, which will be connected to ground.
Humbuckers may have two conductors (one corresponding to the series connection of the two coils, plus a shield) or more. In the latter case, different types of wiring configurations can be developed. For example, a four-conductor-plus-shield pickup is organized so that one conductor wire corresponds to the start of each coil (whether the north- or south-oriented one), and another wire corresponds to its end.
Each manufacturer sets its own criteria for identifying these wires; they are usually identified by color.
There is always one conductor wire (the one coming from the start of the north coil).
Since there are a multitude of configurations, another chapter will be developed for June in order to properly illustrate the possibilities. In this article, we'll describe step by step how to replace the two stock pickups of a Gibson SG (490T and 490R) with a Seymour Duncan Hot Rodded set (SH-4 JB for the bridge position and SH-2 Jazz for the neck position). Both are humbuckers with Alnico V magnets.
Each pickup in this set has four conductors plus shield, and we'll tackle the simplest case: humbucker mode with three switch positions, that is, the same original configuration as the SG. Electronically, this translates into a series connection of the two coils of each pickup.
Seymour Duncan, like most manufacturers, includes schematic diagrams in the documentation that comes with its pickups.
In this company's case, the correspondence between colors and conductors is as follows:
Green: Start of the adjustable coil (polarity oriented to magnetic south).
Red: End of the adjustable coil.
Black: Start of the fixed coil (polarity oriented to magnetic north).
White: End of the fixed coil.
Therefore, to connect the humbucker in series you'll need to solder the red and white wires together (the ends of both coils, to make a series circuit), and connect the green one to ground. That leaves the shield to connect, which goes to ground, and… what about the black wire? That's the hot output wire mentioned above, and it must be joined to the lug of the volume pot (the one linked to our new pickup, of course; be careful not to mix up the controls).
When you change pickups, you must pay close attention to how the wiring was laid out before the change; otherwise, you risk making mistakes.
However, this is usually standard, and companies' websites usually have information about typical wiring configurations (series, parallel and out of phase) — in fact, it's included with our pickups; but when you face unusual configurations, that may not be the case, and you'll have to study the manufacturers' approach, checking the connections made between the switch and the rest of the components.
Right, we have our plan laid out. Now all that's left is to put these concepts into practice with the soldering iron. On to the next stage!
PHASE 3: GETTING TO WORK
Before plugging in the soldering iron, we make sure the conditions described above are met.
Then we need to slacken the strings, unscrew the bridge and remove the tailpiece. In short, remove the components on the front.
Now let's dig into the circuit. We're dealing with an SG, so the first thing we'll do is place the guitar face down, since that's where the cavity with the pots, the pickup selector and the wiring is located.
Now, with a screwdriver (photo 1), we remove the screws and look at the circuitry (photo 2).
We see that the original Gibson pickups have two conductors: the hot output and the shield (braid).
The shields are soldered to the casings of the volume pots. This is because the pots, as you can see in photograph 1, are soldered with a conductor wire that is in contact with the inner part of the bridge which, as I mentioned earlier, leads into the inside of the guitar (ground area).
I insist quite a bit on shielding and grounding because noise problems usually stem from bad solder joints and poor wiring. We'll go deeper into shielding and solutions for improving it in the next chapter.
As you can see, the hot output wire is soldered to one of the lugs of the volume pot. If you forget which of the two to solder, choose the one connected to the lug of the corresponding tone pot.
Note: on Gibsons, the two pots closest to the bridge correspond to the neck pickup and the other two to the bridge pickup, while the pots closest to the selector switch are the volume controls.
Right, now it's time to plug in the soldering iron and wait for it to reach the right temperature. The best way to check that an iron has reached the right temperature is to place a small piece of solder on the tip and wait for it to melt.
Ready? Now it's time to carefully bring the iron to the base of the shield strands and gradually desolder it from the pot (see photo 3).
We must be extremely careful with this procedure, since we're handling metals, which conduct heat, meaning they transmit heat to the elements they're connected to. For this reason, prolonging the process too long or turning the iron's temperature up too high can end up damaging the pickups or other components in contact, as well as causing burns if we're not wearing gloves. A good idea is to use an alligator clip or another aluminum or steel clamp to hold the shield, since that way any excess heat is partly absorbed by the clamp.
We repeat the operation with the hot output wire. We approach the lug of the volume pot and desolder. Be careful not to touch the capacitors with the tip of the iron, as it can make them burst and spray out the dielectric inside, which in many cases is acidic.
These two processes are identical for desoldering either pickup. Remember, especially with a view to installing the new pickups, which pots controlled the neck pickup's parameters and which controlled the bridge pickup's.
Now that we have the pickups desoldered, it's time to turn the guitar over, unscrew the pickguard and remove the pickups from it.
As you know, pickup height can be adjusted thanks to the screws and springs that hold the coils up. Well, if we keep turning clockwise (raising the height), we'll eventually unscrew the pickups from the pickguard (see photo 4). After that, we carefully pull the pickups until the ends of the wires have completely left the body (see photo 5).
Now it's time to take the Seymour Duncans out of the box. We see a black insulating sheath that houses the conductors and the shield. This cable must be stripped to expose them. But there's no need to strip more than a finger's length; any more would only make the wiring messier when soldering (see photo 6, photo 7 and photo 8).
Next, each of the four wires needs to be stripped; half a finger's length is enough (see photo 9).
Right, now we'll do the reverse procedure with the Duncans. We install the pickups on the pickguard (see photo 10, photo 11 and photo 12), and the pickguard on the body (see photo 13).
Now comes the key moment: making a good solder joint.
Under the area where we're going to solder, we'll place spongy, non-abrasive material to keep drops of solder from accidentally falling onto the circuit (see photo 14).
Make sure the solder has a flux core, since this is key to a quality result that doesn't look burned from oxidation.
Now, as indicated above, the pickup's red and white wires need to be twisted together. Then we place the tip of the iron next to the twist and bring the solder wire to the joint. That way we gradually coat both wires with the freshly melted alloy. Be careful, and make sure the twist is well covered, but without forming lumps from excess solder (see photo 15).
Done? We repeat the soldering procedure with the shield and the green wire: twist and solder. Separately, and independently, we'll tin the black one (hot output).
Improving your skill with the soldering iron takes practice, so be patient.
Right, now it's time to insulate the red-and-white joint with electrical tape, to avoid short circuits and/or accidental connections.
Now we first melt a little solder onto the casing of the volume pot. Then we place the green-shield bundle on that plate and put the tip of the iron on it until we get a solid film that holds the twist firmly on the casing, thanks to the solder we applied beforehand.
Keep in mind that this is the guitar's electrical shielding.
What's left? The black wire. This will be the wire responsible for carrying the pickup's electromagnetic response. We'll first add a little solder to the lug of the volume pot mentioned earlier, and then bring the strands of the black wire to the solder, with the tip waiting in between (photo 16).
This whole process is done the same way when installing the next pickup. The only thing to watch out for is not to mix up the pots.
Great! All that's left is to carefully close the cavity, adjust the pickup height to taste, reinstall the bridge, set the intonation, tune… and enjoy our new sound! (see photo 17).
CONCLUSION
Really, it's contradictory to add a conclusion, since we're not finished, even though this is the end of this first article.
As you can see, this first chapter has focused on the basic principles to keep in mind when learning about this field. If you've made mistakes, this is a good time to review what you need to improve before launching into more advanced designs. Basically, this first episode aims to get you to focus on two things: handling the soldering iron well and becoming familiar with electric guitar electronics.
But the laborious and truly fun part will come in the next chapter, which will show more complex configurations, different types of pickups, components (capacitors, shielding cages…) and techniques for optimizing their effectiveness and sound.
Many variations on the theme, which we'll explore in depth. See you then!
