Electric guitar wiring for two singles. Getting different sounds with pickup combinations

Last time I described different ways to get a different sound with pickups. This time I will describe the modifications of the tone block.

Potentiometers

What is a potentiometer? This is a variable resistor. The electronics are designed so that when we “remove” the volume, part of the signal goes to the “ground”, and the rest goes to the amplifier. The origin of the potentiometer does not affect the sound, but their parameters are very even. And by changing the values ​​​​of the potentiometers, you can achieve a different sound.

Potentiometers aren't perfect either. And even when they are twisted to the maximum, part of the signal still goes to the “ground”, which causes power and high-frequency losses. Losses are not very large, but nevertheless audible. Therefore, the greater the resistance of the potentiometer, the lower the loss. Singles usually put potentiometers with a nominal value of 250 kOhm, humbuckers - 500 kOhm, since humbuckers sound muddier and the high frequencies there are initially less than those of singles. A brighter sound will be obtained when using potentiometers with a nominal value of 1 MΩ.

Keeping the top

However, increasing the value of the potentiometer does not solve the problem of losing highs when the volume of the guitar is reduced. And the solution to the problem is quite cheap and simple, and is sold in any radio parts store. It is enough just to insert a 0.001 microfarad capacitor into two contacts of the volume potentiometer and all the upper frequencies will be preserved in their original form. There is one caveat here - a logarithmic potentiometer is required for normal implementation. With linear, the volume change will be sharp and stepped. By the way, this is why the old Fender Telecasters are so sonorous at any volume level.

Going deep

From the previous it is clear that the capacitor conducts high frequencies. Actually, the tone control is a capacitor and a resistor. Usually capacitors with a nominal value of 0.022 or 0.047 microfarads are placed on guitars, but in principle any can be set. The larger the value of the capacitor, the more highs will leak to the "ground" and the muddier the sound will be. Although, it makes no sense to set more than 0.1 microfarads, but you can try.

One of the most interesting devices that was used on some semi-acoustic Gibson ES, including the B.B. King Lucille and some Blueshawks. Unfortunately, I did not find a single exact description of the design of this thing, since there is a lot of various kinds of garbage on the Internet on this topic. Even more unfortunately, I didn't get to play any guitar with this thing. However, from all sorts of descriptions and videos, it is clear that Varitone "cuts off" certain frequencies from the signal. Consists of a position switch and capacitors. About everything in order.

A simple variton, as it is drawn on the Internet, is an ordinary bunch of capacitors soldered to a positioner. When a position is selected, the signal is sent to a specific capacitor and then to a tone potentiometer. In fact, this makes it possible to choose which capacitor to play through and how deep the tone will be. A similar thing was implemented in Gretsch guitars in the form of a toggle switch for three positions.

More interesting is the design of Gibson's original Varitone. It makes it possible to “cut” the frequencies, changing the sound radically. With such a thing, practically nothing more is needed, no equalizer or cutoffs - all sounds are already at hand.

killswitch

Normal switch. A simple two-position switch or button that completely turns off the signal. It can also be used in music - Buckethead constantly uses such a thing.

Built-in booster

Instead of bothering with heating pads, why not build a booster into your guitar? There are battery operated active boosters that will boost the output of the guitar and drive the amp.

Few people know that a booster can be passive, and that you do not need to spend a lot of money on it. To get a real overload from the guitar itself, it is enough to buy in the store ... two diodes. If they are connected correctly, they will give an overloaded signal, and if you also make an adjustment, then no heating pads are needed, and you can raise the output signal with a single switch.
It is sold in stores even, though not in ours. It is called Black Ice and is a few diodes in one small package. By connecting them differently, you can achieve different sounds. But it is too expensive - buying ordinary diodes is much cheaper.

Independence Day

Those who like to turn on two pickups at the same time on guitars with separate volume controls know that if you turn one volume to zero, the sound will disappear altogether. However, the problem is solved by simply rearranging the wires on the potentiometer, as in the diagram. After that, when unscrewing the volume to zero, only a specific sensor will be turned off. To be honest, I don't know what the magic is, but it works.
True, there is a side effect. The fact is that with such a connection, two sensors will always work, but at an extremely minimum volume - at such that the second sensor will not even be heard.

Active electronics: equalizers, preamps, etc.

Nanotechnology allows you to build into the guitar any electronic crap that the user wants. The whole pedalboard can fit in the body of one guitar in this way, but is it necessary?

Recently, I often come across the fact that many guitarists do not understand what a series, parallel connection of pickups is, what coil cutoff and phase change are. Even I did not fully understand everything until I collected the information necessary for this article. So, today we will try to reveal all the secrets of pickup wiring and what it gives to your sound.

Parallel connection of pickups

Understanding all kinds of pickup connection schemes not only makes you a cool techie, but also greatly diversifies the sound of your guitar, moreover, you will begin to understand how circuits work in guitar cabinets, effect loops in amplifiers. There is nothing complicated in these schemes, but it is sometimes difficult to find a clear explanation of how and what works on the Internet. Let's start with the two simplest circuits that are used in most guitars - parallel wiring.

Parallel connection is when 2 or more coils are connected together. You get a part of the sound from each of the pickups, the brightness and volume does not change much when switching pickups. This circuit allows you to get smooth pickup switching, regardless of whether you use single coils or humbuckers.

So, if you switch from one pickup to two at once and the volume does not jump much, then you have a parallel wiring of the pickups. If, when switching to 2 sensors from one, the sound changes a lot and it becomes much louder, you have a serial wiring diagram.

Connecting 2 or more pickups in series allows the power to be combined so that both pickups work at their full potential. They don't sound as bright as they would individually. According to this scheme, 2 coils work in one humbucker, or separate single-coil pickups in guitars such as a stratocaster or telecaster.

When you have 2 sensors working at the same time, when wired in series, they sound louder together than individually. Both schemes can be mixed, examples of how it sounds can be heard and watched in the video at the end of the article.

humbuckers

A humbucker is a two-coil pickup. These coils have reverse polarity, they are also wound the other way around and connected in series. The sound is louder and more powerful than singles, but also more compressed. However, with 4-pin cartridges it is possible to have the coils connected in parallel.

This is reflected in the sound as follows: the pickup starts to sound brighter, closer to the single, more sonorous. This can be done using a separate switch on the guitar. Seymour Duncan's website says that a parallel wired humbucker sounds about 30% quieter than the same wired wired pickup, so this is something to consider if you decide to modify your guitar.

If you change the wiring of the humbucker to parallel, the noise becomes more - like from two single-coils located side by side.

And here's how it sounds. Listen and wind on your mustache;)

So, if you are reading this article, it means that you most likely decided to unsolder and improve the sound of your instrument yourself. I warn you that the wiring diagram proposed in this article may differ from the one that your guitar should have due to the difference in the electric guitar structure.

SCREENING.

Let's start with how to properly shield your guitar.
In general, most decent electric guitars are factory shielded with graphite lacquer or EMILAC (copper powder lacquer). This gives good signal protection from interference and noise.
It looks like this:

If you don't have this type of screen, you can always make your own by replacing the graphite with an aluminum cooking tray, aluminum tape, or copper tape.

Major screening errors:

• the use of completely inappropriate materials (candy wrappers, other non-conductive surfaces, foil glued to superglue, etc.).
• Extremely sloppy execution. In such a case, the shield may simply be shorted to the signal wire or other parts of the circuit.
• Screening where it is not needed. It is necessary to shield only places of solderings open for pickups and not shielded wires. The screen should not lie on the wires or anywhere else, only under the tone block.

The cover of the tone block must also be covered with a screen. When shielding, large gaps or gaps should not be allowed, since the shield is a shell that takes on all interference. It is necessary to make sure that the joints of the aluminum tape not only fit snugly together, but also have contact (if the adhesive layer on the adhesive tape does not give normal contact, then you can solder it using a special flux for aluminum soldering). If the tone block is attached to the pickguard, then only this part can be covered with a screen.

What is a tone block?
At its core, a guitar tone block is a special switching circuit that is located inside the body of a musical instrument.
In the tone block, the signal from the pickup goes to the sensor switch (switch), volume, tone and output jack.
At its core, the screen in the tone block is a continuation of the screen in the signal cable.

Let's move on to the wiring of the electric guitar itself.

You can find your wiring diagram on this site:

And I'll show you how I did it:

In this circuit, there are two 500 kΩ potentiometers, a three-position switch, a 6.3 mm jack socket. Between the tone potentiometer contact and the common minus is a 47 nF and 100 volt capacitor. It is needed to filter high frequencies.
It should be noted that when soldering, it is necessary to move the signal wires as far as possible from the screen, and earth loops must not be allowed.

Using just two pickups on your electric guitar, you can use their combinations to get different sounds without buying additional devices. The usual way to arrange sensors is in parallel or in phase. For sensors whose wires are sealed in the case and not solderable, changing the combination of sensors can be difficult.

In any case, a properly matched pair of pickups connected in parallel and in phase produces the most rock or jazz sound. The standard combination of pickups on the Strat produces a distinctive funky sound.

To get the sound you want, it will take a little time and patience to find the combination of pickups. First you need to place the pickups inside the guitar, and then change the combination of wires, achieving a change in sound. Once you have found the right combination, you need to figure out how you can quickly and conveniently switch between the standard combination and the one you have chosen. It is recommended to use no more than two switches in order to quickly change the sound. The easier way is to stick with traditional combinations that are guaranteed to give good results.

In order to understand how to place the pickups, you need to understand a little about how humbuckers work. The humbucker pickup has two coils side by side. Each of these coils picks up the vibrations of the strings, but at the same time introduces its own interference-noise. Even though humbuckers are less noisy than single-coil pickups, the noise is still there. Alternatively, to minimize noise, the humbuckers were covered with a metal cover, almost all vintage pickups were like that. There are pickups without caps, both humbuckers and singles. I don’t know how effective it is to cover the pickups with caps, I can only say that pickups with caps sound more muffled (blues-like), less aggressive. Therefore, if you are a fan of aggressive music, then it is better to choose sensors without caps, on them you will get the maximum signal that can be sent already to the effects chain.

The figure above (two on the right) shows the connection of sensors in phase and antiphase. Signals in phase will amplify each other, in antiphase, on the contrary, they will be suppressed. The principle of operation of an ordinary humbucker is based on the anti-phase inclusion of two identical coils standing on different poles of the magnet. The useful signal from the strings in the coils is added, and the pickup noise (which does not depend on the magnets) is subtracted. Logically, when the two sensors are turned on in antiphase, we should not hear anything at all, but the string, in addition to the general vibration (fundamental tone), also makes a bunch of small multidirectional vibrations (overtones-harmonics) formed by dividing the sounding string into equal segments. The following situation emerges: at different points, the string moves in different directions and at different speeds. Accordingly, the currents in different sensors will differ slightly from each other. And the closer the frequency component (harmonic) is to the fundamental tone, the more chances it has to be suppressed by the signal from the sensor turned on in antiphase. In general, we will hear the fundamental tone approximately 2 times quieter than when switched on simultaneously in phase (in-phase), and the higher the harmonic serial number, the louder (relative to the already quiet fundamental tone in comparison with the usual inclusion, its share in the spectrum of the main signal will be. The result is a quiet sound, rich in harmonics, and selectively.The sound will become higher, but it will have a different character.Usually, both humbucker coils are wound in the same direction, then connected to each other by internal winding leads (the beginning of one to the beginning of the other). the remaining external pins goes to ground, it will be " cold", the second wire will be the output," hot". You get an anti-series connection of coils, for noise they will be in antiphase, the background will be suppressed (subtracted). Of course, it will not be subtracted completely, but significantly, and for a signal from the strings - in phase, so there will be an addition of voltages from both coils. This will happen if each coil contains magnets in different polarities. For example, if in one coil "north" to the strings, then in the other coil - "south" to the strings. Or between the magnetic circuits of different coils there will be one magnet, touching with its different poles the magnetic circuits of different coils.

Let's try to analyze several options for connecting sensors in more detail on the diagrams.

Gibson's standard neck/both/bridge pickup combination is easy to implement. But, using additional switches, you can also use humbuckers with an output from only one of the coils. An example diagram is below.

Single coil + humbucker

Are in phase. The circuit is very simple, it allows you to use both 4 together and each individually pickup coils. In this case, the sound will be very different, it is desirable that the resistance of both humbuckers match.

separate humbucker wiring

Single-point sensors

The diagram below shows how to make the wiring for singles, as a result of which it will be possible to use each single sensor individually or together.

Below are a few more circuits that allow you to use humbuckers and a single coil in various combinations. You need to understand that the selection of the combination you need and, accordingly, the sound should completely depend on your decision, and the more wiring options you try, the more likely it is that your pickups and guitar will sound the way you need.

Wiring diagrams depict schematically the actual wiring

The wiring diagram in Figure 2 shows how the wiring works, while Figure 3 shows the actual wiring in the guitar and may be more helpful when soldering components.

So far, I have considered the sensor in isolation from everything else. As soon as you connect the sensor to something, an electrical circuit is formed that changes the characteristics of the sensor. The simplest form of electrical circuit is a sensor directly connected to an output jack (1) and an amplifier that controls volume and tone. In this electrical circuit, the sound of the pickup is determined only by the resistance of the cord, the impedance of the input of the amplifier, and, above all, the capacitance of the guitar cable.

The volume potentiometer circuit (2,3) is another example of a simple electrical circuit that suits a large number of guitarists who are intimidated by the abundance of all sorts of switches, sensors and their many combinations with their complexity and distraction from playing. A volume potentiometer on a guitar allows the player to adjust the volume of the sound without constantly running to the amp. In addition, it also serves to match the output of the guitar with the input of the amplifier, which is very sensitive to various kinds of deviations. When the moving contact of the potentiometer is turned at full volume, towards the petal to which the pickup signal wire is soldered, no current flows through the potentiometer's resistance track and therefore passes without attenuation. When moving the moving contact of the potentiometer to the opposite lobe, which is connected to the common wire, the signal weakens, and eventually disappears.

The volume potentiometer also has an effect on the sound of the sensor. Usually, 220k or 250k pots are used with single coils, and 470k or 500k with humbuckers, but this is also a matter of taste. Volume potentiometers are not exempt from unpleasant side effects, although the moving contact of the potentiometer is connected (through the resistance of the potentiometer) to the common wire, some of the high frequencies are cut off. This typical feature of electric guitars - turning on the volume potentiometer causes the sound to become more muffled, due to the fact that the height of the resonant peak, which makes the sound bright, in addition to the inductance of the pickup and the capacitance of the cable, is affected by the resistance of the potentiometer.

This high-cut problem becomes even worse when the potentiometer is wired incorrectly (4). As the volume decreases, the coil grounds more and more, until eventually it is completely closed to ground. What happens to the resonant peak in this case, I think it is not necessary to explain.

Output jacks

The standard jack used in electric guitars is 6.35mm (1/4"). Since this type of jack is also used as an input jack in an amplifier, both plugs on the ends of a standard guitar cable are the same, so it doesn't matter which one is plugged into the guitar, but what in the amplifier.

Mono jacks have two contacts (1), one of which is connected to the body, the other to the contact tab. When a plug is plugged into a socket, its specially shaped tip comes into contact with the contact lug of the socket while the other part comes into contact with the housing (2). This is clearly visible on open nests. On insulated, plastic sockets, the contact located closer to the input is common. Some sockets also have additional contacts that can be used as a switch (4). They are activated when the plug is inserted. Stereo jacks and stereo plugs have an additional third pin (3).

Potentiometer types:

(5) Standard potentiometer

(6) Stereo potentiometer: two moving contacts on two resistance tracks are moved simultaneously by one slider.

(7) Slider (longitudinal potentiometer): the moving contact moves in a straight line along the resistance track. This type is not used on electric guitars.

(8) Fixing nuts

(9) Potentiometer with a thinner slider.

Circuitry rules

The common wire is the most common element in electrical circuits. The electrical circuit allows you to schematically depict, for ease of reading, the connection of wires and elements. The elements and in particular the common wire (11) are depicted by symbols, and the conductors by lines. This ground mapping is especially useful for complex electrical circuits, otherwise the intricacies of common conductors will greatly clutter up the circuit. In a real wiring, all common contacts must be soldered to each other and to the common contact of the socket.

The connection of conductors on the electrical diagram is represented as a bold dot (12).

Two wires crossing each other without a connection are often represented by two intersecting lines without a dot (13), and in American circuits as in figure (14).

Potentiometers

The volume of the guitar sound (Volume) is manually controlled using a three-terminal variable resistor called a potentiometer. The two extreme terminals are connected to the resistance track, and the middle one is connected to a movable contact, which is moved by the slider along the resistance track, thus changing the resistance. Linear potentiometers change resistance evenly: for example, when the moving contact is in the middle position, the resistance is equal to half the total resistance of the potentiometer. Audio potentiometers, or logarithmic potentiometers, are a special type of potentiometer in which the change in resistance is exponential. This type of potentiometer is often used for volume and tone controls because they give the impression of a gradual change in volume or tone. Of course, linear potentiometers can also be used, after all, this is a matter of taste. Linear potentiometers are usually denoted by the letter B, and logarithmic by the letter A (audio). Thus, a 250kV potentiometer is linear and a 250kA potentiometer is logarithmic.

The representation of a resistor or potentiometer in an electrical circuit is different. In Germany, the DIN resistor symbol is a small rectangle; The potentiometer is represented by an arrow across a rectangle (DIN - German Industrial Standard). The American style is more visual, but also more difficult to draw. This book uses a hybrid view.

Capacitors

Capacitors form an obstacle to the direct passage of direct current, but allow free flow of alternating current. A capacitor consists of two plates separated by a layer of dielectric and placed so close to each other that the alternation of load currents - such as alternating current - causes them to influence each other. Capacitor resistance is small at high frequencies and large at low frequencies. In other words, the capacitor passes more high frequencies than low frequencies. Capacitors are electrical circuit components that can be used as a frequency filter. The higher the rating, the lower the frequencies that the capacitor passes. Low value capacitors can be mica or ceramic. Capacitance is measured in picofarads (pF, pF), nanofarads (nF, nF) or microfarads (µF, mF, ?F). 1nF = 1000pF, and 1000nF = 1µF (i.e. 0.001µF = 1nF = 1000pF). Unfortunately, the capacitance written on a capacitor is too often misinterpreted. On most of them you will find only numbers in general, and the sign of a unit of capacity will be completely absent. The value of such capacitors can presumably be determined based on their size. In principle, it is not difficult if you have common sense. The number "1000" written on a small capacitor will most likely mean 1000pF (=1nF). "1E3" will also be 1000pF. And finally ".001", short for 0.001uF, or 1nF. In addition, some multimeters allow you to measure capacitance.

Another marking is three digits written on the capacitor, the first two of them indicate the capacitance in picofarads (pF), and the third digit is the number of zeros: "503" - 50 pF + three zeros \u003d 50000pF \u003d 50nF \u003d 0.050uF

Switches

Switches are devices that open and close an electrical circuit by mechanical means. They can also be used to change the direction of the signal. Switches are divided according to the number of pins and positions. The simplest type of switches is ON-OF Switch (on-off) (SPST = two outputs, two positions: on - off, implemented as a toggle switch or button). Figure (1) - designation on the switch diagram.

ON-ON Switch (SPDT = three pins, two positions: on-on (2), the middle contact is alternately connected to one of the other two. Thus, the signal can be routed in one of two ways.

Switch ON-OF-ON Switch (on-off-on) three outputs, three positions (3), in the middle position no contacts are closed. Such a switch allows you to connect two capacitors in parallel with the sensor.

The ON-ON-ON Switch (on-on-on) is a special type of switch that works as shown in Figure 4. Three outputs, three positions. In the middle position, all outputs are closed.

A multi-pin switch allows you to close several contacts at the same time. Thus, the on/off (DPDT) switch (5) works like two SPDT switches (2) placed side by side and activated at the same time, or three SPDT switches with three terminals activated at the same time.

If you do not know how a particular switch works, check it with an ohmmeter.

High frequency cut caused by the volume potentiometer, can be reduced by using a capacitor (1). A suitable capacity is selected experimentally. Typical capacitor capacitance is 0.01uF. Because current always takes the path of least resistance, higher signal frequencies will pass through the capacitor without loss. This is the best way to fix the RF loss problem on the potentiometer. For humbuckers connected to a 500k potentiometer, a 0.001uF capacitor and a 150k resistor connected in parallel (2) are best, and a pickup connected in parallel, loaded with a resistance of approximately 300k when connected in this way, produces a tone that is balanced over the entire adjustment range. With singles and potentiometers with a resistance of 250k, a capacitor with a capacitance of 0.0025uF and a resistor of 220k are used, which allow you to transmit the sound timbre without changing at low volume. (I would not recommend using the described tone-compensating chains (Fig. 1 and 2), practice shows that when playing actively with the volume control, they interfere very much)

Capacitors for tone control. (3)

The lower resistance of the potentiometer compared to the capacitor causes some of the guitar's high frequencies to go to ground before reaching the output. Most musicians turn the tone controls all the way down so that the high frequencies are cut less, preventing the sound from becoming muffled. It is recommended to use a logarithmic potentiometer as a tone control (despite the author's recommendations, the vast majority of manufacturers put linear potentiometers on the tone - maybe they just haven't read the article ;-)). Capacitors with capacitances of 0.047uF or 0.05uF (47nF and 50nF respectively) for single coils and 0.02uF (20nF) for humbuckers are usually used for tone control, but of course you can experiment with different capacitances.

If your tone control is a potentiometer with a built-in switch (ON-ON button), you can switch between two capacitors of different capacities (4).

More tone options can be obtained by using a circular switch (galletnik) with capacitors of different capacities soldered to it and connected in parallel to the sensor (5). This method allows you to change the resonant frequency of the pickup, getting a greater variety of sounds. Experimenting with capacitors of various capacities between 0.0005uF (0.5nF or 500pF) and 0.010mF (10nF) will let you know the differences in tones. A larger capacitor connected in parallel will cut off more high frequencies and produce a lower frequency sound than a capacitor with a smaller capacitance. If the rotary switch clicks when switching, connect a 10M resistor in parallel with each capacitor. You can buy ready-made rotary switches with built-in capacitors (6) for most pickups and guitars from German guitar electronics expert Helmut Lemme.

Further experiments may consist of connecting a resistor to a capacitor in series (6-8k) or in parallel (100-150k). This resistor should cut resonant peaks that are too high and make the sound warmer.

humbucker consists of two identical coils, which are usually connected in series, the beginnings of the windings are connected to each other (the so-called middle point), and the ends form conclusions. One of these leads is often connected to a metal base plate (1), thus providing a shield for the sensor. In this case, you need to know exactly which of the humbucker pins is connected to the screen. Usually two pins are enough, but you can get more sound options if the screen is connected to a separate third pin (2). The maximum amount of freedom for switching coils in a humbucker is given by five leads (3) (four wires from the coils (two beginnings, two ends) plus the ground wire).

You can also turn the humbucker into a single coil by separating its coils with a switch (4). Such a circuit will give a typical single-coil sound, but of course the noise reduction effect will be lost.

Instead of using a switch, you can connect a trip potentiometer (5) in parallel with one of the coils. To make it, open the potentiometer and use a knife to cut a resistance path closer to one of the terminals. In this case, at the beginning of such a potentiometer, the pickup will work as a pure humbucker. Then, by turning the potentiometer slider, the moving contact will reconnect with the other output, and by the end the humbucker will smoothly switch to single-coil mode.

Connecting two humbucker coils in parallel will give you new tonal variations while maintaining the noise canceling effect. This is possible by means of a DPDT (two-position, double) switch (6). This parallel connection will give a brighter sound, but less output.

Singles

Manufacturer	Start (first output)	End (second output)	Pole / Winding
			N/clockwise
			S/clockwise
			S/clockwise
			N/clockwise
			S/clockwise
			S/CCW
			S/clockwise
			N/clockwise

Manufacturers and colors of sensor wires

humbuckers

Manufacturer	Correctable polarity	Fixed polarity
	Start End Green - Green - Green - Green -	Start End Red + Green - Red + Brown Red + Red +

When two single coils with their magnetic poles in opposite directions are used at the same time, both pickups can be connected in parallel or in series like a humbucker. Why such a connection is not used for Jazz Bass pickups like the ones shown above is a mystery to me. Both sensors have the same polarity of the magnets, it is very difficult to change it because the coils are wound directly on the magnets.

For sensors that have flat magnets located under the coil, the polarity of the magnetic field can be easily reversed by reversing the orientation of the magnets.

Determining Humbucker Coil Leads

If you don't have a schematic and no idea what coils and wires are coming out of the humbucker, you have two ways to determine this connection: the first is to try to disassemble the pickup (I'm against this path, because when disassembling the pickup can be easily damaged) , the second is to use an ohmmeter to measure resistance, which would then draw logical conclusions from this. Switch the multimeter to the resistance measurement mode, set the mode switch to 20 kOhm and measure the resistance on any two wires. If they are not connected, they are wires from different coils. Continue measuring the resistances alternately on the other wires in relation to one of the first two, until the multimeter shows resistance in the range from 1k to 12k, which means that you have found two wires from one coil. Write down their colors, then in the same way find the wires of the other coil. When you have found and written down the colors of the leads of the second coil, only the wire will remain, which must be connected to the copper plate - the screen. Quite often this wire is connected to the shield wire of the sensor cable and is therefore easily recognizable.

Determining the Electrical Polarity of Humbucker Coils

To determine the polarity of the coils, the wires are connected to a voltmeter and lightly tapped with a screwdriver on the cores of the coils. If the voltmeter shows no voltage on one coil, tap on the other. Eventually, the voltmeter will show either positive or negative voltage. If the voltage is negative, swap the wires with each other. Now write down the color of the wire that is connected to the + terminal of the voltmeter and in the same way find out the positive terminal of the other coil. To get the effect of noise reduction, both positive terminals are used as sensor terminals, and the negative terminals are connected to each other. In this case, one of the sensor's positive leads is connected to ground and the sensor shield. Although this method does not allow one to tell which of the two positive terminals is the beginning and which is the end of the coil winding, it does, however, allow common-mode connection if the other sensors are tested in the same way. Such "tests" are absolutely safe - the sensors remain safe and sound.

Determination of magnetic polarity

The magnetic polarity of the sensor cores can be easily determined using a compass. Just bring it to the cores and see which end of the compass needle will be attracted to the sensor. If the south end, then the cores have north poles at the top of the sensor and vice versa. In principle, if you have a free magnet, you will only need the compass once. Mark the polarity on it according to the above method and bring it to the cores. If the magnet is repelled by the cores, they have the same polarity as the side of the magnet facing the cores.

A pickup switch is required if your guitar has more than one pickup. The SPDT switch shown in diagram (1), although it switches the sensors, will not be able to turn them on at the same time. This can be done with a three-position dual switch (2), resulting in the following options: one first sensor in switch position 1, the first and second sensors together in position 2, and one second sensor in position 3. To avoid a difference in the volume of the sound of the sensors, from - due to the use of sensors with different resistance, both sensors should have approximately the same resistance. By using two single coils with opposite magnetic polarity in each coil, a humbucking effect can be achieved by turning the switch to position 2, in which the coils of the single coils are connected in series.

Special sensor switches allow you to turn on the first and second sensors either separately from each other or both together. One of these models (3,4,8) is very simple: by moving the switch handle in one direction, the contacts close on one side and open on the other, and in the middle position, all contacts are mutually closed. These switches are also L-shaped (4) made to fit into a deck less than 45mm (l3/4") thick. In addition there are also slide type switches (7).

Three position lever type switches (5) are a bit more complex. When you turn on such a switch as shown in Figure 9, it will allow you to implement the following combinations: 1 sensor, 1 and 2 sensors together, 2 sensor.

A 2-way, 3-position, rotary switch (6) can also be used, but most guitarists prefer conventional switches. There are multi-level circular switches (galletniki). Each level consists of a round printed circuit board with pins arranged in a circle and on which a contact strip, driven by a switch engine, walks. Other rotary switches have 12 contacts in a circle, and vary in the number of positions and contacts they make. Depending on the model, there are 1 x 12, 2x6, 3x4 or 4x3 (the first digit is the number of closing contacts, the second is the number of positions). For each level, there is a common conclusion in the middle. On some models, the number of switch positions can be changed by means of a small stopper, thus turning a 2 x 6 switch into a 2 x 3 switch, for example.

With three or more sensors, the number of possible combinations increases and switching becomes more complex. Using three separate ON-OF (SPST) switches is the easiest way to get any desired combination of sensors (10). However, most three-pickup guitars use a special five-position lever switch (11) that gives the following pickup options: 1, 1+2, 2, 2+3, 3.

More sensor combinations are possible when using biscuits. But because guitarists often prefer five-way lever switches, manufacturers produce special versions of this type of switch that give more combinations than usual.

The Megaswitch (11), a high quality toggle switch, can be used in place of a conventional five position switch. In addition to the standard Strat and Tele functions (8-pin S or T models), there is also a P-model that simulates combinations of Paul Reed Smith (PRS) pickups on guitars whose two humbuckers are connected to give the following combinations: 1. bridge humbucker , 2. inner coils of both humbuckers connected in parallel, 3. outer coils of both humbuckers in parallel, 4. outer coils of both humbuckers in series, 5. neck humbucker.

The first such switch was designed to receive five sound combinations from three sensors. For example: single/single/single, humbucker/single/single, humbucker/single/humbucker, and humbucker/humbucker. This Schaller switch comes with detailed wiring instructions, so I won't explain them.

Yamaha's 12-pin, 5-position switch (12) allows for the greatest number of different combinations. Its switching, however, is rather complicated. This switch is available from Stewart-MacDonald. Because it comes with very detailed wiring instructions, I won't repeat it in this book. I would strongly recommend this switch to you if you consider the number of combinations obtained by conventional switches to be insufficient.

The tone block is mounted on a metal plate. I used this circuit on my last guitar. A 0.001uF capacitor and a 150k resistor soldered to the volume potentiometer should make the adjustment smooth throughout the knob's travel.

Anti-phase connection of pickups is another possibility for more tone options. The effect of this is obtained with at least two sensors with approximately the same characteristics. When two or more pickups are turned on at the same time, they are usually connected in parallel and in phase, meaning all pickups respond in the same way to the vibration of the strings in their magnetic fields, producing, for example, a positive voltage when the strings approach the pickups and a negative voltage when the strings move away from them. . When one or more pickups are turned on in anti-phase, the sound is thin and nasal, but suitable for certain styles of music. This can be easily achieved by changing the connection of one of the sensors. Phase switching is possible with ON-ON DPDT (1) switch or potentiometer with built-in DPDT switch. The latter has the advantage, since it does not require drilling an additional hole for the switch. If you have two or more humbuckers, you can connect one of them to the switch as shown in Figure 2 to only change its phasing (the humbucker must have a separate ground wire). Two single coils can be connected to a phase switch in the same way as a humbucker.

Phasing when connecting two coils

The table shows the phasing of a typical parallel connection of sensors when they are switched differently by a switch.

N = North Pole, S = South Pole, HC = Noise Reduction

Winding / Pole	Clockwise / S	Clockwise / N	Counterclockwise / S	Counterclockwise / N
Clockwise / S	in-phase	out of phase	out of phase	Common-HC
Clockwise / N	out of phase	in-phase	Common-HC	out of phase
Counterclockwise / S	out of phase	Common-HC	in-phase	out of phase
Counterclockwise / N	Common-HC	out of phase	out of phase	in-phase

Diodes

Diode - an integral part of electrical circuits, has two terminals ("+" - anode and "-" - cathode), and allows current to flow in only one direction. Diodes can protect the circuit in case the battery is connected incorrectly. If voltage is applied to the terminal of the diode, which is marked with a mark (anode) - mostly a line - the diode is properly connected and allows current to flow. If the opposite (to the cathode), the diode does not pass current.

Active electronics

Using active electronics instead of passive circuits has several advantages: the sound of the guitar becomes independent of the guitar cable, and it can be adjusted to a greater extent (these advantages become less important if a wireless transmitter with external audio equipment is used with a passive). In addition, the use of an active eliminates the disadvantages of passive circuits, such as sound muting by controls, and enhanced switching of signals from sensors becomes possible.

In most cases, an active amplifier is built into the guitar and is powered by a 9-volt battery, which has one drawback - it runs out and needs to be changed, this usually happens at the most inopportune time. Therefore, it is imperative to have a spare battery available. The best solution is to provide for the possibility of switching an asset into a liability and back again during the game.

You can also use a 9V battery, while equipping the guitar with a power supply socket to recharge the battery.

For the battery, you can use special plastic containers. You can buy them at radio stores or music stores. This container makes battery replacement very easy. Most 9-volt batteries have special terminals for connection.

All active systems must have a switch to disconnect power from the circuit. If you forget to turn off the power, the battery will run out soon. The stereo jack can also be used to turn off the power since the cable is usually disconnected from the guitar after playing. The battery negative should be connected to the middle pin of the stereo jack. If an ordinary guitar cable with a conventional mono plug (1) is inserted into such a jack, the battery minus is connected to the common wire of the circuit, including power. When the guitar is not in use, the electrical circuit must be broken by pulling out the cable.

By using a diode, the circuit can be protected from wrong battery connection. Diodes allow current to flow in only one direction and only 0.6V of battery voltage is lost on it, so the remaining 8.4V goes to power the circuit. Almost all diodes are suitable for this purpose. 1N4001 and 1N4148 are the two most used for this diode.

Currently, all active circuits are built on microcircuits - operational amplifiers. Most microcircuits have on board one operational amplifier, and eight pins. The first output on the chip package is often marked with a dot, and the pinout of operational amplifiers such as NE530, TL061, TL071, TL081, LF351, LF411, uA771 and others is standardized. Dual op-amp ICs also have eight pins, for example: TL062, TL072, TL082, LF353, LF412, uA772, NE5532, NE5535, AD712. Quad opamps such as OP11, TL064, TL074, TL084, LF347, uA774 and others are implemented in a 14-pin package.

Analog Devices, Texas Instruments, National Semiconductor are a few names of op amp manufacturers. All of them offer different types of amplifiers and with different parameters. Low-noise, micro-power opamps are used for active guitar electronics. The active circuits that I will describe use micropower opamps - models TL061, TL062 and TL064 from Texas Instruments. On the other hand, there are also low noise opamps (such as TL071, TL072 and TL064) that consume more power. All op amps come with detailed information that describes all of their parameters.

If you want to learn more about active electronics, read the related literature. My knowledge in this area is mostly general, but I will try to describe it all in simple terms. I would not advise you to design asset circuits yourself unless you have the appropriate knowledge and equipment, such as a tone generator or an oscilloscope.

If you have no experience in electronics and don't understand circuits, ask a radio engineer or hobbyist you know to make a circuit board for you. Most guitar makers don't make active electronics and leave it to others. Passive circuits are easier to understand and build.

Installing pickups with active electronics integrated into them is the easiest way to transition to an active; they only need a power source, and they are easy to buy. They have an electrical board built into the sensor body and made from SMD (Surface Mounted Components). The parameters of such sensors are already defined and cannot be changed. They can be connected to the volume and tone potentiometers in the usual way, but these potentiometers should not have a resistance greater than 25k, i.e. 1/10 of the resistance of a conventional passive circuit guitar potentiometer.

Many manufacturers offer ready-made active circuits, the installation of which does not require an in-depth knowledge of electronics. They are often implemented in potentiometers or printed circuit boards. Using the included wiring instructions, you can easily connect the circuit to your guitar. The equalizer allows you to select different cutoff frequencies using a miniature DIP switch.

The voltage follower is the basis of active electronics; it completely eliminates the influence of the guitar cable on the timbre of the pickup. The first way to connect to a guitar is to embed the circuit directly into the guitar, between the normal passives and the output jack. The second way is to install it in an external case that is mounted on a guitar strap and connected between the output jack and the guitar cable. This method has the advantage that the electronics can be used on another guitar. The absence of any cable capacitance makes the resonant frequency of the pickup very high and the sound pleasant and bright. By including a capacitor in the circuit (shown in dotted line on the left) in parallel with the input, the resonant frequency can be returned to its normal level. The capacitance of the capacitor is selected experimentally. The capacitance of standard guitar cables from 500pF to l000pF (lnF) can serve as an example.

Operational amplifiers in standard packages with 14 and 8 pins.

All operational amplifiers mentioned in the text correspond to the standard pinout shown in the figure above. Other types may vary, so be careful.

Operational amplifiers

An operational amplifier, or op amp, is usually implemented as an integrated circuit (IC), and is a voltage amplifier. Basically, these are small chips with a large number of semiconductors, such as transistors, diodes, etc., which form a complex miniature electrical circuit. Their main advantage is extremely high input resistance and extremely low output resistance. They can be used for a variety of purposes as their electrical properties are determined by external components such as resistors and capacitors.

The small circuit board shown on the left is a notch filter made by Helmut Lemme. The quality factor potentiometer is replaced by a mini switch, which is more practical. From left to right: frequency potentiometer, Q switch, 9V battery connector, input wire, common wire, and output wire that connects to the volume potentiometer.