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|We cannot solve problems with the same thinking we used when we created the problem. (Albert Einstein)|
Here's a bunch of pickup wiring ideas, from simple and easy through to some quite bizarre. All have been tested. We'll start with common wiring mods through to some sneaky wiring tricks I've kept to myself for the last 40 years.
Schematics Only - Why No Wirograms?
The diagrams below are schematics. I haven't shown "wirograms" because there are many different components (some of which have opposite connections) and also many different ways to implement these schematics. For example, some may use switches attached to pots while other may prefer to use mini toggles or rotary switches.
I know people like the instant gratification of copying a wiring diagram, but think about it: Just considering a few popular mods such as coil tap, treble bleed, parallel coils and out-of-phase and lets assume we need to draw them each for a couple of different popular switch types. That's 32 diagrams to cover all combinations of just these few possibilities! That's why we use schematics: they're generic.
Even if you can't interpret the schematics, you'll still get a good idea of what's possible and can pay for a professional to puts these mods into your guitar. I've left component values off these schematics; instead, there's a recommended component values section at the bottom of this page.
I've restricted wiring options to those that are practical to use and possible with common guitar components. Some sites have the "more is better" approach, showing convoluted wiring schemes with every possible pickup combination. In my view, and certainly for live use, these schemes are ridiculous: many of the sounds are useless and switching between sounds is complicated. So I hope you get some good practical ideas below for your own sounds.
I've shown lots of different ideas, usually one at a time. Of course, you can combine as many of these as you want. One example I've shown combines out of phase sounds, coil taps and tap links onto a single switch. So experiment as well - my goal is always to have a small number of different and usable sounds available.
Check Your Pickup Cables!
Many of the advanced mods on this page need pickups that have all coil connections available in the connection cable, and a separate earthing connection (usually a braided cable shield). For pickups with 2 coils, this means a 4 conductor cable plus earth, while a single coil pickup should have 2 conductors plus earth. Most replacement pickups have these types of connection cable; probably the only ones you'll have trouble with are those that use a traditional single core cable for "vintage authenticity". Why anyone would care what an internal cable looks like has me baffled. Anyway, I don't recommend disassembling pickups to get access to additional connections unless you really know what you're doing. Connections are often hard to get at and fine coil windings are easy to damage.
Pickups are drawn as coils, because they are inductors that also generate your signal. Notice that they have a "+" sign at one end. This designates the hot connection, but more importantly it means that if you connect the pickups together in parallel with all +'s connected, they will be in phase. So even though your pickups might have a clearly identified hot connection, there's no guarantee it's in phase with your other pickups. When combining pickups, it's important that you've identified the hot connections for your pickups that will allow you to use the in-phase and out-of-phase wiring options presented below. The simplest test is to connect 2 pickups together in parallel. If you get a significant volume drop and a nasal tone, then they're out of phase and you'll need to reverse the connections on one pickup.
There are good Internet resources to help you interpret schematic symbols used in these diagrams. Earth connections are always connected together (even though they're not drawn that way) and I've omitted standard earthing practices from all schematics. For all guitars, the following items should always be connected together and earthed:
Before we get into the mods, I'll show schematics for standard wiring in 3-pickup single coil guitars and dual-humbucker guitars. I'll also explain some of the basic switches and how I've drawn them.
Here's the schematic for a standard 3-pickup strat. Probably the most special thing about this circuit is the 5 way switch. It was originally a 3-way switch that had a "make before break" design. This means that when switching from, say, the neck to middle pickup, the middle pickup connects before the neck pickup disconnects. Players soon became adept at balancing the switch between selections to use the additional sounds (neck with middle and middle with bridge). These became known as the "in-between sounds" and are often incorrectly called "out of phase" sounds. The pickups are not really out of phase, but the sound has a nasal quality similar to certain out of phase sounds. Eventually, Fender started using switches with 5 positions that are electrically identical to the original 3 position switches; they just make it easy to select the in-between positions.
Another unusual feature is that the two tone controls share the same tone capacitor. This has the advantage that additional highs are not lost in the neck + middle position when both tone controls are set to zero. It also saves on the cost of an extra capacitor!
On all of my diagrams, the small circles show the physical switch stops. So there are 5 stops for a standard strat 5-way switch. Because there is no electrical connection for the 2 in-between positions, these are shown grayed out. Note also that the switch arm shows a wiper instead on an arrow to signify this is a make-before-break switch. This means that in the in-between (grayed-out) positions, the middle is connected to one of the sides as well as the switch arm connection.
There are 2 of these switches drawn in the schematic above, labelled S1a and S1b. This means there are 2 banks for switch S1: banks (a) and (b) are 2 switches are physically joined so that they move in unison. For this schematic, this ensures that pickup selections align with the active tone knobs.
This schematic shows standard dual-humbucker wiring. The main differences are that we have a 3-way toggle for the 2 pickups. Because this type of circuit is common with humbucking pickups, I've shown both coils of each pickup, connected normally in series and in phase. The centre pickup selector position combines both pickups in phase and in parallel (the same as the in-between positions on a strat). Also, there is a tone pot and volume pot permanently connected to each pickup. The strat connects its tone pots based on switch position, although the result is similar (one tone for neck, another for middle).
Again, the selector switch shows stops for the 3 position switch, with positions grayed out if they have no electrical connection. High quality pickup toggles use a dual leaf type of switching mechanism with four connections as shown in the schematic (there are 2 banks). Some cheaper types use a sealed box with the 2 "outputs" connected internally with a single external connection. Either type works fine in this circuit. For a dual-humbucker, volume pots are typically 300K or 500K and tone pots are 250K, 300K or 500K. Of course, the same wiring can be used for any dual pickup guitar, regardless of pickup types.
On the Pickup Combinations page we looked at different ways to connect 2 pickups:
A humbucker has 2 coils and these can also be connected in the same ways that you can connect 2 pickups:
The out of phase connections are not useful because the sound of the 2 coils is very similar in humbucking pickups (especially the neck pickup), so the coils nearly cancel nearly each other out, leaving you with a very weak signal. The other options (coils in parallel in phase and coils on their own) are common humbucker mods, so read on ...
Sometimes volume controls are wired in reverse, with the pickup and output "hot" connections swapped. The advantage of doing this is that it allows for a master volume and/or tone control while still having separate pickup volume controls.
The main disadvantage relates to the way guitar volume controls reduce treble at lower settings (due to guitar cable capacitance). Unfortunately, this wiring method is even worse due to the way it loads pickups at low volume settings. On a regular volume control this can be fixed with a treble bleed circuit. Treble bleed also works with reversed volume pot wiring, however, with both pickups selected and one turned off, the treble bleed circuit will actually cut a small amount of highs! This can be avoided by not using the "both pickups" selection for just one pickup, but it's not ideal.
Another impact of reversing volume pot connections could be an advantage or a disadvantage - you decide! The standard wiring shown previously has an interesting quirk: When both pickups are selected and either one of the volumes is turned off, there's no sound. This can be used for violin swell effects by setting one volume to maximum and turning the other volume from off to about 1 or 2 immediately after picking a note. The opposite pickup will quickly increase from off to full volume. You won't hear any of the pickup you're adjusting because low volumes of about 2 will be completely overpowered by the other pickup on maximum volume.
So if you don't use the violin effect, then this reverse pot wiring method can be used to avoid the "problem" of one pickup set off killing your sound when both pickups are selected.
The schematic below shows 2 reverse wiring pickup volumes with a master volume and tone. This is similar to standard Gretsch wiring.
This is probably the most common modification because it's the simplest and gives a noticeable tone change. This mod applies to humbucker pickups that have the centre connection (the internal connection between coils) available in the connection cable. It may be available as a single wire, or as two wires connected together. As shown in the diagram, I recommend shorting one of the coils instead of switching the earth position, because there will be no sound drop-out when changing switch positions. When coil-tapped, the humbucker operates like a single coil pickup, so there is no hum or interference cancellation. Humbuckers generally don't have great single coil sounds, but it can be a useful alternative.
The switch can be a separate mini-toggle or a switch on one of the tone or volume pots. For pot switches, I prefer push-push switches on a guitar; the pull-push switches can be quite tricky to use live with some types of knobs. You can choose to have separate switches for neck and bridge taps, or switch both simultaneously with a double-pole switch.
The coil that is not shorted out is the one that produces your signal. There's very little tone difference between the sound of each coil in a typical neck humbucker; certainly not enough difference to warrant a choice between which coil to tap.
However, there is a significant difference between bridge coils, because this pickup is located close to the bridge. By all means, try both options, but I expect you'll find the inside coil (the coil furthest from the bridge) sounds better - it has more level and is not quite as thin tone-wise. It doesn't matter that this coil doesn't have adjustment screws unless you're using them to improve string balance. In that case, you can turn the pickup around 180 degrees so that the coil with the adjustment screws is furthest from the bridge. If you want to get fancy, you can use an on-off-on 3-position mini toggle switch to allow either bridge coil, as shown in the schematic. Centre position is normal humbucking, while either side selects a different single coil.
See the coil-tap booster circuit below for a way to compensate for volume loss when switching coil taps.
This mod needs a little more wiring and gives a sound similar to coil tapped humbucker, with the advantage that it's still hum-cancelling. The diagram shows a switch for each pickup: The neck pickup is a regular double-pole double-throw (DPDT) mini-toggle, which could also be a switch on a pot.
You could use the same for the bridge pickup, or use a special 3-way switch to select between normal humbucking, single coil tap and parallel coils. The schematic shows this 3-position "on-on-on" mini toggle switch connected to the bridge pickup. These special switches connect the 2 switch banks in opposite directions in the middle position. Use a multimeter to check which way the contacts are switched in the middle position.
With an out of phase connection, either parallel or series, you'll hear the difference between the two sounds. So if the sounds are nearly identical, such as the 2 coils in a neck humbucker, you'll hear ... nothing! To get maximum volume from out of phase sounds, it's important to use sounds that are as different as possible. The best candidates for out of phase sounds are the two sounds that are most different: usually a neck humbucker with a bridge single coil, but we'll get to that later.
For now we're looking at common mods and these tend to be what's obvious and what's easy, not necessarily what sounds best. But it's always worth trying your pickups out of phase, simply because it really is easy to do. The out-of-phase, parallel sound will only be heard when both pickups are used together; single pickup selections are unaffected, even though one is reversed in phase.
This mod needs one of the pickups to have connections to both sides of the pickup separate from the pickup earth. If your pickups are all earthed internally then skip this mod.
There are three ways to reverse the phase of a pickup, and that is to change any one or all three of the following properties.
If you change any two of the above properties, they cancel each other out, and you're back in phase again. This explains how a humbucking pickup works: one coil has the opposite magnet polarity and opposite coil winding direction. So for your guitar signal, the coils are in phase, and the signals combine additively. Interference is picked up only by the coils which are wound in opposite directions, so this signal combines negatively, "bucking the hum".
Back to our out-of-phase wiring, notice that turning the pickup around sideways by 180 degrees doesn't change the phase, because it doesn't change any of the items above. Obviously, reversing pickup connections is the only practical option once the pickup is built and installed. Switch S2 in the schematic shows how to reverse the phase of a pickup. It can be any type of pickup (single coil or humbucking) and it doesn't matter what type of switching you use to combine the pickups. The out of phase sound will be heard when this pickup is connected at full volume with another pickup that's not phase-reversed. I've shown a simple 3 position selector S1 with a master volume and tone.
There's no point in putting a phase switch on both pickups: if you switch them both out-of-phase, they'll be back in phase with each other! Changing the phase of a single pickup doesn't change its sound; you'll only hear the effect when 2 pickups are combined that are out of phase with each other.
Using standard in phase parallel connections, there are 7 possible combinations on a 3 pickup guitar such as a strat. The 5-way selector gives 5 sounds and the missing 2 combinations are all 3 pickups and neck and bridge together. All pickups give quite a full sound, but somewhat characterless, so this option is rarely modded. Neck and bridge gives a tone similar to a Telecaster in the middle position, although you'll never fool a Tele player. Here are a few different ways to implement this mod, shown in the diagram below.
This common mod seems to have had a resurgence of popularity since Eric Johnson revealed he uses a bridge tone control on his strats. Even when the tone control is "off" at setting 10, it still loads the highs of the bridge pickup a little, so it's a worthwhile mod for standard bright strat bridge pickups. I don't recommend this mod if you already have a hot, dark or humbucker at the bridge of a strat. These hotter picks will already be loaded more than normal by the standard 250K volume pot, so the only reason to add a bridge tone pot would be if you actually want to control the bridge tone.
If you use one of the tone pots for the bridge, you'll need to decide what you want to do with the other tone control. There are lots of options, such as a control for just the neck, middle or neck+middle pickups, or even a second volume for your other pickups. The schematic below shows it as a master tone control.
A bridge humbucker is a common mod to strats, however, it often degrades the popular middle + bridge "in-between" sound. Always try it first because it might be fine, but with hotter humbuckers, you'll often find the in-between sound is not much different than the middle pickup on its own. This happens because the lower impedance middle pickup loads the higher impedance bridge pickup, even though that pickup is hotter on its own. The mod below shows how to use just one of the humbucker coils in the in-between position for a better impedance match between the 2 pickups. I also recommend you experiment with each of the humbucking coils to find which sounds best for the in-between sound.
At first glance, it might not be apparent how this circuit works, because there is no connection to the "output" of switch S1b. When the switch is in the in-between positions, it also shorts the centre connector to either side. In this case we're using this feature to short one of the coils in the humbucker. There's more on this feature in the Advanced Mods section further below. If your strat-style guitar has humbuckers at both neck and bridge, you can use the same idea to combine a single coil from these pickups with the middle pickup on the in-between positions:
Due to the capacitance in your connection cable, you'll notice brightness reduces as you lower your guitar volume. At first thought, it might seem that the answer is to use very high quality and short cables to reduce that cable capacitance, however, many players prefer the very subtle reduction in highs at full guitar volume. The common solution is to add some components to your volume control to maintain the same tone as you reduce volume. Some players complain that these circuits add too much brightness at low volumes, but in reality, this means that the mod hasn't been done properly. You should hear no tone change at all when you reduce guitar volume.
On the other hand, some players actually prefer an increase in brightness at lower volumes for certain styles such as funk, or for clearer rhythm tones when using lots of overdrive for solos. Lowering (or removing) the resistor in the diagram below will achieve that effect.
Either way, you'll need to experiment a little with your own cables and amps to get this exactly right, however, I've given some recommended starting values here. Increasing the capacitor value lowers the frequency at which this circuit takes effect. For example, a high-value capacitor value will boost the high-mids as well as the trebles. Of course, lowering the capacitor value has the opposite effect. As above, lowering the resistor has the effect of increasing the intensity of the entire effect. Unfortunately, lowering the resistor value also lowers the frequency at which the treble bleed takes effect and vice-versa, so there's a little juggling of values required.
A sweet switch rolls off some highs like a tone control with a few differences:
This diagram shows how it's implemented on a guitar with a master volume. If you have 2 volumes, you'll need a double pole switch to duplicate the circuitry across each volume control. The resistor doesn't affect tone, it's there to prevent pops when using the switch. As always, experiment with component values: I recommend starting with 0.0015µF then increase for more treble cut, or decrease for less effect. With my strat vintage (bright) pickups, I find that 0.0012µF gives the best sweet effect, 0.001µF is very subtle and 0.0015µF is more noticeable.
Many Gretsch guitars have a tone switch instead of a tone control. This is a 3 position switch that offers a sweet setting (like the sweet switch above), tone control at zero, or no change. Like the sweet switch, this is often an advantage in a live situation where you want quick access to different tone settings.
Gretsch use a capacitor value of .0039µF for the sweet position and .012µF for full treble-cut. These are good values to start with, but experiment to set the tones you like. Gretsch also use a switch that has no effect in the middle position, although I prefer to have this in the down position so the tone gets progressively brighter as you move the switch downwards.
This mod needs a single pole, 3 position switch and this allows you to put any tone setting in any position. It could use a regular 3 position rotary switch, but I've shown in the schematic how a 3 position double pole on-on-on toggle switch can be wired as a 3-position single pole switch. The on-on-on switch could be a mini toggle or a Gibson 3 pickup toggle switch, used on their guitars with 3 pickups. I've also included a resistor (unlike Gretsch) that gives a tiny amount of cut in the off position, just like regular tone control, which is likely to be what most players are used to.
The 1M resistor prevents pops when switching. This would normally be connected to a master volume control as shown in the schematic; but you'll need to duplicate this circuit if you have separate volume controls.
This section shows some lateral-thinking ideas using common switches and pickups. All are my own invention.
If you have on/off switches for your pickups, you can use the off positions for out of phase on series. For out of phase sounds, I prefer series over the more common parallel sounds. Parallel is easier to wire, but the sounds are usually very thin due to the inductive load each pickup places on the other. In series, the effect is similar to the 2 coils is a humbucker pickup - you get more mids, but less highs.
Anyway, this diagram shows how to use 2 pickups with off/on switches. You can turn either or both "on" for the standard sounds, but with both in the "off" position, the pickups are actually connected in series and out of phase. As with all out of phase sounds, the more different the pickups sound, the better the out of phase sound will be. Also, because the tone controls are connected across each pickup when out of phase, you'll find they do some funky things to the sound by killing the highs in just one pickup!
See the series out of phase for humbuckers mod below for more options with this wiring when you have humbuckers.
A standard strat 5-way switch has only 3 connections, intended to select the 3 pickups, but it has 5 stops, allowing you to choose 2 pickups in the "in-between" positions. At first glance, you might think there's no way to use the in-between positions for switching, because there are no connections to the in-between positions. However, you can use the fact that the in-between settings connect the centre position to either side as a switch.
We've actually seen an example of this above for combining a humbucker and single coil. You can use this switching feature for lots of different purposes to activate something in just the in-between positions. Here's an example that connects tone controls in only the in-between positions. So the switch now selects: neck / neck+middle with tone 1, / middle / middle+bridge with tone 2, bridge.
The phase switch and coil tap mods are shown above under common mods. This circuit shows both options together with a twist: Firstly, changing to "out of phase" while in the single coil mode changes the coil used in the bridge pickup, offering a third bridge pickup sound.
Secondly, this shows how a stereo output socket can be used to have the coil tap switch automatically engage a booster to compensate for the volume loss with a single coil. The booster is shown in the next mod:
When you coil-tap a typical humbucker, you'll notice a volume drop and less mids in addition to the change in timbre (character). You can use the preamp shown below to automatically compensate for the difference in volume and tone between single coil and humbucking sounds. When you select a single coil sound in the circuit above, the preamp boosts the volume and marginally cuts some highs to give the single coil sounds the same volume and similar tones to your humbucking sounds. You need to use a stereo guitar cable to connect your guitar to this preamp. It can be placed as the first effect on your pedal board, powered by either a battery or adapter. The coil tap switch in your guitar needs to earth the ring connector on the stereo socket when switched to hum-bucking mode.
A possibility with dual humbuckers is to get some additional in-between sounds. With standard humbuckers, you can get 5 different sounds, all at normal humbucking level. This would be best provided on a 5-position strat-style switch for 5 sounds from full neck to full bridge, but unfortunately you need a special switch, but even worse, most people will not want to attempt this type of woodwork on a good guitar. Instead, I've shown how to get the additional 2 sounds using just a simple switch, which could be placed on a push-pull pot.
This circuit is completely standard, with the only addition being a switch to connect the pickup centre taps together. When connected this way with standard pickups, the neck pickup has a hint of bridge tone, and vice-versa. The neck+bridge sound is unchanged.
Out of phase sounds are best when the 2 pickups sound as different as possible. On a humbucker guitar, the 2 most extreme sounds are usually the neck humbucker and the bridge single coil closest to the bridge (referred to as the bridge outside coil). You might think separating the bridge coils and connecting the neck pickup out of phase would require some complex switching, but no, it can actually be done with a single 2-way switch! This schematic simply moves the pickup earth connection, and leaves the 3 way-switching intact, giving you the out-of-phase sound / both / bridge inner-coil. Note that I recommend connecting the neck tone control across the pickup instead of to earth. This doesn't affect the normal in-phase sounds, but allows for some interesting out-of-phase tone adjustment.
This shows a combination of the above 2 ideas (tap-link and series out-of-phase) also with single coil taps into an all-in-one combo switch. As shown, the switch has these options for the neck and bridge pickups:
Remember that the 3-way pickup selector is unaffected: it chooses the neck or bridge pickup listed above, or both in the centre position. You might like to use just the options here that you're interested in. I find option (1) above the least useful, so I'd probably use a 4 position switch with options (2) to (5). Or you could use a combination of toggle switches (maybe pot switches) to select these options. Take care with this schematic - there's a crossover where the wires are not connected to each other.
This is not a common mod, but some players like it. Regular dual pickup guitars use a separate volume for each pickup. Some players like to use subtle variations of different pickup mixes, so another approach is to use a pickup balance control with a master volume. Another advantage of this mod is that you don't need a pickup selector switch - good if you want to keep controls to a minimum. A possible disadvantage is that having both a blend and master volume adds extra load to the pickups. So using a 500K blend pot followed by a 500K master volume pot is the same as using a single 250K volume pot.
The right way to do this is with a special dual gang pot that has one log taper and one anti-log taper, that's also fully on at half-rotation. The schematic shows that half of the pot rotation is shorted out. This pot will give smooth volume mixing over its travel and both pickups on full in the centre position. At the time of writing, several other guitar part suppliers sell these.
The next best solution is to use a dual linear pot. This type of pot will turn off either pickup at the extremes, from about 0 to 2 for one pickup and about 8 to 10 for the other pickup. Some players might actually prefer this, because it gives a wide sweet spot for pickup mixing between about 2 and 8, however the centre position mixes each pickup at a slightly reduced level (-3dB).
Guitar tone controls cut the highs. You might have wondered if it's possible to have a tone control that cuts bass, for a more twangy sound. It can be done by replacing the tone capacitor with an inductor (coil), however, you'll need quite a large value which means that it's also physically quite large, so it's usually not practical. Unless ...
Some pickup types have a dummy coil to give a single coil sound from one coil while the other just cancels hum and interference. These are common on stacked single coils, but can also exist side-by-side in a regular looking humbucker, such as DiMarzio's excellent BluesBucker model. The dummy coil acts as a high value inductor with very little signal, so it can be used to cut bass when you're using the pickup for its single coil sound only.
But why would you want to use a pickup designed for single coil sound (without hum) for single coil sound with hum? A couple of possible reasons: The single coil will sound different on it's own, because it's no longer passing through a series inductor (the dummy coil). Also, you might find the lower impedance of a single coil on its own combines better with other pickups in your guitar.
This schematic shows how the neck tone control can be used for bass cut when coil splitting a pickup with a dummy coil. The neck tone control is a regular high-cut in the humbucking mode. The bridge coil tap switch is the same as shown above under common mods: it allows for either single coil to be used, or humbucking in the centre position.
Many player find humbuckers a bit wooly and mushy on the lower strings, but find single coils a bit harsh and over-bright on the top strings. Wouldn't it be great to have a pickup that has the twangy bottom strings of a single coil through to the fat juicy humbucker tones on the top strings? Well, you can!
Before we look at the electronic version, it's worth considering a simple alternative. If you have humbucking pickups, you can raise the pole-pieces on the lower strings and lower the bass side of the pickup to compensate. Leave the top E polepiece level with the cover, raise the B just a fraction, a bit more on the G down to the low E which should be well above the pickup face. As always, experiment with different adjustments, but this will give you less boominess and more twang on the lower strings. Of course, if you want more of a single coil tone, just raise all of the screws! This can give you a sound something like a P90 pickup, except it's still hum-cancelling!
Back to the electronic version, this uses a dummy coil (or large inductor if you can fit one in) to coil tap a humbucker. An inductor in parallel cuts bass, so low frequencies are cut more than higher frequencies, giving us the desired result. If you're interested in the idea and especially if you have a pickup with a dummy coil, I'd strongly recommend trying it out. Its effectiveness depends very much on the impedance of the pickups involved.
For bridge pickups that are brighter than you'd like, you can use a special 3-way pickup selector to give you a bridge-only tone control. This means that you can set the bridge tone down just a bit, then switch to both pickups (the middle toggle position) to ignore the bridge tone control, using only the neck tone setting. Of course, the neck tone also works as normal for the neck pickup alone. The special 3-way toggle is the same type used for Gibson SG guitars with 3 pickups, so you'll often see it advertised as an SG selector switch. It works the same as the DPDT on-on-on mini-toggle switches, where the centre position switches one side, but leaves the other unchanged. As you can see in the schematic, we can now connect to one of the switch positions that is not available in a standard 3-position switch. I've only seen this type of switch available in a right-angle style, so it won't fit in a standard Les Paul switch cavity, although you could use a mini-toggle.
A standard dual humbucker guitar has a volume and tone for each pickup, which allows pickup mixing as well as some "bowed violin" swell effects. This is fine for many players, but some prefer a master volume, common on Fender guitars. Wiring a master volume is easy, but now we have one volume, 2 tone controls and another control that does nothing.
One option that might initially seem impossible with a 3-way pickup selector is to have a tone control for each selector position. It is possible with a special 3-way on-on-on selector switch (the same SG switch used for bridge-only tone above), but we need to take the unusual measure of switching a pickup on and off via its earth connection. This means we need to take care not to have too much capacitance between the pickup "cold" connection and earth when it's disconnected, otherwise some of this pickup sound can bleed through when it's switched off. In practice with the short cable runs inside a guitar, this is not a problem.
Here's how it's done. Of course, the pickups can be any type you have on a dual-pickup guitar. Take care with the bridge and "both" tone controls - the capacitor is not earthed so it can't be soldered to the back of the pot.
Choosing the right component values can make the difference between something that's useable and something that's not. I've given some practical starting values below, but please experiment.
Treble Bleed Revisited
Treble bleed is fully explained in the mod shown above. The circuit uses a capacitor and resistor connected in series. The circuit is connected between the volume pot hot and wiper.
The aim of this circuit is to compensate for capacitance in the guitar cable and amplifier input. So component values don't vary as much as you might expect with different value volume pots. For a standard treble bleed, where the intention is to have no tone change as you turn the guitar volume dial, start with series 0.001 cap and 120K for 250K pots, or 180K for 500K pots. Then adjust to suit: a higher value capacitor to let through more high-mids, a higher value resistor to reduce the treble bleed effect. If you want to boost treble as you decrease volume (for funk styles or brighter low-volume rhythm tones), use low resistor values, or even no resistor.
Manufacturers want you to hear a strong effect with the tone control, so they err on the side of being heavy handed by using capacitors as high as 0.047µF. These values were used on the first electric guitars, when they were envisaged doubling as a simulated bass guitar with no highs at all by rolling the tone right off. If you use and like that tone, there's no reson to change, however, you can generally get sweeter tones with much lower capacitor values. I recommend starting with a much lower value around 0.0047µF then experiment within the range 0.0015µF to 0.015µF.
Pots are commonly available in either linear or logarithmic (aka "audio"") tapers. Log pots have less effect at low settings and more effect at high settings. This corresponds to how our ears perceive these volume changes, so this gives an even response over the pot adjustment range. For the same reason, even though Lin pots are electronically even over their range, most of the audible change occurs at low settings.
Log pots should always be used for tone controls - if you've ever had a tone control where all of the change happens from about 3 to zero, chances are it's a linear pot, or the value is too high, or both. One reason to use a linear pot for tone control is if you like to do those wah swells (like Roy Buchanan) by using you little finger to turn the tone control from zero to about 3 immediately after picking each note. This is quite effective and it helps to have a tone control where all of the change occurs over a narrow range. For regular tone controls though, always use a log pot.
Likewise, some players prefer lin volume pots because it allows for volume-swell effects, where a small change (from about 0 to 3) gets you quickly from off to to near maximum volume. For an even volume response, use a log pot for volume. Note that changing between log and lin with the same value pot does NOT change the tone; it only affects the level you get at different settings between 0 and 10.
Pots are often labelled with A or B tapers, but unfortunately they can mean opposite things based on the country of manufacture. To be sure, you'll need to measure the pot at 50% rotation with a multimeter: if each side is roughly the same value from centre it's a linear pot, otherwise logarithmic.
I can't make a strong recommendation for volume pots being LOG or LIN - players have different preferences. The cable/amp loading means that even a linear pot will be slightly logarithmic, but not as much as a log pot (which has the same cable loading). Best to experiment if you can, but the simple difference is that a log pot will have more even volume reduction than a lin pot as you turn the knob. A linear pot will "turn on" more quickly over about the 0 to 3 range.
Guitar pots for passive pickups are usually 250K or 500K in value. You'll occasionally see 1M (that's 1,000K) or some in-between values used, such as 300K. They typically don't have very tight tolerances either, so treat 500K as "roughly 500K". In vintage guitars, 250K pots were used in single coil guitars and 500K pots in humbucker guitars. Today's guitars often have hotter pickups or combinations of different pickup types, so it's worth understanding how pot values affect tone to make the best choices.
A tone pot should have negligible effect when set to 10. You can test this by disconnecting the pot while playing, but a 250K pot is recommended for standard single coil pickups and 500K for humbuckers. Experiment to get an even tone change from 0 up to around 8.
The general rule for connecting electronic stages is that a lower impedance should drive a higher impedance. Your volume control sits between your pickups and amp, so they need to be higher impedance than your pickups and lower than your amp. Low pot values "choke" the highs from high output (and high impedance) pickups, so these need higher value pots. Bear in mind that both volume and tone pots load the pickup at high frequencies, so using both 500K volume and tone pots presents a combined load of 250K at high frequencies to the pickup.
Of course, you can intentionally tame a bright pickup with a lower than standard pot value, or brighten a dark pickup by using a higher than normal value pot. You'll also set the tone you want on your amp anyway, so this doesn't matter quite as much as some people might say.
A log volume pot will give the most even response provided you're plugged into a higher impedance. In practice, regular single coils should just about always use 250K log pots. Standard humbuckers or over-wound single coils are best with 500K pots, but you may need to experiment with logarithmic (LOG) vs linear (LIN) tapers. Very hot pickups generally work best with a 1 meg linear taper, because the amp impedance will load the pot somewhat, making it slightly logarithmic.
Recommended starting values for components