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Offline Elantric

DIY - get-a-grip-on-pickup-phase
« on: April 21, 2017, 11:26:11 AM »

Mod Garage: Get a Grip on Pickup Phase
Dirk Wacker March 10, 2017

Photo courtesy of

Ready to dive back into the nitty-gritty of pickup technology? We began this journey with "Demystifying DCR," an examination of perhaps the most ubiquitous pickup parameter of all—DC resistance. This time, let’s tackle electrical phase.

In short, a pickup’s electrical phase is based on the direction of its winding, which can be clockwise or counterclockwise. But—alas—it’s not quite that simple. To truly understand a pickup’s electrical phase, we have to dig a bit deeper into pickup terminology.

But it’s worth the effort, and here’s why: When you combine pickups, two things control phase relationship. One is magnet polarity and the other is coil-winding direction, and these parameters determine whether two pickups will be in phase or out of phase with each other. We discussed the former in "What's the Deal With Pickup Polarity?," so you might want to take a moment to refresh yourself on that topic. I believe magnet polarity and coil-winding direction should be specified for every pickup that’s sold because these specs can save you a lot of time, money, and hassle when shopping for replacement pickups for a multi-pickup guitar. After all, who wants an out-of-phase sound right out of the box?

Before we talk about clockwise and counterclockwise pickup winding, let’s get oriented. Imagine that you’re looking at a Strat pickup from above, facing the top of the magnets. In other words, we’re looking at the pickup from the strings’ point of view. From this position, when the wire is wound clockwise from the pickup’s starting point—wait for it—we logically say the winding is “clockwise.”

This is also considered “non-reversed.” I think this terminology stems from the early Fender years, where the factory workers wound all pickups clockwise for several decades. Then later, when reversed-wound middle pickups were introduced to provide hum-cancellation in positions 2 and 4 (bridge plus middle, and neck plus middle), most of these “reverse-wound” pickups actually had a clockwise winding. To change electrical phase, workers simply interchanged the two pickup leads.

From an electrical point of view, this is okay, but there are good reasons to create reverse-wound pickups with a genuine counter-clockwise wind. Many players feel that a reverse pickup with a true counterclockwise wind sounds better than a clockwise-wound pickup with reversed leads. Also, if a string accidentally contacts a pickup magnet, it will short out a clockwise-wound pickup with reversed leads and the pickup will go silent. Or, if you touch the magnets of such a pickup with your finger, you’ll be rewarded with a loud humming noise.

But we’re not done yet. Things get even more “interesting” as we go one step further and decode pickup makers’ speech. Besides the clockwise and counter-clockwise terms, the following also describe a pickup’s winding:

• Top right, top going (this is counterclockwise).

• Top right, top coming (this is clockwise).

• Top left, top going (clockwise).

• Top left, top coming (counterclockwise).

At this point, I can imagine you thinking, “What the heck does all this mean?” Unfortunately, “top" indicates two different things. Here’s an example to explain this terminology: “Top left” and “top right” describe how the pickup is attached to the winding machine. If the upper part of the pickup—i.e., the top section—faces towards the machine’s left side, this is defined as “top left.” And vice versa.

When you combine pickups, two things control phase relationship. One is magnet polarity and the other is coil-winding direction, and these parameters determine whether two pickups will be in or out of phase with each other.
Okay, “top going” and “top coming” describe the direction the pickup is moving in the winding machine. When the bobbin is moving away from you, it’s defined as “top going,” and when the bobbin travels towards you, it’s “top coming.” (By the way, top coming is typically not used for winding a pickup, but rather for unwinding it when you need to remove the old wire.)

Now that we’ve waded through our terms, it’s time to get back to the main subject—a pickup’s electrical phase.

The big question is, how do you determine a pickup’s phase? The easiest way is to use an analog meter with a polarity testing option. In the ’60s, analog meters commonly had built-in polarity testers—at least those meters in the upper price range. Most of these vintage meters are sought-after items today, and consequently fetch high prices.

We use a late-’60s Philips meter in our shop. If you have a similar vintage analog meter, here’s how to use it to determine a pickup’s phase. First, connect the pickup wires to the meter. The white (hot) wire attaches to the plus (+) and the black (ground) wire attaches to the minus (-).

Note: For this test, it’s essential to connect the wires this way. If the wires on your pickup have different colors, you’ll need to connect the colors for hot and ground as defined by the pickup manufacturer.

Next, take a large screwdriver or a piece of steel or iron and lay it gently across the pickup pole pieces, parallel to them. If the polarity meter—the small rectangular window on the right bottom of the main display, circled in red in Photo 1—shows plus (+), it means the wire that’s connected to the hot (+) lug of the input jack is, in fact, the hot connection for the pickup. But if it shows minus (-), it means that the pickup wire connected to the input jack’s hot lug is actually the ground. You’d be surprised how many times the pickup’s white wire is not really the hot one!

I don’t recommend using a standard analog meter that lacks the polarity testing function because the needle rests on the left side and is designed to deflect toward the right. When you force the needle on this type of meter to deflect toward the left, chances are good you’ll destroy it. So stay away from this. (I should point out there are ways to tweak a standard analog meter for this measurement, using the scale setting or by putting a resistor in series with the pickup to get the needle off zero and nearer to the middle of the scale, but these topics are well beyond the scope of this column.)

It’s also possible to use a standard digital multimeter by connecting the pickup to it and using the DC/ohms setting, but you must look quickly to note what happens, because on a DMM polarity is indicated in a flash.

All these alternatives to an analog meter equipped with a phase tester are only recommended for experienced techies. I’m pretty sure not many PG readers will have an old vintage meter handy and most won’t be willing to pay top dollar to acquire one and use it only for this measurement. So is there a way around this? Fortunately, yes. In a future column, I’ll show you how to build a full-fledged polarity tester for only a few bucks, so stay tuned. (Though they may exist, I’ve never seen a stand-alone polarity-testing unit for sale, so this will be a fun project.)

Also in an upcoming Mod Garage, we’ll bring all the facts together to understand the relationship between magnet polarity and electrical phase and how to control in-phase and out-of-phase sounds. We’ll also look at the role reverse-wind/reverse-polarity (RWRP) pickups can play in hum-cancelling configurations, and discover why winding direction and polarity are so important in this context.

But meanwhile, let’s give this pickup information a chance to sink in. In the next column, we’ll tackle a mod for steel-string acoustics, and I’ll show you how to make changing strings much easier while simultaneously enhancing tuning stability. Until then ... keep on modding!

Dirk Wacker lives in Germany and has been a guitar addict since age 5. He’s also a hardcore DIY-er for guitars, amps, and stompboxes and runs a website on the subject ( When not working at his guitar workbench, he plays country, rockabilly, surf, and flamenco. Contact him at

Offline Elantric

Re: DIY - get-a-grip-on-pickup-phase
« Reply #1 on: April 21, 2017, 11:28:49 AM »
Here is a handy tool for testing PU electrical phase, and making your own humbucking pickups

this meter has a Null function as well

the analog meters above are MUCH preferred for this task

I used to use a Simpson 260  - but prices on those have gone through roof

Bit the video below explains the basics

« Last Edit: April 21, 2017, 11:32:19 AM by Elantric »

Offline Elantric

Re: DIY - get-a-grip-on-pickup-phase
« Reply #2 on: April 21, 2017, 11:41:04 AM »


You can find all switch plans and layout plans for Schaller switches and Megaswitches here.

Art. No. (3-Way)
Art. No. (5-Way)
E      15310002
E+      15310005
S   15310013   15310003
P      15310004
M      15310006
T   15310011   15310001
Soldering tags on the printed circuit are marked from 1-7 or from A-X.
Mount the switch so the PC (Printed Circuit) is facing to the strings.
This applies to normal right-hand guitars. On left-hand guitars, the plated side faces away from the strings.




These switches substantially broaden the range of possible sounds on electric guitars. They allow coil combinations on the pickups which are impossible to create using conventional standard switches.
Installation is simple – neither woodwork nor drill holes are required on the back plate . Simply remove the wires from the old switch by heating the connections with a soldering iron, then remove the switch and replace it with the Megaswitch. Solder the wires according to the diagram. Finished!

Six different types are available to choose from:

E, E+, S, P, M, T.
This makes a huge range of sound possibilities available to you.

Which Megaswitch is suitable for which guitar type?
Select your current pickup configuration here:

Schaller Megaswitches GC9


Running Number   Pickup-mounting   Description
1.   SSS   Three single coils
2.   HSS   A Humbucker and two single coils
3.   HH   Two Humbuckers
4.   HSH   Two Humbuckers with a single coil between them
5.   HS   A humbucker on the bridge and a single coil on the neck
6.   SH   A single coil on the bridge and Humbucker on the neck
7.   H   One Humbucker only (usually on the bridge)
8.   SS   Two single coils








List of possible applications:
 E    5    7    SSS3    HSS4
E+    5    9             HSH5   HS2
S    5    8    SSS2    HSS1

P    5    7          HH9               
M    5    24   

T    3    8    SSS1       HH1
 HS1    SH1   H1

Potentiometer connections:
L = Left position
S = Wiper
R = Right position

The Megaswitch switch symbols illustrate the following: blacked out points are real contacts and open points are switch positions which do not refer to contact function. The switch is in position 1 when the lever is positioned in the direction of the bridge.

The wiring diagrams are illustrations of right-hand guitars, in which case the Megaswitch is built with the plated side facing the strings. Please note that left-hand designs are not quite reverse images. Here, the switches are positioned with the plated side facing away from the strings and the potentiometer (control knob) connections are reversed, since left-hand versions (i.e. "logarithmically negative” versions) and the control knobs with numbers in reverse order to match them, are rare. The electrical switch diagrams per se are more or less the same for both left and right-hand models.


Correct phasing of coils
When the coils of various pickups are combined on a single instrument, they sometimes fail to work together, i.e. they operate out of phase. The resultant sound is very thin and hollow and the bass end lacks considerably, which is not necessarily desirable! When the pickups on a guitar are all made by the same manufacturer, they usually (but not always) work correctly. Complications are quite common when the pickups are made by different manufacturers. If you want to avoid this prior to installation, it is wise to inform yourself of the technical characteristics of the pickups you intend to combine. Unfortunately, manufacturers don’t usually make such information readily available to end-users.

In technical jargon, so-called hot and cold connections are often referred to. The term ‘hot’ connections refers to wires that carry signal. If you touch them with your finger, your amp buzzes. Conversely, cold connections are those which are connected to the earth/ground, the zero potential, - the outer contact of the jack socket, the potentiometer housing, inner shielding, strings…If you touch these, no buzz comes out of your amp. Principally, hot and cold connections can only be clearly defined on pickups which have a single-core insulated cable, i.e. many old Humbuckers and single coils type P90 / P94. By contrast, the Stratocaster type doesn’t have a fixed hot and cold wire per se. They have two non-shielded cables i.e. they are symmetrical.

 Schaller Strat-pickup

 Figure1. Stratocaster pickup (symmetric by nature)

In the case of Telecaster pickups, one of the wires becomes the cold one when it is connected to the metallic base plate, (on the neck), i.e. connected to the metal cap (on the bridge, figure 2) Both of these parts must be earthed/grounded. Some designs do not include the ground connection however. Instead, they have 3 wires, one on each of the two ends of the coil and the earth/ground wire (figure 3). These are symmetrical.

 Schaller Tele-pickup

Figure 2. Telecaster bridge pickup. With this model, the black wire is connected to the base plate. For some switch positions, this connection must be disconnected and the base plate is then connected via an additional wire to the earth/ground.

 Schaller Tele-pickup neck

Figure3. Telecaster neck pickup. This version has 3 connecting wires: black and white are wire windings and yellow is for the metal cap. Many models have just two wires, in which case the black wire is connected to the cap.

However impractical the hot wire is often referred to as plus and the cold wire is referred to as minus. These terms originate from the world of direct current. By contrast, pickups only use alternating current.

Nevertheless, pickups do have a kind of electrical polarity or operating direction. When a single pickup operates alone, polarity is insignificant. However, as soon as two or more are in operation this polarity becomes important. Terms such as coil base, coil end and coil direction aren’t really helpful here. Likewise, a better definition than plus or minus is the following: You need an analog multimeter (moving-coil instrument). This kind of measuring device has become somewhat out of fashion in recent years but is still available and is quite useful for some applications. A rather simple model which costs under 100 Euros is adequate. You select the most sensitive current setting, e.g. 50 microamperes and connect it to both ends of the pickup. You then bring something metal such as a scissors close to the pickup and allow it to be pulled towards the pickup by magnetic force. (Figure 4). The measuring device reacts by pointing to the far left or the far right. When you remove the metal object (such as the scissors) again, the needle points in the opposite direction. On testing a number of different pickups, it becomes apparent that some of them show a positive, then negative reading, whereas other pickups generate a negative, then positive reading. Similarly, if you test the polarity of a pickup and then switch the pickup connections, a second reading illustrates the opposite characteristics. The electrical polarity of a pickup is defined at best as follows: It should be connected so that the needle points to the right when a metal device (e.g. a scissors) enters its magnetic field and points to the left when the metal device is subsequently removed. When the pickup is connected accordingly, the connection which is made to the plus pole of the instrument is indeed plus, and the other connection is minus.


Figure 4. Testing the electrical polarity of a pickup.

It is worth noting that in practice, the white wire is not always plus and the black is not always minus. It is equally possible that the opposite is the case. Similarly, the generalization that shielded cables are always inner = plus / outer = minus cannot be taken for granted. In practice, the designation of plus and minus is quite arbitrary. Each manufacturer decides for themselves and rarely defines which is plus and which is minus, therefore it is strongly advisable to test the connections accordingly.

Whereby two pickups are switched in parallel, both minus poles and both plus poles respectively must be connected with each other in order for them to operate correctly. In the event that the pickups are in series, such as in a Humbucker, the minus pole of one coil is connected to the plus pole of the other coil. This causes the signal voltage to be added together. If an opposite phase combination is desired, the plus pole must be connected to the minus pole of two coils in parallel operation. The opposite is the case if they are to be switched in series, i.e. either both plus poles are connected together or both minus poles. The best so-called out-of-phase sounds are obtained when both coils which work against each other are positioned as far apart as possible. On a Stratocaster, for example, these would be the neck and the bridge pickup. It makes no sense to switch the coils ‘against’ each other within a single Humbucker for example, since they literally cancel each other out and the signal becomes extremely quiet.


Buzz-free switching
Many musicians find it annoying when buzz or hum from the amp is audible while they are playing. This occurs with common single coils. They pick up magnetic alternating fields from the vicinity caused by electrical transformers in amps, line-level devices such as effects units and from ambient sources such as fluorescent lamps and overhead wires for trains and trams. The Humbucker was invented in order to solve the problem. It is made of two coils which are combined to cancel out interference from outside sources. To avoid the string sounds from compensating each other, the magnetic north poles point in the direction of the strings through the one coil, the magnetic south poles point through the other. Usually, both coils are in series. This doubles the signal, i.e. the output voltage is twice as strong as from a single coil. This also occurs with parallel switching, which is possible on guitars that are fitted with more than one single coil. The nearest single coil or ‘immediate neighbor’ is given ‘reverse wound, reverse polarity,’ RWRP. On a Stratocaster, at least in the second and fourth switch position, the resultant sound of the instrument is buzz-free. As a rule, an even number of coils must be switched on at a given time with an equal number of north and south pole coils. It is irrelevant whether they are parallel or in series. In any event, they must be switched as outlined above.

Using a Megaswitch is somewhat more complicated. Here, for example, one coil of a Humbuckers on the bridge is switched in parallel with a single coil in middle position. If buzz-free operation is desired, then these must be north pole and south pole. Furthermore, plus must be connected to plus and minus to minus. Here, it is important to establish which magnetic polarity a single coil has before assigning the switch positions so that when the Humbucker is split, the coil which has the opposite magnetic polarity operates at the same time.

How can you establish the polarity of a single magnet? Tie it on one end of a piece of thread and let it dangle in the air at least a half a meter away from a large metal object. Initially it moves, but after a short period it comes to rest in a given position. The end which points to the north is the north pole; the other end is the south pole. (In the vicinity of the earth’s geographic north lies the magnetic south pole!) This also works with single coil pickups which have single magnets or with a single bar magnet under the coil. It doesn’t work with Humbuckers or with single coil pickups that have two magnets under the coil, such as the P90 or the P94. To establish the polarity of such devices, take a single magnet or a single coil the polarity of which is known to you and test how it attracts and repels the pickups you wish to test. A minimum of 1 cm distance from the pickup must be maintained. The physical law whereby the same poles repel each other and opposites attract is demonstrated when (1) the distance between both magnets is big enough and (2) both magnets are of similar strength. Magnets which differ greatly in strength always attract each other over short distances because the stronger one reverses the polarity of the weaker one. It is important to avoid being misled by this.

In some cases, the opposite magnetic polarity to that which has been supplied by the manufacturer is required. Although Fender type single coils cannot be altered in this way, Humbuckers can usually be changed. On the underside, the four small screws which hold the coils in position are removed. The base plate is then removed, the magnet is turned around as illustrated below, and the part is reassembled i.e. screwed into position accordingly. On P90/P94 pickups, both magnets must be turned. It should be noted that the electrical polarity is also changed by doing this. The plus poles become the minus ones and vice versa.


Figure5. Magnets in most Humbuckers may be turned

When a buzz-free out-of-phase sound is desired, two coils with the same magnetic polarity must be switched opposite to one another to achieve it.

A completely buzz-free result can only be obtained if both coils have the same number of winds. A typical Humbucker which has been manufactured with care usually has identical coils. This is not the case, however, when two different Humbuckers are switched to single coil position, i.e. are split and the remaining coils are used together. The same applies to a split humbucker and a single coil. The number of winds on the coils often differs, which causes incomplete compensation and therefore, residual hum. Although it is not ideal, it is considerably quieter than the hum generated by a single coil by itself.

With four-wire Humbuckers, the question often arises, which wire goes on which coil? The answer depends on the brand. A black wire can correspond to a red, green or white one, for example, which means it is important to consult the instructions. If the instructions are not available, this can be established quite simply using an Ohmmeter. The typical resistance of a coil is approximately a few Kilo-ohms. Which pair of wires belongs to the coil with the adjustable screws and which ones belong to the one with the fixed poles? This information is rarely included in the instructions. Das You can test it yourself by soldering a jack socket and connect the coil with a guitar cable with an amp that is switched on. You touch the poles in turn gently with a small metal device such as a screwdriver. The pole which makes a loud cracking noise is the one to which the wires should be connected.

The colored wires in the switch positions shown here are those which were used by Schaller pickups. They are designated as follows:

White and green: North pole coil

Yellow and brown: South pole coil

Light colors (white and yellow): Plus according to the aforementioned definition

Dark colors (green and brown): Minus

These colors must then be altered according to the individual colors of a particular manufacturer.


About the potentiometer values
It has become common practice to use control knobs with 250 kOhm for single coil pickups and those with 500 kOhm for Humbuckers. This is not a hard and fast rule, however and neither is it always the case in practice. Generally, the following applies: With 500-kOhm volume control knobs, higher frequencies are more accentuated than with 250-kOhm volume control knobs. The difference is not substantial, however. If someone using single coils wants a brighter sound, they can replace their 250-kOhm volume control knob with a 500 kOhm version. Conversely, the high frequencies of a Humbucker can be reduced by switching to a 250-kOhm volume control knob. In essence, the choice of volume control knob is a matter of taste and the resultant sound depends largely on the amp. In any event, trial and error, rather than theory is the best policy.

When the volume control knob is turned down to reduce the volume the sound usually loses its brightness. This undesirable ancillary effect can be reduced by installing i.e. soldering a small capacitor between the input (i.e. the right position) and the output (the wiper). Optimum values here are 330 pF, 470 pF or 680 pF. The eventual choice is a matter of taste. These capacitors are not illustrated in the switch diagrams. It is also worth noting that, with passive pickups, the characteristic transfer of sound also depends on the capacity of the guitar cable. This is due to a physical phenomenon and cannot be avoided.

« Last Edit: April 21, 2017, 11:56:16 AM by Elantric »

Offline admsustainiac

« Last Edit: April 21, 2017, 12:20:54 PM by admsustainiac »

Offline Elantric

Re: DIY - get-a-grip-on-pickup-phase
« Reply #5 on: August 14, 2017, 02:39:37 PM »


Posted on November 15, 2010   by patricia
Muddy sounding neck pickup? Try Seymour’s quick tech fix

By Seymour Duncan Tech Guru Scott Miller

People often call and ask how to fix a muddy sounding neck pickup. Some years ago, Seymour taught me a cool trick to fix this exact problem. If you connect a .047 capacitor in series (directly in-line) with the hot output wire from your neck pickup, it will filter out the excess low-end, and clean up the muddy tone.  Most of the time, this solution is perfect. And, it is an easy mod that most people can do themselves.

Offline Elantric

« Last Edit: September 16, 2017, 03:05:16 PM by Elantric »

Offline Elantric

Re: DIY - get-a-grip-on-pickup-phase
« Reply #7 on: October 04, 2017, 12:37:46 PM »