Guitar pickups are very simple devices. Any coil of wire in a magnetic field can function as a guitar pickup.
Practical limits are imposed by the required output signal size and the physical size of the guitar.
vibration of a metallic string within the magnetic field causes
magnetic flux movements. These induce current in the coil of wire. This
is always alternating current, with a frequency identical to the
frequency of the vibration.
Guitar strings do not vibrate with a
single frequency, but with many frequencies at the same time. These are
the harmonic frequencies and also induce their own currents in the
Different pickups detect varying frequencies more
or less efficiently and these are the characteristics that give a
pickup its' distinctive tone.
are many factors that can affect the tone of a pickup. There are even
more myths (or in some cases lies) claiming to hold the secret of good
The size, shape and strength of the magnetic field affects the response of a pickup.
The material, size, amount of the wire and position of the coil windings affects the response of the pickup.
Almost everything else doesn't, unless it affects one of these two factors.
Given a constant basic pickup design, these are the ways in which the main variables affect tone.
Stronger magnetic field
- more volume, higher proportion of treble content. A stronger magnetic
field also tends to change the mid bias towards the upper mids,
producing a more fucused tone and a stronger attack.
Larger magnetic field
- greater range of harmonics captured, especially mid range and bass.
Therefore higher proportion of mid-range and bass content.
(diameter). Smaller wire diameters produce a larger signal with less
treble content for the same length of wire. If wound to the same
impedance, they produce a smaller signal with more treble content. Finer wires also have a less pronounced resonant peak.
the difference in sizes, a smaller guage of wire may provide the
opportunity to build a pickup that has more output and more treble
content than a larger wire guage. This will occur within the range of
same or greater impedance up to same number of turns of wire. One of
the most important factors in tone is the resonant peak of a pickup.
This is the frequency at which a pickup responds most strongly. A high
resonant peak indicates a brighter tone, a low resonant peak, a darker
tone. thinner wire produces a flatter EQ curve with a less pronounced
often see impedance figures quoted for pickups and take these to
indicate pickup tone. Higher impedance equals more output, darker tone.
In fact it is inductance that we should see, but this is very difficult
to measure correctly and most inductance figures quoted are either
calculated or for the coil only without taking into account the magnet
system and . Like
everyone else, I refer to impedance because it is convenient. The
relationship between impedance and tone only holds for a given pickup
design (single coil, twin coil, stacked coils), a given magnetic field
and the same wire specification. Changing the magnet shapes and sizes
or the wire diameter can very quickly destroy our preconceived ideas of
how pickups should sound.
- In itself, this has no effect. Alnico II doesn't sound any different
than Alnico V or Ferrite. However, it does have a lower magnetic field
strength if the magnet is approximately the same size. Differences in magnetic field strength and size do change the tone.
Coil size and shape
- wider coils sense vibrations from a larger string length, increasing
harmonic richness, particularly in the mid and bass. Narrower coils
sense from a smaller string length, reducing harmonic richness but
producing a higher treble content.
automatically come into the large category. There are additional
effects that change the tone of twin coil designs. Because these have
two focuses on the strings, the two coils sense different frequencies
to a greater or lesser degree. One focus may be near to the peak of a
particular frequency harmonic and the other not. Combining two
balanced focuses produces typical humbucker tones. There are partial
phase cancellations, especially of very high frequencies, which is the
reason humbuckers have less presence than single coils. The increased
harmonic richness in the mid and bass frequencies leads to the fat,
powerful sound we are used to.
further modify the tone of a humbucker. This can be achieved by having
an unbalanced magnetic field or unbalanced coil windings. Gemini
pickups make extensive use of unbalanced coils as this technique allows
flexible switching between different configurations. The results of
unbalanced coils are changes in the resonant peak and changes in the
partial phase cancellations compared to balanced coils. This can be
used to produce humbuckers that sound slightly edgy and raw (small
imbalance) or humbuckers that have high output but relatively low
levels of mids (medium imbalance). Very large imbalances (more than
50%) produce sounds that are not typical for humbuckers at all but more
typical of single coil pickups.
do have an effect on tone because the increased capacitance effectively
reduces the inductance, lowers the resonant peak and makes the pickup
sound slightly darker. The effect is insignificant, however, compared
to the much higher capacitance of the guitar cable, especialy a 10m
has no effect whatsoever on tone. Using thicker insulation (e.g.
formvar) on the coil wire has an indirect effect of making the coil
larger, with the wire on average further from the centre of the
magnetic field. Winding with a thicker poly insulation or a slightly
faster traverse rate would produce exactly the same result.
doesn't directly affect tone. Indirectly, it tends to produce a
physically larger or smaller coil and if excessive, it can stretch the
wire, leading to higher impedance and darker tones.
Myths and Lies
Some of these have been in general circulation for a long time, some are used to try to sell you pickups.
Some of the myths are based on half truths, some on misconceptions and some are straight out lies.
Hand wound pickups sound better because they don't suffer from skin effect. There
is such a thing as skin effect. Skin effect describes the tendency of
electrons to repel each other, leading to flow in the outer portion
(skin) of a conductor. The suggestion is that this leads to higher
impedance and too little treble on pickups that are not wound by hand.
There are three errors in this. Skin effect doesn't apply in
coils, because of the repelling effects of the electrons in the next
adjacent turn of wire. Where skin effect does apply, the depth of skin
is dependant on the frequency of the current. In the relevant range
(100 Hz to 20KHz) the minimum skin depth is over 1mm. However the wire
used is less than 0.1mm in diameter. Thirdly, the suggestion that this
is in any way affected by hand or machine winding is complete fantasy.
Hand wound pickups are better because they are scatterwound. This
is presumably based on the concept of distributed capacitance. The
argument goes scatter winding reduces distributed capacitance and that
lets more treble through because capacitance acts proportionally more
against higher frequencies. The error lies in the assumption that hand
winding is different. wheterh a pickup is machine wound or hand wound
(hand guided would be a better term), the relevant factor is the number
of turns per wrap (layer of wire). This depends primarily on the
traverse rate. At a winding speed of 600 rpm a 4 second traverse
equates to 40 turns per wrap, a 2 second traverse to 20 and a ten
second traverse to 100 which would be close to the maximum possible.
Whether a hand or a machine controls the traverse rate is not
significant. It is just as easy to set the traverse rate on a CNC
machine as by hand. The small amount of variation inherent in hand
guiding makes no detectable difference if the winder is reasonably well
Vintage correct materials and manufacturing techniques are essential for good tone. Most
of the materials have little or no effect on tone. Certainly, the use
of cloth insulation on hookup wires doesn't. In addition, there is no
justification for claiming that all vintage things were good and all
new things are inferior. The idea that no-one has learned anything in
fifty years is foolish. Many of the vintage style pickups available
today are vastly superior to the majority of real vintage pickups and
they can be expected to be consistent as well. Vintage pickups were
mainly characterised by variability. While good and bad tone are
subjective judgements, there is no possible argument for claiming that
random variations produced consistently good results but that
consistent design and manufacturing produces consistently bad results.
The best pickups are produced by black magic
is, of course, absolutely true. All of the Gemini modern and multimode
humbuckers are designed based on the number of the beast. A variety of
arithmetic derivatives of 666 are carefully applied to the design to
ensure the optimum combination of mojo, ju-ju and voodoo is guaranteed
for each pickup. This is why Gemini pickups are better than everyone
else's. Not only do they sound better but they may well enhance both
your playing and your love life.
The exception is vintage models as
black magic is not vintage correct technique. In fact, it wouldn't work anyway.
Vintage pickups are wound using AWG 42 wire. As everyone knows 42 is
the answer to life, the universe and everything and therefore clearly not subject
to modification by the number of the beast.
Copyright Mike Rose 2006 -2015. All trademarks acknowledged. Stratocaster, Strat, Telecaster, Tele, Jazz Bass, Precision Bass are trademarks of Fender Musical instruments corporation. Les Paul, LP, P-90, Burstbucker, "modern classic", Firebird are trademarks of Gibson inc. Epiphone, Wildkat, Casino and Sorrento are trademarks of the Epiphone Company. RIC, Rickenbacker are trademanrks of Rickenbacker International Corporation. Gemini Pickups is not affiliated with any of these companies and the above terms are used for descriptive purposes only.