Note: Descriptions are shown in the official language in which they were submitted.
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Polyphonic Humbucking Guitar Pickup
Background of the invention
1. Field of the invention
This present invention relates to a polyphonic humbucking guitar pickup
transducer for use
with a stringed musical instrument of which the strings are made of
ferromagnetic material
that comprises multiple electromagnetic sensors to capture the sound of a
stringed musical
instrument such as guitar, banjos, violin, viola, and other string
instruments. Furthermore,
the present invention relates to a polyphonic humbucking guitar pickup
transducer for
electric guitars, assembled in a humbucking noise cancelling configuration and
sized as an
industry standard "single-coil" or sized as a "dual-coil" guitar pickup
working in passive or
active mode and also functioning in stereo or mono configuration.
2. Description of the prior art.
Electromagnetic pickup transducers have been utilized for many years in
musical
instruments having ferromagnetic strings such as guitars, mandolins, violins,
violas, banjos
and other string instruments well described in many patent arts.
Electromagnetic pickups
for stringed musical instruments having a plurality of ferromagnetic strings
are used to
transform string vibrations into an electrical signal which is amplified by an
audio amplifier
to produce sound. The basic design of an electromagnetic pickup for a musical
instrument
such as an electric guitar with ferromagnetic strings consists of a magnetic
structure made
of one or more permanent magnets, and one or more coils of wire with internal
pole pieces
made of permanent magnets or of high permeability materials such as soft iron
to form a
magnetic flux structure. The pole pieces are located beneath or adjacent to
each string of
the instrument. Ferromagnetic strings become part of the magnetic flux path,
generated
through the pole pieces by the permanent magnet(s). The magnetic field lines
flow through
the coil(s) and a short section of the strings. By plucking the strings,
vibration of the strings
creates a disturbance in the magnetic flux which produces an alternating
voltage
proportional to the frequency of vibration in the coil(s).
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The output voltage of a pickup depends on the number coil windings, thickness
and
magnetic permeability of the string, number of magnetic flux line density
interfering with the
vibration of the strings, strength of the magnetic field, and the distance
between the
magnetic pole and the strings. There are several types of electromagnetic
pickups: single-
coil, dual-coil and multiple-coil pickups where one or more coils capture the
sound of each
vibrating string separately known as polyphonic pickups. Electromagnetic
pickups are
sensitive to external magnetic fields generated by transformers, fluorescent
lamps, radio
waves and many other sources of EMI. (electromagnetic interference). Pickups
act like
sensitive antennas picking up hum and noise from these sources. The guitar
industry has
made a great effort to create guitar pickups less prone to external
electromagnetic
radiation. Hum cancelation pickups known as humbucking pickups are configured
of two
pickup coils electrically out of phase; the magnetic poles are set to be in
opposite polarity in
each winding of the two coils and are magnetically out of phase which put the
output of
electrical signal from each pickup back in phase with one another.
External electromagnetic interferences such as hum at 50Hz or 60Hz that
radiates into
both coils with equal amplitude and out of phase, canceled each other, but the
signal
generated by the pickup from instrument strings vibration is not canceled. The
sound
characteristic of a single-coil pickup tends to be brighter and crisper than
the humbucking
dual-coil pickup, as well as greater note definition between strings. However,
a single-coil
pickup is noisier than humbucking pickups. In a single coil pickup, faint
harmonics are
buried in hum and are not clearly heard. Dual-coil pickup systems, known by
the industry
as humbuckers are less noisy. Usually, they sound louder and heavier than
single-coil
pickups.
The dual-coil pickup sounds less bright than the single-coil pickup because
the sound of a
string's vibration is sensed by the magnetic poles of the coil in two places
along the same
string simultaneously. If the distance between the two magnetic poles of the
coils is
comparable with the wave length of the sound, the relevant harmonic
frequencies are
canceled because the waves are out of phase resulting in a dull sound.
The shape of magnetic field affects how much of the string is read. Humbucker
pickups
read a larger length of the string's vibration which results in higher
harmonics cancelation.
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The purpose of this invention is to produce a polyphonic humbucking guitar
pickup with
sound characteristic of a single-coil guitar pickup and with the humbucking
noise
cancelation characteristic of a dual-coil guitar pickup, sized as an industry
standard known
as "single-coil pickup" or "dual-coil guitar pickup". In the present
invention, the magnetic
flux lines interacting with the strings are condensed and focused on the
vibration of each
individual string only. The individual coils of the sensors in the pickup are
connected in a
humbucking configuration. The vibration of each individual string is captured
by the
sensors at a single point reducing any sound cancelation from the string
harmonics and
canceling any outside hum interference at the same time.
In many of the preview arts such as single-coil, dual-coil and in some
polyphonic guitar
pickups, the magnetic flux lines between North and South poles of the pickup
coils usually
have a spherical or oval characteristic which makes a long loop between North
and South
poles as well seen in patent US 8344236 B2 by Adam Eugene Mayes.
The magnetic flux lines of these sensors interact with the vibration of the
strings as well as
with the mechanical parts of vibrato mechanism underneath the pickup, which is
made of
magnetically permeable material such as steel or iron; therefore, unwanted
noise is
introduced to the system.
Many of the magnetic flux lines are wasted inefficiently outside of the
string's vibration
area, which makes the pickup inefficient and more susceptible to
electromagnetic
interference. One example of this type of pickup configuration is illustrated
in patent U.S.
7166794 by Henry E. Juszkiewicz, Nathan W. Yeakel, as shown in Fig.1 and
Fig.8. The
magnetic flux lines N-S are divided in two, upper magnetic flux lines which
are intended to
capture the sound of the vibrating strings, and the lower magnetic flux lines
which are
wasted because they are located outside of the string's vibration area and
interfering with
other sources of electromagnetic noises. In addition, the moving metallic
parts of a guitar,
like vibrato mechanics, introduce unwanted noise in the pickup. Similar
problems we see in
patent: US 4348930 by Dennis A. Chobanian, and R. Alan McNaughton. In the
present
invention, the magnetic flux lines of the sensors are concentrated
specifiCally to each
individual string and form a short length of magnetic flux between the North
and South
poles.
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They are focused only on the vibrating string area with an increased density
of magnetic
flux lines, and the interaction with the vibrating strings results in more
efficient distribution
of the magnetic flux lines and less electromagnetic interference. Another
undesirable
sound characteristic of the single-coil and dual-coil pickups presented in the
preview arts is
that when the sound of all the strings are captured at once, the strings'
vibrations interact
with each other producing inter-modulation distortion between the signal of
each string,
resulting in an unpleasant and unnatural sound. In the prior arts, polyphonic
guitar pickups
also suffer for significant cross talk between the strings. Within the pickup
transducer
assembly, cross talk occurs because the string vibration read by one sensor
affects the
adjacent magnetic field read by the second sensor. As a result, there is
magnetic flux lines
interference between two adjacent sensors. In this invention, the magnetic
flux lines in the
assembly of the polyphonic humbucking guitar pickup are arranged strategically
to achieve
minimum cross talk between adjacent strings when compared to prior arts. In
the present
art, the benefits of concentrating the magnetic flux lines around the
vibration of each
individual string along with a specific orientation of the magnetic flux lines
minimizes the
cross talk between adjacent strings and results in greater separation between
each string's
signal. This minimizes inter-modulation distortion and consequently, the
pickup produces a
more natural sound.
The music industry offers many types of pickups with different self-resonance
frequencies
producing different tone characteristics. The frequency response of nearly all
available
electromagnetic guitar pickups, single-coil or humbucking coils, is nonlinear
which creates
a sound variety. Some musicians are exploiting this sound variety by creating
different
sound effects, while others are looking for more accurate sound reproduction
from their
instruments. The resonant frequencies of most available pickups are between
2,000 and
6,000 Hz. Particularly in humbucking or double-coil guitar pickups, harmonics
that are
within the range of the resonant frequency are amplified. Harmonics above the
resonant
frequency are progressively reduced, but the fundamental vibration and the
harmonics well
below the resonant frequency is reproduced without alteration and makes the
sound of the
humbucking pickup less present.
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The high harmonics in those pickups apparently collapse much sooner than
fundamental
frequency, resulting in a sound without definition. Both single coil and
double coil pickups
usually produce unpleasant feedback at the resonance frequency in the most
played/strummed area of the instrument. In the present art the resonance
frequency of
each individual sensor is near the upper end of the audible spectrum, or above
16 KHz
which makes the sound characteristic of the pickup linear below the point of
resonance.
This results in less feedback in the playing/strumming area and the sound has
more
definition and accuracy. In the present invention, the fundamental frequency
is collapsing
together with the harmonics at the end of ADSR (Attack, Decay, Sustain, and
Release)
curve.
Each string of a stringed musical instrument has a particular vibration
characteristic;
therefore, each string requires its own sensor to accurately reproduce its
sound.
Polyphonic pickup contains multiple sensors with each one being particularly
sensitive to
the vibrations of one string and relatively insensitive to the vibrations of
the other strings.
These electromagnetic pickups used for stringed musical instruments are
described in
patent arts such as: U.S. 3983778, U.S. 4096780 U.S. 7166794, U.S. 7285714,
U.S.
6392137, and U.S. 8344236.
Polyphonic guitar pickups are also used in systems where the sound of a guitar
is
processed by a digital signal processor. In the polyphonic guitar pickup
industry, effort has
been made to produce pickups with the highest output and largest separation
between the
strings. However, many of these pickups do not have enough signal strength to
function in
a passive mode without electronic support. One of the reasons for the low
signal strength is
due to the magnetic flux lines intersecting with the instrument's strings and
is being wasted
outside of the vibration area resulting in less output voltage. There are
several ways to
increase the output voltage of a pickup. Having stronger magnets or placing
pickup
sensors closer to the strings gives a higher output but also damps string
vibration by pulling
the strings towards the pickup causing less sustain and less separation
between strings.
Another way to increase output voltage of a pickup is to increase the number
of windings in
the coils. This procedure is limited to polyphonic pickups through the spacing
between
strings.
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By increasing the number of windings in the coils, impedance and capacitance
of the coils
are increased. This results in loss of high frequencies of the pickup and
affects the db
separation ratio between strings. In the present art, the majority of the
magnetic flux lines
are highly concentrated directly to the vibration of each individual string,
resulting in a
higher number of flux lines intersecting the string vibration, and produces a
higher voltage
per coil output with greater separation between strings compared to the prior
arts. The
efficiency of the magnetic flux lines interfering with the string vibration in
this invention also
results in improved attack amplitude, better transient response, better
dynamic range and
sustained sounds. Furthermore, the polyphonic humbacking guitar pickup in this
art is rich
in harmonics with a high degree of signal to noise ratio, and has sufficient
output voltage to
work in either mono or stereo configuration in a passive mode without any
electronic
support.
3. Summary of the invention
1. An objective of this invention is to provide a new and improved polyphonic
humbucking
pickup apparatus for stringed musical instrument having a plurality of
ferromagnetic strings,
and in particular a polyphonic humbucking guitar pickup transducer comprised
of multiple
electromagnetic sensors which capture the sound vibration of each musical
string
separately working in passive or active mode.
2. Furthermore the object of this invention is to provide a polyphonic
humbucking guitar
pickup with humbucking noise cancelation characteristics assembled with
industry
standard size "single-coil" or "dual-coil" guitar pickup.
3. Another objective of this invention is to provide a polyphonic humbucking
guitar pickup
with minimum length of magnetic flux between North and South poles at each of
the
individual sensors and an increased number of magnetic flux line densities
interacting with
each of the strings. By focusing the flux only in the areas of the string's
vibration, the
efficiency of the magnetic flux is increased since it interacts with string's
motion of the
instrument resulting in a greater sensitivity to its movement. As well, the
invention has a
greater separation between the strings, a higher output voltage of the pickup,
a better
transient response, and less electromagnetic interferences than prior arts.
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4. Another object of this invention is to produce a new and improved
polyphonic
humbucking guitar pickup with better dynamic range, improved signal to noise
ratio, better
attack, long sustain sounds, rich in harmonics assembled in a humbucking
configuration.
5. Furthermore another object of this invention is to produce a new and
improved
polyphonic humbucking guitar pickup were the fundamental frequency and the
harmonics
are collapsing together in the same time at the end of the ADSR (Attack,
Decay, Sustain,
and Release) envelope of a sound.
6. Another objective of this invention is to produce an improved polyphonic
humbucking
guitar pickup apparatus where the sound of each individual string is captured
and
electronically processed separately or summed in stereo or mono configuration
with a high
degree of separation and accuracy between adjacent strings, producing less
inter-
modulation distortion.
7. Another object of this invention is to produce a new and improved
polyphonic
humbucking guitar pickup were the self resonance 'Q' of each separate coil in
the
polyphonic pickup assembly is at the high end of the audible frequency
spectrum of (16Khz
or higher) resulting in more linear sound characteristic below the point of
resonance 'Q' and
less feedback interference in the working area of the instrument.
8. Another object of this invention is to produce the polyphonic humbucking
guitar pickup
assembled in humbucking noise canceling configuration where the output of high
harmonics is not attenuated or canceled due to the capture of the sound
vibration of one
string in two places in the same time, where the frequencies of harmonics are
out of phase
as in previous arts of humbucking guitar pickups.
9. Another objective of this invention is to provide a polyphonic humbucking
guitar pickup
that the sound of each individual string can be processed separately in a
flexible way
intended for a wide range of professional audio applications such as ND
convertors, audio
amplifiers and audio processing equipment.
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10. Another object of the invention is to provide a new and improved
polyphonic
humbucking guitar pickup that is simple and inexpensive to manufacture,
industry friendly
and easy to install in most new or existing guitars without major modification
of the original
instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is the perspective view of the polyphonic humbacking guitar pickup
assembly
according to the present invention, assembled according to industry standard
as a "single-
coil" guitar pickup mounted under the guitar strings.
Fig. 2 is the exploded perspective view of the polyphonic humbucking guitar
pickup
assembly of Fig.1 according to the present invention showing six separate
electromagnetic
sensors comprising of six separate coils, six separate L shaped yokes and six
separate
magnets transversal polarized and with polarity strategically arranged to
maximize the
separation between guitar strings.
Fig. 3 is the top view of the polyphonic humbucking guitar pickup assembly
with six
sensors (L1) to (L6) along with an equal number of strings, and illustrates
six magnets
transversal polarized in a specific magnetic orientation N-S attached to the L
shaped yokes
of each sensor in the operational relationship to the guitar's strings.
Fig. 3a is the side view of the polyphonic humbucking guitar pickup in the
working
relationship with the guitar's strings.
Fig. 3b illustrates the A-A section of one of six sensors of the polyphonic
humbucking guitar
pickup displaying the magnetic flux lines traveling from the North Pole (N) to
the South
Pole (S) and engaged in an operational interaction with the strings above 7.
Fig. 4 is the exploded view of the polyphonic humbucking guitar pickup
assembly with one
permanent magnet bar transversal polarized attached to all six sensors which
are equal
with the number of strings of the guitar in the operational relationship with
the strings.
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Fig.5 illustrates the top view of the polyphonic humbucking guitar pickup
assembly with one
permanent magnet bar transversal polarized N-S attached to all six sensors
which are
equal to the number of the strings in the operational relationship with the
strings of the
instrument.
Fig. 5a is the side view of the polyphonic humbucking guitar pickup of the
Fig. 4 in working
relationship with the strings of the instrument.
Fig. 5b illustrates the A-A section of the one of six sensors of the
polyphonic humbucking
guitar pickup as shown the Fig. 4, showing the magnetic flux lines traveling
from North pole
(N) to the South pole (S) and interacting with the strings above 7 in the
operational
relationship according with the present invention.
Fig. 6 is the perspective view of the polyphonic humbucking pickup assembly,
according to
the present invention, and illustrates its operational relationship to the
guitar assembled in
the industry standard size "dual-coil" guitar pickup working in humbucking
mode
configuration.
Fig. 7 is the exploded perspective view of the polyphonic humbucking guitar
pickup
assembly of the Fig. 6, showing six pairs of coils and six pairs of yokes
magnetically
connected together with a permanent magnet transversal polarized to form six
pairs of
sensors with six separate magnetic flux fields for each string in working
relationship with
the strings of the musical instrument.
Fig. 8 is the top view of the polyphonic humbucking guitar pickup assembly
with six pairs of
sensors equal with the number of strings in the operational relationship to
the strings of the
instrument.
Fig. 8a is the side view of the polyphonic humbucking guitar pickup in working
relationship
with the instrument's strings.
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Fig. 8b Illustrates the A-A section of one pair of sensors of the polyphonic
humbucking
guitar pickup showing the magnetic flux line traveling from North pole (N) to
the South pole
(S) interacting with the string 7 in operational relationship according with
the this invention.
Fig. 9 represents the compact view from inside protecting cover 9 of the
polyphonic
humbucking guitar pickup working in humbucking mode configuration and sized
according
to the industry standard as "dual-coil" guitar pickup in relationship with the
strings of the
instrument.
Fig.10 represents the electrical diagram of the polyphonic humbucking guitar
pickup as it is
viewed in Fig. 4, working in active mode where each sensor is connected
separately to an
audio preamplifier and the output of each preamplifier connected to left or
right stereo
output.
Fig.11 illustrates the electrical diagram of the polyphonic humbucking guitar
pickup as it is
viewed in Fig. 2 and Fig. 3, working in active mode and in humbucking
configuration where
each pair of sensors is connected to an audio preamplifier and furthermore
connected to
left or right stereo output.
Fig. 12 illustrates the electrical diagram of the polyphonic humbucking guitar
pickup as it is
viewed in the Fig. 4 working in passive mode and connected left or right to
the stereo
output.
Fig. 13 illustrates the electrical diagram of the polyphonic humbucking guitar
pickup
working in active mode and in humbucking configuration as it is viewed in the
Fig. 7 and
Fig. 8, where each pair of the designated sensors is connected separately to
an audio
preamplifier and furthermore connected to the left or to the right of the
stereo output.
Fig.14 illustrates electrical diagram of the polyphonic humbucking guitar
pickup working in
passive mode and in humbucking configuration where the output of the pickup is
assigned
to the left or to the right of the stereo output.
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DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
This invention is referring to the polyphonic humbucking guitar pickup working
in a noise
canceling configuration, designed to work with electrical guitars in which the
strings are
made of ferromagnetic material. In reference to Fig.1, the drawings represent
the present
invention of the polyphonic humbucking guitar pickup placed inside of the
protecting cover
8 with the shape and size of a standard "single-coil" pickup assembly which is
positioned
under the guitar strings 7 of a conventional electric guitar and mounted on
the instrument
body with a pair of screws 9.
For the purpose of description, there is no need to show additional guitar
body or other
instrument structure. All the sensors from (L1) to (L6) are the same size and
have the
same inductance, capacitance and the same resistance, as well as the same
value of self
resonance Q (above 16 KHz). Each sensor illustrated in Fig. 3, Fig. 3a, and
Fig. 3b is
comprised of bobbin 5 and coil 4, consisted of multiple windings of thin
copper wire
wounded over the insulated iron core 2. The terminals 10 of the coil 4 are
inserted in the
printed circuit board 6 for the purpose of connection with the applicable
electronics circuits.
The core 2 is made of ferromagnetic material such as soft iron having high
magnetic
permeability or a permanent magnet. The bottom of the coil and core is
attached to the L
shape yoke 3, and assembled parallel with the core 2 and coil 4. The yoke 3 is
made of
permeable material such as soft iron having high magnetic permeability and
furthermore it
is attached to the permanent magnet 1. The permanent magnet 1 is transversal
polarized
with respect to the magnet's axis. The polarization is from front to back,
front being defined
with respect of to the direction along the length of the guitar. The magnet 1
produces a high
density magnetic flux structure N-S focused on the vibration of the string 7
area only as
seen on Fig.3b.
The function of the L shape yoke is to provide magnetic support to the
permanent magnet
1 and to conduct the magnetic flux lines from one of the pole of permanent
magnet 1 to the
core 2. In the magnetic loop between the pole of core 2 and the pole of the
permanent
magnet 1 the number of magnetic flux lines exiting the North Pole of the
permanent
magnet 1 equals the number of magnetic flux lines entering the South Pole of
the
permanent magnet 1.
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The surface area of the pole of core 2 is much smaller than the surface area
of the one
pole of the permanent magnet 1 resulting in high concentration of magnetic
flux lines in the
area of the vibrating strings. The system acts as the magnetic flux
concentrator for the
sensor in the area of the vibrating string.
The length of the L shape yoke 3 is not strictly limited by the length of the
coil 4 or the
length of the core 2 and is usually equal to the length of the permanent
magnet. All
components are assembled together to provide the most efficient magnetic flux
structure
for the magnetic pickup sensor. The magnetic flux is focused on the vibration
of the
individual string only. By plucking the string 7, the vibration of string 7 is
disturbing the lines
of the magnetic flux, creating voltage in the coil which is proportional to
the string's
vibration. The voltage is distributed to the electronic circuit to be
processed and
transformed in audible sound.
The distance between sensors (L1) through (L6) has to be positioned in a way
that the
center of each core of the sensor is aligned with the strings above.
According to the present invention as in Fig. 2 and Fig. 3, (L1) to (L6)
sensors are assigned
to each separate string E, A, D, G, B, and E.
The sensors (L1) to (L6) are connected in pair of (L1-L2), (L3-L4) and (L5-
L6), to work in
humbucking configuration. The coils of (L1) and (L2) sensors are electrically
connected
together as in Fig. 11. The coils of (L1) and (L2) are wound in opposite
direction and
connected together to produce signals out of phase. The permanent magnets 1
attached to
each sensor (L1) and (L2) are also polarized N-S, and opposite of each other
to bring the
signal back in phase. Unwanted electromagnetic interferences inside the coils
are equal
and out of phase, and consequently cancel each other, while the signals from
the string
vibration in the coils are in phase and added together. The same working
configuration is
applied to the pair of sensors, (L3-L4) and (L5-L6) and are electrically
connected as
illustrated in Fig. 11. In the present embodiment, the coils (L2) and (L3) are
not part of the
humbucking pair connection. Each (L2) and (L3) sensor have a permanent magnet
attached to it that are magnetically polarized in the same direction N-S to
prevent any
magnetic interference with each other.
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The magnetic flux lines are repelling and not crossing each other, resulting
in good sound
separation between (L1-L2) and (L3-L4) sensor pairs.
The same arrangement of magnets is applied to (L4) and (L5), and the magnets
associated
with (L4) and (L5) are magnetically polarized N-S in the same direction as
seen in Fig. 2.
The magnetic flux lines between (L4) and (L5) repel each other but are not
intersecting
which results in superior separation between the pair sensors (L3-L4) and (L5-
L6).
Fig.11 illustrates a sample schematic diagram of the present invention of the
polyphonic
guitar pickup in the humbucking and stereo configuration. Each pair of the
pickup assembly
(L1-L2), (L3-L4) and (L5-L6) is connected in humbucking configuration and is
connected
separately to the operational amplifiers Ul, U2, U3, with the volume control
R10, R11, R12
assigned to each pair of sensors (L1-L2), (L3-L4), and (L5-L6). Each pair of
sensors
represents the audio signal of the two strings (E-A), (D-G), and (B-E). Each
signal is
directed in stereo mode to the right or to left output as desired by panning
the
potentiometers R13, R14, and R15. The signal from all the sensors can also be
assigned
to one channel only if a mono configuration is selected.
Fig. 4 of the present embodiment illustrates the simplified version of the
polyphonic
humbucking guitar pickup with a single magnet transversal polarized while
providing
magnetic flux to all electromagnetic sensors. (L1) to (L6) and can be
electrically connected
in any desired combination. The sensors can be connected all in series to
process the
signal as a monophonic sound configuration or divided into groups to the left
or to right
channels for a stereophonic sound configuration. Also each sensor can be
connected
separately by the skilled in art to AID convertors to be used in digital audio
processing.
According to the present invention, Fig.10 describes an electrical diagram of
the present
polyphonic humbacking guitar pickup in active mode where the sensors (L1) to
(L6) are
connected separately to operational amplifiers U1 to U6, the output voltage of
each
individual sensor is controlled separately by potentiometers R5, R14, R23,
R32, R41, and
R50. Each sensor can be assigned separately to L left or R right audio channel
and mixed
in stereo L left and R right output configuration by pan potentiometers R6,
R15, R24, R33,
R42 and R5. According to the present invention, the polyphonic humbucking
guitar pickup
also can be used in passive mode; the example of schematic diagram is
illustrated in
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Fig.12 where (L1), (L2), (L3) sensors are connected in series and assigned to
read the
strings E, A, D, and the output signal is sent to the left stereo channel.
Furthermore (L4),
(L5), (L6) are also connected in series and assigned to read the strings G, B,
E and the
output signal is sent to the right stereo channel.
Another embodiment of the present invention is illustrated in Fig. 6, Fig. 7,
Fig. 8, Fig.8a,
Fig. 8b, and Fig. 9.
Fig.6 illustrates the present invention of the polyphonic humbucking guitar
pickup with the
shape and size of an industry standard "double-coil" pickup assembly inside of
protecting
cover 9 and frame 10 to hold the pickup in place. It is positioned under the
guitar strings 7
of a conventional electric guitar and mounted on an instrument body with a
pair of bolts 11
and nuts 12.
Fig.7 represents the exploded view of the polyphonic humbucking pickup guitar
of Fig.6
which comprises twelve separate pickup sensors, wherein each sensor is
comprised of
bobbin 5, coil 4 winded with thin copper wire with the ends 13 inserted to the
printed circuit
6 for further connections. A magnetized pole core 2 is attached at the lower
end of the coil
to the L shaped yoke 3 and furthermore attached to the permanent magnet
transversal
polarized. All sensors from (L1) to (L12) are the same size and have the same
inductance,
capacitance and also the same resistance, furthermore each sensor has the same
self
resonance Q which is above 16 KHz. As described in the background of the
invention, the
humbacking guitar pickups in previous arts suffer from a lack of harmonics and
a loss of
high frequencies due to the simultaneous capture of the string's vibration in
two places at
once where the out of phase frequencies are canceled. In this present
invention the
sensors (L1) to (L12) are connected in pairs of the humbucking configuration
to cancel the
outside electromagnetic noise.
Each sensor of a humbucking pair is connected to another sensor for a
different string, so
the sound of the vibration is not read in two places at the same time. This
results in a
sound characteristic of a "single-coil" guitar pickup and in the same time a
noise canceling
characteristic of a "dual-coil" humbucking guitar pickup, resulting in a sound
present and
rich in harmonics.
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In Fig.8a and Fig. 8b the magnetic flux lines at the lower end of the sensors
are shorted
and redirect through a magnetically permeable plate base 8 to avoid magnetic
flux lines
from traveling underneath the pickup assembly, which can cause magnetic
interference
with the moving mechanical metal parts of the guitar placed underneath like in
the tremolo
assembly as an example. According to the present invention, Fig.13 illustrates
the
electrical connections of the polyphonic humbucking guitar pickup sensors
working in
humbucking configuration and in active mode.
The (L1) coil is electrically connected in series and out of phase to the (L9)
coil, which is
winded in the opposite direction to the (L1) coil. The magnetic field of (L9)
is in the opposite
direction of the (L1) sensor. Electrical noise from outside is equal and out
of phase in each
coil of (L1) and (L9) and cancel each other, but the electrical signals
generated by (L1) and
(L9) from the vibration of strings E and D are in phase and added together and
connected
to an operational amplifier U1 through R1 and R2.
The output volume of the audio signal is controlled by the R19 potentiometer
and mixed by
R25 to the L or R channel of the stereo output. A similar configuration of the
connection is
applied to the pair of sensors (L2-L10) which are assigned to capture the
sound vibration of
strings A and G. Furthermore, the electrical signals are amplified by U2 and
directed to the
output L or R of the stereo output through R20 and R26. (L3-L11) are assigned
to strings D
and B, and are also connected in the humbucking configuration.
The electrical signals are amplified by U3 and the output is directed through
R21 and R27
to the L or R stereo channel. (L4-L12) are assigned to strings G and higher E,
and are also
connected in the humbucking configuration and electrical signals are amplified
by U4 and
the output is assigned through R22 and R28 to the L or R stereo channel.
(L5-L7) are assigned to the strings B and lower E and are also connected in
humbucking
configuration. The electrical signals are amplified by U5 and the output is
directed to the L
or R stereo channel though R23 and R29. Lastly, (L6-L8) are assigned to the
higher E and
A strings and also connected in the humbucking configuration. The electrical
signals are
amplified by U6 and are directed to the L or R channel through R24 and R30.
All outputs
from U1 to U6 can be assigned as desired to a monophonic output.
According to the present embodiment, the polyphonic guitar pickup in
humbucking
configuration can work in a passive mode as is illustrated in Fig. 14.
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The sensors' arrangement and connections of the present embodiment are not to
be taken
in a limiting sense; rather, the illustration are intended to explain the
underlying principle of
the invention and to demonstrate a version of the polyphonic guitar pickup
designed in a
humbucking configuration with monophonic or stereophonic mode options.
