GB2470581A - Stringed musical instrument pickup selection system - Google Patents

Abstract

A pickup selection system suitable for use with electric guitars includes two pickup selection switches 26-27, each interconnected with a plurality of pickups 21-25 such as single-coil or humbucker pickups. The pickups may be arranged into first 21-22 and second 23-25 groups, with each group being connected to a respective one of the pickup selection switches 26-27. A two-position output selection switch 28 allows the pickup selection switches 26-27 to be connected one at a time to respective output terminals. The system may be include a bypass switch 30, one position of which connects both pickup selection switches 26-27 to respective output terminals simultaneously. Alternatively, bypass switch 30 may be omitted and a three-position output selection switch may be utilised, one position of which connects pickup selection switches 26-27 to respective output terminals simultaneously. The pickup selection system may be incorporated into a footswitch connected to the stringed musical instrument.

Description

tV. INTELLECTUAL ...* PROPERTY OFFICE Application No. GB0909 122.4 RTM Date:30 September 2009 The following terms are registered trademarks and should be read as such wherever they occur in this document: Fender Gibson Chapman Stick Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk Stringed Musical Instrument Pickup Selection System This invention relates to an electronic pickup system for stringed musical instruments, more particularly, but not by way of limitation, it relates to an improved pickup switching system for electric guitars.

It is generally accepted among guitarists that the two most useful electric guitar pickup systems are those passive systems originally introduced more than fifty years ago by Fender and Gibson respectively. The Gibson system employs two dual-coil pickups respectively positioned near to the bridge and neck of the instrument, the pickups being selectable singly or together by means of a three-position switch. The Fender system utilises three spaced-apart single-coil pickups selectable singly or in adjacent pairs by means of a five-way switch. The enduring appeal of the Fender and Gibson systems is due to their distinct tonal characteristics, simplicity of use, simplicity of manufacture and inherent reliability. A disadvantage of both systems is the restricted number of pickup coil combinations, and therefore tonal options, available to the player.

Over the years a great many other multi-coil pickup systems have been developed with the aim of increasing the tonal options available within a single instrument.

A common approach is to supplement a Fender or Gibson type system with additional switches which may be used to obtain further pickup coil combinations or to control whether pickups or coils are connected, for example, in series or in parallel. A disadvantage of such multi-switch systems is that two or more switches may need to be manipulated to reach the desired output tone. During live performance, when tonal changes often require split-second timing, it can be difficult or impossible to find the correct switch configuration with the necessary rapidity especially when the switches have one or more intermediate positions.

Another common approach is to employ knob-operated rotary switches. This type of rotary switch, being utilised in many other areas of electrical engineering, is readily available and may comprise of several layers contacts ganged upon a single shaft mounted perpendicular to the face of the instrument. While offering a greater number of switch positions than toggle switches and a multitude of wiring possibilities, knob-operated rotary switches are generally disliked by players for the reasons that they offer less visual indication than toggle switches of the current pickup selection and are somewhat more difficult to manipulate when time is of the essence, particularly when an intermediate switch position is sought.

Most recently, active circuitry has been employed to electronically modify a pickup's inherent tonal characteristics so that, for example, the output signal of a piezo bridge pickup can be modified to mimic a variety of differently positioned electromagnetic pickups. Such active systems are often disliked by players for two reasons: firstly, the batteries required to power the circuitry need to be checked frequently if the instrument is to remain fully operative at all times; secondly, because of the subjective view that electronically modified pickup signals sound somewhat artificial, having less audio appeal than an equivalent signal from a passive circuit.

The aims of the present invention are fourfold: (1) to provide a greater number of pickup selection options in a single instrument than the aforementioned Fender or Gibson systems; (2) to overcome the previously described switching difficulties by providing simple means for interchanging or combining two tonal options pre-selected by the player; (3) to enhance instrument versatility by providing means to enable said two pre-selected tonal options to be output via respective output connections and thus via different sound processing devices; (4) to allow the aforementioned interchanging or combining operations to be carried out by means of an external device such as a footswitch, thus relieving the player's hands of additional burden.

The invention will now be described by way of example with reference to the accompanying drawings: * figure 1 is a schematic diagram of a preferred embodiment of the invention utilising two separate groups of pickups and two output jacks; * figure 2 is a schematic diagram of a footswitch device; * figure 3 is a plan view of an electric guitar showing a layout of pickups and controls relating to figure 1 with those components shown in both figure 1 and figure 2 carrying the same identifying number in each figure; * figure 4 is a schematic diagram of a simplified version of the invention utilising a single group of pickups and a single output jack; * figure 5 is a schematic diagram showing a development of figure 4 utilising a single group of pickups and two output jacks.

It should be noted that, for ease of description, passive electromagnetic pickups only have been depicted in the accompanying drawings though any suitable transducer device may be employed including active electromagnetic devices and pie zoelectric devices.

Piezo pickups are often integrated with of the bridge of a guitar and comprise several small transducers; one transducer contacting each string. In the context of the present disclosure such multi-element piezo pickups will be regarded and utilised as a single pickup device.

It should be further noted that all pickup devices described herein may each be presumed to transduce string vibrations in a group of strings common to all pickups, for example: in a six-stringed guitar it may be presumed that each pickup transduces the vibrations of all six strings; in a four-stringed guitar it may be presumed that each pickup transduces the vibrations of all four strings; and so on.

The present disclosure may also be applied to so-called touch-style' instruments such as the Chapman Stick in which both hands are employed in tapping the instrument's strings against the frets or fingerboard. Touch-style instruments often have two distinct groups of strings, typically a first group of melody' strings and a second group of bass' strings tuned to a somewhat lower pitch than the first. In such instruments the present disclosure is applicable to each string group separately.

Referring to figure 1, the circuit schematic shows a five-pickup version of the invention comprising pickups 21, 22, 23, 24 and 25; first and second pickup selection switches numbered 26 and 27 respectively; output selection switch 28; bypass switch 30; first and second volume control potentiometers numbered 29 and 33 respectively; first and second tone controls numbered 31 and 32 respectively; first and second jack sockets numbered 36 and 38 respectively; jack socket selection switch 34 and stereo/mono selection switch 35.

First and second jack plugs 37 and 39 are depicted to aid clarity, jack plug 37 being of a TS (tip, sleeve) type for monophonic output; jack plug 39 being of a TRS (tip, ring, sleeve) type for stereophonic output. The sleeve section of each jack plug is connected to ground.

First jack socket 36 is a mono type having two contacts 36a and 36e which contact the tip and sleeve sections respectively of jack plug 37. Second jack socket 38 is a stereo type having three terminals 38a, 38b and 38e which contact the tip, ring and sleeve sections respectively of jack plug 39.

Note: jack sockets and jack plugs are depicted throughout this description and the accompanying drawings for purpose of example only, other means of signal output including wireless transmission being equally applicable.

Said five pickups are arranged into first and second groups, said first group comprising dual-coil pickups 21 and 22; said second group comprising single-coil pickups 23, 24 and 25.

Pickup selection switches 26 and 27 are lever-action rotary switches similar to those popularised by Fender, each switch having a wide spanning wiper capable of touching a single terminal or two adjacent terminals. Pickup selection switch 26 is a three-position type having a single pole 26c and two terminals 26a and 26b, pickups 21 and 22 being connected for output at terminals 26a and 26b respectively. Figure 1 shows the wiper of selection switch 26 positioned to contact terminal 26a only, this being the first of said three switch positions.

Pickup selection switch 27 is a five-position type having a single pole 27d and three terminals 27a, 27b and 27c, pickups 23, 24 and 25 being connected for output at terminals 27a, 27b and 27c respectively. Figure 1 shows the wiper of selection switch 27 positioned to contact both terminals 27b and 27c, this being the forth of said five switch positions.

Note: depiction of lever-action rotary switches throughout this description and in the accompanying drawings is for purpose of example only, other types of switching device being equally applicable.

Output selection switch 28 is a double-pole double-throw on-on type having poles numbered 28b and 28c connected to pickup selection switch poles 26c and 27d respectively. Figure 1 shows switch 28 set in the first of its two positions with poles 28b and 28c contacting terminals 28a and 28x respectively. In the second position of switch 28 poles 28b and 28c contact terminals 28w and 28d respectively. No circuit connections are made to either of terminals 28x and 28w, the two remaining terminals 28a and 28d having circuit connections described hereinafter.

Bypass switch 30 is a double-pole double-throw on-on type having poles 30a and 30c connected to selection switch poles 27d and 26c respectively. Figure 1 shows switch 30 set in the first of its two positions with poles 30a and 30c contacting terminals 30x and 30w respectively. In the second position of switch 30 poles 30a and 30c contact terminals 30b and 30d respectively. No circuit connections are made to either of terminals 30x and 30w, the two remaining terminals 30b and 30d having circuit connections described hereinafter.

Stereo/mono selection switch 35 is a single-pole double-throw on-on type having terminals 35a and 35c connected to jack socket 38 at terminals 38b and 38a respectively.

Note: the term stereo/mono in the context of the present disclosure refers to the terms commonly used to describe the type of jack plug to be utilised for signal output, i.e. TRS or TS.

Jack socket selection switch 34 is a double-pole double-throw on-on type. Figure 1 shows switch 34 to be set in the first of its two positions, poles 34b and 34e contacting terminals 34a and 34d respectively. In the second position of switch 34 poles 34b and 34e contact terminals 34c and 34f respectively. Terminals 34a and 34d are connected to jack socket 36 at terminals 36a and 36e respectively, terminal 36e being grounded via the sleeve section of jack plug 37. Terminal 34c is connected to switch 35 at the pole 35b thereof. Terminal 34f is connected to ground via jack socket terminal 38e and hence the sleeve section to TRS jack plug 39.

For clarity, though switches 28, 30, 34 and 35 are all of a switch type wherein each switch pole contacts only one terminal per switch position, this does not preclude the use of switch types in which each pole contacts more than one terminal per switch position in order to carry out alternative versions of the invention.

Tone control 31 comprises a variable resistor 31a connected to ground via a capacitor 31c. The wiper of variable resistor 31a is connected to both switches 28 and 30 at terminals 28a and 30d respectively. Pickup signals passing through the tone control to ground are restricted to a band of higher frequencies according to capacitor value, the amount of attenuation of said frequency band being controlled by means of variable resistor 31a. This type of passive RC (resistance, capacitance) tone control is commonly used in electric guitar circuitry but is presented here for purpose of illustration only, other types of tone control device, including active circuitry, being equally applicable.

Tone control 32 comprises variable resistor 32a connected to grounded jack socket terminal 38e via capacitor 32c. The wiper of variable resistor 32a is connected to both switches 28 and 30 at terminals 28d and 30b respectively.

Volume control potentiometer 29 has one end of its resistive track connected to both switches 28 and 30 at terminals 28a and 30d respectively, the remaining end of the resistive track being connected to ground. The wiper of potentiometer 29 is connected to switch 34 at pole 34b.

Volume control potentiometer 33 has one end of its resistive track connected to both switches 28 and 30 at terminals 28d and 30b respectively, the remaining end of the resistive track being connected to ground via terminal 38e of jack socket 38. The wiper of potentiometer 33 is connected to jack socket terminal 38a and hence the tip section of TRS jack plug 39.

The necessary connections to ground of tone control 31, volume control 29 and said first pickup group are made at the pole 34e of switch 34, pole 34e having contact with one or other of grounded terminals 34d or 34f dependent upon switch position.

The necessary connections to ground of said second pickup group are made at terminal 38e of jack socket 38.

With all switches configured as hereirthefore described and as shown in figure 1, a circuit is completed from ground through pickup 21, switch terminal 26a, switch pole 26c, switch pole 28b, switch terminal 28a, volume control 29, switch pole 34b and switch terminal 34a to jack socket terminal 36a and hence the tip section of jack plug 37, with output signal tone affected by tone control 31. With switch poles 28c and 30a contacting terminals 28x and 30x respectively, signal output via pickup selection switch 27 is disabled.

Changing the position of jack socket selection switch 34 to its second position connects poles 34b and 34e to terminals 34c and 34f respectively thus redirecting the output of pickup 21 to jack socket 38 via stereo/mono selection switch 35 with the necessary connections to ground of tone control 31, volume control 29 and said first pickup group being made via switch terminal 34f and hence jack socket terminal 38e.

Stereo/mono selection switch 35, as depicted in figure 1, is positioned such that switch pole 35b contacts terminal 35a, directing the output signals of pickup 21 to jack socket terminal 38b and the ring section of TRS jack plug 39. Changing the position of switch 35 from that shown connects pole 35b to terminal 35c, directing the output signals of pickup 21 to jack socket terminal 38a and enabling output via a single monophonic jack plug.

Changing the position of output selection switch 28 to its second position connects switch poles 28b and 28c to terminals 28w and 28d respectively thus completing a circuit from ground through pickups 24, 25 and respective switch terminals 27b and 27c, thence via switch pole 27d, switch pole 28c, switch terminal 28d and volume control 33 to jack socket terminal 38a, with output signal tone affected by tone control 32. With switch poles 28b and 30c contacting terminals 28w and 30w respectively, signal output via pickup selection switch 26 is disabled.

Figure 1 shows switch 30 set in the first of its two positions with poles 30a and 30c contacting terminals 30x and 30w respectively; thus, no electrical connection is made and switch is therefore in a disengaged status. Changing the position of switch 30 to the second of its two positions moves switch 30 from a disengaged status to an engaged status wherein poles 30a and 30c contact terminals 30b and 30d respectively thus enabling simultaneous signal output from said first and said second pickup groups, switch 28 being electrically bypassed.

From the foregoing circuit description it can be deduced that pickup selection can be carried out by three different methods: With switch 30 in a disengaged status, a first pickup selection method involves setting the output selection switch 28 to one or other of its two positions and using an appropriate one of pickup selection switches 26 or 27 to make pickup selections in a conventional manner. Thus, dependant upon the position of switch 28, the circuit may be operated in a manner similar to one of the aforementioned Fender or Gibson systems.

A second pickup selection method involves using pickup selection switches 26 and 27 to pre-select two pickup configurations with manipulation of switch 28 enabling the player to interchange between said pre-selected pickup configurations for output as hereinbefore described.

A third pickup selection method is carried out by setting bypass switch 30 to an engaged status wherein both pickup groups are connected for simultaneous output; pickup selection switches 26 and 27 are utilised to obtain the desired combination of pickup outputs with manipulation of switches 34 and 35 enabling output signals to be directed for either stereophonic or monophonic output. Note: with switches 34 and 35 configured for monophonic output, volume controls 29, 33 and tone controls 31, 32 are operative simultaneously.

With switch 30 engaged and switches 34 and 35 configured for stereophonic output, a footswitch device may be used to carry out the functions of switches 28 and 30 external of the instrument.

Figure 2 shows a schematic diagram of a suitable footswitch device comprising four mono jack sockets for signal connection and two double-pole double-throw push-push type switches 102 and 104 which are connected to said four jack sockets and to one another such that they perform functions equivalent to switches 28 and 30 respectively. Figure 2 is provided for purpose of

example only.

Configuring switches 34 and 35 for stereophonic output also enables said first and second pickup groups to be connected to respective sound processing and amplification devices. Thus, with bypass switch 30 disengaged, the player, by means of switch 28, is able to change pickup selection, volume, tone, sound processing devices and amplifier with a single switching operation.

A simplified version of figure 1 may be carried out by omitting bypass switch 30 and utilising a two-pole double-throw three-position on-on-on type switch for output selection. Were switch 28 such a three-position switch, the centre switch position would connect poles 28b and 28c to terminals 28a and 28d respectively enabling simultaneous signal output from said first and said second pickup groups.

Figure 3 shows a layout of pickups and controls relating to figure 1, those components common to both figure 1 and figure 3 carrying the same identifying number in each figure.

Referring to figure 3 an electric guitar 10 is shown having a bridge 14 secured to the face of body 12. A portion of neck 18 is shown extending from the body with a plurality of strings 16 (shown as six) extending from the bridge over neck 18 to terminate at tuning machines located upon the instrument headstock (not shown). Pickups 21, 22, 23, 24 and 25 are arrayed intermediate bridge 14 and neck 18, each pickup being secured to body 12 beneath and transverse strings 16. Pickups 21 and 23 are positioned adjacent one another near to bridge 14; pickups 22 and are positioned adjacent one another near to neck 18; pickup 24 is positioned intermediate pickups 23 and 22. Volume controls 29, 33 and tone controls 31, 32 are rotary potentiometer devices arranged on the lower bout of the guitar near to pickup selection switches 26 and 27.

Output selection switch 28 and bypass switch 30 are integrated with volume controls 33 and 29 respectively, switches 28 and 30 being operated by a push-push or push-pull latching action of the spindle of the potentiometer. This is a preferred feature of the invention, allowing the player unhindered operation of switches 28 and 30 while maintaining an uncluttered layout of controls.

Switches 34 and 35 are located on the rear of the guitar and are therefore not shown.

Figure 3 is provided for purpose of example only; the configuration of pickups and controls varying in accordance with the technical demands and aesthetic properties of each instrument to which the invention is applied.

A simplified version of the invention utilising five single coil pickups will now be described with reference to figure 4.

The circuit schematic shows a five-pickup version of the invention comprising pickups 40, 41, 42, 43 and 44; first and second pickup selection switches numbered 45 and 46 respectively; output selection switch 48; first and second volume controls numbered 49 and 51 respectively; first and second tone controls numbered 52 and 53 respectively; stereo/mono selection switch 50 and jack socket 54. TRS jack plug 55 is shown to aid clarity.

Jack socket 54 is a stereo type having three terminals 54a, 54b and 54e which contact the tip, ring and sleeve portions respectively of jack plug 55.

Pickup selection switches 45 and 46 are lever-action rotary types as hereinbefore described. Pickup selection switch 45 is a three-position type having a single pole 45c and two terminals 45a and 45b. Pickup selection switch 46 is a five-position type having a single pole 46d and three terminals 46a, 46b and 46c.

Figure 4 shows the wiper of pickup selection switch 45 positioned to contact terminal 45b only this being the third of said three switch positions. The wiper of pickup selection switch 46 is positioned to contact terminal 46b only, this being the third of said five switch positions.

Pickup 40 is connected for output directly to switch terminal 46a and via pickup 41 to switch terminal 45a. Similarly, pickup 43 is connected directly to switch terminal 46c and via pickup 44 to switch terminal 45b. Pickup 42 is connected for output to switch terminal 46b only. The necessary connections to ground of pickups 40, 42 and 43 are made via jack socket terminal 54e and hence the grounded sleeve of jack plug 55.

Switch 48 is a two-pole double-throw on-on type having poles numbered 48a, 48b connected to pickup selection switch poles 45c and 46d respectively. Figure 4 shows switch 48 set in the first of its two positions with poles 48a and 48b contacting terminals 48x and 48d respectively. In the second position of switch 48 poles 48a and 48b contact terminals 48c and 48w respectively. No circuit connections are made to either of terminals 48x and 48w, the two remaining terminals 48c and 48d having circuit connections described hereinafter.

Stereo/mono selection switch 50 is a double-throw on-on type having a single pole 50b and two terminals 50a and SOc. The pole 50b is connected to switch terminal 48c.

Volume control potentiometer 49 has first and second ends of its resistive track connected to switch terminal 50a and grounded jack socket terminal 54e respectively. The wiper of potentiometer 49 is connected to output terminal 54b.

Volume control potentiometer 51 has one end of its resistive track connected to switch 48 at terminal 48d and to switch 50 at terminal 50c, the remaining end of the resistive track being connected to ground at terminal 54e. The wiper of potentiometer 51 is connected to output terminal 54a.

Tone controls 52 and 53 are RC devices as hereinbefore described with connections to ground made at jack socket terminal 54e. The wiper of tone control 52 is connected to switch 50 at terminals 50a. The wiper of tone control 53 is connected to switch 48 at terminal 48d and to switch 50 at terminal 50c.

With switch 48 positioned as shown in figure 4 a circuit is completed from ground through pickup 42, switch terminal 46b, switch pole 46d, switch pole 48b, switch terminal 48d and volume control 51 to jack socket terminal 54a with output tone affected by means of tone control 53. Pickup signal output via selection switch 45 and switch pole 48a is disabled, switch terminal 48x having no circuit connection.

Changing the position of switch 48 from that shown to the second of its two positions connects switch poles 48a and 48b to terminals 48c and 48w respectively thus completing a circuit from ground through series connected pickups 43 and 44, switch terminal 45b, switch pole 45c, switch pole 48a, switch terminal 48c to switch pole 50b for direction to either terminal 54a or 54b of jack socket 54.

Switch 50, as depicted in figure 4, is positioned such that pole 50b contacts terminal 50c, directing output signals from selection switch 45 via volume control 51 and tone control 53 to jack socket terminal 54a and the tip section of TRS plug 55.

Thus, with switch 50 set as shown, pickup signals from both pickup selection switches are routed via volume control 51 and tone control 53; volume control 49 and tone control 52 being rendered inoperative. Changing the position of switch 50 from that shown connects pole 50b to terminal 50a thus directing output signals from pickup selection switch 45 via volume control 49 and tone control 52 to jack socket terminal 54b and the ring section of TRS plug 55.

Referring to figure 4 and the preceding description thereof it can be deduced that pickup selection is carried out by two different methods: A first pickup selection method involves setting the output selection switch 48 to one or other of its two positions and using an appropriate one of pickup selection switches 45 or 46 to make pickup selections in a conventional manner. Thus, dependant upon the position of switch 48, the circuit may be operated in a manner similar to one of the aforementioned Fender or Gibson systems.

A second pickup selection method involves using the selection switches 45 and 46 to pre-select two pickup configurations with manipulation of switch 48 enabling the player to interchange between said pre-selected configurations.

With reference to figure 5, a development of the five pickup version of the invention shown in figure 4 will now be described.

Figure 5 shows schematic diagram of a five-pickup version of the invention comprising pickups 56, 57, 58, 59 and 60; first and second pickup selection switches numbered 61 and 62 respectively; output selection switch 63; first and second volume controls numbered 64 and 65 respectively; first and second tone controls numbered 66 and 67 respectively; first and second jack sockets numbered 81 and 82 respectively; jack socket selection switch 68 and stereo/mono selection switch 80. TS jack plug 83 and TRS jack plug 84 are shown to aid clarity.

Jack socket 81 is a mono type comprising terminals 81a and Ble which contact the tip and sleeve sections respectively of jack plug 83. Jack socket 82 is a stereo type comprising three terminals 82a, 82b and 82e which contact the tip, ring and sleeve sections respectively of jack plug 84.

Pickup selection switches 61 and 62 are lever-action rotary types as hereinbefore described. Pickup selection switch 61 is a three-position type having a single pole 61c and two terminals 61a and 62b. Pickup selection switch 62 is a five-position type having a single pole 62d and three terminals 62a, 62b and 62c. As depicted in figure 5, the wiper of pickup selection switch 61 is positioned to contact terminal 61b only, this being the third of its three switch positions. The wiper of pickup selection switch 62 is positioned to contact terminal 62b only, this being the third of its five switch positions.

Output selection switch 63 is a four-pole double-throw on-on type. Figure 5 shows switch 63 set in the first of its two positions with poles 63a, 63b, 63e and 63h contacting terminals 63x, 63d, 63f and 63j respectively. Changing switch 63 to its second position connects poles 63a, 63b, 63e and 63h to terminals 63c, 63w, 63g and 63k respectively. Switch pole 63a is connected to selection switch 61 at pole 61c. Switch pole 63b is connected to selection switch 62 at pole 62d. Switch pole 63e is connected to pole 63h. Of its eight terminals switch 63 has two terminals, 63x and 63w, to which no connection is made. Terminal 63f is connected to ground via jack socket terminal 82e. Circuit connections to the remaining five terminals are described hereinafter.

Stereo/mono selection switch 80 is a single-pole double-throw on-on type having first and second terminals 80a and SOc connected to output socket 82 at terminals 82b and 82a respectively.

Jack socket selection switch 68 is a double-pole double-throw on-on type which is shown in figure 5 set in the first of its two positions with poles 68b and 68e contacting terminals 68a and 68d respectively. Changing switch 68 to its second position connects poles 68b and 68e to terminals 68c and 6Sf respectively.

Terminals 68a and 68d are connected to jack socket 81 at terminals 81a and 81e respectively. Terminal 68c is connected to switch 80 at the pole 80b thereof. Terminal 6Sf is connected to ground via jack socket terminal 82e. Switch pole 68e is connected to switch 63 at terminal 63g thereof, terminal 63g thus being connected to ground via one of jack socket terminals 81e or 82e dependent upon the position of switch 68.

Pickup 56 is connected for output directly to switch terminal 62a and via pickup 57 to switch terminal 61a. Similarly, pickup 59 is connected directly to switch terminal 62c and via pickup 60 to switch terminal 61b. Pickup 58 is connected for output to switch terminal 62b only. The necessary connections to ground of pickups 56, 58 and 59 are made via output selection switch 63 at pole 63e thereof, pole 63e being grounded via one of terminals 63f or 63g.

Volume control potentiometer 64 has first and second ends of its resistive track connected to switch 63 at terminals 63c and 63k respectively. The wiper of potentiometer 64 is connected to jack selection switch 68 at pole 68b thereof.

Volume control potentiometer 65 has first and second ends of its resistive track connected to switch 63 at terminals 63d and 63j respectively. The wiper of potentiometer 65 is connected to jack socket terminal 82a and hence the tip portion of jack plug 84.

Tone control 66 comprises variable resistor 66a and capacitor 66c connected in series to switch 63, capacitor 66c being connected to terminal 63k. Tone control 67 comprises variable resistor 67a and capacitor 67c connected in series to switch 63, capacitor 67c being connected to terminal 63j. The wipers of variable resistors 66a and 67a are connected to switch 63 at terminals 63c and 63d respectively.

With switch 63, as shown in figure 5, set in the first of its two positions a circuit is completed from ground through pickup 58, switch terminal 62b, switch pole 62d, switch pole 63b, switch terminal 63d and volume control 65 to jack socket terminal 82a.

Output tone is affected by tone control 67. Pickup output via selection switch 61 and switch pole 63a is disabled, switch terminal 63x having no circuit connection.

Changing the position of switch 63 from that shown to the second of its two positions completes a circuit from ground through series connected pickups 59 and 60, switch terminal 61b, switch pole 61c, switch pole 63a, switch terminal 63c, volume control 64, switch pole 68b and terminal 68a to jack socket terminal 81a. Output tone is affected by tone control 66. Pickup output via selection switch 62 and switch pole 63b is disabled, switch terminal 63w having no circuit connection.

Changing the position of jack socket selection switch 68 from that shown to the second of its two positions connects poles 68b and 68e with terminals 68c and 68f respectively; output from pickups 59 and 60 thus being redirected to jack socket 82 via stereo/mono selection switch 80 with the necessary connection to ground of switch pole 63e being made via switch terminal 68f and hence jack socket terminal 82e.

Stereo/mono selection switch 80, as depicted in figure 5, is positioned such that switch pole 80b contacts terminal 80a thus directing the pickup output signals to jack socket terminal 82b and the ring section of TRS jack plug 84. Changing the position of switch 80 from that shown connects pole 80b to terminal 80c thus directing pickup output signals to jack socket terminal 82a and the tip section of TRS plug 84.

Referring to figure 5 and the preceding description thereof it can be deduced that pickup selection is carried out by two different methods: A first pickup selection method involves setting the output selection switch 63 to one or other of its two positions and using an appropriate one of pickup selection switches 61 or 62 to make pickup selections in a conventional manner. Thus, dependant upon the position of switch 63, the circuit may be operated in a manner similar to one of the aforementioned Fender or Gibson systems.

A second pickup selection method involves using the selection switches 61 and 62 to pre-select two pickup configurations with manipulation of switch 63 enabling the player to interchange between said pre-selected configurations, each thereof being connected for output via a respective volume and a respective tone control.

An important feature of figure 5, made possible by the use of a four-pole output selection switch 63, is the isolation of volume and tone controls 64 and 66 from their counterpart controls 65 and 67. This allows the volume and tone settings respective to each pickup selection switch to be maintained when switches 68 and 80 are configured for signal output via a single monophonic jack plug.

Claims (5)

1. Claims 1. A stringed musical instrument pickup selection system comprising: a plurality of pickups each thereof providing string vibration transduction confined to a group of strings common to all said pickups; a system output including first and second output terminals and at least one ground terminal; a first switch for pickup selection each position thereof connecting said first output terminal to a single one or a plurality of said pickups different from the other of said first switch positions; a second switch for pickup selection each position thereof connecting said second output terminal to a single one or a plurality of said pickups different from the other of said second switch positions; and an output selection switch including first and second positions having circuit connections such that changing between said first and second positions disables pickup signal output via one of said output terminals and enables pickup signal output via the other of said output terminals.
2. 2. A stringed musical instrument pickup selection system according to claim 1 wherein said plurality of pickups are arranged into first and second groups of two or more pickups, each group being connected to a respective one of said first and second switches.
3. 3. A stringed musical instrument pickup selection system according to claim 2 including a bypass switch having a first disengaged position wherein no electrical connection is made and a second engaged position wherein circuit connections are made such that said output selection switch is electrically bypassed and pickup signal output via said first and second output terminals simultaneously is enabled.
4. 4. stringed musical instrument pickup selection system according to claim 2 wherein said output selection switch includes a third position enabling pickup signal output via said first and second output terminals simultaneously.
5. 5. stringed musical instrument pickup selection system substantially as described with reference to and as illustrated in the accompanying drawings.