GB2049226A

GB2049226A - Improvements in or relating to apparatuses for tuning stringed instruments, such as electronically amplified stringed instruments

Info

Publication number: GB2049226A
Application number: GB7916358A
Authority: GB
Original assignee: VISCONTI A
Current assignee: VISCONTI A
Priority date: 1979-05-11
Filing date: 1979-05-11
Publication date: 1980-12-17
Also published as: FR2456360A1; DE8012864U1; JPS5632185A; DE3018140A1; DK206380A; GB2049226B

Abstract

There is provided an apparatus for tuning a stringed instrument, such as an electric guitar or bass. Means such as an electromagnetic pick-up 8 is provided for determining the pitch of each string 9 and is connected to means 14 for comparing the pitch with a reference signal corresponding to the correct pitch. The comparing means output controls a drive, such as a motor 11 with gears 12 and a tuning rod 10 adjacent the instrument bridge 3, which changes the pitch of the string 9 until it is correctly tuned as determined by the comparing means 14. When the pitch equals the reference a circuit 16 operates a lock and removes power from the motor. <IMAGE>

Description

SPECIFICATION Improvements in or relating to apparatuses for tuning stringed instruments, such as electronically amplified stringed instruments The present invention relates to apparatuses for tuning stringed instruments. Such an apparatus is particularly suitable for use with the solid-bodied electric stringed instruments such as electric guitars and electric basses.

According to the invention, there is provided an apparatus for tuning a stringed instrument comprising means mounted on the intrument for adjusting the pitch of each string individually, means for determining the pitch of each string connected to means for comparing the pitch of each string when played with a reference signal, and drive means connected between the comparing means and the pitch adjusting means for causing the pitch adjusting means to change the pitch of the played string to correspond to the reference signal.

Preferably, the means for adjusting the pitch of each string comprises an electric motor connected via reduction gearing to a shaft which is mounted adjacent a bridge of the instrument and to which the string is attached after having passed over the bridge.

Preferably, there is provided means for locking the adjustment means when the corresponding string is correctly tuned.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a solid-bodied electric guitar including a preferred apparatus; Figure 2 is a cross sectional view of a part of the guitar of Fig. 1 showing the preferred apparatus; and Figure 3 is a block schematic diagram of the preferred apparatus.

Fig. 1 shows a solid-bodied electric guitar, for instance a Fender Stratocaster (Registered Trade Mark) guitar which is particularly suitable for incorporating the preferred apparatus.

The preferred tuning apparatus 1 is mounted at the back of the solid body 2 of the guitar.

The guitar has a bridge 3 and electric pickups 4 mounted on the body, and a conventional patent head 5 with conventional tuning rods 6 are connected via a neck 7 to the guitar body 2. A special pick-up 8 is also mounted on the guitar body under the strings 9, each of which extends from a respective tuning rod 6, over both of the pick-ups 4 and the special pick-up 8 and over the guitar bridge 3 to a winder 10 provided in the apparatus 1. Each string is connected to the corresponding winder 10 by means of several string windings therearound.

The apparatus 1 includes a direct current servo-motor 11 whose shaft is connected via a reduction gearing 1 2 to the winder 10 so as to turn it for adjusting the tension in the corresponding string 9. The motor 11 is connected to a circuit arrangement 13, which is also connected to the special pick-up 8.

The special pick-up 8 comprises a separate electromagnetic transducer for each of the strings 6 of the guitar. However, whereas in conventional pick-ups of the type shown at 4 all the transducers are connected in series, the individual transducers of the special pick-up 8 are individually connected to a frequency analyser 14, which is provided in the circuit arrangement 1 3. The frequency analyser 14 has an output connected to the input of a control circuit 15, whose output is connected to the motor 11 so as to drive it. A second output of the frequency analyser 14 is connected to a further control circuit 16, which is arranged to lock the shaft of the motor 11 when correct tuning has been achieved.The frequency analyser 1 4 provides a plurability of reference signals corresponding to the correct pitch of the individuai strings 6 of the guitar and includes means for comparing the frequency of a string 6 with the corresponding reference signal to produce an "error" signal at its first output. The control circuit 1 5 receives this error signal and causes the motor 11 to rotate in a direction such as to change the pitch of the corresponding string so as to reduce this error signal.The further control circuit 1 6 also receives the error signal on the second output of the frequency analyser 1 4 and detects when the string is in tune, at which point the circuit 1 6 actuates a locking device which prevents the motor shaft, and hence the winder 10, from rotating. At the same time, power is removed from the motor 11.

The frequency analyser 14, the control circuit 1 5 and the further control circuit 1 6 are preferably formed as one or more integrated circuits in order to reduce the space requirement and weight of the preferred apparatus.

The power for the circuit arrangement may be provided by batteries, for instance of the rechargeable type, provided as a part of the apparatus mounted on the guitar body. Alternatively, the apparatus may be powered from the mains supply, for instance, via a lead carrying the direct voltage at which the circuit arrangement works. Such a lead may be combined with the output signal lead from the guitar to an amplifier and so does not impede the mobility of a musician playing the guitar.

An on-off switch for the preferred apparatus is preferably provided on the front of the guitar body to allow the musician to switch off the apparatus since, otherwise, it would attempt to re-tune the strings while the guitar was being played. To use the preferred apparatus, the guitar strings are adjusted to approxi mately the correct pitch by means of the conventional tuning rods 6 in the patent head 5 of the guitar. The apparatus is then switched on and one of the. strings is plucked.

The corresponding transducer of the special pick-up 8 supplies to the frequency analyser 14 a signal corresponding to the pitch of the string. The analyser 14 compares this pitch with a reference signal corresponding to correct tuning of the string and produces an error signal, for instance, of positive polarity if the string is flat and of negative polarity if the string is sharp. Thus, in the case when the string is flat, a positive signal is supplied to the control circuit -15, which causes the servomotor 11 to rotate the winder 10 via the reduction gearing 1 2 so as to increase the tension in the corresponding string 6 and thus increase its resonant frequency or pitch.In the case when the string is sharp, a negative signal is supplied to the control circuit 1 5 which causes the motor 11 to unwind the string from the winder 10 so as to reduce the tension in it and thus correct for the mistuning of the string. When the string is correctly tuned, the further control circuit 1 6 detects this condition and actuates a locking device which prevents the motor from rotating further, thus holding the winder 10 to retain the correct tension in the string 6. This operation is then repeated for each of the other strings of the guitar. Means may be provided for indicating when each string is in tune so as to allow the guitar to be tuned as quickly as possible.

The preferred apparatus may thus be used while the guitar is connected to an amplifier and the volume control of the guitar may be.

turned on or of without affecting tuning.

Thus, the guitar may be tuned automatically with the volume control turned off so that tuning may be performed during a live performance. This method of tuning is much more convenient than using an acoustic method and the apparatus is easier to use than the "stroboscopic tuners" previously used, for which it was necessary to unplug the guitar from the amplifier and plug it into the stroboscopic tuner and then tune the strings individually by means of the conventional tuning rods while watching the display of the stroboscopic tuner.

The functioning of the preferred apparatus is substantially unaffected by humidity or different string thicknesses, tuning being determined solely by the pitch of the string when plucked during the tuning process. It is possible to tune an electric guitar within ten seconds, which is a great advantage during a live performance when environmental factors can substantially affect the tuning of the instrument. The ease and quickness of tuning is also an advantage when new strings are used, since they tend to go out of tune relatively quickly.

The preferred apparatus is particularly suitable for solid-bodied electric stringed instruments, such as electric guitars and basses, since the presence of the apparatus behind the bridge of the instrument does not substantially affect the sound quality produced thereby. However it may be possible to adapt the apparatus for use with acoustic stringed instruments so as not to substantially alter the quality of the sound produced. Also, in the case of a solid-bodied instrument, the device is hidden behind the body of the instrument and thus does not detract from the appearance of the instrument.

Claims

1. An apparatus for tuning a stringed instrument, comprising means mounted on the instrument for adjusting the pitch of each string individually, means for determining the pitch of each string connected to means for comparing the pitch of each string when played with a reference signal, and drive means connected between the comparing means and the pitch adjusting means for causing the pitch adjusting means to change the pitch of the played string to correspond to the reference signal.

2. An apparatus as claimed in claim 1, in which the means for adjusting the pitch of each string comprises an electric motor connected via reduction gearing to a shaft which is mounted adjacent a bridge of the instrument and to which the string is attached after having passed over the bridge.

3. An apparatus as claimed in claim 1 or 2, in which there is provided means for locking the adjustment means when the corresponding string is correctly tuned.

4. An apparatus as claimed in claim 3 when dependent on claim 2, in which the locking means comprises means for locking the rotational position of the motor shaft and means for preventing the supply of electricity to the motor.

5. An apparatus as claimed in any one of the preceding claims, in which the pitch determining means comprises a pick-up mounted on the instrument under the strings and having a separate output for each string.

6. An apparatus as claimed in any one of the preceding claims, in which the comparing means comprises means for producing a reference signal corresponding to the correct pitch of each string, and means for comparing the output of the pitch determining means for each string with the corresponding reference signal, the comparing means being arranged to produce a first output signal, when the output of the pitch determining means substantially corresponds to the reference signal, and a second output signal which has a first polarity when the string is sharp and the opposite polarity when the string is flat.

7. An apparatus as claimed in claim 6 when dependent on claim 2, in which the motor is connected to the output of a drive circuit whose input is connected to receive the second output signal.

8. An apparatus as claimed in claim 6 or 7, when dependent on claim 3, in which the locking means is connected so as to be controlled by the first output signal from the comparing means.

9. An apparatus for tuning a stringed instrument, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

10. A stringed instrument including an apparatus as claimed in any one of the preceding claims.

11. An instrument as claimed in claim 10, comprising a solid-bodied electric guitar or electric bass.