Patent Application
20110017048
1. The Field of the Invention
This invention relates to systems to modify the electrical output of an musical instrument that generates an electrical output reflective of sound at a particular tone level and more particularly to devices that modify the electrical output so that it can be broadcast unmodified or modified, or combined in multiple formats.
2. The Relevant Technology
In order to create a musical effect, it is sometimes desirable to present the music as written at a lower or different pitch or tune. The process has been referred to as drop tuning. Drop tuning is typically associated with guitars. Drop tuning is discussed on several web sites on the world wide web such as at www.learnclassicalguitar.com. To drop tune one or more strings, those one or more strings are tuned down or dropped the equivalent of one or two or more frets. Drop tuning involves modifying the tuning of the guitar and thus is something that is not lightly undertaken because when the use at the lower or dropped tune level is complete, one must retune to the normal level. Alternately, one must have multiple guitars all tuned differently.
Electrical musical instruments like electrical guitars produce an electrical signal at a selected tone level. The electrical signal is typically amplified and sent to speakers which convert the electrical signal into sound. Users may wish to drop tune their electrical guitars or similar electrical musical instruments. However, the means to drop tune an electrical guitar are essentially the same as the non electrical instruments. Devices or systems to effect drop tuning easily without actually having to retune an electrical guitar are not known.
A device for modifying the electrical output of a musical instrument has an input configured to receive the electrical output of the musical instrument which is at a first pitch or tone level. A suitable electrical instrument includes, but is not limited to an electrical guitar or electrical bass guitar, acoustic guitars and even an electric bass fiddle. The device has change means to generate change signals for changing the first tone level to a second tone level. An analog to digital converter receives the analog electrical output at the first tone level and converts it to a first digital signal that is supplied to a digital signal processor. The digital signal processor is configured to change the first digital signal to a second digital signal that is the same as said first digital signal but modified to be at a second tone level that is different from the tone level of the first digital signal and to supply the second digital signal as the signal processor output.
The device has a controller that is connected to receive the change signals. The controller is configured to generate and supply control signals reflective of the desired change communicated by the change signals to create a second tone level different from the first tone level. The controller supplies signals to the digital signal processor to cause the digital signal processor to use the first digital signal to make or create the second digital signal as the signal processor output. The second digital signal is then supplied to a digital to analog converter to convert the signal processor output into an analog electrical output. The analog electrical output is then supplied to an output device which receives the analog electrical output and then supplies it as the device output for connection to a system for converting the analog electrical output into sound at the second tone level. The device also includes a power supply connected to its components to supply power thereto.
In a preferred arrangement, the change means is configured to generate a plurality of change signals to cause the electrical signals reflective of the sound at the first tone level to change to an electrical signal reflective of the sound at any one of a plurality of second tone levels. The change means may be a computer or other automatic device to generate the change signals in accordance with certain triggers which can be sounds or patterns of sound detected as music is being performed. Most preferably the change means is one or more manual switches positioned in a chassis or housing positioned for operating by the user. The housing or chassis is preferably of the type that can be positioned on the floor with switches being buttons operable by the feet of the user.
In a more preferred configuration, the device includes display means connected to the controller to receive the control signals and to the power supply to receive power there from. The display means is arranged to generate a visually perceivable image of the selected tone level from the plurality of tone levels available for the device output.
In a more preferred configuration, the device includes an output switch connected to receive the analog electrical output. The output switch is also connected to the device input to receive the electrical output of the musical instrument at the first tone level. The output switch is operable between a bypass position in which the electrical output of the musical instrument at the first tone level is supplied as the device output and a second position in which the analog electrical output is supplied as the device output.
Preferably the output switch is controlled by the controller which is connected to said output switch. The controller supplies control signals to cause the output switch to move between the bypass position and the second position. The change signals supplied to the controller preferably include a bypass signal. The controller, in turn, generates control signals that are sent to the output switch to cause the output switch to move between the bypass position and the second position.
In a more preferred configuration, the digital signal processor includes shift means for changing the first digital signal to any one of a plurality of second digital signals each being the first digital signal modified or shifted to be at any one of a plurality of tone levels each different from each other and from the first tone level. The controller supplies control signals to the digital signal processor. The control signals include a shift signal to cause the shift means to change the first digital signal to the second digital signal. Even more preferably, digital signal processor includes a mixer to cause said first digital and the second digital signal to be mixed and supplied as the signal processor output. The mixer being is operable between a non mix position in which the signal process output is the second digital signal and a mix position in which the signal processor output is the sum of the first digital signal and the second digital signal. Even more preferably, the first digital signal is mixed with a second digital signal that is an octave below the first digital signal. This is called an octaver.
In a more desired arrangement, the change means is configured to supply a mixing signal to the controller to cause the controller to supply a mix signal to the mixer in the digital signal processor to cause it to operate between the non mix position and the mix position.
In a preferred assembly, the display means includes an array of light emitting diodes each reflective of a tone level. The display means includes a driver to operate each of the light emitting diodes of the array in accordance with the control signals.
In a more preferred assembly, the device includes an input amplifier connected to receive the electrical output at said first tone level. It is configured to and to amplify the electrical output at said first tone level and to supply the amplified electrical output at said first tone level to the digital signal processor. Similarly, an output amplifier is connected to receive the analog electrical output and to supply the amplified analog electrical output to the output and more particularly to the output switch. Most preferably, the input amplifier and the output amplifier are each variable amplifiers operable by the user by any suitable means such as a knob.
The device in any of the above arrangements and configurations is part of a sound system that includes an instrument of the type that generates electrical signals reflective of sound at a first tone level upon operation by a player. Electrical guitars, electrical bass guitars, acoustic guitars, violins, and similar instruments are contemplated. The system includes a speaker system connected to the device to receive the device output and to broadcast sound reflective of one of the musical instruments' output at the first tone level and at said second tone level and at the mixture of the first tone level and the second tone level.
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore, not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Music is typically written to be performed in a key that may range over several octaves depending on the particular music. The music being performed can be said to be performed at the sound level or tone level desired by the writer. On occasion, the performer may wish to play the music at a different level or tone level than as originally contemplated by the writer. As an example, one could play music an octave lower than as written by the writer of the music. For music to be performed by certain instruments like a guitar, the performer may wish to drop tune or change the sound level or tone of the music being performed for artistic reasons. Guitars and similar instruments may be specifically adapted or tuned to a different sound level or tone level that is typically below or at a lower tone level that the music as written. The practice of drop tuning instruments like a guitar has become accepted so that procedures for drop tuning are available from a number of sources. See, for example, HOW TO TUNE A GUITAR at www.howtotuneaguitar.org/tuning/drop-c on the world wide web.
The output of the electrical instrument is supplied to the input 12 of the device 10. The input 12 is a suitable receptacle sized to receive a connector at the end of a suitable wire or lead coming from the electrical instrument. The input 12 may be hard wired; but it is typically a female receptacle sized to receive a standard male connector. The input 12 may also be an array of receptacles to receive one male connector that may be one of several different sizes. The input 12 may also be configured with a fuse circuit (not shown) to protect the device 10 as well as appropriate line filters as may be desired to filter out undesired electronic signals that may be acquired (e.g., electromagnetic interference). The input 12 as shown has a node 14 to which a bypass conductor 16 is connected to transmit an incoming electrical output at a first tone level directly to the output 18 as more fully discussed hereinafter.
The input 12 is connected by conductor 20 to supply the incoming electrical output at a first tone level to an analog to digital converter 22 through an optional amplifier 24. The incoming electrical output is a first tone level that is an analog signal in that it may be viewed as a complex wave form that is varying in amplitude. The analog to digital converter 22 converts the incoming electrical output to a first digital signal for transmission via conductor 26 to a digital signal processor 28. An AK5358 ETP 24 bit converter available from AKM Semiconductor, Inc. of San Jose, Calif. is believed to be a suitable device for electrical guitars. Of course, other suitable analog to digital converts (A/D) should be available from other manufacturers.
The digital signal processor 28 receives control signals from a micro controller 30. The control signals supplied by the microcontroller 30 include a shift signal via conductor 32 and a mix signal via conductor 34. The digital signal processor 28 includes a shifter 36 that is configured to shift the first digital signal at the first tone to a second digital signal at a second tone level selected or determined by the shift signal supplied to shifter 36 from the microcontroller 30 over conductor 32. The second digital signal is the same as the first digital signal but at a tone level that is different. More specifically, the tone level can be lower than the tone level of the first digital signal. Indeed, the tone level can be lowered in acoustic ½ steps up to and including 7 half steps or 3½ tone levels plus one step that is an octave and another that is an octaver.
The mixer 38 in the digital signal processor 28 is a summing circuit that can combine the second digital signal as the output of the shifter 36 with the first digital signal received via conductor 40 to produce a signal processor output that is supplied to a digital to analog converter 42 via conductor 44. The mixer 38 is operable between a non mix position in which the second digital signal is supplied as the signal processor output and a mix position in which the signal processor output is the combination of the first digital signal at the first tone level and a the second digital signal at the second tone level. A TMS 32006745 from Texas Instruments is believed to be a suitable digital signal processor 28. Other possible digital signal processors are discussed at http://en.wikipeida.org/wiki/Digital_signal_processor.
The microcontroller 30 is a small computer that is specifically configured to generate digital control signals for the digital signal processor 28 and, more particularly, the mix signal that is sent via conductor 34 and the shift signal sent via conductor 32. Microcontrollers of the type used are discussed at http://en.wikipedia.org/wiki/Mircrocomputer. A C 8051F335GM made by Silicon Laboratories, Inc. of Austin, Tex. has been found to be a suitable microcontroller 30. The microcontroller 30 also supplies a digital control signal or bypass signal that is also supplied via conductor 46 to the output 18 to control a relay switch 48 which moves between a by pass position in which the electrical output at the firs tone level is received via conductor 16 and supplied as the device output via conductor 49 and connector 50 and a second or drop tune position in which the device output is received from the digital to analog converter (D/A) 42 via optional amplifier 52 via conductors 54 and 56. The connector 50 is a male receptacle sized to receive a standard female connector. It may also be an array of receptacles to receive a connector of a different size.
Change means 64 are provided to supply change signals to the microcontroller 30 to cause the microcontroller 30 to supply the control signals via conductors 32, 34 and 46. The change means 64 can be any structure configured to supply signals to cause change. Thus, a computer system or any other automatic or semiautomatic device may be configured to supply change signals in accordance with instructions provided to the computer. However, the change means 64 as shown and as presently preferred includes a decrement switch 58 which supplies an electrical signal to the microcomputer to cause it to generate a shift signal to, in turn, cause the shifter 36 to shift the first digital signal down or decrement the first digital signal to create the second digital signal. Of course, the second digital signal is then supplied to the mixer 38 which is connected to and supplies the signal processor output to the digital to analog converter 42 via conductor 44. Similarly, an increment switch 60 is connected to supply an electrical signal to the microcontroller 30 to generate a shift signal to cause the shifter 36 to shift the first digital signal up an increment upward. Thus, the shifter 36 may be at a level to cause the first digital signal to be lowered 2 and ½ steps. By operating the increment switch 60, the shifter 36 is configured (e.g., moved to a desired ½ step) to step the second digital signal toward or to the first digital signal. The decrement switch 58 can be operated (e.g., depressed) to cause the shifter 36 to decrement down up to 3½ steps or 7 half tones plus one octave and to an octaver position. The increment switch 60 can be operated to cause the shifter 36 to move up from the octaver position to the octave and through the 7 half step positions as desired by the user/operator. The increment switch 60 and the decrement switch 58 may preferably be spring loaded push button switches. Suitable switches are available from NKK switches on the world wide web at http://www.nkksswitches.com.
The change means 64 may also include a bypass switch 62 that is operable to supply the bypass signal via conductor 46 to the output 18 and in turn cause the relay switch 48 to move between the by pass position and the second or drop tune position.
Returning to the digital signal processor 28, the signal processor output is supplied to a digital to analog converter 44 such as 24 bit AK4388ETP offered by AKM. The second digital signal or the combination of the second digital signal and the first digital signal is supplied as the digital signal output of the digital signal processor 28 to an analog signal that is optionally amplified by an amplifier like a NJM 4580E that, in turn, is provided as the device output through the relay switch (such as a SC1C-5HS that is offered by World Products) when the relay is in the second or drop tune position shown in
In
The LED Driver 66 also receives a signal from the mixer 38 via conductor 34 and microcontroller 30 reflective of the level of the acoustic signal being supplied as the signal processor output. The level or volume of the signal is then displayed in a multicolor level indicator 84.
The device 10 of
It may also be noted that the input amplifier 24 and the output amplifier 52 are each operable by suitable means to vary the amplification level. As shown, the amplifiers have a variable resistor that is operable by a dial, knob or slide 98 that are ganged together to move both up and down 100 so they are operated in tandem or together. Thus, the amplifiers 24 and 52 are operated at substantially equal levels.
A system is shown in
In
An alternate chassis 138 is shown in
In operation the device 10 of
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
