Abstract:
A combination distortion pedal and amplifier includes a foot pedal controls the distortion and the amplification of audio signals. The level of distortion and amplification are determined by the position of the foot pedal with a low level of distortion and amplification when the foot pedal is in a released position and a high level of distortion and amplification when the foot pedal is depressed. Various intermediate distortion and amplification levels are provided when the foot pedal is in positions between fully released and fully depressed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to provisional patent application No. 61/182,654, DISTORTION PEDAL, filed May 29, 2009 which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    With reference to  FIG. 1 , a top view of a distortion pedal  101  is illustrated. The distortion pedal  101  includes a tone control  105 , a distortion control  107  and a on/off pedal  111 . The distortion pedal  101  is used with an electric guitar to distort the audio signals produced by the guitar. An audio cable is connected between the output of the guitar and the input  109  of the distortion pedal  101 . The distortion pedal  101  has a pedal  111  that switches the distortion pedal  101  between on and off modes. In the off mode, the audio signals can go through the distortion pedal  101  without being modified and in the on mode, the distortion pedal  101  modifies the audio signals to the tone and distortion levels set by the tone control  105  and the distortion control  107 . The distortion pedal  111  audio processing is either on or off. Because guitar requires two hands to play, it is not possible to adjust the tone by rotating the tone control  105  or the distortion levels by rotating the distortion control  107  while the user is playing. What is needed is an improved distortion pedal that allows the distortion controls to be adjusted with the user&#39;s feet while the guitar is being played. 
       SUMMARY OF THE INVENTION 
       [0003]    A distortion pedal includes a variable tone or audio distortion control and a variable amplification control that can both be controlled by a foot pedal. In an embodiment, the input audio signals are processed by the tone and amplifier controls. When the foot pedal is pressed, the maximum distortion and the maximum amplification can be applied to the input audio signals. Conversely, when the foot pedal is released, a minimum distortion and minimum amplification can be applied to the audio signals. In an embodiment, the maximum variable distortion and amplification levels are set using control knobs on the distortion pedal. The distortion and amplification applied to the audio signals is then controlled between the set maximum values and minimum values such as no distortion/amplification by the position of the foot pedal. 
         [0004]    The distortion pedal may also include a DB line boost that can be controlled by a control knob that sets the amplification level. An on/off button controls the amplification of the audio signals. The processed audio signals are then output through the output connector. In an embodiment, audio signals from an electric instrument or microphone are transmitted to the input of the distortion pedal. The processed audio signals are then output to an additional power amplifier and speakers which emit the audio signals as sound waves. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  illustrates a top view of a prior art distortion pedal; 
           [0006]      FIG. 2  illustrates a tope view of a distortion pedal with boost; 
           [0007]      FIGS. 3 and 4  illustrate side views of the distortion pedal with boost; and 
           [0008]      FIG. 5  illustrates a block diagram of the signal processing performed on the audio signals by the distortion pedal. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    In an embodiment, the inventive distortion pedal includes a foot pedal that allows the user to vary the distortion level rather than simply turning the distortion on or off. With reference to  FIG. 2 , a top view of an embodiment of the distortion pedal  201  is illustrated and with reference to  FIGS. 3 and 4  are side views of an embodiment of the distortion pedal  201 . The distortion pedal  201  can include a variable output level control  221 , a variable tone/distortion control  225  and a fixed output control  223 , a DB line boost switch  226  and DB line boost indicator  237 . The distortion pedal  201  also includes a foot pedal  227  that has multiple settings within the movement range, rather than functioning as an on/off switch. The foot pedal  227  may rotate about a hinge  229  and a spring may hold the foot pedal  227  in the fully up position when a downward force is not applied to the foot pedal  227 . The distortion pedal  201  also includes an input  231 , an output  233  and indicator lights  239 . 
         [0010]    Rather than functioning as a fixed distortion level unit, the inventive distortion pedal allows the user to adjust the distortion level based upon the distortion pedal  201  position. The movement of the distortion pedal can range from fully back as shown in  FIG. 3  to fully depressed as shown in  FIG. 4 . The foot pedal  227  can be coupled to a hinge or pivot point  291  and a linkage  293  that is pressed into the distortion pedal  201  when the foot pedal  227  is depressed. 
         [0011]    The range of distortion controlled by the foot pedal  227  can be controlled by the variable tone/distortion control  225 . A high distortion setting will result in a wide range of distortion control by the foot pedal  227  and conversely by setting a low distortion range, the foot pedal  227  may control a smaller range of distortion levels. In an embodiment, the fully back position can cause the least amount of distortion and the fully depressed position can cause the most amount of distortion. In other embodiments, the control by the foot pedal  227  can be reversed with the fully back position resulting in the most amount of distortion and the fully depressed position resulting in the least amount of distortion. 
         [0012]    The tone control can consist of a network of highpass, lowpass, and/or bandpass filters. In their most basic form, they attenuate the high or low frequencies of the signal. Active tone controls may also amplify or boost certain frequencies. This is called treble or bass boost or cut, respectively. More elaborate tone control circuits can elevate or attenuate the middle range of frequencies too. The tone control circuits can be passive or active circuits. Passive circuits can utilize resistors, capacitor and/or inductors. The tone control circuit can rely on the property of capacitive reactance or inductive reactance to inhibit or enhance an AC signal, in a frequency-dependent manner. The inductors and capacitors can be used to control different frequencies. For example, capacitors can let more of the higher frequency tones unaltered, while inductors can reduce the amplitude of high frequency tones. In order to boost or cut frequencies in the middle ranges, use is made of the resonance at the frequency at which the reactance of a capacitor equals the reactance of an inductor. In other embodiments, amplifiers can be used to enhance these tone control characteristics. While tone distortion has been described, in other embodiments, different signal distortion processing can be performed by the distortion pedal such as: overdrive, wah, ring modulation, pitch, delay (echo), reverberation, etc. 
         [0013]    In addition to tone control the distortion pedal  201  may also include a variable output level the controls the amplification of the input audio signal. In an embodiment, the amplification level may also be controlled by the foot pedal  227 . The maximum amplification may occur when the pedal  227  is fully depressed and the minimum amount of amplification may occur when the pedal  227  is full up. In other embodiments, this arrangement may be reversed with maximum amplification with the pedal  227  up and the minimum amplification when the pedal is fully depressed. 
         [0014]    In addition to variable amplification, the distortion pedal  201  may also include decibel (DB) line boost amplification. A switch  226  can be controlled by the user&#39;s foot to either on/off positions and light  230  may be illuminated to indicate that the DB line boost amplification is on. When switched on, the DB line boost amplification can amplify the input signal regardless of the foot pedal  227  position. In an embodiment, the amplification can be measured in terms of DBs which is a logarithmic unit of measurement that expresses the magnitude of sound pressure. In different embodiments, the amplification can be represented by a maximum DB gain which can be a fixed number such as 6, 10, 40, etc. 
         [0015]    With reference to  FIG. 5 , a block diagram of the distortion pedal components is illustrated. An input  431  receives audio signals from a musical instrument such as an electric guitar. The audio signals are processed by the tone control  435  which is controlled by the foot pedal position  437 . The distorted audio signals are then processed by a variable amplifier control  439  that is also controlled by the foot pedal position  437 . The processed audio signals may then go to a DB line boost amplification  441  and then the output  433 . If the DB line switch  440  is not turned on, the audio signals can bypass the BD line boost amplification  441  and go straight to the output  433 . 
         [0016]    It will be understood that the inventive system has been described with reference to particular embodiments, however additions, deletions and changes could be made to these embodiments without departing from the scope of the inventive system. Although the systems that have been described include various components, it is well understood that these components and the described configuration can be modified and rearranged in various other configurations.