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Digital Augmented Guitar

A series of Force and slide touch sensors onto an electric guitar table sending continuous control flows for real time Sound morphing such as by hand wah wah effetcs
Application Field: 
Digital Music Instrument
Application Product: 
Custom Controller
Contributors: 
Rodolphe Koehly, Papier Logik, France

Augment your electric guitar with paper sensors

This augmented guitar has been augmented with paper sensors transmitting a position or a pressure. The guitar audio signal passes through a computer, as well as the sensors signals collected by the sensors and transmitted to the computer via a joypad connected in usb. Then, various sound morphing strategies using softwares like MAX-MSP or Pure Data can be used to modify in real time the guitar signal in function of the sensors signals variations. Sensors can also be used to trigger supplementary sounds through MIDI or other sound synthesis softwares.

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The once modulated sound is next fed back into an amplifier, like for a standard electric guitar. In order to meet ergonomic prerogatives and play comfort, we opted for a "U" position sensor, (see figure 1), equipped with a pressure sensor located above the pickups of the guitar. This allows controlling the effects while playing and & nbsp; without loosing the & nbsp; plectrum.

 

In addition, we have also placed a pressure sensor under the protection plate of the guitar below the microphones. Finally, the joypad was installed after the bridge at the end of the guitar.

 Guitar_view_of_the_first_4

Once realized, we got a guitar augmented by two pressure sensors, a position sensor and joypad sensors.

Usage / Mapping:
In the case of augmented guitar, the idea was to use sensors to control effects applied to the audio signal, and others to launch selected sounds stored in the computer ( sampling).

- Position and pressure sensors & nbsp; have been dedicated to effect control, let's take the example of a "Delay effect": in this case the pressure sensor can allow a setting of the delay tempo (tap tempo). Concretely it allows to adjust the tempo of the delay to the tempo of the piece that we are playing & nbsp; simply by beating the measurement with the plectrum or the finger on the pressure sensor. The position sensor, meanwhile, can allow a fine adjustment of the duration of the delay (time), its volume or any other parameter of the delay. In the case of a "tremolo" effect, the pressure sensor can function as an on / off switch of the effect, and the position sensor will adjust the speed of the "tremolo", or another parameter of the chosen effect. The interest of the position sensor in controlling the parameters of an audio processing by an effect is immense, because it allows a control of the parameters over a large scale of values, assignable to our liking. The possibilities are limited only by our imagination.

The pressure sensor located under the protection plate has been dedicated to launching selected audio samples stored in the computer. The selected sound is launched by simply pressing the guitar protection plate. This sensor has been coupled to the joypad to allow an incrementation in the list of selected sounds, so by manipulating the joypad we choose the desired sound and it triggers by pressing the protection plate at the desired time. Here, this system can trigger a storm sound, a door noise, a sound texture, or any audio source from the guitar directly: again, the possibilities are endless ... Of course, all the modifications realized on this electric guitar do not remove anything of its acoustic qualities or the integrity of its violin making: the system being adaptable to any other instrument.

Conclusion:

The obtained instrument, the augmented guitar, is unique for many reasons:

- the flexibility of its use related to the number of possible combinations between the different sensors and the & nbsp; choice of modulated parameters.

- the very apprehension of this instrument, that is to say in the manner that one can have to play, and & nbsp; thus to envisage the creation under other lights once the instrument parameterized according to its own wishes.

- its modularity, quality mainly due to the facility of manufacture of the paper sensors allowing the extension of the possibilities according to the inspirations or the requirements of the musician.