Music performers frequently pursue the ideal tone for their configuration and are open to introducing deliberate distortion into the audio signal to achieve it. While this may appear counterintuitive, when executed properly, it can produce remarkable results. Have you ever pondered about the alterations that occur in the signal during distortion? And is it possible to replicate these effects? The reply is affirmative, and it can be accomplished using fundamental numerical operations and Arduino programming.
The Diode Clipping Technique
One of the most basic methods for altering the signal from an electric guitar is through the utilization of a diode clipping circuit. This setup involves utilizing an op-amp with antiparallel diodes either placed in series in the feedback loop or diverting the output to the ground. The diodes restrict the peaks and troughs of the sine waves, changing them into a form more akin to a square wave. This square wave adds supplementary harmonics and richness to the audio, leading to the desired distortion outcome. It is this uncomplicated method that elucidates the extensive availability of distortion pedals in the market.
Emulating Distortion with Computational Logic
In a demonstration, [Sebastian] elucidates how distortion can also be imitated using computational algorithms. He dissects the mathematical processes involved, which are remarkably comprehensible. The algorithm comprises of a step operation with a linear segment, a quadratic phase, and a rigid-clipping function. Additionally, [Sebastian] derives an alternative, more computationally effective algorithm from the Schockley diode equation, leveraging a natural exponential step function. To execute these models, [Sebastian], utilizing an ADC to transmute the analog guitar signal to digital and assigning a DAC to each of the two algorithms. Every distortion impact possesses distinct characteristics, catering to varying preferences. Some may prefer the severity of the step function, while others may be inclined towards the exponential algorithm.
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