Four-Point (Three-Gradient) Linear Interpolation Extension for One Dimensional Data

Background In developing digital signal processor for Deepstomp (do-it-yourself digital multi-effect pedal platform), I have to optimize all computation in fix point math since the employed signal controller is just a cheap 32-bit processor with no floating point unit  (ARM Cortex M3 microcontroller). The most important effect especially for electric guitar is distortion effect, which can be simulated using sigmoid […]

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Fold-Back Distortion: Producing “Phew” Effect Using Software and Hardware (Analog Electronic Circuit)

Introduction: What is Fold-Back Distortion? I was introduced to a term of  “fold-back distortion” in the past by an article from an old book which I forget what the title is, but the book contains schematic diagrams of many circuits collected from old publication of Elektor magazine (www.elektor.com). The article presents the circuit’s schematic diagram and how it works. I […]

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Symmetric Distortion Using Clipper Diodes for Guitar Effect

Introduction While almost every audio equipments  pay whatever it cost to minimize distortion, this kind of device does the opposite: distortion effect for electric guitar. Many methods have been implemented in producing a distorted signal from electric guitar pick-up, such as over-driven vacuum tube, solid-state (transistor), or diode clipper. The simplest form is passive diode clipper, which is implemented as […]

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