Monthly Archives: May 2012

A wavetable oscillator—the code

Posted on May 25, 2012 by Nigel Redmon

The wavetable oscillator code follows the basic structure of most audio processing blocks, with three types of functions: at the start: initialization—create the oscillator and its wavetables as needed: control—change the oscillator frequency, and pulse width for PWM every sample: … Continue reading →

Posted in Digital Audio, Oscillators, Source Code, Wavetable Oscillators | 27 Comments

A wavetable oscillator—Part 3

Posted on May 9, 2012 by Nigel Redmon

In Part 2, we looked at how to use subtables designed to cover one octave each, removing upper harmonics for each higher octave to avoid aliasing. Here’s a view of the nine wavetables for our sawtooth oscillator, with the starting … Continue reading →

Posted in Digital Audio, Oscillators, Wavetable Oscillators | 10 Comments

A wavetable oscillator—Part 2

Posted on May 8, 2012 by Nigel Redmon

From Part 1, we have an oscillator. But we need to broaden it to allow scaling of harmonic content based on pitch so that we have all the harmonic content we need at the low frequency end, and, as we … Continue reading →

Posted in Aliasing, Digital Audio, Oscillators, Wavetable Oscillators | 25 Comments

A wavetable oscillator—Part 1

Posted on May 4, 2012 by Nigel Redmon

There are many ways to make an oscillator. Without looking for further motivation, I’ll propose a wavetable oscillator. Wavetables are a fairly obvious extension of the general playback of digital audio. Such oscillators are easy to understand, and their extreme … Continue reading →

Posted in Digital Audio, Oscillators, Sample Rate Conversion, Wavetable Oscillators | 5 Comments

A wavetable oscillator—Introduction

Posted on May 3, 2012 by Nigel Redmon

Years ago, Cristoph Kemper told me how the Access Virus came to be. He had coded a filter on a DSP and wanted to test it. Of course he needed an oscillator, so he coded that…pretty soon he had a … Continue reading →

Posted in Digital Audio, Oscillators, Wavetable Oscillators | Leave a comment