[sdiy] RE: Polyphonic synthesizer (controlling with vactrols)

[mikko.a.helin at nokia.com]

I've implemented the BLIT osc (only saw so far, though only in VSTi, no Linux code yet). It's nice, no aliasing at all (you have to use windowing when you calculate the sinc table data btw.), though the waveform is not as straight saw graphically as you'll get with additive synthesis. That paper is great as is his other papers on Moog VCF's etc. See http://musicdsp.org/ source code archive for examples.
-Mikko

> -----Original Message-----
> From: ext Andre Majorel [mailto:amajorel at teaser.fr]
> Sent: 22. April 2002 22:18
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] RE: Polyphonic synthesizer (controlling with
> vactrols)
> 
> 
> On 2002-04-22 18:10 +0300, mikko.a.helin at nokia.com wrote:
> 
> > Nice synth! I've been recently playing with Linux and I'm
> > considering to build a poly synth with the digital software
> > oscillators and analog filters.
> 
> For waveforms such as sawtooth, square and triangle, software
> oscillators are hard. If the frequency is not a whole
> submultiple of the sample rate, aliasing occurs. Unless you
> generate the wave form additively, and that can be quite costly
> in terms of CPU for low fundamental frequencies (at 50 Hz, there
> are 400 harmonics).
> 
>   http://www-ccrma.stanford.edu/~stilti/papers/blit.pdf
> 
> -- 
> André Majorel <URL:http://www.teaser.fr/~amajorel/>
> std::disclaimer ("Not speaking for my employer");
>