[music-dsp] oscillators on dsp based synths

[David Olofson]

On Tuesday 16 December 2003 20.38, Jens Blomquist wrote:
> Roel,
>
> It depends.
>
> If you want to do true simulation of analog gear then yes.
>
> If you want to code anything that runs fast then no.
>
> I think it's better to focus on how oscillators drift and how they
> interact ( I would guess that this is part of what the Novation
> guys calls ASM (analog sound modeling) on their nova synths. )
>
> On most synths you have an option like: Oscillators always running
> yes/no?

Note that this doesn't necessarily have to mean that the oscillators 
actually generate audio all the time. It could just be that the synth 
keeps track of the phase one way or another, so the oscillator starts 
in the right state whenever it's output is needed.


> And in some cases you really want the oscillator to start from the
> an exact position every time you receive a not on (When simulating
> drums for example).

Yeah... Keep in mind that for this to be truly useful, the synth must 
allow you to keep *everything* (oscillators, EGs, LFOs etc) in exact 
sync, or you can pretty much forget about serious analog style 
percussion sounds. Don't use sample accurate oscillator triggering 
with N-sample granularity EG processing. Forget about IRQs and 
multithreading.

You don't *have* to make everything sample accurate; that's not the 
point. Just design things so that a patch without explicit random 
components will always generate the exact same output.


//David Olofson - Programmer, Composer, Open Source Advocate

.- Audiality -----------------------------------------------.
|  Free/Open Source audio engine for games and multimedia.  |
| MIDI, modular synthesis, real time effects, scripting,... |
`-----------------------------------> http://audiality.org -'
   --- http://olofson.net --- http://www.reologica.se ---