[sdiy] DCO drift test

[Antti Huovilainen]

On Mon, 7 Jun 2004, ASSI wrote:

> On Monday 07 June 2004 18:40, Antti Huovilainen wrote:
> > I did a little simulation of VCO drift with digital oscillators in
> > Matlab. One set is normal (alias free) digital oscillator with
> > constant tuning, other uses drift recorded from Pro-One.
>
> I really think that this discussion would make more sense if we started
> talking about multiple oscillators. I hope everyone agrees that a pure

Yes. A single oscillator would have to vary quite a lot to be audible.
With two or more oscillators even a small difference can be audible
because of the relatively large change in spectrum.
I did the simulation using two oscillators, because that's what I had
recordings from. I uploaded mp3s without filter sweep to
http://www.acoustics.hut.fi/~ajhuovil/vco/osc12.mp3 and osc34.mp3

> the "sound" of a DCO versus a VCO at other waveshapes IMHO is that the
> DCO is predictable and repeatable across multiple oscillators and
> invocations unless you specifically provide for randomization. Even

Yes. Big question is how exactly should one vary the DCO to replicate the
sound of a VCO?
It seems to me that scientific data on this is pretty much nonexistant.

Antti

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