[sdiy] jitter in oscillators for music purposes

[Magnus Danielson]

From: "Czech Martin" <Martin.Czech at Micronas.com>
Subject: RE: [sdiy] jitter in oscillators for music purposes
Date: Mon, 12 Jul 2004 19:35:39 +0200
Message-ID: <D9D56E8FA1A73542BE9A5EC7E35D37FF01C4EFD6 at EXCHANGE2.Micronas.com>

> true, therefore it is not phase modulation allone.
> It's getting more complicated.

We see a horrilbe mix of phase modulation, frequency modulation and
amplitude modulation. The frequency modulation is really just a signal 
integrated before it contributes to the phase modulation. The total phase
modulation signal will contribute to the amplitude modulation.

The power supply DC part will affect the amplitude but not the frequency.
The power supply AC part will contribute to both frequency, phase and amplitude
modulation. 
The modulation AC part will cause phase/frequency modulation (due to the lower
corner for the integrator to actually act as an integrator) where the lower
frequency part is phase and the upper part is frequency modulation. 
The comparator noise AC part will cause phase and amplitude modulation.

Simple, huh?

> Time to set up a mathematical model and let the machine do it's job.
> But the creation of saws via discrete *integration* 
> will create some alias as well....

Indeed.

> I wonder if oversampling will help a lot...

It will, but if you want to do it properly you should sinc here and there...

Cheers,
Magnus