[sdiy] Analysis of frequency variation in analogue synths

[Ian Fritz]

At 09:09 AM 5/3/2007, Nicholas Gregorich wrote:

>Sorry if I have offended you.

Not at all.  Just curious as to what your specific experience is.  Thanks 
for the clarification.


>The only thing I found suspect was the crystal oscillator simply from
>experience of them behaving less than ideally in a digital setting
>[possibly operator error/learning] and wondering how to measure the
>variations with temperature, noise, by pass capacitor effects, etc. I
>guess I could probably find something useful on the data sheet. :)

Well, does anyone think a xtal oscillator sounds "warm"?  Certainly a 
reasonable characterization of "warmth" could involve a comparison between 
VCO and xtal oscillators.


>Combining that with Paul Perry's comment, I would be back at one
>wondering how to measure the accuracy of my FM discriminator.

I would think it would be OK to assume the xtal oscillator is nearly 
ideal.  One would then look for a difference in the discriminator signal 
between the two sources.  If the difference is very small, then it may be 
difficult to resolve this way.

   Ian