[sdiy] Midi oscillator!!

[cheater cheater]

Successful troll is successful

On 7/15/08, Tom Wiltshire <tom at electricdruid.net> wrote:
>
>  On 15 Jul 2008, at 20:05, Samppa Tolvanen wrote:
>
>
> > I know midi is 31.25k Bauds a second, but You can divide all the important
> > frequencies from that, right?
> >
>
>  No, not really. The Juno 106 uses what is basically a divider-based
> oscillator for its DCO, but it clocks it at 1MHz in the worst case, and at
> 4MHz in the higher range. A shade over 31KHz isn't even close.
>
>  You won't have anything like enough frequency accuracy as you go up the
> range. Think about the number of steps in each octave:
>
>  Octave 1:  31250 / 1000 = 31.25Hz
>  Octave 2:  31250 / 500 = 62.5Hz
>  Octave 3:  31250 / 250 = 125Hz
>  Octave 4:  31250 / 125 = 250Hz
>  Octave 5:  31250 / 62 = 504Hz
>  Octave 6:  31250 / 31 = 1008Hz
>
>  As you can see, there are 500 hundred different frequencies I can generate
> in Octave 1, but only 250 in octave 2. This gets worse as I go up, until I
> only have 31 frequencies in octave 5. It'd be nice if these lined up with
> quarter tones, but they won't. On top of that, errors in the division creep
> in by octave 5, where the true value should be 62.5, but I have to divide by
> 62.
>
>
> > I'm not looking at making any existing solution obsolite
> >
>
>  No, you're not!
>
>  Regards,
>  Tom
>
>
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