[sdiy] [synth-diy] numerically controlled superoscillator without hard sync

[cheater00 .]

On Mon, Feb 10, 2014 at 12:38 PM, cheater00 . <cheater00 at gmail.com> wrote:
> On Mon, Feb 10, 2014 at 12:25 PM, Roman Sowa <modular at go2.pl> wrote:
>> And the crossfade between mips can be determined by tuning voltage that
>> drives VCO controlling the sample rate.
>>
>> Is it possible that for example at 1V control step the sample rate VCO goes
>> up only by half octave and sample rate converter goes from 512 to 384
>> samples so actual output frequency is one octave higher?
>
> This could be a fun way to do things as well, but I don't think it's
> exactly necessary. It could add its own touch, though. Filed under
> crazy synthesis.
>
>> In this particular case 10 octaves is no longer 50kHz to 50MHz of sample
>> clock range, but only up to 1.56MHz. Easier for VCO.
>
> We don't need 10 octaves we just need 1 octave plus a bit more for a
> smooth hand-over :-)
>
> Cheers,
> D.

I forgot to add... if you use the DMA/IRQ trick, and use mip-mapping,
your oscillator only ever needs to move between 22 kHz and 44 kHz,
plus a margin for hand-over. It's really the sample clock, nothing
else.

Cheers,
D.