digital control of analog component question...

[Harry Bissell]

I believe that the major difference between the DCO and the VCO is that most DCO's
produce a waveform that starts over from the beginning of the wave with each change
in frequency...  sort of an unintended reset function. Most samplers work this way.

VCO's respond with a continuous waveform... even a jump between octaves is a smooth
transition... and glide etc is always smooth, not a series of steps...

And some circuits are halfway inbetween... but few... very few...

VCO's... because I can taste the difference....

:^) Harry

The Proteus wrote:

> Gents,
>
>         This opens up a whole new topic of discussion on how to interface
> the D/A to the analogue circuit. I was grilled on a question about the
> difference between VCO's and DCO's in an interview for my current
> employer, and the only difference I could think of is that a DCO is a VCO
> with D/A on all the CV inputs. Then it got me to thinking, how many
> current output DACs there are out there, and even some of them having
> logarithmic current output. Why have an I->V converter on the output of a
> DAC, then go trhough another V->I converter on the input of the VCO? Since
> most VCO's I've worked with and built have an OTA current-control gain
> cell at its core, this could prove to be an advantage both in noise and
> parts cost. Anyone care to followup on this thread? Any other differences
> between a VCO and a DCO that people have noted over the years?
>
> The Proteus - Morphing the convergence of technology and passion.
> -- Musician - Producer - Engineer  -  UNIX Admin Extrordinaire --
> "...the best workaround for a bug in a UNIX utility is to install
>  the GNU version" - Kragen Sitaker
>
> On Wed, 12 Jan 2000, Magnus Danielson wrote:
>
> >
> > Yes, this is one of many popular ways of doing it.
> >
> > Then there are more ways to control curcuits by digital meants, like CMOS
> > switches and such. There are also all kind of hybrid solutions by which the
> > frequency generation is done digitally but waveshaping is done by analog etc.
> >
> > Cheers,
> > Magnus
> >