[sdiy] Imperfect VCO

[Harry Bissell Jr]

The ringing effect could be synthesized by a SVF
in resonance... you could differentiate the saw wave
(RC hipass filter) to get a single, narrow spike...

then feed this to a filter at high resonance to
generate
the ringing signal, then add the two back together...

I suspect if the ring frequency is too high, or too
short in duration... that MC is correct (not audible).

Is it 'worth' it...? let us know your result :^P

H^) harry



--- Scott Gravenhorst <music.maker at gte.net> wrote:
> From that accuracy standpoint, that is why I wanted
> to start with an
> accurate VCO and then do wave shaping instead of
> trying to create a poor
> VCO to get a particular sonic character.  Using
> waveshaping then allows
> one control over the harmonic content without
> worrying about the VCO going
> out of tune.
> 
> But I'm mystified by Martin's comment that the
> ringing artifact will
> produce no useful character change.  Does that mean
> I would be largely
> wasting my time to develop a VC ringer?  My
> practical experience isn't
> large enough to determine that on my own.
> 
> Ian Fritz <ijfritz at earthlink.net> wrote:
> >At 08:45 AM 7/31/2003, Czech Martin wrote:
> >>Well, using a state var band pass or low pass with
> resonance
> >>is again filtering. If the poles are too far out,
> you won't hear
> >>the ringing, in spite of the fact that it is
> clearly visible
> >>on the scope.
> >>
> >>I think high frequent wave oddities like ringing
> with 100kHz
> >>or glitches with 10us width are NOT audible on a
> saw wave signal.
> >>And also not on a tri wave.
> >>It might be different on a sine wave...
> >>
> >>m.c.
> >
> >Right.  As an aside, I would mention that the main
> reason for developing 
> >oscillators with minimal glitching and ringing is
> not because of their 
> >sonic qualities, but rather to obtain more accurate
> tracking.
> >
> >   Ian
> >
> 
>
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