[sdiy] Generating acyclic waveforms?

[nicolas]

If you want something to sound string-like, then sticking to the one pitch is not what you want.  Strings (and wind instruments too I think) vary their pitch (slightly) depending on the volume.  Hence the common synth technique of feeding a little bit of the ADSR to the VCO as well as the VCA.  So if the technique for getting you the inharmonic sharpening results in your synth note going very slightly sharp (especially at the loudest point of the attack) then it is a good sign that you are modelling 
things correctly.

Cheers,
Nicolas


--- On Mon, 22/3/10, cheater cheater <cheater00 at gmail.com> wrote:

> From: cheater cheater <cheater00 at gmail.com>
> Subject: Re: [sdiy] Generating acyclic waveforms?
> To: "Scott Nordlund" <gsn10 at hotmail.com>
> Cc: synth-diy at dropmix.xs4all.nl
> Received: Monday, 22 March, 2010, 2:08 PM
> Veronica,
> thanks for your email.
> 
> > This is one of the reasons I started looking at
> additive synthesis and the Synergy. I have tried to do this
> in the analogue world with several sine VCOs but it wasn't
> easy.
> 
> Yes, executing the additive approach in analogue seems a
> bit like
> we're barking up the wrong tree here. I think the *key to
> this* is to
> find some electronic process that inherently generates
> anharmonic or
> aperiodic oscillations, be it stretched tuning or not.
> 
> > Adding noise to the reset level in a VCO is not going
> to modulate the harmonic content over the duration of a note
> to mimic harmonic sharpening.
> 
> That's the cool thing about it. It makes the waveform
> acyclic while
> keeping the wave at the old pitch, making the effect
> indistinguishable
> to our pitch perception.
> 
> On Mon, Mar 22, 2010 at 01:33, Scott Nordlund <gsn10 at hotmail.com>
> wrote:
> >
> >> I consulted a fellow composer and he says that
> pretty much all western
> >> instruments have different tuning starting the 6th
> harmonic of their
> >> central pitch. So the harmonic series looks like
> this:
> >>
> >> C C G C E G (Bb) C...
> >>
> >> but the Bb is out of tune with the ieal equal
> temperatment tuning (and
> >> I assume the following C too, but not sure). I
> didn't get to know
> >> which way it's out of tune (sharp or flat),
> because he's busy dumping
> >> MIDI. Those composers, sheesh.. ;-)
> >
> > That's just the 12 tone equal tempered scale, it has
> nothing to do with
> > inharmonicity or aperiodic waveforms.  The Bb isn't
> the only one out of
> > tune either.
> 
> Yeah, agreed - it was just a comment on a general practice
> in an
> every-day setting; i.e. in general you start tuning
> differently at the
> 6th harmonic. Since this is said to be a general practice
> for *all*
> instruments, I am deducting that we're not talking about
> something
> esoteric that nobody ever encounters.
> 
> D.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>