[sdiy] ... Simulating a Moog

[Julian Bunn]

Hi Harry, 

> --- john mahoney <jmahoney at gate.net> wrote:
> 
> > Julian,
> > Uh oh, this is like discussing religion and politics
> > at a party! ;-)
> 
> No... discussing religion and politics at a bar
> brawl...

Sorry for being so politically incorrect :-)

> 
> Perhaps the actual Moog synthesizer is just an analog
> representation of a more perfect, archetypal synth
> that
> exists in another universe. I suppose THEY say that it
> is somewhat lacking in its interpretation as well :^P
> 
> It is possible to spice model such a beast. The
> biggest
> problem would be to validate the model... you'd need
> to
> compare to the 'real deal' for that.

Yes, someone with a real device would have to do some
careful double blind testing ... 

> 
> Spice is very much NOT real time. You might record a
> simulation and make it into a .wav file. Someone on
> this
> list mentioned doing that once (sorry I forget who...)

I guess the correct approach would be to simulate each of
the individual modules separately and confirm each simulation
was working as well as possible, and then virtually patch them
together.

If it was possible to mathematically parameterize each module's
output as a function of its input, then that would make the
job very easy.

> 
> The BIGGEST problem will be the modeling of PARASITIC
> circuit elements... the stray inductance, resistance,
> and capacitance that real components have, and most
> models lack. These will slow the simulation down by
> orders of magnitude, and you will not be able to
> predict what parasitics color the sound in
> identifiable ways, and which ones... er.. slow the
> simulation down by orders of magnitude (uselessly).
> 
> Another problem is to simulate mutual coupling (if it
> exists)... even harder to do than simulating
> parasitics.

Yes that would be very hard. The computing time would be considerable,.
but that's what we have the Grid for, right? We could have the
equivalent of SETI @ Home doing the grunt work.

> 
> I use spice for synth circuits all the time. I have
> not
> listened to any of them. I use it to narrow down a
> range
> of components and operating parameters, then build it.
> 
> "If you build it - they will come"
> 
> H^) harry (well, at least they will breathe hard...)

LOL! A real instrument is so much more tactile. I suppose this
discussion is similar to comparing the merits of virtual versus
real sex ...

Julian
>