[sdiy] ... Simulating a Moog

[Julian Bunn]

Hi Richard,

Thanks for the interesting reply. Some comments below: 

> [snip] 
> Controllability really isn't any kind of an issue. There are 
> plenty of 
> knob-laden external interfaces now. In fact you can get more 
> control from 
> them than from a modular because everything is one place 
> instead of spread 
> out over square feet of panel space, and you never lose knobs 
> or indicators 
> behind patch cables.

I confess to having a deep routed desire for any device that
features a high knob count. It doesn't really matter what it
is, it just appeals. Must have been some trauma in my childhood:
maybe a synthesizer fell on me or something.

> 
> The one downside is that today's screens are still too small. 
> A laptop with 
> a 21" screen would be a very wonderful thing. A 12,000 by 
> 8,000 pixel wall 
> projector would be even better.

In my day job I am building sceintific analysis systems that use 
the Grid. We have the same need: lots of screen real estate. We 
put together a four 1600x1200 screen device (with a Matrox 4-head card) and
PC for less than $5000. That's about 5000x1200 pixels. You can buy
an IBM T221 for $3000 that has 3840x2400 pixels. Four of those
in a square would do it for you :-) 

There's a picture of our four screen setup here:
http://pcbunn.cacr.caltech.edu/GAE/four-screen.jpg

> [snip] 
> But I think there will come a time, certainly within ten 
> years and possibly 
> within five where there will be no reason at all not to use 
> the simulation 
> approach. With enough bit resolution and a high enough sample 
> rate, and 
> careful enough modelling, I don't see any reason why digital 
> techniques 
> won't be able to accurately simulate anything and everything 
> that's ever 
> been done using hardware.
> 
> But I think the pseudo-Spice approach is more likely to do this 
> successfully than trying to characterise transfer functions. Analogue 
> hardware is more complex than it looks, and DSP techniques that are 
> transfer-function based absolutely fail to capture a lot of 
> the subtleties, 
> which may change according to DC offset (not rare in a 
> modular synth), 
> temperature (including self-heating) and other semi-random processes.

Yes, self-heating ... must be hard to simulate. Certainly this Minisonic
I'm building would need that particular effect very well parameterized!

> > [snip]
> >This reminds me of discussions about speaker cable ... I think some
> >people just have very discriminating cochleas, or vivid 
> imaginations :-)
> 
> I know some people who used to run a company stripping wiring 
> out of old 
> military aircraft and repackaging it as super-exotic 
> worth-more-than-gold 
> speaker cable.
> 
> I've also heard at least one person say that they only like 
> listening to 
> their hifi in the early hours of the morning because the 
> mains supply is so 
> much cleaner then.  :-)

LOL. This is another of those statements that initially sounds absurd,
but then the more you think about it, the more you wonder if it really
is so daft :-)

Julian

> 
> Richard
> 
>