[sdiy] 2 unrelated questions.

[Dave Krooshof]

>    Secondly, please forgive a not strictly analogue question:
It doesn't say [asdiy] does it?

> Chaos oscillators.
>fractal pictures are just so cool looking, i wanted to see
>what kind of sounds i could get from chaos
I found that fractals that look good, often do not sound good, whatever the
method of converting.
I remember listening to a nice fractal that happend to write circle-ish
patterns on a x-y-scope. It was nicely noisy, yet not wave+noise-y or wave
modulated by noise-y.
Can't remeber the formula.
Main issue in setting fractals into sound is which variable is going to be
your time axis.

>The other i can think of would be
>more flexible but digital: a digital chip that can output a waveform
>dependant on the input algorithm (e.g. y= sin x just to get it to output
>sine wave,) or a non linear equation  (y =x(1-x) for more fractal sounds).
>This way the algorithm could be changed for different sounds, and the input
>values could be varied also for different sounds.
Very true, very flexible indeed, and you could work with it from yr math books.

But I guess it can be hardware too.
The main advantage of a fractal is recursiveness: reworking the output.
The appleman (mandlebrot) is a diagram telling how much reworks can be done
on a x-y input before a treshold on the output is reached.

Oscilators rework their input, but they are kind a steady, as they only
allow a certain input to be fed back, in a way. A fratal/ish osc would be
one with a more complex feedback circuit, not only an R and a C...


>my question being: any ideas on how to implement this, and what chip to use.
Well, from your email header I can see you have a mac.
I guess there's no Fractint version for it. I can send you some nice visual
proggys though. Soundwise there are two excellent programs that might serve
your needs.
They are both meant for building musical interfaces, and allow math to be
part of the process.
The first is Super Collider. If you are not afraid of typing some code, nor
of learning a new object oriented language, SC is the way to go. It allows
audio syntheses with math with very simple commands. It's a little od here
and there though. There's a clever internet community using it. Doing
fractals can't be too far fetched in SC.
The other major one has the math a little bit under the otherwise easy
interfacing. It's MaxMSP. You program that by connecting boxes with wires.
A box can contain anything from a midicommand/input to math to sound
output. (really cool for building virtual analogue stuff too, or pseudo
neural nets).

So to answer your question on what chip to use, I'd say, use your 604,
750(G3) or whatever's inside your mac.

One bedtime story: A friend (Isaak Cazemier) from the conservatory was
doing recursive stuff in the analogue studio, and he was playing that in an
episode of the serious 'discussion concert' series. The noises gradually
were becomming more spacey. Suddenly a piano began to play, and it appeared
he crossfaded to Pr. Diana's funeral recored from the telly that very day.


Dave

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Dave Krooshof http://www.xs4all.nl/~krooshof
geluidstechnicus @ http://www.ahk.nl/the/theatertechniek_ov.html
webmaster: http://www.popronde.nl
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