scream

[Scott Gravenhorst]

mbartkow at ET.PUT.Poznan.PL wrote:
>
>> This "screaming" is phase transition between two or more
>> modes. A nonlinear dynamic system is needed.
>> 
>> A state var filter (for example) can do something like this,
>> if overdriven and with a lot of resonance. The self oscillations
>> starts to fight with the input signal, this causes "screaming".
>> The more nonlinear the design , the better.
>> 
>> The WASP filter does this quite nice.
>
>
>A more general (and somewhat "academic") approach would be to build
>a possibly linear state var. filter and insert various nonlinearities
>into the feedback loop. Such structure allows for crazy experimentation
>which is not limited to symmetric or asymmetric clipping/soft saturation,
>e.g. something similar to Serge waveshaper.
>
>As far as I remember somebody mentioned his experiments with various
>distorting elements within SVF. I would be glad to hear more about 
>what kind of sonic effects may be obtained.

That would be me.  I've been distracted by other issues (like work).
Now that USA tax time is past (well almost), I plan to get back at it.

Unfortunately, I have only looked at waveforms produced on an Oscope, and
I did very minimal listening.  The device does, in fact, make wierd noises.

Once I get it stuffed in a box, I'll make some small .wav files and put
them on my xoom site.

One issue I had with construction of this was that I would like to be able
to experiment with nonlinearities without having to heat up a soldering
iron.  I thought I'd put in a rotary switch for selecting circuits I
have tested and like, but I will also mount a piece of solderless bread
board on the box and bring ins and outs to it from one position on the 
rotary switch.

-- Scott Gravenhorst
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