I was thinking about this idea a bit over the past couple of days (in between
reading speed typist Hendry's several different perfect solutions to his
Magic Bus concept!) and I thought how I might like a module to behave in a
similar regard to what motivated my previous question (below).
I'd like to see a VCO that also had a chaotic input. What I mean is with 0V
at the CHAOS input it would track like a good VCO, but as the voltage
increased at that same input, the output would be increasingly indeterminate
(either chaotic or nonlinear in some other way).
I use a similar approach to my guitar playing when playing rather loud to
produce two very different types of feedback. One kind is the more common
controlled style (a harmonic style developed by Buddy Guy, Townshend,
Hendrix, etc.) which involves inducing the string (or strings) to resonate
via the speaker's output. The other type involves holding the guitar pickups
about 12" from the speaker (again at very high SPL) which causes the pickup
itself to resonate (I think most PUs have a resonant frequency of around
8KHz), producing a squealing sound -- BTW, I've come to believe this is
destructive to the guitar's PUs (not to mention ears), so do this at your own
risk.
It is easy to use modules to mimic either type of behavior (harmonic or
chaotic) but it requires a number of modules which are usually better suited
for other purposes. So yesterday I tried a bit of an experiment to induce
chaotic behavior with a small number of MOTM modules.
About 18 months ago someone posted to the DIY list that he'd done some work
on chaotic (Chua) oscillators, and mentioned that chaotic behavior could be
coaxed from a standard VCO by plugging an output into an FM input of the same
oscillator, though it may need to be amplified first. So I took an output
from a MOTM 300 and routed it through a MOTM 110 VCA and then back into the
300 FM input. I used the pressure output from my Serge Touch Keyboard to
control the gain of the VCA (the GAIN knob on the 110 was at full).
While I found this patch did a little of what I'd expected, I needed to add
another 300 as a basic VCO (for tracking the keyboard), and have the chaos
VCO sync to the second VCO, since it didn't seem to track very well. I also
thought that the effect might be more pronounced if my CV source went from
0-10V (the Serge only goes to 5V). If the effect had been more pronounced, I
had intended to try using a VCF in the feedback loop, but that would be
premature at this time. I'm wondering if anyone has any experience with
patches like this, or if anyone else is interested in this type of behavior
from what would otherwise be a standard module?
John (Ziegfried) Barlow
In a message dated 11/5/99 9:24:59 PM,
synth1@... writes:
>No. My feeling was you do not "play" the chaos module. Rather, you
>place limits on the probability of the possible output.
>>From: JWBarlow@...
>>In a message dated 11/5/99 4:54:44 PM, synth1@... writes:
>>>That is what I said: each PIC has a CV input. The CV input determines
>>>just how chaotic it behaves,
>>Stupid question: would this have something like a 1v/oct input? The reason
>I
>>ask is if one is indexing through a number of "standard" musical phrases
>(or
>>referents -- very postmodern!), and they are all in one key (say C), and
>the
>>only means of transposing is to increase the voltage at the chaos input,
>then
>>it seems that one would almost never perceive these phrases since they
>would
>>often not be in the same key.
>>And this comes from a (never in tune) guitar payer!
>>JB