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Re: chaos module

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  • Tim Stinchcombe <timothy@tstinchcombe.fr
    Hi Ethan, Roel, ... I wondered this about the Dark Star Chaos myself, so when Blacet announced they had a load of the hard-to-get chips at its core, I bought
    Message 1 of 15 , Jan 8, 2003
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      Hi Ethan, Roel,

      > > Is the principle for the source of uncertainty coming
      > > from the chaos theory? But what a minute, was the chaos
      > > theory already in existence when Buchla build it's modules?
      > >
      >
      > I'm not sure the Buchla Source of Uncertainty
      > was ever associated with Chaos, however, the
      > Blacet Dark Star Chaos module might be.

      I wondered this about the Dark Star Chaos myself, so when Blacet
      announced they had a load of the hard-to-get chips at its core, I
      bought one (just the PCB and chip). Haven't built it yet, but from
      the schematic and the chip datasheet, the answer is no, the DSC is
      not associated with what I would regard as 'chaos', i.e. non-linear
      dynamics, Chua's oscillator and the like. However, whether it might
      *sound* like a chaotic oscillator remains to be seen (I doubt it
      though - I did breadboard a Duffing oscillator a while ago, and
      it 'shreiked' rather than 'hissed' noisly!). Basically the DSC is
      voltage-controlled digital noise (like A117), with built in env gen,
      filter, VCA and oscillator.

      When I get the time, one of the things I intend doing is to build a
      Chua oscillator, stick a voltage-controlled resistor in it, and see
      what comes out (and if it sounds reasonable, then stick a phase
      comparator and VCO into the mix to see if it can be made to track a
      VCO, PLL style, so that one might be able to play tunes with it...)

      Tim
    • davevosh@aol.com
      In a message dated 1/8/2003 7:07:47 PM Eastern Standard Time, ... tim. i haven`t tried this and, honestly, its probably beyond my simple d.i.y. skills but i
      Message 2 of 15 , Jan 8, 2003
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        In a message dated 1/8/2003 7:07:47 PM Eastern Standard Time,
        timothy@... writes:


        > When I get the time, one of the things I intend doing is to build a
        > Chua oscillator, stick a voltage-controlled resistor in it, and see
        > what comes out (and if it sounds reasonable, then stick a phase
        > comparator and VCO into the mix to see if it can be made to track a
        > VCO, PLL style, so that one might be able to play tunes with it...)
        >
        >



        tim.
        i haven`t tried this and, honestly, its probably beyond my simple d.i.y.
        skills but i do have a comdyna gp-6 analog computer that i`ve been using
        as a control voltage mangler, even being able to patch it for the ueda
        attractor, and its been educatioanl and fun !
        best,
        dave




        [Non-text portions of this message have been removed]
      • Tim Stinchcombe <timothy@tstinchcombe.fr
        Hi Roel, ... I have absolutely only a very rough grasp on any of this, but here goes. Some of what chaos theory about is how a small change in one part of a
        Message 3 of 15 , Jan 9, 2003
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          Hi Roel,

          > What the hell are a Chua oscillator and a Duffing oscillator???
          > Can you eat it?
          > I never heard of this before.
          > Most intriquing, please explain!

          I have absolutely only a very rough grasp on any of this, but here
          goes. Some of what chaos theory about is how a small change in one
          part of a system can have a large affect on another (a favourite is
          something about a butterfly flapping its wings having an affect half
          way round the world...). It's possible to put together electronic
          circuits that exhibit this kind of behaviour, i.e. a small change
          will suddenly make the circuit jump to a completely different state.
          Chua's circuit is a well known example (named after the guy who first
          made it), Duffing is another, and they are both deceptively very
          simple to look at. They oscillate in strange ways, and changing
          component values by small amounts can completely change this. Chua's
          circuit has many different 'modes' - if I can get the upload to work,
          I'll stick a file in the files area with some plots. In it you'll see
          what is called a 'double scroll', for obvious reasons. Altering the
          pot value can make one half of the scroll disappear; at another it
          goes much larger, called a 'limit cycle' (it sort of saturates). They
          can be made to oscillate at audio frequencies, and the top one of the
          pair looks rather like a square wave through a highly resonant
          filter, and apparently sounds quite interesting. I have a paper where
          they control the oscillator digitally in order to make some decent
          sound (in tune I believe) from it.

          The theory is very mathematical, with lots of heavy differential
          equations in many variables. The 'thing' which make Chua's circuit
          work is what the two op amps do - they emulate a negative resistor (V
          over I through a normal resistor is of course R; V over I for this
          thing gives -R, i.e. has negative gradient!).

          And that pretty much sums up all I know. Basically it looks like
          something fun to play with! Just remembered a good website to look at
          is Dan Slater's page:

          http://www.nearfield.com/~dan/Music/chaos/Chaosrel.htm

          It'll explain it far better than I can, and includes stuff on Buchla
          and references to several good papers.

          Cheers,

          Tim
        • andrew dalio <bunnyman@sailormoon.com>
          I ve come up with a chaos patch using Doepfer modules sort of based on the Wiard Woggle bug diagram. When I figure out how to post it, it ll go up on Modular
          Message 4 of 15 , Jan 9, 2003
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            I've come up with a chaos patch using Doepfer modules sort of based on
            the Wiard Woggle bug diagram. When I figure out how to post it, it'll
            go up on Modular Planet. For those of you who don't have one, I highly
            recommend the Woggle bug - an awesome module that provides both random
            voltages and Forbidden Planet-like audio outs. It's too nifty to
            describe, just get one!

            -andrew bunny
          • davevosh@aol.com
            In a message dated 1/9/2003 8:09:32 PM Eastern Standard Time, ... andrew, ditto, w bug is great ! i`ll look forward to seeing your doepfer patch interpretation
            Message 5 of 15 , Jan 9, 2003
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              In a message dated 1/9/2003 8:09:32 PM Eastern Standard Time,
              bunnyman@... writes:


              > For those of you who don't have one, I highly
              > recommend the Woggle bug - an awesome module that provides both random
              > voltages and Forbidden Planet-like audio outs. It's too nifty to
              >



              andrew,
              ditto, w'bug is great !
              i`ll look forward to seeing your doepfer patch interpretation anxiously !
              best,
              dave




              [Non-text portions of this message have been removed]
            • Roel Steverink
              From: Tim Stinchcombe Date: Thu Jan 9, 2003 1:05 am Subject: Re: chaos module Hi Tim and Ethan, What the hell are a Chua
              Message 6 of 15 , Jan 9, 2003
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                From: "Tim Stinchcombe <timothy@t...>" <timothy@t...>
                Date: Thu Jan 9, 2003 1:05 am
                Subject: Re: chaos module

                Hi Tim and Ethan,

                What the hell are a Chua oscillator and a Duffing oscillator???
                Can you eat it?
                I never heard of this before.
                Most intriquing, please explain!

                Roel.

                Tim wrote:
                I wondered this about the Dark Star Chaos myself, so when Blacet
                announced they had a load of the hard-to-get chips at its core, I
                bought one (just the PCB and chip). Haven't built it yet, but from
                the schematic and the chip datasheet, the answer is no, the DSC is
                not associated with what I would regard as 'chaos', i.e. non-linear
                dynamics, Chua's oscillator and the like. However, whether it might
                *sound* like a chaotic oscillator remains to be seen (I doubt it
                though - I did breadboard a Duffing oscillator a while ago, and
                it 'shreiked' rather than 'hissed' noisly!). Basically the DSC is
                voltage-controlled digital noise (like A117), with built in env gen,
                filter, VCA and oscillator.

                When I get the time, one of the things I intend doing is to build a
                Chua oscillator, stick a voltage-controlled resistor in it, and see
                what comes out (and if it sounds reasonable, then stick a phase
                comparator and VCO into the mix to see if it can be made to track a
                VCO, PLL style, so that one might be able to play tunes with it...)

                Tim
              • Roel Steverink
                From: Tim Stinchcombe Date: Fri Jan 10, 2003 12:00 am Subject: Re: chaos module Hi Tim, I know the chaos theory, I have a
                Message 7 of 15 , Jan 10, 2003
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                  From: "Tim Stinchcombe <timothy@t...>" <timothy@t...>
                  Date: Fri Jan 10, 2003 12:00 am
                  Subject: Re: chaos module

                  Hi Tim,

                  I know the chaos theory, I have a book on it. It's fascinating
                  subject, but only until recently I didn't know that they
                  translated the theory in a famous/notorious module!
                  I just never heard of those oscillator's you named.

                  I also went to a lecture on this subject and it was
                  very clearly explained by this professor. I know the chaos
                  theory orginates from theorectical physics. He had
                  a simple model with him and demonstrated the how chaos is
                  created. He had only a swing which had two wheels attached to it.
                  First when he moved the swing, it made preditable moves,
                  but beyond a certain point, totally different things happened
                  and amazing too see, you couldn't predict any of this
                  strange movements anymore. This was the edge of chaos.

                  Chaos travels from the center to the edge, where it reaches
                  a point that totally new phenonomen occur. Like your famous
                  sample of the butterfly flapping it's wings in North America
                  can cause a sandstorm in the Sahara.

                  Thanks for that great link. What a fine site with glass clear
                  pictures!!! I have benchmarked in my favourites and when I
                  have time and are up to it(oops those maths, but I have to be
                  cool and don't turn my back on them!).

                  Roel


                  Hi Roel,

                  > What the hell are a Chua oscillator and a Duffing oscillator???
                  > Can you eat it?
                  > I never heard of this before.
                  > Most intriquing, please explain!

                  Tim Wrote:

                  I have absolutely only a very rough grasp on any of this, but here
                  goes. Some of what chaos theory about is how a small change in one
                  part of a system can have a large affect on another (a favourite is
                  something about a butterfly flapping its wings having an affect half
                  way round the world...). It's possible to put together electronic
                  circuits that exhibit this kind of behaviour, i.e. a small change
                  will suddenly make the circuit jump to a completely different state.
                  Chua's circuit is a well known example (named after the guy who first
                  made it), Duffing is another, and they are both deceptively very
                  simple to look at. They oscillate in strange ways, and changing
                  component values by small amounts can completely change this. Chua's
                  circuit has many different 'modes' - if I can get the upload to work,
                  I'll stick a file in the files area with some plots. In it you'll see
                  what is called a 'double scroll', for obvious reasons. Altering the
                  pot value can make one half of the scroll disappear; at another it
                  goes much larger, called a 'limit cycle' (it sort of saturates). They
                  can be made to oscillate at audio frequencies, and the top one of the
                  pair looks rather like a square wave through a highly resonant
                  filter, and apparently sounds quite interesting. I have a paper where
                  they control the oscillator digitally in order to make some decent
                  sound (in tune I believe) from it.

                  The theory is very mathematical, with lots of heavy differential
                  equations in many variables. The 'thing' which make Chua's circuit
                  work is what the two op amps do - they emulate a negative resistor (V
                  over I through a normal resistor is of course R; V over I for this
                  thing gives -R, i.e. has negative gradient!).

                  And that pretty much sums up all I know. Basically it looks like
                  something fun to play with! Just remembered a good website to look at
                  is Dan Slater's page:

                  http://www.nearfield.com/~dan/Music/chaos/Chaosrel.htm

                  It'll explain it far better than I can, and includes stuff on Buchla
                  and references to several good papers.

                  Cheers,

                  Tim
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