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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Sun Jan 23, 2011 10:01 pm Post subject:
Chaotica Subject description: An extended 3d order chaos circuit |
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Chaotica is an expanded and improved autonomous third order chaos circuit. The features of Chaotica are:
1.) A third order system with a total of four nonlinear elements in the circuit path to provide a wide range of chaotic signals. One of the elements is a comparator circuit which can be switched in to provide double-eye signals, similar to Chua, Lorentz and ChaQuo.
2.) Expo VC of rate (frequency) over a wide range from creeping LFO rates to well up into the audio range.
3.) Lin VC of loop damping, gain and offset. Many interesting sweep and modulation effects here.
4.) A Reset/Inhibit input which allows the system to be set to zero at all stages. This has many interesting uses; eg, the chaos path's evolution can be followed by varying the reset rate.
5.) Output for all three system variables, x, y and z.
I am attaching a couple of composite photos showing a range of patterns I've gotten.
Ian
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Last edited by frijitz on Sun Feb 27, 2011 4:33 pm; edited 1 time in total |
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inlifeindeath
Joined: Apr 02, 2010 Posts: 316 Location: Albuquerque, NM
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Posted: Mon Jan 24, 2011 10:21 am Post subject:
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some of those single eyes look like brains and embryos. super cool! |
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inlifeindeath
Joined: Apr 02, 2010 Posts: 316 Location: Albuquerque, NM
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Posted: Mon Jan 24, 2011 10:22 am Post subject:
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also, nautilus shells! |
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
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Posted: Mon Jan 24, 2011 2:30 pm Post subject:
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Neat! Looking forward to seeing the circuit! _________________ Synth DIY since 1977! |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Mon Jan 24, 2011 4:38 pm Post subject:
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Glad to see a new chaos circuit from you Ian!
A while back there was a discussion of adding CV controls to the Jerkster, is this some of those mods, plus an extra NL stage or two? |
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fluxmonkey
Joined: Jun 24, 2005 Posts: 708 Location: cleve
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Posted: Mon Jan 24, 2011 10:03 pm Post subject:
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nice, hope this will become another available project... i'll have a complete set! _________________ www.fluxmonkey.com |
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RF
Joined: Mar 23, 2007 Posts: 1502 Location: Northern Minnesota, USA
Audio files: 28
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Posted: Tue Jan 25, 2011 7:20 am Post subject:
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These look great Ian!
I really love the chaos circuits of yours that I've done...
Looking forward to more information on this circuit.
bruce _________________ www.sdiy.org/rfeng
"I want to make these sounds that go wooo-wooo-ah-woo-woo.”
(Herb Deutsch to Bob Moog ~1963) |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Tue Jan 25, 2011 8:03 am Post subject:
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andrewF wrote: | A while back there was a discussion of adding CV controls to the Jerkster, is this some of those mods, plus an extra NL stage or two? |
Hi Andrew --
Yeah, that's about it. The basic jerkster has control of Rate and Gain implemented with OTA's, so adapting for VC is just a matter of hooking up standard expo or linear converters. For the new circuit I added VC Damping by replacing the pot with an OTA --a damped integrator stage as described on my website. Including Offset as a parameter is important when generating a wide range of patterns (keeps the overall size under check). This is easy to do by just driving extra current into one of the OTA inputs, which are essentially current-summing nodes. So it's just a couple of pots and resistors.
I used the other half of the extra OTA chip as a current ampliflier to drive a pulse stretcher for the Reset function, which discharges all three integrators. I'm still fiddling with the nonlinearities to try to get a good variety of patterns without wild amplitude excursions -- always a major pain, as I'm sure you have noticed.
Ian |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Tue Jan 25, 2011 9:00 am Post subject:
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I really should try some of these mods, the integrator reset would be good too.
I spent Aug-Dec last year trying to prevent 'wild amplitude excursions' in that memristor* based hyperchaos circuit , yes it was painful and very annoying.
*not a real memristor |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Mon Jan 31, 2011 10:22 am Post subject:
Subject description: schematics |
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Here are the schematics. Part 1 is the main generator and part 2 is the control sections.
There have been a couple of changes since the OP. The comparator nonlinearity has been replaced with my x-x^3 circuit. And an overload indicator, lighting up when x>8V, has been added.
Ian
Edit: Schematics updated 11/9/11
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Last edited by frijitz on Wed Nov 09, 2011 12:39 pm; edited 3 times in total |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Mon Jan 31, 2011 4:08 pm Post subject:
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Thanks Ian
I have this rather strange urge to build it today! |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Wed Feb 02, 2011 12:52 pm Post subject:
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andrewF wrote: | I have this rather strange urge to build it today! |
Maybe you should, then. I'm having great fun playing with it.
It was partly inspired by a 1990 Chua paper where he looked (theoretically) at what kinds of patterns you could get by generalizing the standard Chua oscillator. There are a lot! Some I already had in the Jerkster system, and I've been able to get some more with Chaotica. Not all of them, though.
One interesting one has orbits on a torus. It's real touchy to get working, but it's there!
Ian |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Fri Feb 04, 2011 5:55 am Post subject:
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frijitz wrote: | andrewF wrote: | I have this rather strange urge to build it today! |
Maybe you should, then. I'm having great fun playing with it.
Ian |
stripboard is done, panel made, 'just' the wiring to go |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Mon Feb 07, 2011 12:51 pm Post subject:
Poincare sections Subject description: With music for bugs. |
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The scope shots usually seen for chaotic systems are projections onto a plane. IOW, if you see an x-y shot, like those above, it is as if the whole signal path (the chaotic attractor) had been squished flat like a pancake.
Poincare sections, OTOH are cross-sectional slices of the attractor, for example a map of all the x-y points where the third signal (z) crosses a fixed value. These are easy to extract using S&H circuits, such as the TGTSH.
The figure below shows an attractor from Chaotica with its z=0 Poincare map -- the dots -- superimposed. There are two sets of dots, one for positive-going crossings and the other for negative-going ones.
The mp3 has the x and y output voltages controlling the VCO pitch of two voices. The crossing plane is slowly ramped down with a Saw signal controlling the TGTSH threshold. Thus, the full attractor is traced out, one cross section at a time. The first part of the clip is the upward crossings and conversely for the second part.
It's always a surprise to see how thin the Poincare sections are. The attractors themselves are not big blobby things but rather thin sheets and ribbons that are wrapped around in three-dimensional space.
Ian
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Mon Feb 07, 2011 9:39 pm Post subject:
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haven't got it quite working perfectly, removed the reset FETs when trouble-shooting, but so far it is proving to be quite a character (=mad)
added leds for X-Y outputs
Thanks for sharing this Ian
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
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Posted: Wed Jul 06, 2011 5:09 pm Post subject:
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I love the sounds you are getting, will have to try some of those patches - thanks Ian |
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Argitoth
Joined: Jun 24, 2008 Posts: 152 Location: Gilbert, Arizona
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Posted: Fri Aug 12, 2011 10:03 am Post subject:
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Can we hear more of the actual chaos output in audio rate frequencies? Also, audio rate modulation. |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
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Posted: Fri Aug 12, 2011 8:20 pm Post subject:
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OK, I'll try to make some time to do that. I haven't tried audio rate modulation yet, but I'll bet it's interesting.
Ian |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
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jordroid
Joined: Jan 17, 2010 Posts: 193 Location: ithaca, new york
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Posted: Mon Aug 29, 2011 8:00 am Post subject:
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Wowza, those are very interesting sounds indeed, that's a lot of sound from not very many modules. Great stuff as always, thanks for posting those.
jordan |
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brock
Joined: May 26, 2011 Posts: 112 Location: Canada
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Posted: Tue Aug 30, 2011 12:23 pm Post subject:
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I second that, very interesting sounds indeed.
It's an impressive group of chaos circuits you are building up Ian. I've got to thank you for being such an important aggregator of information over the years, starting with a post of links on this subject to the synth-diy list way back in Jan 2003. Your designs are very inspiring.
Brock |
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emdot_ambient
Joined: Nov 22, 2009 Posts: 667 Location: Frederick, MD
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Posted: Tue Aug 30, 2011 12:36 pm Post subject:
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Very impressive actually. I hadn't thought something like this would be up my alley, but I see that's wrong. I can see where this would be very useful and powerful. Let the strangeness abound! _________________ Looking for a certain ratio since 1978 |
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frijitz
Joined: May 04, 2007 Posts: 1734 Location: NM USA
Audio files: 54
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Posted: Fri Sep 02, 2011 12:46 pm Post subject:
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I have put up two new demos of audio-rate modulation of audio-rate signals:
http://home.comcast.net/~ijfritz/Chaos/ch_cir6_chaotica.htm
These were done quickly just to give an idea of some of the possibilities. There are some very interesting sounds in there (along with many boring ones). This will take some time to explore completely.
Ian |
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