Fritz chaos circuit

[andrewF]

i just finished this one today.
it is one of the most 'out there' modules i've ever tried and an easy build.
nothing at all like usual random voltage generators.

i'll try and get some samples and scope shots up in the next few days
but there are some on Ian's site -


http://home.comcast.net/~ijfritz/ch_cir1.htm

[Uncle Krunkus]

That looks bloody brilliant. Why didn't I think of it?
Definately going on my "to do" list, which is actually wrapped in barbed wire these days.

BTW It actually a perfect Lorenz attractor. Somebody was building one of these on the G2 just a week or so ago.

[fluxmonkey]

[bubblechamber]

this thing looks great...what did you guys use for opamps?

[fluxmonkey]

[bugbrand]

Those lissajous sort of scope patterns on the linkpage look really amazing. I must build one.
Thanks for the link & notice - great project.

[frijitz]

Hello. I've been thinking about dropping by, then I heard you were talking about me.

I have boards for each project available. Please e me if you would like to get one.

Oh, and it's not a Lorenz attractor at all, although both systems have the double scroll.

Hope I can figure out how this forum works.

Ian

[fonik]

hello mister ian fritz, can't believe it you are here...


i am currently working on the double pulse waveform generator - i will get back to you soon, i guess!

[elektro80]

Ian Fritz,

[Blue Hell]

[Uncle Krunkus]

[v-un-v]

[v-un-v]

[Scott Stites]

Ian, It's really great to see you here!!

I may be missing them on your new website (since you changed servers), - are your windcontroller samples still there?

Seriously, those were some of the most beautiful synth samples on the net - the level of expression you were able achieve was astounding!

Best Regards,
Scott

[frijitz]

This looks like a really interesting bunch of folks. I'm going to answer several messages at once -- hope that's OK.

Bubbles -- Op amps aren't critical for the EZ Chaos circuit. I used TL072 and LF351. The circuit runs slow, and noise isn't much of an issue in a chaos circuit. The only possible limitation would be at the low speed end, where a lot of bias current could hurt you. But any general purpose bifet should be fine.

Fonik -- Always glad to see someone working on waveshapers. This is one of my favorite areas. Are you using the double pulser from my site, or the old Electronotes one? I have several versions of this, and it has probably been my most used timbre shaper over the years. Check out the 5Pulser if you want to see a really radical shaper. I've spent a lot of time looking for a shaper that would really give huge spectral variations, and so far this is the best!
http://home.comcast.net/~ijfritz/sy_cir8.htm

Blue -- Yeah, clips are scattered around. Nothing for the clarinet, since it ended up bein basically a rounded square wave. For the chaos clips start here and then drill down.
http://home.comcast.net/~ijfritz/ch_over.htm

Uncle -- The Lorenz system is autonomous (self-oscillating) and involves a couple of multiplications. There is a circuit by Paul Horowitz you can Google for. The Double well system is an externally driven system, with a different nonlinearity. I've avoided multipliers by using zener diodes for the nonlinear response.

Scott -- thanks for picking up the "missing link". I was going to move those but forgot to finish. They are still there:
http://home.comcast.net/~ijfritz/demos.htm

Best to all.

Ian

[EdisonRex]

This is the sort of circuit I like to see. Very simple, and very different.

If I may offer my welcome, too, it's wonderful that these forums are attracting good minds. I'm going to have to train my kids better to build circuits.

It's funny, today I am sitting here breadboarding a logic circuit. My intent is to work on a analogue switch logic based "not sequencer" but I'm just sitting here looking at your schematic instead. Talk about derailing a thought. And here I was thinking about randomness.

I think I remember when Electronotes was discussing this. It's been a long time. Your circuit makes more sense and your presentation via the lissajous patterns and the simplified math makes more sense.

How nice.

[frijitz]

Edison -- Thanks for the kind words. As always, Bernie was at the leading edge with this. I watched all the developments in chaos theory go by in the '70s and '80s, but didn't have the time to really learn much about the field.

I finally got the time and have spent the past three years or so clawing my way through several undergraduate-level textbooks and some of the literature on chaos circuits. The breakthroughs for me were realizing that integrators can be used to obtain derivatives and that you don't have to use polynomial nonlinearities obtained with multipliers to make useful circuits.

I have posted some chaos circuits and demos on my website over the past two years, but only temporarily because of lack of space. Now I have more space and am in the process of getting it all back up. Stay tuned if you missed the original posts!

Ian

[EdisonRex]

[mosc]

Ian, great to have you here.

I was an original subscriber to electronotes. I had a copy of every issue. Then I lent them to someone and I've never seen them again.

[EdisonRex]

[bearblock]

this is awesome

i have a lorenz attractor in my modular, the circuit by Paul Horowitz that was mentioned. it would be nice for it to have a time-base control for musical applications though - maybe could be done with vactrols? i.e. each opamp would be replaced with one opamp to sum, then the vactrol, then another to integrate... but i'm rambling.

Ian, I will have to get a couple of PCBs in a week or so when i have some more free time. Is 3080 a good OTA for the Jerkster?

[jksuperstar]

EdisonRex -- WPI? as in, Worcester Polytech? (I was there from 91-95)

[EdisonRex]

[frijitz]

[frijitz]