Complex Noise Generator Experiments

[Tim Servo]

That looks like something that is begging to have a vactrol added for voltage control of the pitch...


Tim (ain't too proud to beg) Servo

[TekniK]

Some cool samples Uncle.

[v-un-v]

This is some crazy shit here Andrew!

Could be quite mad I suppose linking up a 4017 based sequencer?

Now where's that talking Cyberman card???

[Uncle Krunkus]

Here's a new sample.
I've managed to get half an hour to myself to hook up the first two modules through their Ringmod. I'm using the correct transformers this time. They have an 8R side which I'm using as an input from the samplers which are designed to drive an 8R speaker. The other side is 1K center tapped. The ring is around the primaries, and the taps are the output.
I'll update the schem soon.
The start sounds similar to stuff you've already heard. Then as I start playing with the controls it gets more interesting. I still haven't got it triggering off anything, this is just free running 555s kicking each other around a little bit.
At the end I just pulled the plug on it, to see what it would sound like.

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RingNoise230510.mp3
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Filename:	RingNoise230510.mp3
Filesize:	2.99 MB
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[TekniK]

awesome,i want this thing.

[Uncle Krunkus]

Well, it's cheap as chips to build.
Just start looking around for some appropriate greeting cards. Preferably, you want ones which use tiny 8R speakers instead of piezo transducers, although I don't think that would be a deal breaker. Just use 1K-1KCT transformers all round in that case.
The other thing is to get some which have discret resistors (mine were SMD) on the little board to set the pitch. You might need to pull a couple apart to find what you want.
Mine were being thrown out for about 1/5th of the RRP as too many of the batteries were going flat. Check with friends who work at newsagents and gift shops.
I'll hopefully do another update tomorrow.

[Uncle Krunkus]

Here's the latest schem.
It pretty much shows one half of what I've built so far.
I've decided to stick with the original ringmod design of 1K-1Kct transformers, with the second signal going into the centre taps. It turned out that it didn't improve the matching to use 8R-1Kct transformers, and the output off the centre taps did have a bad effect on the amount of bleedthrough.
I've also improved the triggers by getting rid of the transistors (thanks Les) and including both "on" and "off" time pots.
Still not sure whether to lift the ground off the module outputs. It's mainly there as a reference for the raw module out option which I'm incorporating into the jack switching. Might not be needed. I think everything bleeding through the ground rail is actually adding to the effect though. Some of the LEDs glow in time to other modules when their trigger is switched off. This is probably a good thing!!

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[Uncle Krunkus]

Almost there!
Here we have some nice ringmod happening on the two sets of sample modules.
I've lifted the ground from the module outputs where they hit the first transformer winding. They seemed to be affecting each other too much.
Now we ringmod these two with each other and the result should be,................... . . . . . . . . . . . . . . . .

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RingNoise030610.mp3
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Filename:	RingNoise030610.mp3
Filesize:	1.46 MB
Downloaded:	1318 Time(s)

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[TekniK]

nice

[tjookum]

great samples, good job playing it too!

A friend of mine, knowing I will collect anything that makes any noise, gave me musical greetingcard the other day. It's one of those flasy ones with leds and a pretty loud speaker. Within 5 secs i found the pitchresistor and it was squeeling like crazy. And even better, the leds from this cheap ass card combined with a 555 photoresistor oscilator made some killer sequences. Since then I always keep an eye out for leds flashing in nice paterns .

thanks for posting the schematics, im gonna give this one a try.

[Uncle Krunkus]

Well,....
Just what can you say about that?
Some very nasty sounds.
Relaxing,............. it aint!!
I started this one with a particularly disturbing sound I accidently discovered while testing. Then I just twiddled knobs until the end, where it is doing pretty much what I was looking for when the idea first crossed my mind to build it.
An interesting thing is that when I ran a spectrum analysis on this whole sample, it came up pretty flat. That's what I was looking for! Something related to stock standard noise but in an non-uniform kind of way. There's heaps of variety in the overall sound, yet it contains a wide spectrum of frequencies.
I still haven't automated it at all.
And I think if I referenced to ground through caps, it may end up sounding even better.
Still, there's something raw and nasty about it just the way it is.
I think I'll try subbing it for the noise generator in the MPS before I do any more "tweaking" of the design.
I'm quite happy with the way this has gone. There's alot to be said for keeping an open design plan while doing R&D. Trying to "tie things down" before even hearing the results has worn me out in the past. The first of anything needs to be riddled with flaws. It allows the space to see what's working and what isn't.

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RingNoise050610.mp3
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Filename:	RingNoise050610.mp3
Filesize:	2.05 MB
Downloaded:	1393 Time(s)

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[tjookum]

I did some more work with the greetingcards, they are proving to be a very cool soundsource! I made a video where Ive hooked it up to a 4066 cmos switch wich is controlled by a 4017 sequencer.


And here is a picture of a finished module, Ive used headerpins for the connections since those are what I use in my lunetta but anything should work. The extra header next to the pitchpot is for patching in control voltage, a vactrol might be a better choice to keep things seperated but this is for making noise and not pretty music. I kept the leds(out of view) and regulary use them with ldr's to gate signals in my lunetta. With my 1m trimpot controlling the pitch this board produces a huge range of sounds.

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[Uncle Krunkus]

[Lorenzo]

YEP!!! I love it!!

[TekniK]

awesome,someone should do a pcb run for this

[tjookum]

pcb? Part of the fun for me with these simple circuits is just wetting my finger and be able to touch and interact. The connections are just an extension from that.