Noise oscillator?

Anything about hardware musical instruments.
27 posts since 21 Jan, 2005 from Mortlake, London

Post Tue Apr 14, 2015 5:40 pm

I wonder if anyone can tell me whether this thing is even possible.

There is a difference between pitched noise and noise fed through a filter. You can hear how pitched noise sounds in this video of the vcNoiz module. It sounds pretty cool, I think. Unfortunately, few noise modules offer pitched noise.

The vcNoiz would be great, but there's a problem. When you turn the pitch down quite far, the noise doesn't get deep which is what one would expect and want. Instead, it becomes a crackle. I believe this is because the vcNoiz's "noise oscillator" is digital. At a low frequency, the sound is simply generated less frequently, but still in "bits".

So my question is, could there be such a thing as an analogue noise oscillator, with controllable/sweepable pitch? Is that possible? I don't know how noise "works", so I'm hoping somebody else knows the answer. Second, if such an oscillator is possible, does one exist?

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11459 posts since 7 May, 2006 from Southern California

Post Tue Apr 14, 2015 6:08 pm

Running analog noise through a sample and hold with an audio rate trigger will produce the same result. It's the same effect as running noise through a sample rate reducer in your DAW.

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11459 posts since 7 May, 2006 from Southern California

Post Tue Apr 14, 2015 6:57 pm

In Eurorack, the Pittsburgh Modular Toolbox has noise and a sample and hold in the same module.

This module even has it's own clock, plus a bunch of other stuff. Ultra Random Analog

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12884 posts since 8 Mar, 2005 from Utrecht, Holland

Post Wed Apr 15, 2015 2:24 am

Why not blend the pitched noise with low-pass filtered white/pink noise, so you just add that deep rumble you hear all the time in space ship corridors.

The issue though is that this deep rumble consists of a whole spectrum of frequencies and none of them is more present than another. What I would suggest is taking white/pink noise as source and use a low-pass or band-pass filter with a lot of resonance. The filter resonance will then generate one frequency being perceived as the tone of the noise.
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