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Uncle Krunkus
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Joined: Jul 11, 2005 Posts: 4761 Location: Sydney, Australia
Audio files: 52
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Posted: Tue Jul 25, 2006 5:03 am Post subject:
Noise into a ringmod |
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What do you get if you ring modulate noise and a sine wave?
What about pink or red noise?
The main reason I'm asking is that I'm designing the switching for my ASM2, and I can't remember whether it's worth having noise as a possible ring mod source or not.
I assume that the variations of sine/square/sawtooth/triangle are all valid as separate options for the ring mod source. If any of them sound exactly the same I'd like to know that too.
Thanking you heaps in advance for any help. _________________ What makes a space ours, is what we put there, and what we do there. |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18195 Location: Durham, NC
Audio files: 211
G2 patch files: 60
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Posted: Tue Jul 25, 2006 9:23 am Post subject:
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You can try all that out on the free G2 demo. The G2 is a great DIY synth test bed.
Noise is a useful ring modulator carrier. The output is noise too, but it follows the envelope. You must have a crossfader on the ring mod to fade between the input and the modulator output. _________________ --Howard
my music and other stuff |
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Scott Stites
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Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
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Posted: Tue Jul 25, 2006 10:06 am Post subject:
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If your ring modulator is DC coupled, you might even think of controlling CV's with it. Modulator input positive, output is non-inverted carrier signal; modulator input negative, output is inverted carrier signal.
Think of it is a voltage controlled attenuverter, with the modulator input being the control voltage input and the carrier input being the signal input.
Another nice use of a DC coupled ring modulator is as an improvised VCA - 0 to +V envelope on the modulator will act as a normal VCA. 0 to -V envelope on the modulator will act as a normal VCA, but the output phase will be inverted.
Cheers,
Scott |
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Tue Jul 25, 2006 10:27 am Post subject:
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This is an interesting question. I would guess that since the noise has really no single dominant frequency and "white" noise encompasses a good chuck of the audio band, I would venture to guess that when mixed with a sine wave, all the sums and differences appearing at the output would sound very similar to more noise with no discernable pitch. Hmmm, I will have to try this. A ring modulator is actually a "double balanced mixer" by which only frequency sums and differences appear at it's output while suppressing both input signals from appearing at the output. (F1 & F2 IN)
Thus:
Out= ((F2-F1) + (F1+F2)) + ((.00001(F1)+.00001(F2))
The second half of this simple equation just meerly accounts for any leakage through the ring modulator and the .00001 is variable. Isolation is not perfect ans some of the carrier and signal source will get through.
When mixing non-harmonically related signals, all kinds of convolution resulting in aliasing takes place thus ring modulators are most useful when mixing signals with some dominant tone.
If F1 is the noise source, then the output (Out) would be a fairly wide spectrum signal. Thus, more noise .....
I know I did not answer all the parts of your question. I will leave that up to a couple more of our members.
Tonight I will see how much egg is on my face and run white noise and sine into my Blacet Klanc Werk RM!
Hope this helps you ....
Bill |
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Tue Jul 25, 2006 10:33 am Post subject:
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Quote: | Noise is a useful ring modulator carrier. The output is noise too, but it follows the envelope. You must have a crossfader on the ring mod to fade between the input and the modulator output.
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OK, not too much egg on my face.
Hmm, yes, did not account for the envelope. Yes.
I REALLY want to get one of those Nord GX2 synthesizers. I fell in love with it at the EM06 demos that Janson was doing ....
Looks like our forum has a vast knowledge base on this unit, including yourself!
Bill
Thanks,
Bill |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24075 Location: The Netherlands, Enschede
Audio files: 277
G2 patch files: 320
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Posted: Tue Jul 25, 2006 10:39 am Post subject:
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State Machine wrote: | I would venture to guess that when mixed with a sine wave, all the sums and differences appearing at the output would sound very similar to more noise with no discernable pitch. |
After trying I say "not too bad a guess", but when the noise gets colored to have more low frequencies some tone comes back in, quite usable ! _________________ Jan
also .. could someone please turn down the thermostat a bit.
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Tue Jul 25, 2006 3:28 pm Post subject:
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Quote: | After trying I say "not too bad a guess", but when the noise gets colored to have more low frequencies some tone comes back in, quite usable ! |
Thanks.
I just finished patching a white noise source into my ring modulator and varied the sine wave modulation frequency. As I suspected, I did get noise, but, the pleasant surprise for me was that as I swept the sine source frequency, the noise took on some more interesting character in addition to your observation of coloring the noise itself! Although my results were subtle, it was usable for some interesting "wind noise" simulations. Usable also.
So yes, I say bring in the noise for selection into the ring modulator. Seems like four votes for noise thus far!!
Bill |
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
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Posted: Tue Jul 25, 2006 3:38 pm Post subject:
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Quote: | assume that the variations of sine/square/sawtooth/triangle are all valid as separate options for the ring mod source. If any of them sound exactly the same I'd like to know that too. |
They all have their own character. I personally like using pulsed and sawtooth waveforms as they have heaps of harmonic content for the ring modulator to reap havoc with!! They produce nice harsh bell like tones. The sinusoids produce very soft melodic bell tones. The use of which waveform is now dependant on the musical composition you are planning.
Have fun !!!
Bill |
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Uncle Krunkus
Moderator
Joined: Jul 11, 2005 Posts: 4761 Location: Sydney, Australia
Audio files: 52
G2 patch files: 1
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Posted: Tue Jul 25, 2006 4:15 pm Post subject:
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Okay, noise has just made it onto the ring mod bus. _________________ What makes a space ours, is what we put there, and what we do there. |
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
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G2 patch files: 626
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Posted: Tue Jul 25, 2006 4:20 pm Post subject:
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Maybe the output of the multimode filter would be a good option, specially if it self oscillates. Then you would get to pre filter the noise, saw and rectangles as well as have a good extra sine source.
I use the Ringmod a lot with both inputs from the same sine. |
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
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Posted: Tue Jul 25, 2006 7:22 pm Post subject:
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Quote: | Maybe the output of the multimode filter would be a good option, specially if it self oscillates. Then you would get to pre filter the noise, saw and rectangles as well as have a good extra sine source. |
Good idea ! |
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State Machine
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Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Tue Jul 25, 2006 7:26 pm Post subject:
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Quote: | Okay, noise has just made it onto the ring mod bus. Smile |
So let it be written, so let it be done .... |
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