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Wavewizard 23
Joined: Nov 09, 2015 Posts: 5 Location: Italy
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Posted: Fri Jan 29, 2016 1:28 am Post subject:
Phase + Frequency Modulation Subject description: Simultaneous use of phase and frequency modulation |
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I'd like to have an oscillator with both Phase and FM (with Lin and Trk modes) inputs but it doesn't exist as a preconfigured module. Does anybody know how to create such an oscillator? |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24085 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon Mar 07, 2016 4:34 pm Post subject:
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Basically Phase and (linear) Frequency modulation are the same thing ... but to get it exactly the same you need to apply some filtering to the modulation signal ... now I always forget how to do that ... sooo let's think .... phase modulation with a constant would not do a thing it's change of pahse which does something .. but change of phase basically is frequency ... so to do FM you'd want to to modulate a PM input with a derivative ... I think I got that right ...
for details see : https://moinsound.wordpress.com/2011/03/04/frequency-modulation-or-phase-modulation-synthesizer-technologies/
To make a derivative is easy ... it is the change signal .. so you subtract a one sample delayed signal from the signal itself .. to delay one sample just use any module that passes the signal unchanged .. like a mixer set to gain 1.
Sorry for this late and confusing answer ... but something had to be said here _________________ Jan
also .. could someone please turn down the thermostat a bit.
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24085 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon Mar 07, 2016 4:57 pm Post subject:
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Anaother link : http://dixon.hh.se/urbi/WCS/WCS2/Lecture5_2.pdf
that pdf wrote: | When Frequency modulation is used, it is the momentary frequency of the carrier that carries the information. The momentary frequency f(t) is given by the time derivative of the phase: |
_________________ Jan
also .. could someone please turn down the thermostat a bit.
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Wavewizard 23
Joined: Nov 09, 2015 Posts: 5 Location: Italy
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Posted: Mon Mar 07, 2016 11:17 pm Post subject:
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Thank you, I'll check your links!! |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Mon Mar 07, 2016 11:43 pm Post subject:
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A different approach:
In my diy synth I'm building I use frequency generators, not oscillators.
My favorite is the Analog Devices AD9833 wich has registers for phase modulation.
It is a D(irect) D(igital) S(ynthesis) chip very usefull for LFO VLFO (Very Low Frequency Oscillator as low as 133 sec. when clocked at 1.5 MHz) and audio frequencies generator (triangle, sine and square wave).
You will need a micro processor to have this thing running though...
edit: I'm sorry, this has nothing to do with the Clavia Nord Modular |
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Tim Kleinert
Joined: Mar 12, 2004 Posts: 1148 Location: Zürich, Switzerland
Audio files: 7
G2 patch files: 236
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