LFO Offset?

Algorithm development and general DSP issues

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aziltz
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LFO Offset?

Post by aziltz »

Hi, I'm new to the FV-1 game. Is it possible to generate a 2nd or slave LFO that has a controllable phase offset from a master LFO?

Thanks.
frank
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Post by frank »

Each LFO puts out +/-sin and +/- cos so you have 4 phases all 90 degrees apart from each other. If you need it to be an arbitrary phase then it is not possible.
Frank Thomson
Experimental Noize
aziltz
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Post by aziltz »

I see, thanks. Could an allpass applied to an LFO to give arbitrary control over the phase?
slacker
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Post by slacker »

Haven't fully thought this through but you should be able to do it using the ramp LFOs, you could run them both at the same speed but reset one of them at any point along the other, this will give you what ever phase difference you like.
The ramps can be rectified to give triangles and clipped or filtered to give something approaching a sine.
aziltz
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Post by aziltz »

thanks, I will look into that.
rocket512
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Post by rocket512 »

aziltz wrote:I see, thanks. Could an allpass applied to an LFO to give arbitrary control over the phase?
Good old math might be useful:

sin(x+y) = sin(x)*cos(y) + sin(y)*cos(x)

y could be the arbitrary Phase offset
frank
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Post by frank »

Yeah, rocket512 is right, that would probably work.
Frank Thomson
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aziltz
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Post by aziltz »

I looked that up right before asking my question too! Thanks all.
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