Cho SOF with Sine LFO

Software questions and issues with the FV-1

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HammerheadAudio
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Cho SOF with Sine LFO

Post by HammerheadAudio »

Hi, I'm writing a granular / sample chopper program on the FV-1 where I'm using the built-in sine LFO as a timing and enveloping element.

In the programming manual and AN-0001 it states that CHO SOF can be used to get a crossfade coefficient for a given LFO. It's pretty clear what this does for RAMP LFOs, but nowhere is it stated what this does for the sine LFOs, though the manual states the instruction can be used with either waveshape. I would like to know what this does, as it seems like it could potentially be very useful in this application.

Can anyone give a clear explanation of how CHO SOF works with the Sine LFOs?
frank
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Re: Cho SOF with Sine LFO

Post by frank »

Cross fade coefficients are only generated for the ramps not the sin LFOs so 'CHO SOF' is not really useful for sin LFOs.

For an application like this I would look at FXCore, you could create the desired waveform in the program and use some of the more advanced addressing instructions to access the delay memory.
Frank Thomson
Experimental Noize
HammerheadAudio
Posts: 11
Joined: Wed Apr 14, 2021 3:19 pm

Re: Cho SOF with Sine LFO

Post by HammerheadAudio »

The programming manual directly states that Cho SOF can be used with a sine LFO. Is that a typo?

From the parameters section in the manual:

"LFO select: SIN0, SIN1, RMP0, RMP1"
frank
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Re: Cho SOF with Sine LFO

Post by frank »

While you can use CHO SOF with a sin it does not really return a cross fade value of much use. For a ramp it returns a cross fade relative to the ramp wrapping around from the end to the start of the delay block and sines do not do this. The value is derived from the ramp and shifted ramp so it will derive a value from the sines but how useful it is becomes the question.
Frank Thomson
Experimental Noize
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