Roof function for control signals?

torsig1967

I'm looking for some way to make a roof functions for control signals.
Working something like this.

input: 0-32 --> output: 0-32 (1:1 ratio)
input: 32-64 --> output: 32 (always 32)

I've figured out a way to (almost) do it with NoteVelScal but it's to CPU expensive for my need and seems to me there's no cheaper way.

But I might be wrong.... Confused

blue hell · Posted: Mon Sep 29, 2008 11:57 am Post subject:

Some ideas, non tested.

How about using a cross fader, one input left unconnected the other connected to a constant setting the limit. Then use the fade control input as the input and multiply it by a constant as needed.

For your example the amplification would be two and the limit as set with the constant module would be 32.

Or another way to go could be to use the clip module, set it to work asymetric (its default) and add (or subtract) a value as needed from your input signal that you then subtract (or add) again at the output.

Or maybe easiest ... use cross fader and a compare module, when the input is under the threshold pass trough the input signal and when it's over the threshold switch to a constant value. The constant could be used here as the input for a A>=B comparator and as the input for the cross fader at the same time I think, so just three cheap modules needed.

Wout Blommers · Posted: Mon Sep 29, 2008 9:58 pm Post subject:

Well, don't slam the Nord into my face yet, but I just want to know what a 'roof function' is and what you want to do with it Smile

Maybe it's just a configuration in which all values from 0 up to 32 can be used and all values above 32 will stay 32? Kind of a blue limiter...?

Wout

torsig1967 · Posted: Tue Sep 30, 2008 5:52 am Post subject:

torsig1967 · Posted: Tue Sep 30, 2008 5:53 am Post subject:

[quote="torsig1967"]

torsig1967 · Posted: Tue Sep 30, 2008 2:20 pm Post subject:

Well, this is the best I can do right now.
Input value goes from -64 to 64 while output varies like this:
Input -64 to 0 -> output 0-64
Input 0 to 64 -> output 64

Mathematically:
f(x) = x + 64 , x = [-64, 0]
f(x) = 64 , x = [0, 64]

1% CPU I think.

I'd love to get rid of the diode module to get much less CPU but I can't think of how to replace that with something cheaper....

PS. To modify this for the intervals I was asking for earlier (0-32,32-64) I don't think shoould be too hard. But I don't need that right now so I didn't investigate this. DS.

roof curve.png

Description:

This implements a roof curve (defined earlier in this thread) but with a slightly different input interval. Here the roof curve output goes to a amplifier for testing.

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