Ableton Forum

Operator still freaks out a little when you assign the LFO to an oscillator and set the Mod amount to more than 70% -- it's almost like the shape of the LFO inverts at the peaks, or something.

I generally don't modulate the pitch to such an extreme where I'd need to go above 70%; but every so often I do...

Hi,

What rate do you use for the LFO? At hi rates, extra harmonics, which are not in an even relationship with the fundamental note of the oscillator, are created. But that is the very nature of digital sound: if a frequency would be higher than the highest frequency possible, given the sample rates, they are produced in the 'authorized' range. At high rates, the LFO acts as an oscillator itself, so what you experience is FM.

Badly phrased, but I hope it give an idea of.. well.. the idea.

Is it what is happening to you?

Regards,
Amaury

Hi Amaury,

Yep, I know what you mean. But the problem I am describing is not related to the rate; in fact it's easier to hear the problem at lower rates like <60.

If you use a sine wave and modulate the frequency of Osc A and gradually turn up the Mod amount from 0 you'll eventually hear the LFO go from a nice and smooth sine wave, to a sine that suddenly "jumps up" in frequency when it reaches its lowest peak and then "jumps down" when it reaches its highest peak.

It's actually kinda cool, but not when you don't want it do that.

no_barcode wrote:Hi Amaury,

Yep, I know what you mean. But the problem I am describing is not related to the rate; in fact it's easier to hear the problem at lower rates like <60.

If you use a sine wave and modulate the frequency of Osc A and gradually turn up the Mod amount from 0 you'll eventually hear the LFO go from a nice and smooth sine wave, to a sine that suddenly "jumps up" in frequency when it reaches its lowest peak and then "jumps down" when it reaches its highest peak.

It's actually kinda cool, but not when you don't want it do that.

Hi,

I just tried, and the fact is that the more mod there is, the lower the frequency gets, and I can hear a 'jump' of the frequency, in the lower range. I guess that is a similar behaviour as described above: as the frequency would reach below 0 hz, is 'folds' to a higher harmonic?

Regards,
Amaury

If you want the mod to gradually go up, then use the ADSR section.
The mod parameter can be set to the maximum you prefer.
The rest pretty much depends on how you've set up the ADSR envelope for the LFO.

Okay, that makes sense.

It's a feature, not a bug.

hoffman2k wrote:If you want the mod to gradually go up, then use the ADSR section.
The mod parameter can be set to the maximum you prefer.
The rest pretty much depends on how you've set up the ADSR envelope for the LFO.

I was just telling Amaury to gradually increase the Mod amount manually while modulating the frequency of an Osc so he could hear what happens to the shape of the LFO at higher Mod amounts. It's kinda inverts when it goes beyond a certain point. It was just an example.