Zebra2 LFO Global & FMO wrapping issue

[Friede]

Hi,

I'm new here and I hope, I post this in the right location.

I have an issue with zebra2's (and zebraHZ's) LFO Global (LfoG1) when modulating an FMO's FM mod.

When applied to the FM modulation depth knob directly, it wraps negative values.
For example with a triangle LFO – being bipolar – and FM turn down to 0, it results in double frequency, because negative values are being wrapped around to positive.

While when applied via the modulation matrix, negative values are cut off, so with FM 0 half of the time there's no FM, the other half (positive values) FM is increased and decreased.

This happens only on the FM modulation depth knob, volume for instance cuts negative values the same way in both cases.

Another interesting thing:
volume mod seems to have double amplitude for the same modulation value in the matrix compared to direct modulation. (50% in the matrix is the same as 100% directly). This is seems not to be the case for FM though, when there's no zero clipping happening, both modulation amounts behave exactly the same way.

Is this just different, or am I missing something?
I can of course always work around with modulation matrix, if I don't want the wrapping to happen, but is it intentional? I didn't find anything about it.

Cheers

[Howard]

I don't understand the above - it's probably best to attach an example preset (simplest possible!) or two which demonstrate the problem.

[Chris-S]

Hi,
I can reproduce the issue.

The LFOG is running at 1 hz, but when modulating the FM depth directly, the freq is doubled because of the zero-wrapping.

FMO_Test.zip

[Howard]

Ah yes, interesting! Zebra has many such quirks.

[Chris-S]

Yeah, won't be fixed for sure.

But anyway, whether knob limits should be able to be extended via modulation is a philosophical question...