FabFilter

Hi Charles,

The XLFO is bipolar. In the interface there are little -1/0/+1 markings that show the outgoing levels for the XLFO steps. The EG and EF are unipolar, so their output is in the 0..1 range.

Note that in the modulation slot level control, there is small +/- button on the left that can be used to flip the polarity.

The control's knob always sets the base level, and the modulation level is added to this value.

Hope this helps!

Cheers,

Hi Frederik-

Thanks so much for your kind response. Yes, I was aware of some of the things you mentioned, but perhaps you have the time to clarify a few more points?

The XY Controller is a bipolar control, correct?

Bipolar controllers generate values in the range of -1 to 1, unipolar controllers generate values in the range of 0 to 1, correct? Unless the range has been inverted by the modulation depth control, as you mentioned.

I noticed that the "center point" (the "ctl-click" point) of the Modulation Depth control has a value of 0.160. Is this because the control has some sort of logarithmic curve? The Envelope Follower Attack and Release controls also have "interesting" mid-points, although their "ctl-click" point sets them to zero.

So a full unipolar modulation of the Envelope Follower Release control for example, would take it through the full range of the knob--that is--from 0.05 to 5.0 seconds, and it would have a mid-point of 2.525 seconds?

min mid max
unipolar Mod 0 0.5 1.0
Env F Release 0.05 2.525 5.0

And would the below be correct for the Modulation Depth control, which as I mentioned above, seems to have some curve in its range?

min mid max
unipolar Mod 0 0.5 1.0
Mod Depth 0 0.16 1.0

I know this is pretty small stuff, but I'm trying to understand how to adjust bi- and unipolar controls with modulation sources of the opposite type. Often a modulator will have a switch that will enable it to be either bi- or unipolar to make things easy. For example, a Drive control that could be switched bipolar, and achieve its full range of travel from a bipolar modulator by being set at its midpoint.

Anyway, thanks again for your time, and have a great weekend!

I see that the Tables I made in my previous post were messed up, so I'm taking a chance that the forum software might interpret raw HTML. If a mess, please ignore!

Envelope Follower Release:
<table>
<tr>
<th>Min</th>
<th>Mid</th>
<th>Max</th>
</tr>
<tr>
<td>Unipolar Mod</td>
<td>0</td>
<td>0.5</td>
<td>1.0</td>
</tr>
<tr>
<td>Env F Release</td>
<td>0.05</td>
<td>2.525</td>
<td>5.0</td>
</tr>
</table>

Modulation Depth control:
<table>
<tr>
<th>Min</th>
<th>Mid</th>
<th>Max</th>
</tr>
<tr>
<td>Unipolar Mod</td>
<td>0</td>
<td>0.5</td>
<td>1.0</td>
</tr>
<tr>
<td>Mod Depth</td>
<td>0</td>
<td>0.16</td>
<td>1.0</td>
</tr>
</table>