Dither continues after playback stops - Bug?

I’m getting active dither at my Master Section output even when playback has stopped. This behavior differs from Wavelab 9.5 which will stop active dither processing when the transport stopped. (The way I am diagnosing this is by looking at the dither on a spectrum analyzer- Active in the stopped condition on Wavelab 10, inactive on Wavelab 9.5).

This happens both when dither is inserted as a track effect and in the case when dither is used as a master section effect. I have tested with two different dither plugins from two different software publishers.

When inserting dither, the audio output is quiescent until playback is started. Upon stopping playback the dither continues. This remains the case whether auto-blanking is activated on the dither plugin or not.

I’ve checked to make sure that active input is not checked on the master section, and that input monitoring is not selected at the track, but the system is behaving like its detecting some other active audio input.

Is there something else I should be checking? How can I confirm that other audio inputs are inactive? I have no active analog inputs into my system, so even if Wavelab is summing with a digital bus on my audio card, I it’s summing with straight zeros.

Why this important to me:
1)I I want the confidence of knowing that my processed audio is not inadvertently being summed with an active input that is not in my control.
2) I want my dither to be repeatable so that I can compare audio images bit-for-bit.
3) I don’t want to load my audio processing with extra activity that loads down the DSP budget.
4) If rendering high bit depth audio, I don’t want some leaky dither plug filling up the bottom 8 bits of my mantissa.


Can’t really confirm here with dither plugins UV22 and MBit
Have tried in “MS” Master Section
Track and as Clip but I don’t see why to use dither
other than in MS as post out to master
when I stop audio there is no dither in playback or on Meters
OSX 11.2.1 Big Sur and Built-in audio device

regards S-EH

In WaveLab 10, like in other DAWs, but unlike WaveLab <= 9.5, when stopping playback, then streaming still continues through all plugins (not just dither plugins), with silence injected in the plugins.
If you want to really stop streaming, a hidden method is to click on the Stop button of the transport bar, while clicking Control (Command on Mac)

Ctl+stop works.