I’ve noticed when using a volume plug-in such as the regular mono or stereo volume plug-ins, they don’t actually mute a signal when set to zero.
Is this a bug with those plug-ins?
In some cases a switcher would work - to fully mute, but if I want a knob to have variable volume, I would also want the zero to be zero, but with high-gain signals, or signals that get gain after the volume plug-in, I can hear the signal.
Are you using a plugin that works in decibels? Minus a bazillion decibels is still not technically zero. I think there are so-called volume plugins that will go to zero, but there are also so-called gain plugins that do not.
On an old analog mixer, the fader subtracts more and more decibels before going down to minus infinity decibels right at the end, which fully mutes the signal. To achieve this type of thing, you might want to use one of the “volume” plugins and set it to use a logarithmic curve.
I’m not at my dwarf right now so I can’t verify any of this, but this is what I remember.