I've work on coding the dither algorithm and i think, i never talk about this "dither" in vvn forum.
This is quite simple but important though, it's actually a wall of text for technical, but I’ll make it as simple as possible
When should you use dither ?
Always use dither when saving out to 16 or 24-bit files.
That’s it.....lol (if it too short, please read the detail below)
The single most misleading piece of advice, which I keep seeing, is “only dither once”.
I do agree you should only use it once within a single DAW application, on the main stereo output – so you don’t need it on every channel, or in-between plugins, for example – but you do need it once when saving your file before mastering, and then again when exporting the final 16-bit master.
So a better rule would be
Always dither – unless you’re staying at 32-bit floating point, in which case once is enough.
Other versions of this advice I often see include only dithering when saving to 16-bit, or only at the mastering stage. Again, I disagree. It’s true that the truncation distortion caused by not using dither at 24-bit is much harder to hear than at 16-bits, but it’s there, and it’s horrible.
So when you’re saving out at 16 or 24-bit before mastering a file, especially more than once, correct dithering is essential.
And if you’re bouncing tracks internally, to remove plugins and reduce CPU overhead – you should definitely dither ! (Unless you’re saving at 32-bit floating point)
There is more technical detail for sure.
If you like it, i will write it, but this should be enough.