Hi,

My experience suggests that dither below the LSB of 16-Bit signals is ineffective, no matter the resolution of the DAC, dithering the lower bits of 16-Bit signals does have an effect, if this is a positive one or not is a debatable issue.

What is usefull though is to take 20 or even 24 Bit and use dither in the process of reducing bit-depth. I feel that for example using 88.2KHz sample rate and 24 Bit bitdepth is a good idea in recording and mastering, then use software SSRC algorythms to get back to 16/44.1 and your losses should be minimal.

Ciao T