Running DCS Vivladi DIRECT?

Yes, to have some range to go louder above the "comfortable listening level", but if the max SPL you listen to has the volume control always set at -9-14dB then the 0.6V output is too hot.

Here’s another way to look at it, maybe this way you’ll get it:

0.6V @ 0dBFS = -2.21 dBu
0.2V @ 0dBFS = -11.76 dBu

Now apply 9dB of digital attenuation to the 0.6V signal, you get:

-2.21dBu - 9dB = -11.21dBu = 0.21V

So whether you use the 0.6V (with 9dB of digital attenuation applied) or the 0.2V (with no digital attenuation) output setting, the DAC outputs the same voltage basically at 0dBFS.

Fine -- and when I change my phono stage and drop from 45dB gain to 40dB the 0.2V may also be a better match than the 0.6mV

But still no explanation of why the direct connection does such a relatively worse job of handling dynamic range (if we put all the soundstage stuff down to coloration, which btw I wholeheartedly do not) -- and no it’s nothing to do with the -9dB cut as the dCS volume control is digital and non bit stripping

Aside from the 0.2V  output setting for the direct connection, I'd also toggle between the different filters available since the one you prefer when listening through the preamp might not sound the best when going direct.

I believe that there is a hint, of seeing/hearing the forest through the trees perhaps?.

Cheers George