Ok I've found good info in a thread called "A Graph of MIDI CC vs dB for Vol & Expr Faders" by @Macker.
That info agrees with my first test run. I've done some more test runs at different fader settings and they all agree too. So the spreadsheet is out of whack. Macker's formula is 40*log (ratio) but the spreadsheet's formula is 20*log (ratio) which doesn't match the fader scaling. Solved! Props to Macker!
I suppose the secret to mixing with Synchron Player is to ignore the MIDI CC settings on the Master Volume and Expression faders. When listening doesn't tell me enough I'll rely on the dBs shown in the DAW automation.
Slowly getting the hang of working with VSL's beautiful instruments. Just a matter of care, patience and knowing what's what and who's who - just like always 👍
Hermann
"The US 1st Amendment does NOT allow you to yell "FIRE!" falsely in a packed cinema, nor in an online forum." ~ Dobi (60kg Cane da pastore Maremmano-Abruzzese)