DSMP Pure Audio Enabled/Disabled?

I read in this forum, but now cannot find it, about the function: Pure Audio. Some conflicting discussion went about if this should be enabled or disabled, and that from factory should have been “enabled”. When I checked my new DSMP, this function was “disabled”.

This function is located in a secret screen in the setup menu and comes up by touching the right-hand lower corner.

If Pure Audio should be “enabled”, then shouldn’t have my new, out-of-the-box, DSMP have been “enabled” from the factory?

Thanks. And apologies if this discussion has already taken place at length. I simply cannot find it again.