Interesting question that implies that there is something about the volume control in Bartok that is an issue for you and that you hope Rossini may overcome. Care to reveal?
Interested too — I have a vague recollection of someone at dCS saying that the Vivaldi volume control implementation had room for more attenuation before the biffed bits became problematic, but never found out why or how this was the case. Perhaps the same is true for Rossini. (Or perhaps I just have a crap memory.)
I recall that was to do with the attenuation level where it became an issue in regard to resolution loss with dCS products before the current 3rd generation. In regard to e.g. Scarlatti or Paganini that level was -20dBfs.
Given that I am correct then the Rossini and Vivaldi are the same on this issue and resolution is not an issue until a lower setting ( was it -26dBfs?).
I am using the Bartok direct into my dag momentum stereo driving Wilson Yvettes. @ 2V my listening volumes range between -15db and -26db. According to dcs [FAQ] Can I omit the preamplifier and drive the power amplifiers directly from a dCS DAC? for at least the Rossini these volume levels should still translate into minimal to no resolution losses. I am just a wondering if the volume control on the Rossini is a step up compared to the Bartok, and if I might gain some additional resolution at my current listening levels when switching over to the Rossini