I previously shared my experiences with respect to the clock when comparing the sound of the Rossini Player with my previous reference, a Wadia S7i:
Rossini Player alone - good, but not as good as the Wadia. Less focused soundstage, no palpable sense of “space.”
Rossini Player with Clock - the room was suddenly present, and very obvious. You could tell the size of the room, you could easily hear where the singer was in the room, it was amazing. By switching the clock off, the walls of the room went away and it was just a vocalist in space. Turn the clock back on, and the room and sense of the space all came back instantly.
Is that important? Only you can decide of course, but if I had a choice between the Rossini Player without the Rossini Clock and getting nothing, I would have declined to purchase the Rossini Player as it wasn’t an upgrade.
That shows you how good the Wadia S7i was; it took the combo of Rossini Player and Rossini Clock to beat it.
It’s not actually all that surprising when if you go back and look at Wadia’s “ClockLink” technlogy as implemented between the S7i’s internal transport and the DAC (the DAC drove the clock of the transport directly, not unlike the Rossini Clock driving the Rossini Player’s electronics.)
Jitter is the enemy of all digital audio systems and precise clocking is the only way to defeat it.