Read more about this here:
http://www.tnt-audio.com/sorgenti/zero-one_e.html
24 bits/96kHz via S/PDIF is the limit of the S/PDIF standard -->> I think this is BS, SPDIF standard can do 24/192 too,
the TI48 however maybe not
QUOTE:
The sound card is only used to extract the digital audio from either the DVD-ROM or HDDs. From the sound card, the signal is sent via the Zero One custom 24/192 I^2S cable to the DAC. I^2S is a Philips proprietary data transmission protocol, also used by Accuphase whose implementation is rumoured to use a shared clock. Zero One's separate clock technology should enable a genuine 24bit 192kHz transmission by interleaving two 24bit 96kHz channels. It may seem strange for a start-up company to adopt an uncommon interface standard in its first product, but it gives them absolute design freedom to optimise every link in the data chain to match their particular needs rather than bodge to fit existing audio technology. The I^2S output is supplemented by a S/PDIF coaxial (RCA) and a TOSLink optical inputs & outputs but these would prevent use of the Ti48 features that make it unique, so they're superfluous.
END QUOTE