From glancing at the 950 spec's as listed in the manual, the top digital input is 96khz. The real limitation, however, is finding a source at that level. I understood the limitation on digital frequencies to be created by the recording/movie industry. Thus, for example, the DIGITAL output of an off-the-shelf DVD-Audio or DVD player is limited to cd-quality output (44.1khz). Higher frequencies are down converted for the digital output. Otherwise, you have to use the audio output if you have a DVD-A player.
The exception, at least for my DVD player, appears to be non-copyprotected material recorded at higher bitrates (e.g., 96khz). My DVD player's setup (RP-56) gives the option not to down sample non-copyprotected bitstreams (at I presume a max of 96khz because that's the limit of its DAC). When I have the chance, I will see if I can't record a 96khz sample on my computer (e.g., using SoundForge) and either run it directly to the 950 digitally or burn it on a cd and try it on the DVD player. Except for recording live music, however, I don't see much practical usefulness in this, as most sources of 96khz music will be DVD-A--which per industry standard cannot be sent digitally to the 950 or ANY OTHER external processor. Perhaps there is a way around this limitation by playing a DVD-A disk on a DVD-ROM player in a computer (which will almost always have a digital output).
Not being an engineer, if anyone has reason to believe that these future trials will blow up my DVD player or the 950, please let me know!!
Robairdo