The Aureon Fun is AC97 and seems to resample to either 44.1 or 48 kHz (AC97 system, and 44.1-48 digital out).
The specifications of the two others are necessarily wrong, since they specify both up to 48 kHz 16 bits, and 96kHz digital recording.
The maximum sample rate is either 48 kHz or 96 kHz, not both !
QUOTE
Digital Audio
8 / 16 bit recording & playback at up to 48 kHz (mono/stereo)
...
Externe Anschlüsse
Digital output, optical, 44.1 kHz / 48kHz / 96 kHz (TOS link)
Digital input, optical, 44.1 kHz / 48 kHz / 96 kHz (TOS link)