[sgrossklass]

Quite unexpectedly, I found that a better-than-stock line-in S/N could be achieved in the combination:
Aureon 5.1 Sky (7.1 Space) + Prodigy 7.1 EEPROM + Aureon (!) Windows drivers
PSU harmonics are almost totally gone, which reflects in the peak noise value of -76 dB or under (which barely reached -73 dB before).
Loopback 32/48
Loopback 32/96
Since I don't have any docs on the EEPROM contents, I can only guess why apparently amp gain settings are affected here and how to benefit from this effect without losing the Aureon control panel (which refuses to work with the Prodigy EEPROM contents).

 

[Glassman]

EEPROM stores just the PCI BUS device identification, not any settings, it's just an identifier which driver checks..

 

[sgrossklass]

Then the drivers obviously set amp gain / output level differently, depending on what card they find. The question remains for which model these settings are intended, maybe the Universe...

Whatever, I'm back to the Terratec EEPROM contents now. With the default device for Windows audio being another card, only default devices being used and the Aureon control panel closed most of the time, I hope the driver will behave.