Ehider ... USB DACs are RAM buffered because USB does not stream the data at the bit rate required by the DAC.
Since it's possible to buffer for USB then it's possible to do the exact same for SPDIF.
A more likely explanation is that the USB DAC you heard happened to be a better designed DAC (or more to your taste) than any other SPDIF DAC you'd previously heard.
Since it's possible to buffer for USB then it's possible to do the exact same for SPDIF.
A more likely explanation is that the USB DAC you heard happened to be a better designed DAC (or more to your taste) than any other SPDIF DAC you'd previously heard.