Following on from the 'Testing a few digital cables' thread (
http://www.phasure.com/index.php?topic=3723.105), I've been thinking about something...
If I set up my Tascam recorder to capture the output of my USB-to-spdif converter digitally, will different SFS and Q settings in XX sound different on the digital captures?
For example, let's assume I set vol = 0, and no upsampling/filtering, ensuring a bit-perfect output from XX. Now, let's say I take two different captures:
1. with SFS=1
2. with SFS=120 (all other settings remaining identical)
Through a DAC, even though the output from XX will be bit-perfect in both cases, these two SFS settings will definitely sound different - we all know that, right?. However, captured
digitally these outputs should be identical - the SFS and Q settings have no bearing whatsoever.
Why? Well because the only mechanism that could possibly cause them to
sound different (implying playback through a DAC) is noise-induced jitter. There can simply be no other mechanism at play. And this mechanism is only at play
at the point of conversion to analogue. When the output of the USB-to-spdif converter is fed to the Tascam's digital input, there is no conversion to analogue, so both captures should be identical, irrespective of XX's SFS and Q settings.
This then implies that XX is just like any other bit-perfect player in the digital domain. Perhaps this is why some people believe that 'bits are bits'. But what they totally fail to understand is that the different noise signatures from different players will cause different noise-induced jitter in the DAC, which in turn will affect the sound that the DAC produces.
Any thoughts?
Mani.