I orginally asked for info on this topic last year (
http://yabb.jriver.com/interact/index.php?topic=41251.msg281549#msg281549 In response to my question, Matt said:
To restate what Alex said, MC's internal volume operates on the 32-bit playback chain.
That means you haven't lost any signal information by turning the volume down. You could turn it back up and it'd be bit-perfect. *
However, if you output that 32-bit signal as 16-bit, you're throwing bits away because fractions have to be rounded off. So it's best if you can use a 24-bit or 32-bit output mode so this isn't an issue.
* Assuming your input is some reasonable bit-depth less than around 30-bits (a CD is 16). Also, remember that it's about impossible to hear past 14-bits of precision (especially at low volumes -- i.e. when it's turned down) so this is mostly academic.
Therefore, I now wonder: I am using asio4all to output a bit perfect signal to my dac. That signal is 16/44.1. (In case it matter, I am using a Chaintech av710 and signal is sent via spdif). I would like to use the MC volume slider as my pre-amp does not have a remote. Should I be using dsp to output a 24 bit signal instead of setting it for source bitdepth? Would that even have any effect if I am sending out a bit perfect signal? Any thoughts on the topic are appreciated.