24 or 16bit to older DAC

[memphiskat]

Hello

 

Should I run 24 or 16 bits into a DAC I believe is a 16bit DAC?

 

My set up:

iTunes on MacBook > USB > M-Audio FastTrack Pro -> sp/dif coax -> Marantz SR880 receiver

 

Whatever I set the M-Audio to (16 or 24bit) that is what is selected in Audio-Midi Setup.

So if the Marantz is a 16bit DAC (can't seem to find the info online, but it is 96k compatible and

will indicate when it is receiving 96k data), what happens to the other 8bits? When playing standard 16/44.1 files should I send the Marantz 16 or 24 bits?

 

What happens when I'm playing 24/96 files?

 

Another question- does iTunes need to be restarted when changing bit rate, or only when changing sample rate? I assume the former but.......

 

Should I always send the Marantz 24/96 data and let iTunes upsample.......... yea thats a controversial one I would guess :-)

 

Karl