Hi Rockyboy,
If you're using the analog outputs from the DVD to your preamp, don't worry about it...the player will do all of the converting for you. If you hook it up digitally to the Resolultion Audio DAC (which I suggest you try...it may sound better than the DACs in the Pioneer), then you should probably set the DVD's digital output to whatever the DAC will accept (16/44.1...16/48, etc).
If you're using the analog outputs from the DVD to your preamp, don't worry about it...the player will do all of the converting for you. If you hook it up digitally to the Resolultion Audio DAC (which I suggest you try...it may sound better than the DACs in the Pioneer), then you should probably set the DVD's digital output to whatever the DAC will accept (16/44.1...16/48, etc).