There is no such thing as an external multi-channel DAC to play DVD-A and SACD formats. Right now multichannel DVD-A and SACD are decoded by the players themselves... no interface has been defined for these formats.
In terms of any music encoded on a DVD using AC-3 or DTS, this is how a HT processor works... it receives a single digital connection from the DVD player and outputs 5.1 channels to the amplifiers from its DACS...
In terms of any music encoded on a DVD using AC-3 or DTS, this is how a HT processor works... it receives a single digital connection from the DVD player and outputs 5.1 channels to the amplifiers from its DACS...