The iPod uses a cruddy, standard Wolffson Microelectronics low-power DAC; headphone amplification is handled by the same chip. It is built into the ipod, rather than the dock, unfortunately.
You might as well use your computer or one of the newer digital media servers as a lossless source, and then rout this into a good upsampling DAC. Some of the newer upsampling CD players (eg. Cambridge Audio, Quad) will allow for digital inputs, as well.
You might as well use your computer or one of the newer digital media servers as a lossless source, and then rout this into a good upsampling DAC. Some of the newer upsampling CD players (eg. Cambridge Audio, Quad) will allow for digital inputs, as well.