The DAC section of the SACD 30n comes from a patented technology Marantz developed for their more expensive Ruby series. It's actually pretty interesting what they do with their Musical Mastering HD processing. Audiophiles know if you can upsample digital files, you get better sound, but one side effect of this can be sample rate conversion errors.
Marantz first converts PCM signals to 256DSD. Then a system looks at the signal and decides how to upconvert it based on the bit rate of the incoming signal. If it is a multiple of 44.1kHz, the signal gets upsampled to 11.289.600MHz. So this applies to 44.1, 88.2, 176.4, 352.8 files. Files that are a multiple of 48kHz get upsampled to 12.288.000MHz, which applies to 48, 96, 192, and 384 files. This process requires two precision clocks but Marantz claims it eliminates any chance of sample rate conversion. The premium DAC’s then convert this signal to analog before it passes into a discrete analog preamp board.
If you want to use headphones, the SACD 30n certainly has you covered. The headphone section has three gain settings for different headphones and its own discrete volume control.
Finally, like the MODEL 30 integrated amp, the 30n was tuned by the Marantz Sound Master. Overall, this is a lot of tech in one heck of a beautiful chassis for $2,499!