The MMM-Stream section of the process replaces the oversampling filters normally used in digital to analog conversion and allows the implementation of the Marantz Musical Mastering filtering. These filters - one providing a slow roll-off and very short impulse response, the other offering the option of a medium roll-off with short pre-ringing and longer post-ringing - are essentially the same as those found in the Marantz SA-11 disc player and NA-11 network music player, but here they're implemented at a much higher oversampling rate, thanks to that up-conversion to DSD11.2.
In fact, two system clocks are used, to ensure the most accurate up-conversion of the incoming signal, whether its from disc or the digital inputs: the 44.1kHz of CD, and its multiples - 88.2kHz, 176.4kHz and so on - are up-sampled to 11.2896MHz, while 48kHz and its multiples are taken up to 12.288MHz. This is done for maximum precision, and to avoid any need for sample rate conversion of the kind were the system to have to convert, say, 192kHz audio to DSD12.2MHz.
In addition, all of this conversion is now done in Digital Signal Processing with 32-bit floating-point precision, rather than the 24-bit integer method used in such systems in the past.