Normally in one-box receiver or one-box stereo system there's one power supply for source, preamp and amplifier section.
In separates power supplies are separate. This gives a huge advantage isolating small signal path from the large signal giving a clean signal to an input of the power amplifier. The small signal components do not need large power supplies that ponentially can be more noisy. A power transformer for the larger power is always noisier than one for the smaller. Therefore I kinda like the idea of having source and preamp together: DAC-preamp, CD-Player-preamp-DAC-headphone-amp...
In separates power supplies are separate. This gives a huge advantage isolating small signal path from the large signal giving a clean signal to an input of the power amplifier. The small signal components do not need large power supplies that ponentially can be more noisy. A power transformer for the larger power is always noisier than one for the smaller. Therefore I kinda like the idea of having source and preamp together: DAC-preamp, CD-Player-preamp-DAC-headphone-amp...