PCB and Power Layouts
In the DAC2488 design, digital signal processing and analog signal processing are done separately on 2 printed circuit boards to minimize cross interference. And further reduce of the interference arises from digital-to-digital transformation, digital-to analogue conversion, and pure audio playback (separate L & R Channel and SNR), 4-layers PCB are used throughout the design.
Even the noise performance particular for analogue stage, 4-layers PCB have better result that compared with the common double and single layer of PCB system.
In the DAC2488 power design, the transformer for digital operation is also separated from that of the analog operation to reduce electro-magnetic interference