I have been optimizing my digital rig (before my DAC) for the last 2 years.
I found out that everything matters to a more or lesser degree: from Ethernet cables, to power supplies, to power conditioner and to switch...
Ethernet cables: I am using Ethernet cables from sotm and they had a significant impact on the static noise levels with especially older recordings
Power supplies: I am using Farad3 LPS for my swith and audio PC and they contributed to the soundstage width
Power conditioner: I am using an Audioquest Niagara 1200 to power my switch and audio-pc and it contributed to the musicality (with an little more energy in the sound)
Next update will be replacing my modified HP swith with a Farad3 LPS to a maxed out sotm switch with Farad3 LPS and Hurricane cable...