A DAC and its connected input signal components require ultra low noise power for best sound. This cannot be overstated. For DACs with a direct DC input, avoid the factory provided switch mode supply and rather use one with a better regulation/filtering design. Battery-based power supplies can be better but even they may generate internal noise from logic modules or integrated AC inverters. Consider a LiFePO₄ (LFP) battery for the lowest electrochemical discharge noise.
RF•STOP™ DC Filter ensures even the best power supplies are properly RF noise filtered. Power supplies with upgraded fuses or improved wiring offer only a nominal level of additional RF filtering. RF•STOP uses a two-stage design with inductors of highly permeable core material for excellent attenuation of common-mode and normal-mode noise. RF•STOP's wideband filtering extends from 10kHz up to the critical RF frequency of 500MHz. Support from 3V to 30V @ 4A power is sufficient for most all DACs and components.
RF•STOP also helps with noise isolation between components that are powered by the same DC power supply (via a splitter cable). Installing RF•STOP DC Filter between the power supply and component prevents transfer of RF noise along the DC cable. Use 2.1mm connections for input and output and a well shielded DC power cable such as Gotham GAC-4/1 11301 UltraPro Star Quad available from Ghent Audio. For maximum isolation from radiated RF noise via cable antenna effects, use a short cable (<1.0meter).