itsjustme correct, all servers are essentially optimized computers, the optimization is the critical difference between them. I consider actual computer diy solution, off the shelf server already done for you.
Its also correct that much of the noise upstream of dac can be eliminated by various means. Optical conversion of ethernet is one good way, do this just prior to dac or various usb renderers.
Network optimization pays great dividends. In the end, many paths to great streaming sound quality.