My favorite audio resource for those designing or evaluating audio amps and DACs is NwAvGuy's blog[0]. The blog posts explain what performance parameters matter, what don't, and evaluates the performance of various products and components.

Equally interesting is the mysterious story about the anonymous author himself [1]

[0] http://nwavguy.blogspot.com/

[1] https://spectrum.ieee.org/tech-history/silicon-revolution/nw...