@ckr1969 With the Aurender N20, AES is best, followed by RCA / Coax. This is due to the N20’s clock being far superior to that of the one inside the Aavik. Given the way each cable’s interface works, AES and Coax will use the clock in the Aurender. USB uses the Aavik’s clock. Given the Aavik has no AES input, I suggest you go with a digital RCA / Coax.
@oddiofyl The N200 is the sweet spot in the Aurender lineup in terms of price to performance ratio. At 2x the price, the N20 is 20-30% better, and it excels more in tonal density and soundstage size. Clarity/articulation is quite good already at the N200, and while the N20 improves slightly, the benefit is more in the tonal density, dynamics/punchiness, and more natural delivery, whereas the N200 is a bit thinner sounding in comparison. I just performed this comparison less than two weeks ago. The difference in the N20 and N30SA is even smaller, but it is that last inch that makes the difference, despite again double the cost. The N20 is punchier than the N30SA, but the N30SA is more effortless and refined, delivering more of everything in a more natural presentation.