DAC for Aurender N200

@hickamore It will depend on the cables you are using and your personal sonic preferences. As you likely know, SPDIF leverages the Aurender's internal clock and then gets reclocked by the DAC 200's internal clock, while the USB chain only uses the DAC 200 clock.

In my experience, I've found Coax to be more organic and harmonic sounding unless using a very high quality USB cable. Personally, being spoiled with great audio, I've only LOVED the Final Touch Sinope and Synergistic Research SRX USB cables in terms of USB, and I've otherwise largely been a fan of SPDIF. If you want maximum detail and a crisper, snappier sound, USB may be more your cup of tea, but it often comes at a slight expense of jitter and loss of midrange magic. If you are maxing out the chain with quality power conditioning and cabling, then Coax can deliver excellent dynamics and detail as well.

Of course, SPDIF is also limited in the rate of DSD that can be used (DSD64, and at times DSD128), whereas USB can deliver up to DSD 1024. USB can also deliver PCM up to 768, whereas Coax typically maxes out at 192. That said, the human ear is unable to perceive anything greater than 192, with most not even being able to discern differences greater than 96KHz.

if coax sounds better than USB it means, in most cases, the DAC clock isn’t as good as the clock in the transport/streamer.

@hickamore I have compared the N200 via stock USB vs. via SPDIF using DH Labs digital cable. Yes the coax sounds a bit softer and it may appear to sound slightly more natural at first but the soundstage collapses in comparison and the dynamics are subdued. I haven’t used anything fancier than the DH Labs coax because I saw no point in it - USB sounds more resolving, more dynamic and destroys the coax in soundstage. I use Bricasti M3 DAC and it has a really nice DDS clock that the engineers at Bricasti optimized for their DACs.
I’ve upgraded to AQ Diamond initially and just moved from AQ to Stealth USB after comparing several USB cables. YMMV but you should experiment and determine for yourself in your system what works best for you

I’d second or third the recommendation of the Bricasti M1. I’ve been using this DAC for years because of its detailed but organic sound. Just as importantly, Bricasti really stands behind their stuff and the reason I’ve had mine for 8 years is their upgrade path. In the time I’ve had it, Bricasti has offered upgrades from free software upgrades, to power supply, Roon, and even a processor swap. Some I did myself and some I sent the unit back for. When I did the Roon upgrade, they swapped the whole back panel to add ethernet inputs. I had the unit back, VA to MA, to VA in 2 days. Remarkable! Used M1s are commonly available in the OP’s price range. I bought mine used and Bricasti treats me the same as an original owner.