DAC for Aurender N200

There are a number of good DACs in your price range. Many people like the PSAudio. I would definitely recommend a used Audio Research Reference 9... it is more refined and detailed while remaining extremely musical. The ARC REF9 is an outstanding DAC an will get the best out of the N20 and N30 Aurrender streamers.

I am a big Aurrender fan. The entry level Aurrender streamers use USB only... I have a N100 on my headphone system. All the Aurrender streamer above entry level have coax and AES. On my main system I have a W20SE and use AES. I remember trying the coax and not finding any obvious differences in sound quality.

USB streamer output puts a larger amount of processing on the DAC. A simplified look at USB is that the bitstream is retimed by the DAC... with the other connections it is not. 

Take a Look at the T+A DAC 200 - works well with Aurender, is very musical, has a separate DAC circuit for DSD and is also built like a tank and made to last.  Fits into your budget as well.

My understanding is if you use USB then you don’t get the benefits of the excellent clock in the N200, which would seem like a waste.  I believe @audphile1 has mentioned the best connection to use is AES/EBU with the N200, but not sure on that but it makes some sense.  For the DAC, it totally depends on what improvements and sound characteristics you’re looking for — let that be your guide and if you share that info you’ll get some great recommendations here.