Best DAC under 2k US ?

A non oversampling DAC such as the 47 Labs Shigaraki could be a consideration as it fulfills your criteria. Pre-owned ones show up on Audiogon from time to time at favorable pricing. New retail pricing may make them less competitive with some other lower cost offerings. I'm very happy with mine that I've been using for the past few years.

You should probably consider the Eastern Electric Minimax. Maybe even the previous version used.

There is a Metrum Octave on here new for just under $1000. It is a NOS dac that has gotten exceptional reviews.I am currently waiting on one from the factory myself. I had a Rega NOS dac and really liked it; the Metrum is suppose to be better, although the Rega has more outputs and inputs for those who need them.

The Mhdt Labs DAC's such as the Paradisea and Havana are also good choices and worth looking into. Lots of reviews on each of those. I had an original version of the Paradisea that was quite nice sounding. Choice of 5670 tube can tailor the sound to your personal preference.

The Metrum Octave DAC mentioned above has received very favorable user comments. It appears to be a very good value.

I would also highly recommend the MHDT paradisea or Havana DAC. I have had both and still use the paradisea in one of my systems. It's a great DAC especially for the price