Should I sell my DAC

The dac in the oppo isn’t that good. If you have a $2000 budget, you will definitely hear a big improvement in SQ. Also, you can get a much better dac by spending $4000 and then get a much better dac by spending $7000. I like my $7000 dac more than some of the others that sell for $15k but the DCS would be an improvement but not worth the cost for the difference in SQ IMO.
Also, the bluenode streamer isn’t that good. The Auralic Mini is better for a few hundred $$$$ if you can find 1. I used to own 1 for my living room. If you want a much better streamer for $1000, get a used Auralic Aries, used to own 1 of these too. If you want something cheap and can stream music from iTunes or be used as a Roon endpoint, get a 3rd generation Apple TV, I use these in 6 rooms around the house for background music, same quality as the bluenode streamer. 

At $1800, the Ayre Codex is dramatically better than the Oppo, and everything else I've seen in this thread. You might be able to find a used one.

My Bluesound Node2i stopped putting sound out the RCA plugs about 6 months.  I bought a Qutest.  That sounded better, although very bright.  I forgot about the Node2i and just called them for service - 13 months after buying.  They want near $300 to fix it, so it is pretty much a paper weight.

I hear significant differences based on my player. Roon vs Audirvana are significantly different sounding (not tweaking settings) to the same DAC.

I have the red Firefly USB DAC and I don't think it sounds as good as the DAC in my Samsung Note 8 phone.  I sound better than my laptop.

I have the Fiio M15 coming tomorrow.  I'm kinda excited about that, main because it is new, but it has some new chips.

I also bought and sold the
-Fiio Q5 - good DAC.
-Fiio M11Pro - really good DAC, not as good as the Qutest - but more mellow.

The musical fidelity v90 dac is an outstanding little component for the meager cost of $299. It is a border line class A component in Stereophile. 

Used Bel Canto Dac3 for 600 bucks.