Help me pick a Dac

You have a nice system worth a good digital stack, sell the Node and Gaincell and either go for a streamer/DAC

Budget - Lumin D3

or

Expensive - Aurender A200

I have carefully listened to 6 DACs in the last 6 weeks in a system set up to do level matched A/B or in one case A/B/C comparisons.  The differences in DACs are generally small so any "upgrade" you make may not provide you with the improvement you are looking for.  Having said that, the Eversolo A8 was equal to or better than some DACs costing 4x as much.  The software is a bit funky but it should meet your streaming needs and if you have a lot of stored music then adding a SSD internal drive is going to provide you with the best quality it is capable of.  I would buy it used for about $1500-1600.  If you buy it new just know that it will need several hundred hours before it achieves its best audio quality.

I can highly recommend Audio Research DAC2 for you. Currently there two units available, one here in Audiogon and the other other at High Performance stereo. I believe unit from High Performance Stereo has new caps installed. 

AR DAC2 is a solid state DAC built around Ultra Analog D20400A DAC chip, one of the best that has come to the market. If you are wondering, some of the top of the line DACs from  Stax , VTL, Manley, Mark Levinson, Sonic Frontier, etc., were designed and built around this particular chip. It is one of the best DACs in addition to Burr Brown PCM63 another best performing DAC chip. Both are 20 bit implementation and multibit DAC chips.

You can get AR DAC2 for $1,300, well under your allocated budget. Keep the rest for software.  

Owned an ARC CD2 years ago and was very familiar with the DAC 2 and 3 which was a tube DAC. I would be really surprised if the old ARC DAC 2 is going to better your current DAC. I own a Bluesound Vault 2 and for the money it’s good. I would explore a better streamer first. If you have a CD player with digital out try that into your DAC and compare to the Node. The CD or Blueray player as transport is likely going to show you the Node is good but you can do better. 
 

As far as the older Audio Research  CD2 I owned, I sold and went with a Cambridge 851C which is a far better player. I use both the Bluesound and Cambridge into my DAC and the Cambridge is noticeably better. I just picked up a Airlens which I haven’t thrown into my system yet so we’ll see how it does. 

@adg101 AR CD2 is based on Crystal semiconductor CS4329 – 1 bit DAC. This Delat-Sigma chip is no comparison to the UA D20400 and they are universes apart. But I get your point. I think D20400 is so out dated people who owned Stax X1T, ML 30.5, etc., DACs were dumped to the second hand market and gone with the new latest and greatest DACs. There are so many of these DACs now available in the used market, one can buy those under $100 bucks!

But even the new DACs still have to work with the old geezer limited by 44.1kHz sampling rate and 16 bit word length subjected to quantization errors and what not. I get it, they have new clocking mechanisms like accurate for femtoseconds with >120 dB channel separations. I guess it was my bad that I didn't know OP could hear these differences.