DAC: Before I jump in...

I've an older but pleasing to my ears system (Acoustat, ARC) and recently I've dabbled with digital by buying, and enjoying, a Bluesound Node2i. I'm starting to look at a separate DAC. The 2i sounds pretty nice via it's internal DAC but I'd like to improve things in a thoughtful, and reasonable, manner i.e. I'm not going to spend way more on a DAC than my other components. As a means of comparison, I have an ARC SP8 MkII and ARC VS110. My question is has technology progressed such that buying a newer though lower class DAC would be superior than an older DAC like an ARC DAC2? Would something from Schiit or Jolida, for instance, sound better. I'm looking for some general, constructive thoughts on the matter really to help guide my search.
Thank you and happy listening!
That you'd like to "improve things" over the Node's internal DAC doesn't really give us much to go on here.  What sound characteristics are most important to you and what would you like to improve upon over what you're hearing now?
My vote is for the Schiit Modi 3.
Hands down excellent DAC for a mere $99. 
I just got one this week and I am loving it.
Pick one up I bet you will feel the same way.
I am not sure what the budget is here.  Is it limited by the price of the least expensive component?  Would that be the Node2i?
Using an external DAC can improve the sound quality from the Node 2i, but the DAC that's included is really good for the price.  I am running my Node 2 through an Auralic Vega in my main system and a Mytek Liberty in my 2nd system.  In addition to some of the previous questions, are things like MQA important to you?  I listen to Tidal a lot, but MQA is not a big deal to me (the Vega doesn't decode it), but it might be to you.   Also Roon, etc.
Good questions! Regarding the sound I’m looking for, well, I don’t know what I don’t know really. More dynamic range? Detail? When you buy a component are you looking for a specific sound quality or just “better sound”? As for the budget question, picking a number let’s go with $1500. And that can be a new or old. 
Carry on!
Do some research on R2R ladder dacs in that price range.MHDT Orchid,Denafrips,Audio Mirror Tubadour are a few brands.
I like DACs that don't sound "digital". The MHDT Orchid fits that bill for me and is under your budget.
The MHDT Orchid is the easy best buy.  Easy.  I have one and it sounded better than dacs costing up to $4 in my system. It is just wonderful sounding. Love this dac! 
My old mhdt Constantine is getting a bit long in the tooth as DACs go but stil love it. Wish mhdt would come out with a new DAC like it ie sans tube.
Sorry for the typo.  Meant to say “up to  $4,000”.  
Love my MHDT Lab Pagoda.

@mapman .. I read a while ago MHDT Lab was considering a DAC in which the tube circuit could be turned off/on. I’d love to have that option.