DAC upgrade, new or used, $1000

I am looking for suggestions from the Audiogon community for a DAC upgrade.

My system is; Classe CT-2300 amp, Classe CP-800 preamp, Focal Profile 918 speakers TEAC-CDP650 CD player/transport, TEAC UD301 DAC, Bluesound node 2i, Mac computer for downloaded music.

I listen to jazz and classical using downloads, CDs and streaming qobuz,

I have compared the DAC in the CP-800 vs UD301 using the same source (CD player) and the UD301 sounds better. I have compared the DAC in the UD301 vs node 2i using the same source (streaming qobuz) and the node 2i sounds better.

The DAC in the node 2i is not accessible to my other components but the node 2i has an optical out to bypass the DAC in the node 2i, so I need suggestions for a DAC upgrade.

DAC can be new or used and I have a max of $1000 to spend, WSF (Wife Spending Factor)

Thank you for any suggestions.

In your shoes I'd be targeting the following:
Used - Ayre Codex for around $950
           Bryston BDA-1 for around $700
New (or used for that matter)
          Mytek Liberty - list price is around $1000
          One of the Schitt Audio midtier DACs such as the Bifrost 
           which can be had new starting at $699                       
I agree with Jazzman7’s recommendation of the Ayre Codex.  Used one before moving up the Ayre line to a QX5/20.  Connect it to the Classe CP-800 using the balanced (xlr) for best results.  
The good news is your amp has XLR inputs

Now consider one component that 'could' replace several in your system: Oppo 105 with upgraded power wire loom and linear power module. The 105 has XLR outs and VVC. My original intent for getting one was just for hi-rez formats. I was using a modified Pioneer PD 65, which eventually died.

While I was in search of an affordable CD player that could be used as a transport (I settled on a Marantz HD CD 1) I used the 105. It wasn't great on red book, but I came across the upgrade parts on eBay and haven't used my Audio Alchemy DDP-1 (preamp/dac) + PS 5 (outboard power supply) since

I will do some research on the suggested Ayre Codex, Myteck Liberty and the Schitt Gungnir. 
Has anyone listened to the Audiolab M-DAC+ and if so what are your opinions? How does the M-DAC+ compare to the first three?
Can’t speak on the DACs noted above but I own an Oppo 205 and I wouldn’t consider an Oppo. I do own a Bluesound Vault 2 and I find its DAC is decent and believe for the money it’s a great product but its internal DAC can be easily outclassed. I also own a Cambridge 851C and it is more refined, open, transparent, draws less attention to itself than say my Oppo UDP 205 and is way beyond what the Bluesound is. The great thing about my 851 is having digital inputs and I run my Vault through it. That being said, the Oppo is better sounding than the Bluesound DAC as well, but I wouldn’t consider a Oppo, as for a $1,000 you’re going to find many DACs that will eat what your Node or any Oppo can deliver. 

If you pick up a DAC, don’t run optical through your Node; I would suggest SPDIF/Coax. Speaking of your Node, I hope you’re not using the stock power cord. If you are using the stock cord I would start with a better cable and also hardwire if you’re running wireless. If you do Ethernet don’t skimp on the stock cable or the one you stole from your PC as that cable makes a difference as well. If you look at my system you can see how I run my Vault as far as cables.
You should be able to find a MHDT Labs Orchid used for under your budget, or stretch it just a little to get a new one.  The Mytek Liberty is a decent DAC.  The Orchid is more neutral and "organic" (analog like?) while the Liberty is going to sound more "digital" and perhaps a little more detailed (some might call it "bright").  I prefer the Orchid.  No experience with the other DACs mentioned. 

I'm surprised at your finding that the Node 2 DAC sounds better than the Teac.  The DAC in the 2i is pretty decent, but will be bested by a lot of standalone DACs.
i had my NAD D1050 in for repair at the NAD shop and once fixed i compared it to the DAC in the Bluesound 2i.  no contest, in 5 seconds the 1050 was much better.  wish NAD would update their DAC line up.
The Black Ice FX Tube DAC DSD WIFI ain’t no punk. A best buy from Underwood HiFi if your preamp handles RCA signals alright. Just happened to be present at the famed “Arizona Audio blind shootout” and while I don’t recall it winning outright, it was an extremely satisfying DAC.
Since you already like the sound of the Teac UD-301, I’d recommend looking for a used Teac UD-503.

I had the Teac UD-501 and thought it a highly underrated DAC. I eventually replaced it with a Singxer SU-1 (highly modified - SBooster PS, upgraded discrete voltage regulator and caps) and a Gustard x20 Pro DAC. The cost of the Singxer (including upgraded parts) plus the Gustard came to almost $2,000 which put it in a different league altogether.
The Node 2i has an optical in. I’ve never used it, and I think a stand alone DAC would still be a good move. It’s a combo 1/8” jack for analog in or toslink in.
mhdt (any model) with upgraded we 2c51 tube
ayre codex
metrum octave or amethyst