Recommendation for Dac for streamer


I'm thinking of replacing my current integrated amp that has a Dac with a Luxman 590 AX11integrated amp without a Dac.  The seller recommended a Luxman D-03x CD player that has a Dac.  I have Aurender ACS10 and Nucleus Plus streamers.  Can those streamers use the Luxman Dac or should I forget the D-03x, and buy a really good separate Dac?  I'm relatively new to this, and may not be expressing myself well.
daj2832
If your streamer has USB output then the Luxman CD player will work. That disk player seems pretty good, especially of you plan on still playing disks (like me).

Before you spend too much $$ on a DAC try out the Gustard X26 Pro for $1500 with 30 - 45 day home trial. It will compete and better a lot of much more expensive DAC’s.

You can make this DAC sound warm, detailed, in-between with NOS/OS, 4 custom filters
I meant to add Aqua La Voce as well to the post above, but edit function wouldn't let me... 
I'd definitely add the Aqua LaScala and Formula DACs to your list at the high end of the price range and the Denafrips Pontus II and Venus II at the lower end of the price range. Cheers,
Spencer
Based on your description, I would be inclined to think the following three DACs would be brilliant for you:

Rockna Wavelight - This is an R2R DAC with an FPGA interface.  It delivers a massive and very engaging soundstage with a slight emphasis on bass which delivers warmth.  It is not the be-all-end-all in terms of detail but it is very good and one of my favorite products in the $5K range.  It lists for $4950

Weiss 501/502 - This is a delta sigma with significant processing capabilities including room correction and analog mode.  This has a warm musical quality to it that is just to die for.  It is everything the Wavelight is with reference level detail.  This will go toe-to-toe with a Chord Dave or dCS Bartok in terms of detail.   It lists for $9k/$10 depending on whether you want/need a balanced headphone amp.  

MSB Discrete - This is a pure R2R and entry level DAC to one of the best DAC maker's in the world.  They have an amazing trade-up program if you think your journey will continue to higher end DACs that makes this a very appealing option.  MSB has a warm musicality to it that is second to none.  I believe the MSRP is in the $11K range and options can push the price higher as it is highly customizable.  

Reviews are available on all of these items.  Do a little research and it will boost your confidence.  Full disclosure, I am a Rockna and Weiss dealer.  I have no affiliation with MSB other than we have several very happy customers in common.  
Based on that, I'd recommend an Audio Note DAC in your price range. If you're handy with a soldering iron, consider ANK Audio Kits (Audio Note):

https://ankaudiokits.com/product-category/dac/
The sound that I like is precise, but not analytical.   I want it to be musical, if that makes sense. I grew up with records and tubes, and I loved that sound.  That sound is probably driven more by the rest of the system (equipment, cables, room, etc.) than the DAC, but I'm open to suggestions.  The rest of my system will be the Luxman 590 AX11 (I'm replacing the Bel Canto ACI 600), Paradigm Persona 7f, OPPO 205, and an assortment of cables from Cardas (speakers, balanced cables), and Nordost.  I also have one REL 212 SX subwoofer.)
I have a Aurender N10 and the DAC is the Ayre Codex planning on upgrading to Aesthetix Pandora  at $6500

Enjoy the Music
Tom
Really depends on what sound characteristics are most important to you.  DACs come in many flavors/types and there are a lot of very good ones out there these days so would help if you could narrow it down by sharing your sound preferences. 
The Aurender is a great streamer. Looking at mostly the cost of the Luxman Transport / DAC I would also think given the rest of your system a single purpose DAC (not transport also). What about the LUXMAN - DA-06 DSD DAC. This seems to be more in line with the rest of your system. 
Given that you have an ACS10, the D-03x seems pretty redundant.  You don't need a disc transport and although Luxman doesn't make a bad DAC, it's not like they have this sterling reputation for making incredible DACs. 

I would buy a separate DAC.  Given the quality of your gear, I might look a bit higher end.  Not sure what your budget is.  

In the $4500 - $6500 range, Audibyte HydraVox, Rockna Wavelight, Chord TT2, Bricasti M3, Holo May are all excellent but different.  Depending on if you prioritize soundstage and image vs detail retrieval and then if you want something brighter vs more neutral dictates the choice.  

At the next level up ($9K-$12K); Rockna Wavedream, Chord Dave, Bricasti M1, Weiss 501/502, MSB Discrete - there is very little compromise.  it is just how warm, neutral or bright you would like your sound profile to be.