Physically connect a Bluesond Node 2i to a downline, stand alone Chord Qutest DAC

I have a Bluesound Node 2i feeding a Chord Qutest by both Tributaries Coax and by Audioquest Vodka Toslink.   Both sound very good, but if pressed I’d choose the Vodka Toslink.  YMMV depending upon the actual cable employed.   BTW, one of the nice things about using an outboard DAC with the Bluesound Node, is that for MQA the Bluesound does the first unfold, getting you all the way to 96K.   IMHO MQA via the Bluesound / Chord combo sounds superior to my ears than MQA full unfold via the Bluesound’s analog outputs, even though the Chord is not an MQA DAC.

@hilly230
My experience with the Bluesound Node2i / Chord Qutest combo is that the Node2i via its analog output using its own DAC produces a polite (some might say forgiving), warm sound that leans to the dark side; by comparison, with the Qutest the sound is richer, more detailed, and the sound stage is both wider and deeper, and may I dare say more ebullient.
In my system it's a very noticeable difference.
Given that you have already experimented with trying different output voltages, my next thought would be to look to the interconnects, especially the digital interconnects. The quality and character of the interconnects can make a big difference.

@hilly230
My personal experience with 75 Ohm digital coax cables connecting Node2i to Qutest are limited to Tributaries and Transparent. In both cases those cables are terminated with RCA connectors, using an Audioquest RCA to BNC adapter to mate with the Chord Qutest.
The Tributaries Delta Digital cable is decent, but as mentioned in my earlier post from 2 years ago in this thread, felt it was outperformed by a smidge by an Audioquest Vodka Toslink cable. Since that posting I acquired an entry level Transparent coax cable which to my ears outperforms the AQ Vodka Toslink. Today my Node 2i resides on my desktop connected to KEF LSX speakers via the aforementioned Toslink. My Qutest still resides in my main rig, but connected to a Roon Nucleus via USB. If I was shopping for a Coax cable today, among the brands I’d consider would be Transparent, Wireworld, Audioquest and DH Labs.
On a budget, DH Labs in my experience offers very good price performance. If you don’t have a local dealer to work with, where you can maybe borrow and check out some different cables in your system, you might want to reach out to the folks at The Cable Company. I’ve had good dealings with them, and among other things, they have a cable lending program. Good luck. Hope this helps. And do let me know how things work out for you.

@hilly230  
First off. In general, regardless of source device, bits are never just bits; with respect to the Bluesound Node in particular, some of its flavor is being imparted, even if you are using its digital outputs (it's like there will always be some NAD in there, and that "NADness" can never be completely eliminated). The Qutest is a highly resolving DAC. In my opinion it's in another league as compared to the Node's internal DAC.  That being said, the Node's internal DAC is very listenable all on its own. 
I also think that the Node 2i / Qutest combination can be stellar, and that the impact of the wire linking the Node to the DAC should not be discounted.