Help Please:Upgrade Coax cable between Node 2i and Chord Qutest..?

I can attest to @williewonka comments regarding upgrading the power cord with Zavfino power cables, as I did just that this week, replacing the stock cable with a Zavfino Fina https://zavfinousa.com/collections/power-cables/products/fina-occ-power-cable-14awg with an adaptor plug from Wireworld.  I immediately benefitted from a larger sounstage, increased transparency, bloom and dynamics.   It really made a significant difference and I highly recommend it.

I have done a lot of testing and experimentation with digital COAX S/PDIF cables.  I have owned the DH Labs D-750 cable.  It is a very good cable for the money, excellent bass.  However, you have two things going against you.  The .5 meter cable is just TOO SHORT for a good S/PDIF cable.  You really need 1.5 to 2 meters to avoid signal reflections back to the source transmitter (I always use 2 meter).  A short cable will cause a loss of high frequency detail and the music just does not sound right (reflections causing distortions in the digital square wave pulses).  The second reason is using RCA connectors on the cable.  Granted, I understand the Chord Qutest has BNC input which is great, but the Bluesound will only have RCA.  I have tested all sorts of RCA connectors for digital coax (the DH Labs D75, WBT Nexgen, Eichmann Bullet Plugs, Furutech Rhodium).  The DH Labs makes an OK rca plug, but with all RCA plugs, you have a loss of high frequency detail as well.

The best results I have had is from cables that have BNC terminations and used BCN-to-RCA adapters for RCA sockets.  The BNC combined with BNC-to-RCA adapter presents a closer impedance to 75ohm than just a raw RCA connector (which is closer to 25-30 ohms).

The Black Cat cables recommended may be a good choice.  If you can find a Nordost Heimdall at 2 meter, that would be a good choice.  The Heimdall has excellent bass and incredible depth of sound, but it is slight laid back in the upper mids/highs.  Excellent sound.  The Black Cat cables may have better resolution, but I have not listened to them.

Another cable that you could try (if you wanted) is the Oyaide DR-510 with the Oyaide BNC connectors.  They make a 1.3 meter version.  It is $315 retail, but you can find it on ebay from Japan sellers for under $200.  It uses a 20awg solid-core silver conductor.

Appreciate the responses - even the snarky ones. LOVE all these guys who think that Tidal sounds better if you spend more $$ on a "better" streamer.

Have you tried it?  If not, then you're the one "who thinks" and is being "snarky".  I'm not trying to be snarky, I was just trying to be as nice as I could in how I said it's dumb to spend $300 for a cable on a $500 mass produced streamer. 

You "think" that all digital sounds the same?  OK.

I tried all kinds of upgrades to the Node 2 - external DAC, power supply, better cables, etc.  It is capable of small improvements, but you can only take it so far and at some point you've spent as much or more as it would cost to have a much better digital front end. 

My initial move was from the Node 2 and a nice external DAC to a TEAC NT-505.  That was a nice step up in performance.  Currently I'm running a Roon Nucleus and an Aqua La Voce S3 in my main system and it rivals my analog setup.  Of course that's a significant step up in terms of cost from Bluesound, but the NT-505 isn't after you factor in all those cables, external DAC, power supply, etc.  I'd also look at the Lumin products.

It's your money though, carry on... however, if you'd like to spend your money more wisely and realize more significant improvements, then be open to suggestions from people that have actually gone through what you're contemplating.

I second these.