Streaming vs CD transport direct comparison

Interesting comparison and we appreciate you sharing the results.  I will say that I directly compared Roon to Lighting DS through my Auralic Aries G2.  LDS was significantly better in every regard than Roon which I subsequently dropped.

I’m not suggesting that the outcome of your comparison would be different, but I do agree with jbuhl that, in a shootout, I wouldn’t use Roon.  Fabulous interface, but the sound quality - not so much.  I tried it straight through and with up conversions, etc.  Same result.

I no longer have a CD player so i can’t do a similar test but you’ve piqued my interest and I wonder why it would be the case.

I love the Roon sound and interface. Roon sounds great in my system so I am a tad confused on the notion Roon does not offer first class sound. I use a modified Innuos Zenith with the Roon/Squeezelite option. Mojo Audio Evo dac taken to the max with upgrades. Not at all my experience. In my system I also found that CD vs streaming depended entirely on the recording. Qobuz 24/192 sounded better than CD in my system. CD sounded better than some 16/44. Frankly the differences were  small many times. Seems there are too many variables for absolutes and this outcome will always be system dependent.

@grannyring 
I too loved the Roon interface.  And it certainly sounded good. It was only when i did a direct comparison that i noticed it was deficient in comparison. And, BTW, I perused the manufacturer's forum and found that many users had the same experience  Not incidentally, your DAC is better than mine (new one on the way!) so perhaps that was your difference.  

My speculation is that the native app (Auralic Lightning DS in my case) is able to better integrate with the operating system and properly use the large buffers built into my unit whereas Roon might not be able to. 

In any case, I certainly have to agree that there are too many variables to draw any universal conclusions.  So, as in all things related to this, YMMV.

An interesting thread, but hardly conclusive, as perhaps a different CD transport and a different streamer would have yielded outcome, not to mention the small sample of the listening group.  Personally, I get better results in my system with a CDP transport, but the difference isn't world beating.  I appreciate the ease of the CDP as well, as it's just plug and play, and it is actually easier to find my genre (Classical) on the shelf rather than ploughing through the maddening file organization schemes.  I also don't have to worry about gapless play, my ISP throttling my bandwidth, etc. ymmv

If Ethernet connection was used, then whatever the online streaming source was, it was severely compromised by the connection. I was fascinated and elated to find that employing the systemOptique optical cable converter (Ethernet to optic) when the SONORE Signature Rendu SE was upgraded with that feature improved the streaming significantly. The noise floor dropped, and the dynamics improved. I believe that use of the optical connection was a boost to the quality of the streaming source, Tidal's upper tier through ROON. 

Also, I find that defeating all of ROON's settings, returning to a less manipulated stream, is preferable, at least in terms of the ROON's digital engine. 

There are many results possible, so it is not as significant as might be expected to declare CD always superior. I have also been able to get CD to sound better than streaming. However, change a power cord, a cable, a player, DAC, etc. and the result shifts in potentially negative ways. I would not subscribe to the notion that CD is universally superior. For instance, simply using a different DAC in each setup can make either one superior sounding. Perhaps if 4 or 5 DACs were used in the comparison, then a more general conclusion could be reached. The comparison would need to be made in many iterations. Who is going to sit through that, and compile the notes, experiences? Very few people. I might, if I found it worthy topic of consideration. 

CD was my playback source, and streaming had to reach a comparable level, or at least close enough that the difference was akin to a couple of power cord changes. Once that level was reached, I chose to dump the disc in favor of streaming and file playback. That was a few years ago now, and the digital playback has kept improving, quite suitable for reviewing. 

So, can I make a CD source sound better; sure, that's not difficult. But the question is whether it is universally superior. Without many systems, i.e. 5 to 10, to assess, I consider a statement of its universal superiority a limited conclusion.