Is there a difference in sound quality when streaming TIDAL Vs CD player


I hard wired my modem located in my family room using Cad6 cable to my Apple TV and direct wired my Apple TV to my ARCAM AVR550.  I have an OPPO 203 connected by both an RCA cable and by HDMI to my ARCAM.  

The dealer I purchased my ARCAM from told me to play my CD’s through my RCA connection and to watch DVD’s through HDMI.  If I listen to CD’s through the RCA, aren’t I using the DAC on the OPPO player rather than the DAC on my ARCAM and wouldn’t the DAC on my ARCAM be a better DAC.  My friend told me I should use a digital cable rather than an RCA to improve sound quality to utilize the DAC on my ARCAM?  If this is the case, wouldn’t the HDMI be the same as by using a specific digital cable?  I listened to my CD’s through the RCA Vs the RCA cable and I thought it sounded better through my HDMI cable.

i will be looking forward to your responses.

Thank you,
128x128larry5729
My approach is that overall system synergy between all of the parts from the breaker box to the wires to the collection of equipment to the room construction to the seating position is more critical than the particular parts.  I have heard systems >>$100K that left me cold and systems that cost 1/10 that much that had me in seventh heaven.  Its a matter of how all the parts work together in your room with your ears.

Starting with the speakers is a common place because that is where the sound comes out, and speakers may editorialize the sound more and interact more with your room than other pieces.  Next to the speakers, the source, turntable or DAC, add the most “flavor”.  But having a great speaker with a noisy or weak amp, or a stridant DAC will only paint you a terrific picture of upstream weaknesses. Balance, balance, balance.

I provided a couple DAC brands and a budget target for you to consider, above.  More than that would require some thought.
Qobuz is as good as a CD if content is CD or better HR. The problem was they dont have many songs. If they did, my CD player would be on Audiogon. =)  
Here are some DACs between $1500-$3,500 I think would surpass the DACs in your Arcam.  If you are all in on digital music, it would be worth it to check these out.  Which is for you depends on your budget, personal tastes and synergy with your other gear and your room.

-Auraluc Vega
-Bryston BDA-3
-Chord Qutest
-HoloAudio Spring Kitsune Tuned Edition Level 3
-iFi Pro iDSD DAC
-Mytek Hifi Brooklyn DAC+
-Naim DAC-V1
-Schiit Audio Yggdrasil

Don't rule out Qobuz if you talk about stream. You should try Qobuz studio 192khz/24 bit. Compare to CD, it is day and night. Try it yourself.