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

Larry, welcome to modern hifi.  You have touched in some manner here on several hot topics.

1. I hear a difference between Tidal and CDs, and the same digital files saved to my computer server on both my systems. Generally, Server > CDs > Tidal.  This is with the upgraded subscription. I don’t notice that much difference with Tidal served on my computer via ethernet (I.E. “hard wired”) or wifi, or via my iphone, with all feeding DAC via USB cable.

2. Your Arcam does likely have a better DAC with better jitter control than the internal DAC of the Oppo 203, which is optimized for video.  So it is not surprising you find better sound playing CDs through the Arcam’s DAC via HDMI versus RCA cables from your Oppo, regardless the quality of the RCA cable.  The RCA cable can’t fix mistakes upstream.  You might try running a (single) coaxial digital RCA cable from your Oppo’s coaxial out to the Arcam’s coaxial in to see if that sounds better than the HDMI cable.  Simpler cable with only function to deliver digital sound.

That said (number one), I have an older Arcam receiver than yours, and I find that I like the internal DACs better for Bluerays and DVDs than for CDs spun from my consumer grade Samsung Bluray player - all via a decent HDMI cable.  CDs played through my external Arcam irDAC via optical cable from my modest Blueray player, and decent quality RCA cables out of the DAC to my Arcam receiver, sound better than straight from the Blueray player to the receiver via HDMI cable.  The difference is not subtle.  

All this makes me think the internal DACs in the Arcam are optimized for multichannel and higher resolution recordings on DVDs and especially Blurays.  Get one of the Guitar Festival Bluerays and you will see what I mean.  It also makes me think you might get better two channel sound by adding an external DAC between your Oppo AND your Apple TV (Via different digital cables running to the same DAC) and your Arcam receiver.  The Arcam is a fantastic amp and home theater reciever, but for two channel you can do better with an external DAC.  Instead of spending $5000 on a set of cables, spend under $2,000 on a Benchmark or Chord or some other well-regarded DAC, and your system (including whatever speakers you currently have) will sing like you’ve never heard it.

3. That said (number two), I hear a noticeable difference between different digital, RCA, speaker or AC cables.  Even inexpensive systems benefit from upgraded cables.  Be smart, set a reasonable budget, and try some different wires.  The Cable Company will lend them to you for a fee if you want to rent and try before you buy.

good luck,

kn

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.

Oh, and add the Benchmark DAC3 HGC to the list above.

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