Where/how to start?

The standard "starter" answer is get a Bluesound Node and Tidal Subscription $~600). I prefer Qobuz but note sure if Node supports that. Node got all you need to come out of the gate for your first experience. Just run RCA into one of your Pre or use one of the Optical in on the Oppo, DAC proly better in that unit than the Node. Stream with that while you acclimate to the digital landscape. 

Got wired ethernet at your 2 channel set up or Wifi?

I am not sure about the Node model number.  Its the basic unit with no disk storage.  I am purdy sure the Node is Wifi capable so you can start with just setting up the node on you existing network.   If that is flakey and you are getting drops then you can augment your network.  Many people on this forum have success with extenders and wal warts but I personally think that technology sucks.  At least it has for me and people I know.   I would suggest exploring going to a mesh network topology.  Little extra $$ but worth it if you are going to stream, easy setup as well. Have one of the network-nodes at your rig and hardwire ethernet to the Blue Sound-Node. 

The Cambridge unit is also nice but its double the $$.   But also a good choice. 

Test the waters with the Node.  If streaming is for you (hooked on the crack pipe)  then you can start to explore whether you want separates or all in one streamer/DAC from high end manufactures like Bryston, Lumin and Moon.

Can somebody comment on Node’s DAC? Would it be better than the DAC on Oppo?

Node DAC is a Burr Brown PCM 5242 and the Oppo is a ESS Sabre. It really comes down to the implementation of the DAC chip. You would have to really dig deep to find the implementation details. If I was venturing a guess/bet I would go with the Oppo as it is 2x the cost of the node so it might have a little bit more engineering $ spent on the DAC.

Excerpt from Oppo review regarding the DAC:

"

Oppo have of course put extra effort in the sound of the 105 model. It has two ESS Sabre32 Reference Audio-digital converters, 7.1 outputs and a stereo output. Both use a 32-bit Hyper Stream DAC topology that is said to provide a wider dynamic range and minimize both jitter and distortion. There is both balanced and unbalanced dedicated analog stereo output and digital outputs in the form of RCA and Toslink.

​Had I made a pure CD player in the same price range and a bit upwards, I would be nervous - Oppo BDP-105D certainly sounds compelling with music. Sure, you can find CD players that sound better, but probably not at this price. And it can play all discs and can handle both two- and multi-channel, even a HDCD filter is built in. Considering all the things the Oppo 105D can do picture-wise in addition, it is simply brilliant value for the money.

​I have heard many significantly more expensive CD players that gets beaten by the Oppo 105. You get a sound with the calm, the detail and the super quiet background that I really only expect from dedicated CD players of high class. The DAC has a slightly different, slightly warmer character than the Burr-Brown type I’m used to, but it’s just another side of the same coin. It’s still a good DAC."

@ihcho You wouldn't happen to have a late model iPAD would you or iPhone.

My iPad is about 4 years old and I have iPhone 11.

So, I can use either iPad or iPhone to control the music? Then, the connection between iPhone and Node is through WiFi, right?

If I use a direct network connection, do I still use iPhone to control the music? Well, things will get cleared once I get a Node.

Once you get the Node you will control it/music via phone and yes over network. Music will stream directly to Node over your wifi and you control what it streams via an app on the ipad/phone.

If you have an ipad with with a USB C connector you could use the Qobuz app on the ipad to stream directly to the USB B input on the Oppo. Dont even need a node.

On the iphone 11 or iPad with a lighting port you can use an apple usb lighting to digital camera adapter. This adapter has a usb c port on it. You then connect a USB cable that has USB C to USB B. The USB B plugs into oppo.

This effectively sends a digital signal from you phone/iPAD to the Oppo allowing you to stream up to 24/196 Khz (high rez) Directly to the Oppo from the Qobuz app on your phone. You can even download the physical files from Qobuz to your device and play them from there. I have actually done this.

Maybe not a long term solution but for less than a $75 you can do a free Qobuz trial and I think you be surprised how good it can sound.

If you interested you can contact me directly and I can walk you though it.

Camer adapter for iphone/iPAD

Here is what mine looks like.  This adapter only has the lighting to USB A connector.  Then the USB A to USB B cord.

https://www.dropbox.com/s/n7t5u4f28f82jt3/IMG_5088%20Medium.jpeg?dl=0 

Here is a little movie of the Qobuz app on my ipad connected directly to my DAC via the adapter and USB.  you can see the 96K on the DAC display.