Help a digital luddite

I have enjoyed putting my current system together over the last few years with an emphasis on vinyl and cd/sacd playback.  My current system consists of the following:

Marantz PM 11S3 integrated amp
Marantz SA-11S3 SACD player
Manley Chinook phono preamp
Music Hall MMF 9.1 turntable
Clearaudio Maestro cartridge
Focal Electra 1028BE speakers
Focal Chorus SW800 subwoofer

This system has proven to be an excellent balance of clarity and musicality in my 14'x18' listening room. My tastes run the gamut with a fairly heavy emphasis on blues and jazz and a healthy dose of both classic rock and "alt country" artists.

In an attempt to interest my millennial kids in joining me in listening to music, their response has been to ask why I do not have a way to listen to digital formats other than CD's.  While I defend the quality of my chosen formats, I frankly am too simple minded to understand the best way to incorporate either streaming audio or downloads on their laptops.

I have no interest in abandoning my current components but would like to supplement them with equipment of comparable price / quality.  My PM-11S3 has a well regarded built in phonostage, but upgrading to the Chinook made a meaningful difference.

According to Marantz, my Sa-11S3 SACD player has the following features:

"Digital versatility is the hallmark of the SA-11S3, as the player does double duty as a reference quality DAC and is equipped with numerous digital interfaces to accept a wide variety of formats. The front panel features a USB-A port for connection to a portable device such as an iPod, iPhone, iPad and the like, as well as compatibility with other devices. There's also a USB-B port on the rear panel, which provides compatibility with a wide range of digital formats, including up to 192 kHz/24 bit digital audio, and is compatible with asynchronous data streams from a computer (drivers are available for download on our website). In addition, there are coaxial and optical digital input ports for connection to other digital audio sources."
So - how do I best incorporate digital input from either my kids' laptops or a streaming service? Are any of the features of my SACD player sufficient to meet these goals or do I need a freestanding DAC or other piece of equipment.  If I want to just use my current equipment do I need any special cables?  Will a freestanding DAC dramatically improve sound quality over the built in DAC? If, so, any specific DAC recommendations? I am generally aware of the difference between compressed vs uncompressed files, but my eyes glaze over when talk turns to the various formats (mp3;wam;wav;mic;key; mou;se).  My goal would be to either achieve SQ comparable to my SACD's or better or just forego the effort.

I greatly appreciate any guidance you can provide.

Your Marantz is probably all you need in DAC.  Now you you just have to feed it some digits—i.e., get a digital source.  Since the main reason that you are doing this is the (probably fruitless) desire to look cool to younger generations, I would keep it simple and get a Bluesound Node2i.  It will connect to your Marantz in multiple potential ways.  You can connect to the internet through either Wi Fi or Wired.  You can get every streaming service imaginable, such as Spotify or Tidal.  And it has Bluetooth, so your kids can stream their music from their phones when they visit.  Bluetooth is a step down quality wise, but the millennials won’t know or care, and it can still sound pretty good.
Happy Holidays.
Personally, I wouldn't get bogged down with formats. Yes your system can be improved with a stand alone DAC but since your SA-11S3 accepts external inputs I would look at adding a streamer. A good choice would be an Aurender N100H which can usually be found used in the $1800.00 range. That way you can stream any music which would involve the rest of the family without having to purchase CD's. Save your money for the future when it comes to a stand alone DAC. I haven't checked the specs. but if your Marantz has an output from the transport that will allow you to use an external DAC then that offers an opportunity for upgrade. Most of all, enjoy the music!
Thanks.  I assume the Node 2i is a streamer ( you are talking to a luddite here).  Can you explain which of the various connection inputs on my SACD player is the preferred one to use? I have no idea the difference / merits of coaxial vs optical vs USB-A vs USB-B.
If the goal is playing music from your kids laptops its as simple as a $20 earphone to RCA adaptor. That's what I use for sound when watching movies from my laptop. 

I wouldn't go anything more than that. Because fundamentally, when it comes down to it, you are trying to introduce your kids to quality while they have been drawn into the modern fixation with quantity. They want you to be able to stream infinite variations on crap. You are trying to show them there value of selective quality. Both in music and in sound quality.

So if you succumb to temptation and buy buy buy more crap (streaming services, players, etc) all that does is blur the lines. What you want to do is hook up their laptop, play their music, let them hear how it sounds. Nobody cares about sound quality unless first they care about the music. So you get them listening to their music that they like and sounding the way they play it, by using the adaptor. Eventually they notice your music sounds better. Yes this works. Been there. Done that.

I'm using coax from my Bluesound Node2i to my Dac. I have a very good CD setup and streaming comes very close to it in terms of quality. And it's more fun with almost unlimited choices in music.

The quality of the cable (USB, coax) does make a difference in sound quality. I auditioned many cables to get where I am, but I suggest you start with an affordable coax cable from Blue Jeans Cable or Audioquest.

If your kids will be using their laptops it’s probably better to stream wirelessly to a Bluesound Node 2i as, if they’re like my kids, I doubt they’ll take well to being tethered by a cable to another device. A Node 2i can be had for around $550 or less used, and you can either use its internal DAC and connect to your Marantz via regular analog interconnects or via digital cable if you want to use the DAC in your Marantz. The DAC in the Node is pretty decent, so it might be fun to try both and compare. If you need a digital cable I’d highly recommend initially getting an Apogee Wyde Eye from Amazon that’s only $40 for 1m RCA cable. It’s a very good digital cable (make sure you pay attention to the directional arrows) and may be all you need although you can obviously always upgrade later if the streaming bug ends up biting you. It did me. BTW, Qobuz is offering a special at $15/month including hi rez music if you sign up early. I’ve had my subscription for about a week and have already discovered so much great new music I’m absolutely hooked. Consider yourself warned. Heh heh.

The Node2i is a streamer.  You can stream music on a HD, including High Rez files.  It plays Internet Radio.  As mentioned previously, it interfaces with every streaming service imaginable.
  It has coax, optical, and usb outputs to attach to a DAC.  For me, coax and optical sound the same, usb a little less. Ymmv.  I wouldn’t get hung up on what cable to use.  It also has analog outputs that can connect to your pre amp, so you can test the quality of the DAC in the the Node2i vs the the Marantz DAC.     For you as a newbie, the Bluesound products are the sweet spot in quality, price, ease of use.  If you decide streaming isn’t for you, you haven’t made much of an expenditure.  The quality is pretty good and you may never feel the need to upgrade.  If you really get into streaming, you can buy better sounding products for greater outlay.
Oh yes, another good feature with the Bluesound is internet radio. I listen to some classical stations from Germany. And it also streams your local radio and indicates the sampling rates.

@soix , can the kids stream the subscription service thru their laptops since they interface with the router?