Hi PP
Firstly do you have a your own phone, tablet or laptop you can install and use Spotify (other streaming services are available) on?
If yes these are some options;
1) If your phone/tablet/laptop has a headphone socket then it has a inbuilt DAC, so get a 3.5mm to RCA cable for £5-£10, and just connect via a cable, at least to get you started.
However if the idea of having a phone/tablet/laptop wired to your amp, so not really usable when playing music, doesn’t appeal then:
2) Get a Bluetooth enabled DAC, something like the ifi Zen Air Blue for £99, that you will connect via RCA to your amp and will allow you to play any audio from your phone/tablet/laptop without wires. Bluetooth is purely for convenience. It just provides a wireless way (you still need to connect the Bluetooth DAC via RCA to your amp though) for you to connect your phone/tablet/laptop to your amp.
However there are three primary issues with Bluetooth, i) bit rate (just think sound quality) is less than CD, but you probably won’t notice, ii) if you move your phone/tablet/laptop out of range of the Bluetooth DAC, typically 15-20 ft (depends on your room, walls, how old your phone/tablet/laptop is as there are newer better versions of Bluetooth that get closer to CD quality and offer better range), the connection will be compromised and you’ll not get music, and iii) all the time you are playing music you’ll be draining the battery on your phone/tablet/laptop faster than normal.
3) Get an all in one DAC and streamer, if you value convenience. Just think of this like a CD player (with a DAC as most are) but instead of a remote to control CD playback, you control it with your phone/tablet and you can play anything you can find (search for) within the streaming service of your choice. Another benefit of a streamer, especially if used with something like Spotify Connect, is there is no drain on the phone/tablet when using it. It’s purely a device to select what is being played. Once selected the actual music is streamed via the streamer.
Two issues, i) these are typically overpriced for what they offer in terms of sound quality. A Wiim Mini (£89 streamer) and something like a Topping E30 Mk 2 (£149 DAC) both from Amazon, arguably offer equivalent sonic performance to the £450 (currently £100 off) Bluesound Node and £799 Cambridge CXN V2, as they both use fairly budget oriented DACs, ii) some use awful streaming software known as DTS Play-Fi. You’ll have to take my word for it that this is very poor (and could put you off streaming for good), but as an example DTS Play-Fi doesn’t properly support gapless playback, so you get a significant pause between tracks, which is particularly noticeable on albums like The Dark Side of the Moon. It also offers limited streaming service support. Unfortunately this means you’ll need to avoid anything by Pioneer or Audiolab (until they stop using DTS Play-Fi) but there are other brands that also use DTS Play-Fi and often this isn’t mentioned in the spec. If you don’t care about gapless playback and you’ll only ever use Spotify, DTS Play-Fi may not be an issue, but it is generally not recommended. Roksan and Nad both use the software found in the Bluesound Node, which is far superior, but the Bluesound Node just isn’t particularly good value as a dedicated streamer due to the quality of its DAC.
4) Get a streamer like a Wiim Mini (the size of a hockey puck) and an external DAC such as the previously mentioned Topping E30 Mk 2 (the size of a small book - there are lots of alternatives) both which are very small and can be hidden away behind or on your existing equipment. Have a look on YouTube for a review of each and you’ll see what I mean. Provided your house has Wi-Fi you can be up and running in 5-10 minutes with your daughters help.
The negatives are i) box count (so additional power requirements) and potential clutter, but the options I mentioned negates this, and ii) getting a DAC that doesn’t work well with your amp and/or your personal sonic preferences. You’ll probably need to look into this in more detail. That would also apply to the all in one options.
Based on your feedback it feels like something with Bluetooth as robdmarsh suggested, like the ifi Zen Air Blue (£99), might be the best option for you, but the three negatives I mentioned might be significant for you. The ifi Zen One Signature (£350) robdmarsh mentioned is more flexible as you could also connect it to a streamer (like the Wiim Mini) later, and it may offer a better sound signature than the Topping E30 Mk 2 (perhaps too analytical) I mentioned.
Despite your comments I would recommend the streamer and DAC option (that you can hide away) if you value sound quality. If you decide you like using streaming, my parents are primarily vinyl and CD users, but have really come to appreciate the practicality and massive increase in their library, that you can also take with you, you can always upgrade the DAC later. A dedicated DAC may even improve the sound quality from your existing CD player if it has an optical output.
I hope that helps. If you need clarification on anything just ask. If you’d prefer not to use a phone, tablet or laptop, optical out of your TV into a DAC then into your amp as you mentioned is probably the best option. The negative to this is you’ll be compromising how you’re able to use the streaming service if relying on your TV being on all the time and its remote control to use it.