Digital streaming/library


I have purchased a rather substantial 2 channel audio system, and two of the components are a streamer and an audio nas...a melco. I want to build a digital music library. I would love to have the hd level tracks, but the downloads are so expensive. I already have thousands of lps, and thousands of cds. I have iTunes, and it (and rhapsody) allow you to download tracks into your computer...but they are not cd quality. I have a streamer, and I could get the tidal or deezer hi res subscriptions, but do they allow you to download tracks into your computer/nas drive for a digital library?
128x128easola01
I don't know about deezer, but you cannot download tunes from Tidal.  They stay on their servers, you pay a monthly fee, and they stream them to you on demand.  With the correct version of Tidal, you will get 16/44.1 aka CD quality data stream and there may be some higher rez formats supported also, but as others have pointed out, often the source material is lower rez and the hi-rez stream is just up-sampled.  As far as I know, the way to get CD resolution material onto your NAS is to either buy CDs and rip them, or buy CD quality downloads. 
Well, I guess I will have to stick with itunes then. With itunes, you can download tracks/albums right into your storage device. Rhapsody too. I was hoping to get better resolution than the 256kbps from itunes, but okay!
easola01, It is best to avoid conversion by Audio Core.  Because I play 16/44.1 I set Audio Media to 16/44.1.  I tunes gets my CD without any conversion as 16/44.1 and sends it to Airport Express as a data.  Airport Express send it to my DAC as 16/44.1

Shadorne, Audio Media was set as 16/44.1    In fact AirPlay was not even shown as output device.  When I added it, it showed as 16/44.1
Okay thank you kijanki, but I am wanting to build a library from what will be a boatload of music I do not possess in cd format...music I don't possess and music I haven't heard yet but will while I am browsing my streaming. I am just surprised that, given the fact that one can build a library with itunes and rhapsody, both which are lossy, that there is no comparable way to do the same and build a library in lossless files?
easola01, I'm not familiar with streaming.  My whole library consist only of CDs on HD  in ALAC format.