To be honest I don't have anything against MQA - it just doesn't interest me.
(Excluding all the "horrible people trying to take over the music industry" part of the discussion...)
However, it's not even as simple as "whether they do the first unfold or not"... because MQA isn't that simple.
To be technically correct MQA is a high quality lossy compression.
Lossy by definition because, no matter how many "unfolds" you do, you will not end up with a bit-perfect version of the original.
The claim is that it "audibly bit-perfect because, at a given bit RATE, it gives you an analog output that is audibly closer to the original".
Basically, without going into technical detail, they're sacrificing specific bit accuracy to make room for saving other information that they believe is more audible.
In other words they're claiming that what comes out is "a more perfect copy of the original analog audio than a bit perfect digital copy would be".
To me this all comes out sounding like "another way of making a remaster that sounds a tiny bit different in a way that many people find pleasing".
And that has been my experience with their content.
So, yes, they're sort of "doing the first unfold" inside the Tidal client...
But that isn't specifically bad because they're ALSO using MQA as a streaming CODEC...
However, while I haven't personally verified this, the basic claim against them at this point is that there is essentially no "bit perfect option".
In other words, even on albums NOT listed as "high-resolution" or "MQA", the bits that come out have been modified from the original.
Now that's NOT say that the difference would even ALWAYS be audible - but merely that "they ain't bit-perfect" - even with "plain old CD content".
However a lot of people have said that a lot of their content does sound "a bit different than the CD".
(But also, to be fair, with most popular CDs, there are so many different pressings and versions that it can be tricky to make a proper comparison anyway.)
I personally prefer Amazon Prime Music...
But, while it's possible to get bit-perfect playback out of that at a specific sample rate, they don't support WASAPI mode...
(And that's another down-side from a purist perspective... because it means that, in order to get bit-perfect at different sample rates, you have to keep fiddling with settings.)
So, to be honest, I go with Amazon because they have the better selection (and I already have an Amazon Prime account.)
However, the bottom line is that the subscription version of Spotify sounds pretty darned good.
(They use Ogg Vorbis compression, which sounds quite good, especially at the higher bit rate they use at the subscription level...)
And they have an EXCEPTIONALLY good selection...
And a lot of people like their user interface...
And virtually every streaming device out there supports Spotify...
There's also the lesser known fact that, with some high-end streaming solutions like Sonos, and a few others, SOME streaming clients are built into the hardware.
This means that, with those products, and those specific services, you can pick a playlist on your phone, but you DON'T have to keep your phone connected after that to play music.
And, in most cases, if they support one or two streaming services in this fashion... Spotify is almost guaranteed to be one of those few.
(In many cases, with streaming devices and services that are controlled through a phone, the phone must remain on and connected in order to play music.)
The free version of Spotify uses a relatively low bit rate version of Ogg Vorbis - which is more or less equivalent to MP3.
The subscription version of Spotify uses the same high quality lossy format - but at a higher bit rate.
And SiriusXM uses something else (I don't know what it is - but it doesn't sound very good).
Services that offer "lossless CD quality" should be similar - but, of course, that would depend on which version they started with.
Some services also apply other processing - for example some form of "replay gain" so everything you listen to plays at about the same volume.
And then, of course, Tidal is now reported to apply MQA processing to most if not all of their high quality content.
(Even if your playback gear doesn't support "for real MQA" they are still using the MQA CODEC to stream your content... and that is lossy.)
I will probably move away from spotify eventually, but it works good for me now and it's the only service with "spotify connect". I tried tidal through the yamaha app and that was not a pleasant experience, tidal connect is not supported on my device.
I've been hesitant about Tidal because I don't want to support MQA. If they do the MQA first unfold even though I dont have an MQA-DAC, well then Tidal will never be my choice.
