Sorry but it has to be said (opinion only obviously) SPOTIFY is not a serious audiophile music source.

Me too. I've found Tidal and Spotify to be highly capable of excellent sound quality.

I downloaded Spotify onto my iPad (just the free version). It's quite nice to use too. It may never go any further than that for me but it's useful to hear albums on.

To use it as a genuine source, I would need a Dac that will just play whatever I select on the iPad through the hifi without wires, downloads, firmware or anything remotely connected with computers and their associated hassle.

I'd also need one or two things that matter to me but may not to others,

No Chinese made or flimsily built kit
No wall wart or similar wires, attachments. I want a proper 1 box DAC with a real built in power supply
Unlikely to buy new, so must be available used
Substantial sound quality that won't be left wanting, if the best I can hope for is cheap CD player level, I will pass.

Is there anything that springs to mind that would fit the bill? Basically I'm looking for a proper hifi product, not a computer gadget. If it's not going to match or beat a decent Naim CD player for sound, just say and I will forget the whole idea  

As another guide I once tried a Caiman with a USB from my laptop to play my iTunes lossless. Nowhere near good enough to bother with. Again, if it's at or below that sort of level, it's not for me. I just don't listen to music unless it's produced the way I like it.

I thought it was a bit of a long shot. I have things I know in advance I can't live with, so it's best to recognise them up front.

As we have all discussed before, there are real differences in what we seek from listening to music. I'm probably on the audiophile fringes of the spectrum in that I'd choose silence over music that is in any way short of the mark or comes with any added hassles in getting it playing.

I once had a Chord DAC that used Bluetooth or wifi or both. I thought something like that might work without any other gubbins. I can't remember the name of the Chord but it was OK sound-wise and nicely built. Not expensive either, I don't keep up with technology but that was 2013 and I had assumed others would have made similar things.

If it's 2 boxes to get already existing music across to my system I'd rather not bother. Thanks for setting me right, Martin.

Edit: the thing I had was a Chordette Gem

Here you go then, Andrew. Single-box streamers that are Spotify Connect capable.