I need help to select a music streamer

ahofer
@geoffkait not quite, it is also possible for bad test design or mishandling to effect one component and not another, so a positive can also be false.

>>>>But that case would be a negative result, not a positive one, for the component that was mishandled. That falls under the heading “error in system.” It wasn’t a false positive, it was a negative. I only gave two examples of things that can go wrong. Obviously there are many others such as operator error, unfavorable weather, system not revealing enough, cables or components not broken in, etc. In any case, this highlights why it’s important for multiple blind tests to be performed on multiple systems by multiple testers. 

Does the Bluesound have the capability to play MQA?  Would the Bluesound sound better or as good as the Bel Canto if I added expensive digital coax cable like Chocolate Audioquest?  This would cost $1,000 less than the Bel Canto.

Bluesound does a partial decoding of MQA, if I recall correctly.
FWIW, I find higher resolution to be just as good or better than MQA.
That 'secret sauce' recipe is something that I don't want to touch.- Like Dolby.
B

Is there really much of a difference in sound quality between different music streamers?  A Bluesound costs $499, a Bel Canto eOne costs $1,600 and PS Audio $6,000.  Does it all have to do with the quality of their processors?  So far, I think Roon to be gimmicky.  If I used either a Carbon or Coffee Audioquest digital cable using the Bluesound, wouldn’t this sound good enough and better than steaming TIDAL through my Apple TV using Coffee Audioquest HDMI cable?

Does the Bluesound truly stream MQA.  If so, how much difference in sound quality will I hear?

Positive results for a single test, on the other hand, are more credible since positive results were obtained in spite of any problems or errors that may have occurred in the test.

Most blind tests are simply to hear a difference.  So you are defining positive results as one where the user heard a difference and we are sure there was no error that produced an audible difference where there otherwise would not be one.  But if you knew there was operator error, you'd throw out those results, so, if there's error, it's unknown by definition.  

I would describe both a)hearing a difference due to unknown operator error, as well as b) the well supported bias towards hearing a difference* as false positives, and difficult to quantify.  

Anyway, legit or false, positive results (blind tests of cables, amps, hi-res vs redbook) remain vanishingly rare, so there's not much to be credulous over.  

* See the Stereophile tests in the link, particularly the devastating footnotes, for a hilarious read on this.