Is there a link to this review where he does the comparison?

As it happens last week I did a comparison between TEAC VRDS 701T transport and Novafidelity X50D streamer. same DAC (AQVOX).

DAC and streamer had been modified with SMPS power supplies in both replaced with linear.

CD was Joni Mitchell 'Blue' - local streaming vs transport. Comparison was done single blind. I couldn't tell them apart, I was just guessing.

I suspect it would be the same comparing with Tidal or another streaming service assuming the streaming service was providing the exact same mastering as the CD. Which they probably won't be (my CD of 'Blue' is the original release but there are multiple remasters, as with most famous albums from that era).

So if the reviewer didn't compare blind and didn't compare the same master, it's not a reliable comparison.

Just one more thing - in my comparison, using a CD transport meant the DAC was the same for both. If using a CD player it would need to be used as a transport only, or if it has a digital input the streamer would need to use that so the DAC and the output level remain the same for the comparison.

Okay, the differences between DACs can only ever be very slight due to how they work, but still a potential source of a difference that has nothing to do with format.