No idea, but it was long ago. Back when I subscribed, which I quit around 1994 or so.
The story, as I recall, it was not Stereophile it was just published there. It was NOT a test like you're thinking, asking a bunch of audiophiles which system they like better. Nothing so crude as that. Very clever, they asked questions more along the lines of which music did you like, would you like to hear more of it, consider buying, etc. So the subjects if anything would were focused on the music and NOT the system. They had no idea. They couldn't even see anything. Even the girl with the questions, who came from behind. They saw here arm, nothing more. Double-blind? HA! Quadruple blind!
Double blind is of course a canard. Red herring. Waste of time. Distraction. Refuge of scoundrels, etc etc. If you hear it you hear it. If you think anyone needs anything more, go read the previous sentences a few more times.
Ditto the state of digital. Replace double blind with the state of digital, previous sentences stand. One hundred percent. Because you could say the same about all the analog gear that was used. Its all a lot better today. Across the board. So might as well quit dodging and face the music. Heh.
Especially since one of the little-appreciated tricks they played was to use tube gear and solid state. So it wasn't just digital/analog. And lo and behold, the results placed the analog/SS below all analog and above digital/SS. Just like happens with everyone I've ever seen.
Everyone, that is, who is no audiophile. Only the audiophiles, they are the only ones who ever even think to say crazy stuff like I don't believe my own ears or what I heard might be in my head or gosh if only I were double blind instead of merely solo blind.
What a crock. Do you hear it? Or do you not hear it? If you do then why do you need your own experience validated by anyone else? So I can only conclude you cannot hear.
See how it works?