Yes, it's possible in sighted listening for prejudices to creep in. But forced-choice blind listening *always* removes small differences.
>Do you think the blind wine tasting back it the 70's where the French finally admitted that California wines could be as good or better than theirs would have happened if the judges had been aloud to see the labels?>
Of course not - the French judges had a lot to lose. However an audio reviewer who finds the latest megabuck component favorite to sound awful would be considered a hero.
>If you can hear the difference with a bit of time, knowing what the equipment is and is supposed to sound like, then why would listening over a period of time, NOT KNOWING, make them sound any different?>
Ah, the old simplistic ABX argument. 'Not knowing' isn't the issue - listen to A and B without knowing what they are and you'll hear plenty of differences. It's only when you're forced to chose one as X that things fall apart. Blind wine tastings are not forced-choice. They're just AB, like most audio listening.
>If it all sounds the same under blind testing conditions, maybe it does all sound the same.>
Right, and your Japanese reciever sounds just as good as those Krell or VTL separates.
>Wine tastes different so blind tastings only take away any preconceived ideas about a certain wine. Speakers sound different in a blind test because they have audible differences. The blind test just might takes away the same prejudices.>
Fine, as long as you limit the blind testing to ABAB, like you do with wine. You'll hear plenty of differences.
>Or do you feel blind tastings of wine are a waste of time? If not, why?>
No, blind tasting, or any other type of tasting can be informative. Just like almost any type of audio listenting...except blind forced-choice.