When have A/B comparisons led you astray?

I'm with Bjp, sort of: If you have to squint to see it (or rather, hear it), don't pay for it. Because of the psychological factors people have mentioned, to say nothing of the difficulty of doing A/Bs where everything else is constant, I have near zero confidence in my judgment when the differences are less than pretty dramatic. I also find it useful to do comparisons with a non-audiophile, be they male or female, since they may be less motivated to detect "small but significant" differences that may not really be there.

No doubt, others are more discerning, and they may reliably make small magnitude discriminations -- and be willing to pay for them!

John

"I also find it useful to do comparisons with a non-audiophile, be they male or female..." VERY good advice!

Agree with a few of the above posters:
Snap judgements are frequently wrong.
Time is, in this case, your friend.

Differences may be easy to hear, but better?

Just from a setup standpoint, I make many changes fairly quickly when doing a fresh install. Than I listen. Tweak/Listen for a couple weeks. Let it sit and listen some more. The last few changes? maybe a couple weeks between.

Oddly I find my A/B work is only really let me down when I really wanted one option to be better. Usually it's a factor that appeals to my engineering brain, aesthetic brain, or cheap skate inner self. When I am honest with myself I have been satisfied with my comparo's. I have been pretty good on the audio side but I'm completely useless on the guitar/motorcycle side of the equation. Last couple audio A/B's I did indicated that I could hear a difference but neither were enough to warrant the cost in my opinion. Went home happy with my existing system.

Exactly, Paul......expectations and wishes. Stuff like....
'It costs more, so it MUST be better'