Are there any studies that follow up on double-blind preference tests to see if the preference holds after the listener is unblinded? That is, if someone picked out a product based on a double blind test. They then have to get it home and listen to it knowing what it is and carrying the weight of our biases. Can we get ourselves to obliterate our biases with listening tests? Have you found that to be the case in your own listening tests?You think you do. You don't know. There is so much folklore around tubes that vast majority of people are biased by that. I have done countless listening tests of tubes. They are either transparent or distortion factories. Neither matches what you and others claim. Until you perform a controlled, blind test, you don't know what you really prefer.