Nuance, I'm sure that this is discussed extensively in one or more forums, but it seems that almost any reported change in equipment results in an improvement in sound quality. This may be something like the "subject-expectation effect" in psychology: the individual who has bought a new whatever expects a benefit and, in the case of the typical audiophile who participates in this kind of forum, hears that improvement and spreads the news. This generates the same kind of expectancy effect in those who read the post. Let's imagine an experiment in which 100 people receive Dac X with the included wall-wart and 100 receive it with a good quality regulated power supply. Now, let's swap power supplies for half of each group, telling everyone that their power supply is being changed for one that has a good chance of improving the sound. Don't tell anyone which group they are in. If people can be completely ojective, 50% of them, not having had any change from the initial power supply, should report "no change", while 25% go to the regulated DAC and should report improvement and the other 25% go from the regulated DAC to the wall-wart and should or may be able to hear the deterioration. If such an experiment could actually be performed, what do you think the result would be?
