>"I do believe in a highly controlled test (such as the one Paul S described), I will not be able to tell the difference between two amps. The problem is, people don't normally listen to music, or watch movies under those "controlled" conditions. For example, classical music, or movies such as LOTR & Star Wars, tend to expose the weakness of a cheap receiver, due to their demand on dynamic range alone. Shiu hit the nail on the head. Such "highly controlled" studies remove the subject being studied from reality. Paul, I am well aware of the $10k challenge, and if you weren't so intent on showing how clever you are, you would see that I agree that neither I nor anyone else (IMHO) could beat that challenge. But Shiu's comments explain exactly why. In REALITY, if you hook up a 10wpc tube amp or car amp and crank it to play Armageddon or seriously transient classical (try the Jean Gillou version of Mussorgsky's Pics at an Exhib. or the Mercury Living Presence recording of Tchaik. 1812), you're going to drive that amp to clip and blow out speaker components. That's just the way it works. But much more powerful solid state amps just aren't going to do that. In real-world scenarios ... actual listening ... there are major differences in how amps perform. THAT'S my point Paul. No one including myself can hear the diff. between amps playing material the tester selects in circumstances they control. The study is set up to prove their point. It does not prove that no one can hear diffs between amps in all circumstances.