The thing I don't understand about the "receivers sound different" argument is in this context we're referring only to the amplifier component of the receiver. IOW one amp sounds different or better than another.
Yet I thought the job of an amp is to perfectly reproduce the input signal, or as close as possible. In EE classes you learn about the "ideal amplifier", which does this. If one amp sounds different from another, that implies that one or both are not perfectly reproducing the input signal. Wouldn't that be noise or distortion?
I also don't buy the argument that you can't measure it. It's essentially comparing two sampled waveforms. The bandwidth involved is very low (audio range), so it doesn't take particularly exotic data acquisition equipment. 25 years ago there were digital oscilloscopes with 50Mhz sample rates. Today you can buy a PC Card that does that. I wonder if anyone has done such a study?
