Basically just means very low noise.
Um... no. It's called solid state because the charge carriers pass through a solid material (i.e. germanium or silicon for example) rather than through a vacuum.
I always enjoy reading this thread. I am a scientist (Physicist) who prefers to scientifically test and then study numbers and graphs before drawing conclusions on pretty much anything. From a scientific method I agree with most of what I read here, however, I also understand that the placebo and nocebo effects have been observed in nature within studies and therefore can not be ignored.
With this in mind, if people believe things sound better/worse then they will convince themselves of this. No amount of research and evidence will ever convince the human brain that it did not hear a change if it believed that it did. If we look at medical trials and the fact we can trick the brain into thinking that it received medication when it was just a simple sugar pill we will never understand what is happening when listening to something as subjective as music.