The commonly used theory of feedback has several sneaky pitfalls, which disable the possibility to calculate the response of electronics exactly and enforces the use of approximations and simplifications. As a result, the calculated and realized properties can differ significantly. This can explain why there is so much controversy around this subject, especially in the High-End community and why electronics with similar specifications can sound rather different. The paper also explains why testing with continuous sine waves of fixed amplitude gives ambiguous results, which do not correlate well with perceptual observations.
