To create high-end equipment or systems you need the skill to design with your ears as part of the measurement arsenal. This is because there are multiple design paths yet not all of them give you high-end results.
There are multiple ways to lower distortion in a circuit - which of those sounds best?
There are multiple ways of designing a crossover in a speaker - which of those sounds best?
Think of this like choosing a route to get somewhere. You arrive at the same destination but by which path and what happens along the way?
Two preamplifiers that measure the same don't sound the same. This is where high-end comes into play.
It's a big subject and tomorrow I will explore a few examples.