This is from an old Naim dealer manual
System Precedence:
The choice of components for a hi-fi system should be governed by the basic rule that no component can improve the quality of its incoming signal. The very best that any individual component can do is deal faithfully with its input without loss of musical information.
A simple and logical hierarchy is thus established. Source components of a system, such as the tuner, compact disc player, tape and record player come first as they define the absolute signal quality retrieved from the storage or carrier medium.
The preamplifier and power amplifier come next, in that order. If the preamp is inadequate it will make nonsense of the demands of a good source, but neither amp nor preamp can improve the quality of their incoming signal. In fact the better they are, the more clearly they will expose, instead of masking, any faults in that signal.
Thus loudspeakers are last in the hierarchy. As the slave of the amplifier, even moderate speakers properly driven by a very good amplifier will outperform speakers that are potentially the best possible, but are less well driven. A loudspeaker cannot improve the quality of its incoming signal.
The aim of a good system is to allow you to respond to music without the system getting in the way, and a well balanced system made up of very moderate components that mask each other’s faults may allow you to do this better than a badly balanced system containing the best amplifier or the best loudspeakers that can be obtained.
The better the system the more the intentions of the composer will be revealed in the skill and feeling of the players and the precise quality of the instruments. The less good the system the more this will be obscured by minute alterations of pitch and amplitude.
Music is a language, and in order to understand what the musicians and composer were trying to communicate to the listener, it is not only important to hear all the notes played by the musicians, but also to be able to hear whether they were enjoying themselves; intonation, which is so much a part of the spoken word, is also vital to the understanding of a piece of music.