Not an easy question to answer.
Just my opinion, but I think it may depend on the design, but I think the design among other factors, is also driven by personal preference for sound(that is why there is a house sound). I have not heard high-end amplifiers that would sound the same. Each of the amps would have some sort of a sonic print. You just have to do research and listening to determine what amplifier you like the most.
Also, I think all of the components are equally important in order to arrive with a sound that is balanced, extended and natural. And the amplifier would have a huge sonic impact on the final sound.
Also, aside from the basic sonic signature of the amp, there should be no compatibility issues in the source->preamp->amp chain. If there is an impedance mismatch, you may be abole to make a smooth sounding amp sound harsh and bright sounding amp sound muffled at high frequencies.
And of course, the last piece of the puzzle is how capable are the speakers.
The most important is to select the speakers that would do justice to the type of music you listen to.
Every piece in a system adds coloration. Are there neutral components?
I would be interested to know how one defines neutrality when it comes to music reproduction.
There are too many variables, starting with a source material that begins in the recording studio, all the way up to your room acoustics and your ears. So to me, neutrality is a vague term, especially when the components are interconnected with cables.
My reference is live music. I do believe a satisfactory results can be achieved with a properly selected components that make a "system", but I really don't think it is possible to exactly replicate a live event through a stereo system, no matter how good this system is.
Trying to replicate in your house with your system, how a Mahler's 5th symphony sounds live in Carnegie Hall, my best wishes to you.
:)
Anyway, this is a very interesting thread and should be fun to follow.