What is most important part of a system?

plutos  I agree that it all starts from a source, but if preamp is not able to deliver it without veiling and distorting the signal, the source makes no big difference.

I would disagree with that statement.  Again, I have built various preamps, amps, DAC's etc.  I also have repaired components for over 25 years.  Any preamp that I have repaired goes into my system just to make sure it works as it should.  I hear the differences in them but having what I consider is one of the best sources, you can hear what my source does without question.  Each preamp has a sound but they do allow the source to flow though without an issue.  The sound only gets better with better preamps.  Someone mentioned TVC, yep I use one in my active preamp that has no caps in the signal path.  The amps make a difference but overall the source IMO again from building my own components does not have the degree of sound improvement compared to the source.  The speakers improve the sound but the source still has the most effect on the sound.  Happy Listening!

bigkids,

Of course, experiences will vary because they depend on so many different things. There`s no absolute truth. Different people, different experiences.

I suspect that you`re premap sounds remarkably good. TVC for volume and no caps in the signal path. This can`t be bad :=))
BTW. Did you use single or double transformer per channel?

I guess there are many different opinions on this topic!
I agree with the above well described weakest link theory. But to my logic and ears, speakers will impart the biggest personality influence on sound quality. Yes, lousy room acoustics, poor recording and distorted amplification will ruin sound quality and it goes without saying that these weak links must be removed in order to have even decent sound. With none of the weak links present, a change of speakers will have the biggest impact in sound. Spending extreme sums on cables, cords and other minor influences prior to getting speakers, room and source right is a fool’s folly propagated by ultra high end manufacturers who make serious profits. Speakers and room, if done right, are unfortunately the most expensive part of the equation requiring the most time, money, effort and wife acceptance. Cables and cords, to my obviously tone deaf ears, don’t make much difference relative to the cost. I have heard great speakers with average electronics and have been wowed but have been underwhelmed by great electronics paired with sub par speakers.

Speakers.....60%
room............20%
source/music/ amp.....15%
all else.........5%

Estimated margin of error 5% depending on component combinations and sound preferences.

The above is my ball park assessment of importance relative to achieving sound quality. I too cringe when I see a virtual system with a large fortune spent on components with no attention paid to room, furniture and acoustics. Take a look at one celebrity’s $500k system with marble floors, glass walls and no acoustic treatments (he must have limited upper end hearing if he thinks that echo chamber sounds right). In the end, to each his own. 

Ok if speaker/room/amp interface is a fundamental then I cast a vote for the preamp!  IME I have used lessor sources with a great preamp had very good sound. I have not however had great sources sound to my liking with a lessor preamp.  Long live the stand alone preamp!!