How important is the amp?

Everything is important in the audio chain; it is true that the speakers are the last element in the chain (plus the room) and they can have a profound effect on good/not so good/terrible results for audio playback but consider those systems you've heard with otherwise good speakers pushed by bad or at least not ideal component choices including amp and pre-amp, digital front-end, cabling, power, etc....and the whole adds up to less than the sum of its parts so to speak. Conversely, remembering several systems with older or less expensive speakers backed by extremely intelligent choices of amp, front-end, cabling, power, etc...exuding much more performance out of a speaker than its price point would indicate and you see the other side of the coin.

There are also many examples at shows, etc...of so-called 'high-end systems' and speakers that simply don't sound good at all...

This 'religious debate' has no winner IMHO and often tons of personal agendas stacked upon it.....the entire system is important, the sound we are looking for, how we build it, how we choose compoents, synergy of each with the other, including speakers and room AND the musical material and quality thereof that we play...it all factors in.

My 2cents....

He insisted that it was the preamp & that I would surprised it was the preamp hence his design effort to minimize the distortion from it.

Well if we are going to talk about distortion and coloration, preamps make very little of it, often a 1/10th or 1/100th of that of the amp, which in turn often pales compared to that of the speaker.

Here is a wonderful set of comments condensed into an pdf by one of the world's leading designers- its well worth the read:

http://jockohomo.net/data/johncurl-v.0.1.pdf

^Interesting link. Thanks.

The room used and its acoustic properties is perhaps the single biggest part of a home system and the one you have least control over to change as needed. So after that, you have to have speakers that can perform well as needed in the room. Then you need an amp up to the task of driving the speakers to their potential. Now you have a solid foundation for good sound you can tweak as needed. After that, you are in a position to focus on teh quality of the source devices used, but these days, with modern digital in particular, getting good results there is less problematic and much harder to go wrong altogether. Of course, teh quality of source material played can vary widely as well, even if all the rest is done to perfection. You have little control over recordings as well other than to try various releases and remasters if needed.

Simple: If your amp mates well with your speakers, than you can possibly change it when you change speakers to find better match.