Importance of Amplifier versus Preamp?

My experience suggest source and preamp is where I hear the most significant differences. I submit the preamp is the hardest component to get right...at least that's what I'm going through at the moment.

Using the same manufacturer doesn't guarantee anything. I have a Parasound A21 and recently purchased a Parasound JC2 preamp. I thought that would end my quest, but I hated it. Going direct from my PS Audio Directstream was better to my ears, but something is still missing. My quest for the right preamp continues!

Prior to my recent experience I was an advocate for the preamp having the most impact on the sound. I sold my Parasound A21 and listen to a friends Jeff Rowland 125 amp over the weekend. Despite having half the power, going from the A21 to the 125 was the most significant difference that I've heard. I submit it depends on what you currently have and what your going to determines how much impact the component will have on your system.