Do preamps have a material affect on high level sources?

There are two ways to look at the question being asked, what you measure and what you hear. Different preamps DEFINITELY sound different in the same system. Whether they add coloration, distortion, or whatever else, is a matter of taste and what you like your music to ultimately sound like. The idea of daisy chaining several preamps is simply silly unless you want to show off your equipment rack.
By the way, the topic has previously been discussed ad nauseam and a quick search can/will prevent a long and pointless debate. 

"...thought up by active preamp makers to aid in their product sales."

Funny to hear this from someone who floods these threads constantly pushing his own passive preamps. Just stick with technical inputs and leave out the editorials.

george, fair point. I should have said "pushing passive preamps" instead of "pushing his own passive preamps". But in your case that makes no difference. Either way, your remark to Ralph was completely unnecessary.