Amp preamp impedance matching...can anyone explain?

@mulveling 

You might find this article interesting:

THE 600 OHM AUDIO STANDARD, WHERE DID IT GO?

@dpop 

Right near the start of that article: "600 Ohms in order to achieve maximum power transfer to the receiving equipment". Power transfer is not a requirement in this application. It's an interesting article and I'll read it, but I also think this is all confusing the main topic here, which concerns impedance matching a preamp to power amp for efficient voltage transfer, not power transfer - all meaningful power is supplied by the power amp reacting to the input voltage.

@mulveling 

Yeah, I guess I drove it off the rails a bit, but no one else seemed to be paying any attention to the original part of the discussion, so I figured no big deal.