FACT!!! most sources today that have variable volume output have output stages that equal and sometimes better most preamps, especially tube ones.George, what analog source doesn't absolutely need a preamplifier gain stage?
I have been in this game for a long time, as a listener, distributor and dealer. Not all passive/active "preamp" devices are equal but I have never heard a passive unit that sounded anywhere near as good as a decent active preamp, at all price points over $1K. The key is matching the preamp to your upstream and downstream components. For me, preamps are the heart of my systems. AMps come and go but great preamps stay (almost) forever.