Marakanetz,your concern about passive to active circuit is excactly what I asked the 6Moons reviewer about. Here is his response:
"A few people are confused about the concept of no gain but active circuitry behind it. It's very different from the Music First concept. The W4S doesn't care at what volume setting you use it. It does its magic anywhere. The Esoteric C-03 is the same. These pieces perform impedance stabilization and run off high supply voltage rails to guarantee current, color and drive so they're most defnitely not passive even though they have no gain. The Nelson Pass First Watt F4 has no gain either and is a power amp that drives speakers with an iron first. So you need to first understand the concept to stop assuming that there is any similarity to your preamp in terms of being passive -.)"
I know our understanding is shaped by the description in the adds, so you might find his closer a little sharp in tone, while his understanding is likely correct. I myself would want to see second opinions with other equipment and or tastes.
"A few people are confused about the concept of no gain but active circuitry behind it. It's very different from the Music First concept. The W4S doesn't care at what volume setting you use it. It does its magic anywhere. The Esoteric C-03 is the same. These pieces perform impedance stabilization and run off high supply voltage rails to guarantee current, color and drive so they're most defnitely not passive even though they have no gain. The Nelson Pass First Watt F4 has no gain either and is a power amp that drives speakers with an iron first. So you need to first understand the concept to stop assuming that there is any similarity to your preamp in terms of being passive -.)"
I know our understanding is shaped by the description in the adds, so you might find his closer a little sharp in tone, while his understanding is likely correct. I myself would want to see second opinions with other equipment and or tastes.