Georgelofi, Why would you say, "A properly implemented passive comes closest to this," I don't know how you would ever prove this. The only proof that I can imagine would be for music going into passive and active units compared with that coming out and an assessment of differences.
I might also note that you imply generic differences but you add "properly implemented." How would we ever know this? I have had six passive units now over about a 30 year period. I only once had two at the same time and they sounded in many ways different. In fact I strongly believe that until my present BMC unit, those earlier unit shared only a sense of purity and a lack of dynamics or pace. Which was properly implemented? One was only a silver transformer with multiple taps.
Similarly, I have had many, many active units and have never hear two that sounded alike. Some manufacturers have gone to extremes in pursuit of "proper implimentation." Some sounded better than others, but generically none were as smooth as passive units and all were more dynamic.
I might also note that you imply generic differences but you add "properly implemented." How would we ever know this? I have had six passive units now over about a 30 year period. I only once had two at the same time and they sounded in many ways different. In fact I strongly believe that until my present BMC unit, those earlier unit shared only a sense of purity and a lack of dynamics or pace. Which was properly implemented? One was only a silver transformer with multiple taps.
Similarly, I have had many, many active units and have never hear two that sounded alike. Some manufacturers have gone to extremes in pursuit of "proper implimentation." Some sounded better than others, but generically none were as smooth as passive units and all were more dynamic.