Paul is correct. Those who dismiss them as wimpy and lacking dynamics and bass simply don't know what they are talking about. That may have been their experience with them but that isn't the fault of the passive, it is the fault of the people trying them with other components they weren't well suited for and not knowing enough about the principles involved to solve the problem. Hook up a high impedance source to a low impedance passive into a low impedance amp and you get wimpy. Do it right and you get world class sound.
Here is the ugly truth about about preamps...the volume control inside all of them, active or passive, is a passive device. It is either an inductive voltage divider like a TVC or a resistive voltage divider like a potentiometer or stepped attenuator, but they are all passive. An active preamp adds a buffer stage so it mates well with a wider variety of equipment than the voltage divider by itself. If you choose wisely as Paul states, paying close attention to the source that's driving it and the amp after it then you don't need that buffer and you get glorious results with world class dynamics and bass. In fact, it is better than an active because you've taken out an unneeded gain stage.
Active preamps are for those who can't figure out what it takes to integrate a passive into their system, their source can't drive the amp loud enough so they need more gain, or they simply are trying to use a passive with components they will never work well with. Yes, you limit your choices for other components but there are plenty out there that mate beautifully with a passive.
Like I said earlier nothing has been said here that hasn't been said before.
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