Passive Pre - No Regrets?

The better sound of the active unit comes as no surprise. The real question is whether the active unit is competitive with less expensive active units.

Tbg, the nice thing about the Placette marketing model, is you can try it in your home for 30-days and determine how it compares with what you have. So they make it easy to answer the question for your self, directly, in your system, for your taste. I won't say something silly like it smoked the ARC,Lamm, or CAT, but I prefer its sound to theirs (they are all excellent units). Personal taste rules, but the Placette should be on the audtion list, not just with comparably priced units, but with anything out there, IMHO.

Has anyone tried the Musical Fidelity Tube Buffer to address the impedence matching problems? Does this make any sense?

Kensetsu, I think that does make sense. Do you have specs on the unit? Output impedance?

Sure I've pasted it below:

Input impedance 470K Ohms
Output impedance < 33 Ohms
Total harmonic distortion < 0.004% 10Hz to 20kHz
Frequency response 20Hz to 65kHz +0, - 0.5dB
Crosstalk Better than 80dB, 20Hz to 20kHz
Signal / noise ratio
(reference full output) Better than 93dB unweighted
Better than 106dB 'A'-weighted
Valve (tube) type 6112 twin triode (two)
Power requirement 12 - 0 - 12 Volts AC 500mA
(via mains adaptor supplied)

Or you could check out this link: http://www.musicalfidelity.com/products/smlx/x10v3.html#