My Only Question Is.........

As you can see from the responses- there are no simple answers to your question. I fight with passive/active myself. The bottom line is it depends on the rest of your system- and one little thing like a power cord/interconnect (Tek Line Concorde Super Sonic) , or better PLC (PS Audio/Equi=Tech/Quantum), or proper isolation products (Symposium) or room treatments (Argent RoomLenses) by themselves can take your system over the top. If you are unfamiliar with these products you can read reviews at www.audiotweakers.com

The purpose of a preamp is not to "improve" the sound of the source component. The best a preamp can do is not to degrade the music signal passing through it. Anyway that's how it works with an analog preamp. A fully digital preamp is a whole other story. A digital preamp can definitely be used to "improve" the source's sound. EQ, expansion, time/phase alignment, etc. can all be used to make what goes out sound better than what came in. Assuming well designed software and sufficient DSP power (32 bit or greater), than there is the possibility of no sonic degradation from the insertion of an extra device into the music chain.

I'm in the same boat you are. There are 2 active preamps that I will be auditioning that will, as I have been told, be much better than my Wadia 860 direct into an FPB600c. The 2 preamps are absolute hot rods from very small companies. Solid state: 1)reflectionaudio.com Battery powered and best with either cd or phono playback. Tubed 2)homeontheweb.net/presence/ The presence ultimate can even be made switchless and with dual mono powersupplies and main chasis. I will be auditioning both of them shortly, just after I get my 860 upgraded to an 861 status. Check them out. For a preamp it seems as though they are designed very near the limits...

Theoretically a good preamp can improve the sound over your straight wire scenario in only one situation I can think of. If the Wadia's output impedence is much higher then the input impedence of the amp you might suck the current out of the Wadia's output stages. A low impedence output preamp would then act as a high current buffer for your Wadia thus improving the sound. Probably not likely with most top quality amps these days.

I don't see how the Wadia's output impedance would be higher than the input impedance of ANY power amp. The output impedance of my CD player is 50 ohms RCA, and 100 ohms XLR. What amplifier has an input impedance less than 50 ohms?