Passive preamp vs. powered


I have a custom made passive pre-amp that I purchased from A-gon some months back for about $150. It only has a volume control and 2 inputs - perfect for my needs.

It sounds excellent...

My question is... what would be the advantage of a much more expensive powered pre-amp? Sure, maybe I would have powered switches and more inputs, but I don't need any. Are there some differences in sound quality that I'm not hearing?
djembeplay
All passive models I have listened to have been a disappointment ultimately. The Adcom is clean, but the stage is so much smaller, and flat, the Creek is almost as clean, but also small sounding, but both very clean and uncolored, and others have been of a similar genre. I would rather have a bit of color from an active line amp and get the size, drive and control in the bass. My choice is a good tube line amp/preamp with 12AX7 or 6922 /7308 drivers. Try all you can....jallen
The manual for my AR PH3-SE states that it will not perform its best with a passive preamp.
Wow, lots of responses - thanks for the input everyone.

Am I off in my hypothesis that the input impedence on an amplifier would make all the difference in the world? I mean, as this varies, it will react differently to a given output level of the pre-amp... One might boost the signal before it hits the output stage to a fixed level... whereas another might not alter the level at all, making the effective output MUCH more dependent on the signal level it receives.

I digress... maybe I'm not making sense here.
Rleff, It is the interaction between the cable, the source resistance (which is a combination of the passive control and the actual source, including the cable from the source to the passive) and the input impedance of the amp that creates the bass/dynamic filter that many passives are guilty of being. The only way around it is to use really low impedances, something that most sources cannot handle.

So in effect passive controls are a form of tone control. The fact that they can sound better then some actives is simply the measure of how bad those actives really are. The only way I have found to make a passive work is to eliminate the cable between the control and the amp, IOW put the control **in** the amp. This eliminates convenience but then the control works.
implied in mmany of the comments so far is that a is better than b. so many times this position has been taken --opinion assumed, but there has been no statements(s) as to what constitutes "better". having both active and passive preamps, i would refute the statement that actives are "better" than passives, since better is what i think is better. any comments ?

by the way generalizations are usually wrong in all aspects of life..