You do, you do, you do
Actually, it'll depend on your system. The old saw about it only being as good as the weakest link. That must be addressed first.
But if everything is nicely balanced according to your funds; nothing sticks out as being overshadowed in quality by other components; then I have found that the apparently "redundant" component of preamp can make a
really big difference. The amp/speaker interface is married at the hip. Once that's locked in because it works for your room, don't mess with it.
Sources these days, at whatever given price point is sensible for you, no longer make the big difference they used to. The range of differences between various $3,000 machines is not very big, at least in my experience. Make that price anything you want, compare what's there and I think you'll find that the differences between those machines become smaller still.
The question then becomes, for a given amount of upgrade money you can invest in your system, where will it make the most difference? That's always hard to predict but if the amp/speaker thing is under control, I'd say the preamp over the source. In this case, not the preamp per se but that mondo power supply. It's a real injection of color and drive and scale... a bit like improving your amplifier in fact.
Or put it differently. If the
active preamp, functionally and for those of us living with one source, is essentially superfluous and just an added complexity (especially if your source has variable outputs), then it gives the designer a good reason to prove that no, his preamplifier isn't just an invisible switch and attenuator but actually
improves the signal passing through it. The question to ask is, does it really improve as in, benign
signal conditioning (more robust current, more drive, better impedance matching), or does it color it to overlay a footprint that makes every CD or LP carry the same recognizable signature? If you don't detect that kind of coloration but things sound fuller, more dynamic, with more intense colors, more swing... then the active preamp has proven that it's still useful and superior over a passive preamp (in that particular application). Suddenly the superfluous component whose only job is to switch sources and manipulate the volume (and the latter nearly exclusively below unity gain) becomes far more vital than suspected and improving it has an unexpectedly large impact on the overall system performance.
