First off, the main difference in outputted signal between passive and active instruments is typically the load it likes to see. Passive (unbuffered) instruments typically need to see an input load somewhere north of 500k ohms to avoid "loading" of the pickups, which generally results in some sort of "sucking" of tone. This is why active DIs were invented, and why people complain of "tone-suck" over long cable runs and through long chains of pedals with passive instruments.
Active instruments are buffered by their preamps, which mostly avoids the problems listed above with passives.
The difference you speak of is output voltage, which generally is higher in active instruments, but not always. When you bring preamp design, pup config, series/parallel, and other variables into play, the difference can be non-existant.
And of course, cutting your volume knob will bring down the voltage. If you're worried about overloading your preamp, use whatever pad functionality is built into your amp and listen for clipping.
Edit because i'm not an electronics expert and some of this explanation may be misguided. Either way, don't worry about it too much. Just set your gain and go.
Originally Posted by plangentmusic
That's life. No guarantees -- especially with musicians.
Last edited by funkybassinator : 09-03-2013 at 05:07 PM.