Hello, I've already started a thread before for help on purchasing a new guitar, and I was wondering about active and passive pickups, how will they work on my behringer 250fx? I saw a website referring it should need a pre-amp to boost the signal. Is it true? Because I've seen some good guitars but most of them have active pickups, and I don't want to be unaware of this feature.

Thank you!
- John
Regardless both style of pickup will work completely fine with that amp there is absolutely no reason to think otherwise. Passive pickups are the standard in most guitar and haven't really changed in design since Seth Lover invented the Humbucker. Active pickups use an internal preamp in the guitar to increase gain levels even further. You wont need to boost anything, in fact it usually works the opposite way, sometimes you have to attenuate the signal when using active pickups depending on what you are plugging into. This is because active pickups have more gain they can cause solid state amps of multi-fx boards to clip a lot faster (not good) so they put in what is called a PAD switch that attenuates the signal a bit so it isn't overloading your digital input.
2011 Gibson Honeyburst LP Trad. w/ SD Whole Lotta Humbuckers
2014 Gibson Ocean Water Standard Plus
Marshall Haze 15W Head/Cab
Hughes & Kettner Tubemeister 5
My friend said a friend of his thought active pickups sucked because sometimes they let a string vibration out, i mean, after you stop the strings, one might keep on playing or some sort. I've heard alot of downsides and upsides, but will it affect much? If not, i'll just get active pickups, most of the sound comes from the amp, right? I actually just need a guitar that can handle it, because mine right now feedbacks a lot. I have an active pickup bass, is that comparable to a guitar with active pickups? If so, I don't find any actual difference. My bass is perfectly fine, and I enjoy its sound quite alot
Active pickups don't accidentally send extra signal, that's total crap. Your friend is wrong.

As for the rest of your post: though most of the sound comes from the amp, the pickups still have a big effect on tone, so having active pickups doesn't really mean you're getting more tone from the amp. Think about it this way - the amp can only amplify the input, so it's not a matter of having a neutral input (because that would mean nothing; the amp can't 'make' the guitar have a better tone), but about having an input that works well with the amp.

To that end, active pickups are usually much higher output and tend not to play well with solid state amps. So in your situation passive pickups might be the better option.

To make things even more confusing, though, it may not be the pickups causing your guitar to feed back. What guitar is it? Have you tried it with a different amp?
My guitar is an SG from Acepro, got it from one of those $200 kits for begginners many years ago. I've tried it with about 5 amps, they all do that, but i think it's normal, that guitar isn't made for bigger amps. Thank you all for the information then, I'll try to find some with passive pickups then (though it's hard as hell from the models i want, and I don't know if i can afford a guitar and pickups separately)