Active Pickups?

thegummy

This might seem like a silly question to some people...

Do active pickups work in the way that a condenser microphone works, in that the the signal is actually picked up from changes to an active electronic field?

Or are they actually just very low output passive pickups with a preamp built in to the guitar?

I hope the question makes sense...

Clarky

low output pups with a preamp..

I have a couple of students that have them on some of their guitars...
my personal option is that [aside from metal riffing] they really suck..
for the following reasons that are entirely my personal opinion..
- they seem very unresponsive, sterile and a bit compressed
- the tone is quite uniform / one dimensional no matter where along the string or how strongly you pick the string
- for clean tones I'm really not a fan at all
- for soloing they can be quite shrill and thin
- when the battery fades, their nasty tone gets worse

personally I prefer moderate hot passive pups for the ways they oppose the reasons above..
especially the tonal non-uniformity and responsiveness, because it's something I like to exploit..
it's a bit like having a tone control driven by your picking hand's technique

however....
if you're a hard core metal riffer and do pretty much nothing else and you want that tonal uniformity, they're perfect

horses fa courses etc...

thegummy

Ah thanks.

I had always kind of half-assumed they'd actually be active in the way a condenser mic is rather than just having a preamp.

Surprised they would be compressed - with passive pickups it tends to be the hotter the pickup the more compressed they are so would think that very low output pickups would be less so

sweepy

EMG’s do work better at 18v I have found but are very much an acquired taste in tone compared to regular passive pickups, whether some of that is down to the drastically reduced string pull etc but that’s a whole different can of worms

Sporky

I had a set of EMGs in a Parker Nite fly M, and liked them. They sound like pickups to me. Not weird ones, so some might hear them as generic or characterless (they are not lipsticks or Filtertrons, obviously), but they worked a treat in the Parker.

A lot of the other options I tried in that guitar were rather "plinky" - possibly due to the carbon/glass wrapped neck and steel frets. 

guitarfishbay

The compression depends on the headroom, which is determined by a bunch of factors:

1. The internal ceiling of the pickup, ie how loud a signal can the preamp take cleanly before clipping. This varies pickup to pickup and is most often a problem with humbuckers.
2. The proximity of the pickup to the string, closer delivering a louder signal that may get closer to the clipping point
3. The battery - as noted you can run some active pickups at higher voltages and this will increase headroom (and through this change dynamic response and potentially tone). If the battery is running low headroom will be reduced.
4. Guitar setup and playing style - thick strings and heavier playing both create a louder signal which in turn could be closer or go beyond the clipping point.

Personally I love active pickups in guitars. But one of the main reasons is they have very clear sounding treble (which I think is why some people hear them as sterile).

I find the typical rich harmonics you get from most passives often translates to hazy fizz on the plain strings under higher distortion, and I always struggle to get a sound with tight low strings and clear yet not shrill plain strings that have more body than they have fizz if you’re picking notes in a chord. I tune low which compounds this issue by making it harder to get the bottom end tight.

I find my guitars sound better balanced across all the strings with actives. The only passive humbuckers I tend to like are A2 PAFs which again don’t have so much of that higher treble fizz (as compared to a hotter ceramic typically).

Danny1969

Most active pickups, like EMG's are basic low winding pickups directly connected to an internal opamp inside the pickup, normally in a differential config. The opamp is generally a very low current device like an LM4250

A condensor mic works by using acoustic pressure to move the 2 plates of a capacitor, which changes the value of capacitance which is then converted to a change in voltage so No, active pickups don't work in the same way

Alegree

They're not really that low output. They're wound to PAF output.
It's the filtering done in the active portion of the pickup that is more so responsible for compression than internal clipping.

That being said, I don't think they're nearly as compressed as people make out - I think them playing actives after being a passive user and them reacting differently to dynamics gives the perception of more compression than is really there.