QUOTE(beastwars @ Nov 12 2008, 07:08 PM)
errr...magnetic pole?
im abit lost here
sorry...
here's some history lesson for ya because i'm bored.
in the early days, pickup was designed with magnetic pole pieces (those round dots). in the late 70's or early 80's, some manufacturer (i have no idea which one, possibly EMG) decided to use a magnetic bar or "rail" instead. the logic is, with pole pieces, some sustain could be loss during a bend when the string moved from the centre of its pole piece. the magnetic rails remedy this by providing an overall magnetic field all over the pickup, instead of just under the strings. however, magnetic rails does not has a strong field like magnetic poles piece (since the field is distributed). this is why you will mostly see magnetic rails being used on active pickups and magnetic pole pieces are used on passive pickups.
i hope i got my history correct

.
also don't mistake covered pickup with actual magnetic rail pickup. and pickup with magnetic rails does not necessarily means it's active. again, this is design-based.
btw, emg81,emg85 and emg60 are still considered as humbuckers.
This post has been edited by zeroglyph: Nov 13 2008, 12:36 AM