#1
what are with the screws on the pick ups? what happens or what are the effects of adjusting them?
Guitars
Epiphone Les Paul Custom (Alpine White) (retired)
Gibson Les Paul Swamp Ash studio
Gibson Les Paul Standard Faded (Tobacco Burst)

Bass
Squier Vintage Modified Jazz
#2
dont adjust them, you dont need to know what they do, dont adjust them at all
dont take any guff from these bastards man

Quote by Fenderhippie69
I only smoke when I've been drinking and I only drink when I've been smoking.
#3
It moves the pickups closer to or further away from the strings. Moving them closer gives a hotter output from the pickups, but it also decreases sustain because of increased pull on the strings from the magnets in the pickups. Moving them further away has the opposite effect obviously, that is, weaker output and increased sustain.
#4
On them or at the side of the pickups, if there in the side it adjusts height on the pickup and im not sure what the other one's do.
#5
I think he meant the ones you get opposite the pole pieces on some humbucking pickups. I'd be interested to know too.
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#6
Oh yeah, those! Sorry, my bad...

Those are for adjusting the individual pole pieces up and down, that is you adjust them individually for each string. The same still applies in regards to output and sustain as for when you move the entire pickup.
#7
In the simplest terms I know:

They're for adjusting the output for each individual string as opposed to the pickup as a whole.
ESP LTD EC-256 and a Fender Deluxe VM
#8
thanks for clearing things up! very helpful indeed
Guitars
Epiphone Les Paul Custom (Alpine White) (retired)
Gibson Les Paul Swamp Ash studio
Gibson Les Paul Standard Faded (Tobacco Burst)

Bass
Squier Vintage Modified Jazz