What is the distance between strings and humbucker pickups? Thanks.
(Hagerstown MD USA)
There are not any strict regulations about the distance, really.
I have a book called "Gibson Les Paul Manual - how to buy, maintain and set up the legendary Les Paul guitar", the book recommends keeping 3/32in (2.4mm) distance at the sixth string and 1/16in (1.6mm) at the first for both the neck and the bridge pickup.
The guys from Gibson suggest that having the pickups to high will produce a muddy, overly distorted sound; and having them too low will give a weak, unfocused sound.
On my "Les Paul Epiphone Standard" guitar I've set the humbucker pickups as close as possible to the strings. It gives me more output and a nice tone.
On my "Cort M600T" guitar I've set the humbucker pickups low (far from the strings) especially at the neck.
I noticed that when the pickups are high, yes they give the most output, but the tone becomes pretty plain, when I lowered the pickups I got a more interesting tone with pleasant subtleties.
If you feel like experimenting, grab a screwdriver and adjust the bolts at the top and bottom of your pickup.
It's better to cover the polish of your guitar with some cloth around the area of adjustments, it will help to avoid scratches you might get if the screwdriver will accidental jump out of the groove in the bolt.