this took me ages and ages to finally “know”.. but i’ll save you a lot of time and frustration chasing sound..
back in the 80′s when i was after high gain guitar sound, the conventional wisdom was carrying over from the late 70′s that hotter wound pickups were the be all, end all to get that crunch we all were hungry for that we heard on all the good records..
naturally i did a lot of reading and the magazines and players all said to raise your pickups til the magnets start to affect the sustain of the string, that was the “magic spot” to stuff your pickup. basically jam it right up against the strings, almost, and thats how you got the magic distortion sound! well i have the extremely string worn bobbins to prove it.. i tried it.. yeah louder, muddier, woofier.. hm.. well 1/3 aint bad!
fast forward to me getting a set of lower gain pickups in a les paul that was “properly” set up a long while back.. i plugged the guitar in the amp, and struck a chord. MAGIC! wow.. overtones! chime! CRUNCH! high gain was no big deal, the pickups didnt feed back! i could hit the strings HARD with the pick and dig all kinds of cool sounds out of the guitar. strummed chords rang out true, for a long time, and with easily discernable notes. no clashing! NO MUD.
after scratching my head, and whipping out a meter, and ruler, i started trying to find out what was what? the pickups were “vintage” gain, around 7.5k.. and they were MILES away from my precious strings! yet the guitar sounded killer through an amp. no weakness!
sometime during the 80′s amp guys started stuffing the gain further down the signal chain: THE AMP.. hey! less noise! less feedback! less garbage and stuff that didnt belong, soundwise! keep going through the 90′s and insane gain levels in tube guitar amps now made it possible for a wimpy little singlecoil equipped guitar to tear your head off with thick metal sounding crunch!
a lot of guys are running older 70′s designed pickups that are very high gain (over 13K+ DC resistance) with the tribal knowledge that high/hot wind pickups make for great crunchy heavy tone. NO! unfortunately what some of you guys dont know is that the companies that make those pickups are STILL USING THE SAME MARKETING LANGUAGE that they were when they first made thes pickups way back in the stone age of aftermarket pickups!!! yeah, your dad or grandpas quest for black sabbath sound? they probably read the same ad sentences you are.
for the BEST clarity and crunch and definition under high gain/high volume amp setups, i typically reccomend running something more in the 8 to 7K range for humbuckers (FWIW dimarzio PAF classics are cheap to buy and definitely get the sound, thats what i run in my SG at the shop for testing).. higher gain pickups muddy things up, and lack clarity in exchange for gain..
if you cant swap pickups, lower the ones you have as far as they can go without losing too much bass response. i find that typically level with, or even below the stock pickup rings is where the sweet spot is on most humbucker guitars. go past where you think is “too low”.. keep going a little bit. now plug in and listen.
look at the level of the bobbin top and the pickup ring!
just hit the low and high strings with the guitar on your lap and lower the pickup till it starts to sound weak plugged into your amp. then raise it back up 1/2 turn. compare the treble and bass strings to make sure the bass strings arent too much louder than the treble.. thats the magic spot. let the amp do the rest of the work. trust me. the clarity improvement is HUGE.. it took me 15 years to figure that one out. i used to jam my pickups right aginst my strings thinking more sound = better.. not true for high gain stuff..
if you are on the fence. just count the number of turns for each screw you lower, write it down! you can always raise them back up where you started with no harm done..