250K vs. 500K
Generally, 500K-ohm pots are used with humbuckers and 250Ks are used with single-coil pickups. 25K pots are used for active systems.
You can use any value you like, but a 250K will give a slightly warmer tone than a 500K pot. The 250K pot bleeds off (attenuates) some of the high frequencies to ground. A 1Meg-ohm pot will attenuate even less than a 500K pot, so if you want to hear your guitar "wide open" you may want to try one.
We also have push-pull control pots, blend-pots, and dual concentric pots for special wiring applications. Refer to Understanding Guitar Wiring for more information on these electrical components and how they work.
All of our pots include two mounting nuts, two flat washers, and a lock washer for proper installation. Extra Mounting Nuts and Lock Washers are also available.
from
www.stew-mac.com
all pots bleed a certain amount of signal to the ground on your guitar, generally 250 k bleed a little more than 500k . 1 meg pots bleed almost nothing and have the wide range of the humbucker, usually the bleeding happens with the treble . Basically 250 k aren't very good except for single coils and even then in some instances aren't great.