250k or 500k pots?
The two most common pot values used in guitar circuits are 250k and 500k. 250k pots are commonly used in single coil pickup guitars ie. in a Strat or Tele, whilst 500k pots are generally used with humbucker pickups.
What is the difference and how does it affect my tone?
The value simply refers to the resistance of the pot. Pots are essentially variable resistors. Higher value pots will give the guitar a brighter tone and the lower the pot value, the warmer the tone will sound. The higher the value of the pot, the less the load on the pickup which prevents the treble frequencies from bleeding out. Put simply, the higher the pot value, the more treble you will hear. This is why a Les Paul will generally use 500k pots as they are better at retaining the high end frequencies for a slightly brighter tone, whilst Stratocasters tend to use 250k pots to add warmth and depth to the tone by reducing the high frequencies. This is to counteract the naturally high sounding single coil pickups. Humbucker pickups are well known for their deeper, mellower tones with less treble than single coils so 500k pots are used to offer a little more brightness and reduce the treble loss. Obviously, this isn’t set in stone. You can use either value for any type of guitar and fiddle around with the different impacts on tone. If you have a really bright sounding pickup in the neck position on a Les Paul/SG etc…try replacing the tone pot with a 250k to reduce some of the treble.
Changing the pots from 250k to 500k will make your guitar sound brighter. Its not a major difference, yet it is noticeable.
There are other pot values to consider - notably 300k pots. 300k pots are often found in Gibson Les Pauls.
Guitar Wiring FAQ