The pots (potentiometers) in an electric guitar have quite a significant impact on the overall tone, more specifically, on how bright they pickups sound. In this article I’ll explain the difference between 250K and 500K pots, and why they don’t sound the same.
250K guitar pots sound warmer in comparison to 500K pots which sound brighter. This is because 500K pots do not bleed as much of the high-end frequencies in comparison to 250K pots. 250K pots are typically used with single coil pickups and 500K pots are usually used with humbuckers.
|250K Pots||500K Pots|
|Lower resistance||Higher resistance|
|More high-frequencies lost||Less high-frequencies lost|
|Warmer tone||Brighter tone|
|Typically used with single coil pickups||Usually used with humbuckers and P90s|
How Guitar Potentiometers Work
Before we jump into the nitty gritty of why 250K and 500K pots sound different, we need to be clear about how they actually work.
Guitar pots are variable resistors. A resistor regulates the flow of electrical current, in this case, from the pickups.
There are 5 main parts of a guitar pot to consider:
- The lug that connects the pot to the pickup (lug #1)
- The lug that connects the pot to the guitar output jack (lug #2)
- The lug that is grounded (lug #3)
- The resistor that runs along the outside
- The wiper that allows you to vary the resistance
Here is a diagram of the inside of a guitar potentiometer (pot) to demonstrate.
Electricity flows from lug #1 (the connection to the pickup) to either lug #2 (the output to the guitar jack) lug #3 (the grounded lug).
The wiper allows you to control how much of the electrical signal goes to either the guitar output jack or the grounded lug. If all the signal goes to the output jack, the maximum tone/ volume will be sent to the amp. If all the signal goes to the grounded lug, there will be no volume.
The wiper is able to do this because it has contact points with both the resistor, and the metal track which connects to lug #2 (the output to the guitar jack).
- When turning the pot to maximum, there is no resistance = maximum signal goes to the output to the guitar jack (lug #2)
- When turning the pot to minimum, the resistance is at maximum = no signal goes to the output to the guitar jack and instead just goes to the grounded output, resulting in no signal
Here is a diagram to demonstrate.
Why Do 250K and 500K Pots Sound Different?
Even when the tone or volume pot is set to maximum (#10), a small amount of the signal will still escape to the ground lug. This is known as circuit bleed.
As you’ll already probably have realised, the the resistor in the pot can either have a resistance of 250K or 500K.
The higher the resistance value of the pot, the fewer high-end (treble) frequencies will escape to the ground lug. The result is that more treble frequencies are passed to lug #2 (the guitar output jack) rather than lost to lug #3. Hence, they sound brighter and have more clarity.
250K pots have a lower resistance which allows more circuit bleed to lug #3. The result is that more high-end frequencies are lost and not transmitted to lug #2 and then onto the amplifier.
- 500K Pot = brighter tone, more high-end frequencies
- 250K Pot = warmer tone, less high-end frequencies
250K vs 500K Pots for Single Coil Pickups
Typically, 250K pots are used for single coil pickups. This is because single coil pickups are naturally very bright sounding and produce a lot of high-end frequencies, so using a 250K pot prevents the signal from becoming too bright.
If you use a 500K pot with single coil pickups, more high-end frequencies will pass from the pickups to the amplifier, which can cause the tone to sound overly bright and harsh.
This is why 500K pots are used in guitars like Stratocasters and Telecasters which typically have single coil pickups.
Here is a YouTube video comparing 250K and 500K pots with single coil pickups.
250K vs 500K Pots for Humbucker Pickups
500K pots are usually used with humbucker pickups. This is because humbucker pickups are naturally warm sounding as the two coils cancel out a lot of the high-end frequencies. A 500K pot allows more of the high-end frequencies to go from the pickups to the amp, and prevents the humbucker from sounding too warm.
If you use a 250K pot with humbucker pickups, the tone can sound too warm and mellow and lack clarity. This is because 250K pots transmit less high-end frequencies. This is why 500K pots are used in guitars like the Les Paul which has humbucker pickups.
Here is a YouTube video comparing 250K and 500K pots with humbucker pickups.
250K vs 500K Pots for P90 Pickups
Since, they sound brighter than humbuckers, but not as bright as traditional single coil pickups, choosing whether to use 250K and 500K pots is a little more difficult.
Typically, 500K pots are used with P90 pickups because they sound quite dark already. Using a 500K pot preserves more of the high-end frequencies and prevents the pickups from sounding too dark and warm.
There are however some players who like to use 250K pots with P90 pickups, but this will of course result in a more mellow tone with less bite and clarity.
There is a third option that we’ve not mentioned yet though.
300K pots sound brighter than 250K pots, but not as bright as 500K pots. Although less common than 250K and 500K pots, 300K pots can be a great option for P90 pickups as they are more balanced.