Pots.

[LastDon]

Can someone please explain me what's the difference between a 250K pot to
a 500K pot?
What kind of pots American rstat has?
Mexican?
What will happen if I change a 250K
put for eg to a 500K pot or more?
Thanks.

 

[John Phillips]

The number is the resistance of the pot track. The higher the value, the less the pickups are loaded and the brighter the tone.

Generally, single coils sound best with 250K and humbuckers with 500K, but there are some exceptions (eg P90s which usually use 500K).

US and Mexican Strats are both fitted with 250K, but the quality of the pots is different and this affects the tone as well.

There's also a difference between "logarithmic" (Log/A-taper) and "linear" (Lin/B-taper) pots, in terms of the way they change as you turn them down. You generally want Log for both volume and tone pots on a guitar, although some people prefer Lin for volume - especially if they play clean and like to control the volume from the guitar. Log is better for 'cleaning up' a dirty sound from the guitar.

If you're rewiring a Strat, I would go for CTS (brand, the standard on US Fenders and the best commonly available IMO) 250K Log. That's the stock fitting on US Strats anyway. 500K will probably sound a little shrill unless you've fitted extremely hot pickups (or humbuckers).

 

[Bluewail]

I've always wondered about the 250 Vs 500K pot recommendations. I apoligize if these are really dumb questions but my very basic understanding leaves a lot to be desired.

- If either pot is run wide open, isn't the resistance 0 ohms? If so, than the pot value would only come into play as you backed off on the control. Run wide open, would'nt both values sound the same regardless of pickup type?

- If that is true than would'nt either pot sound the same set anywhere in the 0 to 250k range regardless of pickup type?

- If so, than would the difference in tone only be evident at the lower end of the volume taper where you would get be able to get higher than 250K readings on the 500K pot therfore making it brighter, but only at lower volumes.

 

[Jim Collins]

The fact that the lower end of the volume pot is connected to ground is what makes the difference. At full volume, the resistance of the pot is in parallel with the pickup, thus the value of the volume pot makes a difference. As you roll off the volume, the pot moves from parallel to series.

 

[KLB]

Originally posted by Bluewail
- If either pot is run wide open, isn't the resistance 0 ohms? If so, than the pot value would only come into play as you backed off on the control. Run wide open, would'nt both values sound the same regardless of pickup type?

Wide open, the resistance to ground is 250K ohms for a 250K pot.
On zero, there is basically no resistance to ground, hence no sound.

Another option is to modify the tone control so it drops out when on 10. This will give you extra brightness when you need it.