MIMF

What value of pots do you guys use for bass guitars?
250k? 500k? other??

It is not dependent on the type of instrument, but the type of pickups. It can come down to some personal preference but for the most part, single coils get 250K pots, and humbuckers get 500K pots.

That's been the rule of thumb for a while but as they say, so much depends on your signal chain and personal preference. I tend to err to the bright side and put 500Ks in everything as it's much easier to remove the brightness than it is to add it in later. Where you'll really notice it is with blend pots. I always use a 500K there and would go with a 1M if they existed.

So, it is basically the same as an electric guitar.
Singles get 250, Humbuckers get 500.

Thanks.

I'm no electronics guy, but the way I look at it is by the DCR (direct current resistance) of the pickup - generally singles lower, HB's higher. Above 7k use 500k, below use 250k for volume pots, but not hard and fast. Since the total pot resistance always shunts part of the signal to ground, it acts as a voltage divider causing some signal loss even when turned all the way up. A 5k PU with a 250k pot will lose about 2%, where a 15k PU with a 250k pot will lose about 5.6%, and with a 500k pot 3%. The losses are small, so it probably doesn't matter much. I don't know why 500k volume pots would sound "brighter" - there must be some LCR stuff going on. The purest PU signal is when the PU is wired directly to the output jack, with no tone or volume controls.

With tone controls, capacitance being equal, there is less high frequency signal loss at the beginning of its rotation with a 500k pot, so this may be what the brightness is due to. But when it hits the 250k point they are the same.

As David says, so much depends on the rest of the signal chain - pickup, cap, preamp/amp, - so the value of the pots probably has the least important effect on the tone. Just my .02.

The value of a volume pot effects frequency response because the impedance of the pickup varies with frequency. DC resistance is an oversimplified and relatively meaningless measurement of a guitar pickup.

"Resistance tells you as much about a pickup's tone and output as the shoe size tells you about a person's intelligence!" -Bill Lawrence

Thanks, Paul. That led me to this interesting article:

http://www.buildyourguitar.com/resources/lemme/