So, lets talk pot

[Kev]

Guys, had a quick search on the forum but cant find the answer to this one...

Could anybody explain the difference between pot k. Ive got 250k in my strat and am thinking of putting 500k in with the alnico pro 2 bucker.

It seems the general idea is that 500k = brighter but i just wanna know why?
I thought k was resistance, so a higher k would let less through :S Could it be worth testing a 1Meg-ohm pot!?

But anyway, my logic is flawed- so need to know whats really going on haha!

On a final note, there is nothing else i'd need to change when changing pots on a strat is there- so just yoinking the pots out and putting 500k ones in is all good!?

Kev

 

[Erlend_G]

Re: So, lets talk pot

I'm not completely sure on this either, but here is my theory:

With the pot open (all the way up), there will be a little leakage from the centre lug (hot signal) to ground, which would increase with lesser resistance in the pot, also, "lower k".

I'm not completely sure on this, though.

 

[kylewrt1986]

Re: So, lets talk pot

apparently : higher value pots put less of a load on the pickups which prevents treble frequencies from "bleeding" to ground through the pot and being lost. For this reason

 

[RevJToad]

Re: So, lets talk pot

My understanding, from doing various mods in my strat, is that the tone circuitry in passive pickup guitars basically bleeds off signal to ground through a capacitor, with the pot determining how much.

So, when your tone is set to its brightest, that means that the full value of the pot (ie. 250k in a stock strat) is sitting in between the pup and the cap, limiting the amount of drainage to ground. If you set it low, the pot is shorted, so there is a direct connection to the capacitor-ground, making for no highs.

Thusly, if you change your pot to a 500k, that means that when it's turned all the way "up", there will be twice as much resistance between the pup and the cap-ground, meaning that it keeps more highs in the circuit than with a 250k, which is why 500k pots are brighter.

The value of the cap also affects brightness, but I can't remember whether higher value means more or less treble...

 

[Kommerzbassist]

Re: So, lets talk pot

Actually this is because resistors, and pots are just variable resitors, are not 100% the same resistance for all frequencies and the value of the resistor also changes the pattern of the frequencies that can pass through it.

 

[Empty Pockets]

Re: So, lets talk pot

You definitely want the hi-grade **** no the lo-grade ****; a good way to tell is if it has seeds or not. No seeds and it's probably chronic or something similar...you just gotta ask yourself, what would snoop dogg roll?

-X

 

[Artie]

Re: So, lets talk pot

Resistors control the flow of current. (Amperage.) A pickup generates voltage. Voltage is "pressure". That pressure pushes a degree of current based on what the "load" is, (resistance).

So, since the load of a volume pot is to ground, a higher resistance is less of a load on the pickup. This does two things. It lowers the current flowing through the pup's coils, up to a point. Thats a generalization. The whole voltage-to-winding's thing is a bit of a bell curve.

As you increase the load, (lower the resistance), the pup tries to push more current. But it can only generate so much. Thats why power supplies have fuses. As the current goes up, the highs (treble) tend to attenuate. If you keep increasing the load, like using a 25k pot for instance, you'ld start to attenuate all frequencies.

A tone pot is just another volume control that has a filter (capacitor) the limits what frequencies it controls the volume of. Treble, in this case. You could substitute an inductor for the cap and control bass frequencies instead, but with high volume losses.

Hope thats clear. Its early for me too.

Artie

 

[Dirt123]

Re: So, lets talk pot

You definitely want the hi-grade **** no the lo-grade ****; a good way to tell is if it has seeds or not. No seeds and it's probably chronic or something similar...you just gotta ask yourself, what would snoop dogg roll?

-X

Hmmmmmm..... Huh?

Oh, Riiiiiiight.


(I suppose somebody had to say it)