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Can someone please explain when and why you would use a 250K pot versus a 500K pot. I'm not sure what that's all about. Thank you.

General rule of thumb ....

250K for single coils amp; 500K for humbuckers

Really there is no hard and fast rule though, use what makes you guitar sound the way you want it too. Generally speaking 500K will brighten your tone relative to 250K.

500k pots allow more highs to come through.
250k pots don't allow as many highs.

Humbuckers (in series, of course) naturually have a darker sound with less treble, so we use 500k pots to let more treble come through.
Single coils tend to have lots of treble, so we use 250k pots to tame them down.

There are always exceptions to the rules though!!!! These are speaking in general.

Higher value pots will retain more highs than lower value ones. Single coils are brighter than humbuckers, so that's why generally people use 250k with SCs and 500k with HBs, to balance things out a bit, if you get it.

And which ones are usually used in a H-S-H designed guitars?
Which ones in a quot;classicquot; Les Paul?

An H-S-H axe probably has 500K in it. Open up the cavity and look. Sometimes the value is listed on the pot.

A lot of Les Pauls use 300K Gibson pots. Exactly what model are you looking at?

I just wanna trace which pots I used to have on my Jackson PS-4 that I had ages ago... It was an average guitar with very poor pups, but they sounded very meaty in higher octaves! It was a HSH system. I assume it had 250 pots... not for sure though...


Originally Posted by jackieTHEjokemanCan someone please explain when and why you would use a 250K pot versus a 500K pot. I'm not sure what that's all about. Thank you.

Are you talking about volume control or tone control? These are two different types of circuits.


Originally Posted by AmateurAre you talking about volume control or tone control? These are two different types of circuits.

Actually about both! How do they affect the sound (for 2 humbucker system)?

1) 250K vol 250K tone
2) 250K vol 500K tone
3) 500K vol 250K tone
4) 500K vol 500K tone

Thanx!

For volume control, you usually need a 500k pot for a humbuvker and a 250k pot for a single coil pick. The reason you need a higher impedence for the humbucker is because it has more output and thus needs a higher attenuating impedence to regulate the volume. A 250k pot may not have enough impedence to cover the total range of a humbucker's output.

For tone control, you usually need a capacitor to go with a pot. That's what we called an RC (resistor amp; capacitor) circuit. The purpose of this circuit is to ground out or bleed off the high frequencies of the signal coming from the pickup. Notice you cannot add any more high frequency, you can only attenuate what you have. This is the circuit that people tend to have their own opinions. The norm is a 500k pot usually goes with a capacitor somewhere around 0.047 uf and a 250k pot with a 0.022 uf capacitor. You may want to do some experiment by changing the capacitor values with different value pots (not to exceed 1 meg) and try to find out what you like. Since the capacitor stores the charges and then release them in a non-linear rate, The response is also non-linear. I usually stay with the norm and call it because I consider that is good enough for me. If you really want to find out how a circuit responses, you can have the circuit output plot out by a computer according to the RC circuit formula but I think that is extreme and it does not worth the effort.

Wow, that's a damn science!

So, simply for humbuckers it's always 500k volume!
As for tone there is a possible variation from 250k to 1000k! Right?
And what about capacitors? How do they affect the sound?

Let's say I want to add some fatness to the E-B-G strings, what shall I do with tone pot and cap?


Originally Posted by DmitryWow, that's a damn science!

So, simply for humbuckers it's always 500k volume!
As for tone there is a possible variation from 250k to 1000k! Right?
And what about capacitors? How do they affect the sound?

Let's say I want to add some fatness to the E-B-G strings, what shall I do with tone pot and cap?

The capacitors are actually the main component for tone control. It is what allows the high frequencies to bleed off. You can try from 0.01 uf to 0.1 uf and see what kind of results you can get. My guess is that you probably won't like anything that goes beyond 0.05 uf.

To add fatness. you may not get very good results from working the pots and caps. You either get it right from the pickup or you can turn up the gain in your amp. I would suggest you get the Duncan SFX-01 Pickup booster pedal to increase the gain and resonance. It is highly recommended.

You should also pay attention to the manufacturers recommendations about wiring up your pickups. For example the Fender Noiseless pickups use 1K ohm tone pots rather than the 250K ones and I believe it also uses a 500K volume pot (not sure about that last part). So just be careful about generalizations with regard to which pots and caps to use.

If you're looking for your own sound, then experimentation is probably the way to go. There's always the active electronics route to explore, too. The ratings for quot;standardquot; electronics layouts and combinations are pretty much tried and true, though. The values stated have become the norm because most people (including the guitar builders) seem to think that those values work the best.

yeah all the pot does is reduce the amplitude of the sine wave coming from the pickups. so there is really no point on having a difference in 250k vs 500k because when they are at cero ohms, thats when you have full volume because the let the whole wave through, but if they get at 250k and 500k, thats when they stop the wave through, hence, for a higer output pup, you need a higher resistance pot.

I cant figure out how a higher value pot changes tone, being that the pot is used at cero ohms most of the time (when you are playing) and cero ohms is the same in a cable, wire, 500 Mohm pot, 1Gohm pot or anything.


Originally Posted by LPCustomYou should also pay attention to the manufacturers recommendations about wiring up your pickups. For example the Fender Noiseless pickups use 1K ohm tone pots rather than the 250K ones and I believe it also uses a 500K volume pot (not sure about that last part). So just be careful about generalizations with regard to which pots and caps to use.

I have 250k pots with nioseless pickups in my Fender Strat on both volume and tone controls. They sent then to me as a package when I re-fitted my guitar. I bought it right from Fender.


Originally Posted by DonLdukyeah all the pot does is reduce the amplitude of the sine wave coming from the pickups. so there is really no point on having a difference in 250k vs 500k because when they are at cero ohms, thats when you have full volume because the let the whole wave through, but if they get at 250k and 500k, thats when they stop the wave through, hence, for a higer output pup, you need a higher resistance pot.

I cant figure out how a higher value pot changes tone, being that the pot is used at cero ohms most of the time (when you are playing) and cero ohms is the same in a cable, wire, 500 Mohm pot, 1Gohm pot or anything.

Hey Don; I don't mean to sound argumentative - but thats almost completely wrong.

When you have volume control on quot;10quot;, the pot is the same as a resistor across the output of the pup. The pickup is a small, AC generator. The resistance of the pot is the quot;loadquot; that that generator operates into. The load affects the amount of current that goes through the coils, and thus, the strength of the electrical field that cuts across the magnetic field. Even if the pot is on quot;10quot;, you are still impacting the characterisitics of your electrical circuit. The lower resistance, (higher load), will shape the EQ curve of the pup, generally resulting in less highs. But there will always be a quot;sweet-spotquot; in any pickup. An quot;idealquot; load. But thats also based upon the equipment you use it with. I use 250k's with all my guitars, even the humbuckers, because I play through a system with tweeters and midrange. 500k's seem too bright to me.

You can go to this post in The Vault and see a simple way to wire up a volume control so that you can hear the difference yourself as you adjust the load from one value to another.

Artie


Originally Posted by ArtieTooYou can go to this post in The Vault and see a simple way to wire up a volume control so that you can hear the difference yourself as you adjust the load from one value to another.

Artie

Artie, when you say quot;sweet spotquot;, do you mean the tone sweet spot or the volume sweet spot or something else. Also what does the second resistor on your diagram that has no label represent?


Originally Posted by AmateurArtie, when you say quot;sweet spotquot;, do you mean the tone sweet spot or the volume sweet spot or something else. Also what does the second resistor on your diagram that has no label represent?

I should probably update that pic to make it more clear. That second resistor and cap are used to simulate a tone control on quot;10quot;, so that you can test the volume pot value in a quot;realquot; condition. In other words, you wouldn't necessarily want to experiment to find the perfect volume pot value, without having a tone control installed. Then again, you can just use a standard tone control.

By quot;sweet spotquot;, I just mean the the overall perfect pickup load, tone pot value, and tone cap value, to get just that perfect tone out of a given pup. For instance, a 500k pot will generally cause a pup to have more highs. A 1 meg pot, even more. But you don't always want more highs. You want to find that balance, where the pup sounds good to you. Of course, using the method I linked to in the vault could create a situation where 322k was the quot;perfectquot; value for you. But you have to work within the constraints of standard pot values. There's a couple of ways to get around this:

1. You could permanently connect the proper size quot;offsetquot; resistor between the ground lug of the volume pot and ground to customize the pot value. (Then the volume control wouldn't go completely to zero.)

2. You could also replace that pot with a toggle switch, and just select back and forth between a 250k and a 500k resistor. Then choose whichever came closest to what you wanted.

There's actually several other ways to do this, but I don't want to get too long-winded here. May already be too late.

Artie

hi artie too.

I thought about it and I know what it is now. I was wrong.

I drew the circuit of one pickup, tone and volume pot in pSpice. Let me know if its right

from : localhost/set 1H for Pup since you cant really tell how much it really is unless you have Z for a certain frequency. anyways. since the Pup is a AC gen, its got to have an output impedance, which I guess its the 16K or whatever common value. I read for the EMGs its 10K, I measured a ESP pup standard and it said 15.3k. Its very high output impedance, but considering the pots are 500k.

Then comes the tone pot Rt and Ct capacitor... Then the volume.

for cero volume (no sound) the Vo reference would be at ground, hence, Vo = 0-0 = 0

and for full volume, the Vo reference would be at the node at the top, so the 500k from Rv would be in parallel with both impedances from the Pup and the Tone Rt and Ct, creating a tank circuit (low pass filter?)

If this is right, then it wouldnt be a problem silencing a high output resistor with a low value (250K) resistor.

Since we dont change the frequencies we play (range from 60 to 6k aprox), neither the reactance from L and Ct and resistance from Ro, all there is to change is the Rt's and Rv's values that affect our H(s), hence if you put a pair of 250k and then a 500k, the circuit will have a different H(s), increasing or decreasing the bandwith of our tank.

The resonant point, when you get the most out of your Pup, would be when the reactances cancel each other out. or when Im(Ztotal) = 0 . That resonant point would be different for each note and impossible to obtain.

It looks good to me, except that you want your tone cap to be .047uf rather than .47uf. At .47, you'll be passing all the frequencies to ground, making your tone control, a variable quot;mutequot; control. Kinda like a volume control except the signal doesn't get out.

Artie