Elementary question about pots

[thendrix]

When discussing tone and volume pots, what do 250K and 500K mean and what is the diffrence in the two?

[Jazz P Bass]

250K means 250,000 ohms total resistance.
500K means 500,00 ohms total resistance.
Potentiometers are a variable resistor.
They are usually drawn as a resistor with an arrow pointing to the side of it.
The two outside legs on the pot are the resistor.
The middle leg is the arrow.(the wiper)
It slides up & down the resistor "picking" different resistance readings.
Pots can be wired up in many different ways.
It depends on the circuit.
A common way is to connect one end to ground & the other end to a voltage.
The middle "wiper" will now see a different voltage as the pot is turned.
Pots also come in different "tapers"
A- audio (logarithmic)
B- linear
A taper is like a curve
B taper is a straight line.

[thendrix]

Thanks for your help. Now how does resistance affect tone, output, etc.

[Jazz P Bass]

Sorry, I am not bighting on that one!
It depends on The Circuit.
It's like asking what a capacitor does.
It depends on The Circuit.

[David Schwab]

Thanks for your help. Now how does resistance affect tone, output, etc.

The lower resistance pot will load the pickup more, which flattens its resonant peak somewhat, so what you hear is a warmer tone. The higher resistance pots will load less and sound brighter. The added brightness might make them sound a little louder. If you were to install 100K pots in a humbucker equipped guitar, it would sound rather dull with reduced output.

It's also dependent on the impedance of the pickup. Hotter pickups need larger pots to retain their brightness.

[thendrix]

Now let me ask a more specific question. I have a Squire strat. I have swapped the stock pickups for a Fender Noiseless single coil setup. The Squire is now a little hotter and is a LOT brighter then my american strat with Suhr vintage 60's. I don't want the same tone but I do want to "quiet it down" a little. If I change to pots with less resistance, might this achieve what I am looking for?

[Steve Conner]

I take it you tried turning down the volume and tone knobs? Isn't that what they're for?

[thendrix]

I take it you tried turning down the volume and tone knobs? Isn't that what they're for?

It's been my experience that messing with volume and tone during a live show is a good way to loose the sound you have. I play the 2 strats and an Epiphone Dot with two humbuckers and have a pretty good compromise in tone for all three. Just not something I want to mess with. Any more smart ass comments?

[Steve Conner]

Since when was using the volume and tone knobs considered a smart-ass comment?! If Leo Fender hadn't thought they would be useful, he wouldn't have put them there.

Plenty of guitarists seem to think that they need to play the guitar with the knobs all up full all of the time, but I say that if it sounds better with the volume on 8 and the tone on 5, do that. Then whack the knobs up to 10 for your solo. The controls on the guitar are part of the instrument.

If your amp has High and Low input jacks, have you tried the other one to what you normally use? The two jacks not only have different gains, they also have different impedances that load the pickups and controls differently. I've found that the "Low" jack damps the resonance of the pickups more. It's warmer on 10, but it doesn't get muddy when you turn the volume down.

Going to a lower resistance tone pot will certainly make the guitar less bright. So will a lower resistance volume pot, to a lesser extent. Some Fender guitars have a tone pot with a wiper that goes completely open-circuit at "10", so the 10 setting is very bright. Swapping that for a normal pot would tone it down a little too. I don't know if Squiers have that, though.

[thendrix]

Since when was using the volume and tone knobs considered a smart-ass comment?!

Steve, the way your comment came across I felt you were questioning my knowledge of how to use my amp or my instrument. If this is not the way you ment it then I appologize. However, you may want to consider reading comments from both sides before posting.

Thank you for your help though. I have played with the tone on both guitars. In fact I have a Dimarzio fasttrack in the bridge of the american strat and use it with the tone at about half. I don't really like doing this because I feel that it puts me in a box so to speak. I would rather have the entire range.

Will the pots be labeled as to what resistance they are or do I need to use a multimeter?

[Steve Conner]

Yes, the resistance should be stamped or printed somewhere on the body. The hard part is figuring out whether they're linear or audio taper. One is labelled "A", the other "B", but Asian manufacturers use the opposite convention to American ones. The volume control is always audio taper, but tone pots can be either.

If you find that you never run the tone control more than halfway up, and that annoys you, well, that's a case where you might want to replace the tone pot for one that has half the resistance.

Well, unless it was an audio taper pot, in which case "halfway up" is more like 1/3 to 1/10 of the total resistance. You can get pots less than 250k, but they're not as commonly sold in guitar parts stores.

[J M Fahey]

1)

it puts me in a box so to speak. I would rather have the entire range.

The Squire is now a little hotter and is a LOT brighter then my american strat with Suhr vintage 60's. I don't want the same tone but I do want to "quiet it down" a little.

Excuse me, but I find both statements quite contradictory.
2) I think that using lower than "normal" pots would be a rather drastic and unhealthy way to do this, specially because to go back to the unpadded sound involves major surgery (opening the guitar and replacing the original ones)
*If* you think that loading your pickups is your way to Heaven (nothing against that), may I suggest adding a microswitch and a loading resistor, say 47K/100K (your choice) so it can be put in parallel with the pickup itself (or in parallel with the volume pot, which is about the same)?
That way, your pickup would see either the original resistance (250 o 500K) *or* a much lower one , at the flick of a switch.

[thendrix]

I wasn't aware that could be done. Thanks for the suggestion. i will look into it.

[thendrix]

1)

Excuse me, but I find both statements quite contradictory.

I don't understand what is contradictory about my statements. I don't like the tone from the squire. It's got to much treble for me and it is a little hotter then my american strat. If it has to do with playing the american strat with the tone at half way, I don't like to do that because I don't have the full range of the tone control. Sorry but I don't understand the issue.

[Mark Hammer]

Whenever this topic comes up - and it comes up a lot - I hasten to remind people that the value of pot values will ultimately depend on how you use your volume pots.

The loading that this or that value of volume pot will impose on the pickup is a phenomenon that occurs at maximum volume, when the resistance between pot wiper and ground = pot value, and that value is MUCH higher than the resistance to ground of the pickup (e.g., 6.2k or 8.4k).

Of course, turn the volume down a bit, and the pot wiper moves over and shifts some of its resistance in series with the pickup so that instead of 6.2k to ground from the output jack through pickup path, and 250k to ground via the pot, you might have 56.2k through the pickup path and 200k through the pot, or 106.2k through the pickup path and 400k through the pot. Under those circumstances, whatever benefit a 500k pot might have delivered with respect to treble preservation, is effectively lost.

So, if you are the sort of player who leaves the volume up full and only turns down when the guitar is placed in the stand, then choice of pot value is very much a tonal choice. If you are the sort of player who constantly fiddles with your volume, then of much greater concern is any compensation network connected to the volume pot, that will determine how the treble is preserved at less-than-maximum settings.