What pot to use in a circuit?

[bluesman1218]

Can anyone explain how to determine what pot value to use in a circuit? I'm sure there are general guidelines, but I'll be darned if I can find this info.
I have read R.G. Keen's article, as well as ESP and many others. I understand how a pot works, but not how the value is determined for the application.
I gots to know, I just gots to!

[Hides-His-Eyes]

What understanding do you have of the word "impedance"?

[bluesman1218]

What understanding do you have of the word "impedance"?

If your question is the answer, then a smaller value would let more of the current/signal pass through at max resistance, correct? I get that. What I don't understand is why different values are spec'd for various circuits.

In practicality, if a 100k (regardless of taper) pot is spec'd, would there be a negative or positive effect with a significantly higher or lower value? What determines the spec'd value? Is it a datasheet, a formula, just "knowing" what it should be, trial and error, etc.?

[digi2t]

It may sound a bit simplistic, but I'm a simple guy. Given that one end of the pot represents 0 resistance (or close to it, max signal passage), and the other end represent the max resistance (250K, for example, on a 250K pot  ). I tend to think about these 2 extremes when choosing a pot for a particular application. For example, a voltage starve pot. If I know that the whole circuit will crap out at 3K of resistance, I won't be installing a 100K pot. The range of the dial will be to small, and extremely hard to tune. So, I'll use a 5K, and have a wider "spin" range. I sometimes even tend to mod my pots with a trimmer directly on the pot, to get a perfect rage i.e. make a 3K pot out of a 5K, but that's a whole different kettle of fish.

Like I said, very rudimentary application here, but one example of many. I hope it helps you a bit.

Cheers,
Dino

[bluesman1218]

Thanks, Dino. Makes perfect sense and it's the first true answer to help me on my way.