Master volume/voltage divider pot values question

[midwayfair]

Talking about the simple voltage dividers at the end of ODs and such. Is there a general rule for the volume increase or decrease you'll get from changes in the pot's value? Like going from 100K to 500K -- will the result likely be closer to 50% louder or 500% louder? I know I could test this with a bunch of different pots in the three or four circuits I'd like to mess with, but I can only really have one thing on the breadboard at a time, and why reinvent the wheel?

Thanks for any help as always.

[R.G.]

I'm not sure which of two interpretations your question intends.

One way I read it says "If I change the end-to-end value of a pot, does the output get louder/quieter?"

The other way is "As I change the setting of a pot from 100K to 500K, what is the change in loudness as heard by a human?"

For the first interpretation, whether the end-to-end value of the pot makes any difference at all depends not on the pot but the circuit it follows and the input impedance after it. If the circuit before the pot can drive (for example) a 100K and a 500K pot equally well, and if this is going into a tube amp with an input impedance of 1M or more, it probably makes no audible difference which pot value you choose. If the circuit after the pot wiper has a 100K input impedance, the 500K pot will have a lower apparent loudness, as the circuit loads it down. So the real answer is "it depends on what comes before and after the pot."

For the second, you have to know that human hearing compresses sound excursions, so that the audio power needed for an apparent doubling of loudness is not 2x the sound pressure, but about 10X.  Changing the end-to-end value of a pot will make no difference on this at all. Changing the setting of a pot will make a loudness change, but the amount of change per unit rotation has to be ever-increasing as the rotation increases. This is the "audio taper" business, and it's used to make changes in loudness, not voltage, be apparently linear with pot rotation.