JB control pots setup

[bozha]

As I plan to install new controls and wiring on Jazzbass type passive bass, have some thoughts, and maybe I'm into something...

*Traditional 250k pots leaks hi frequencies because their low resistance. In that manner, volume pots are doing some tonal changes. They called it "warming" the sound, but basically, that's just loss of highs that can't be controlled. Nothing much left for tone pot.
*High resistance 1Meg pots preserve more original frequency range of pickup, keeping most of the highs on. Then using large value capacitor for tone control (.1uF) can give maximum effect from totally bright on full open, to low deep and boomy when closed, and guess, wide range of tones in between.

That is one 'the bigger-the better' assumption. I'm aware I could miss something important, something that makes them using same old values for decades. So please, let me know before I mess it up with soldering...

 

[slyjoe]

Pots don't have a frequency response by themselves. When you put pots in as a volume control, they are interacting with other elements of the circuit, including the capacitance of the pickups. So the amount of highs you lose with a lower value pot also depends on the other components in the circuit. Unfortunately, pickup manufacturers will sometimes give you inductance of their pickups, and DC resistance, but usually not the capacitance. So it's hard to predict what the frequency response in a given bass will be.

For maximum tone control, you could also switch in different capacitor values.