What does the tone knob on my Pbass do?

BrandonBass · #1 06-26-2011, 04:17 AM

I know it sounds dumb, but what exactly does it do? I hav a 09 am std pbass, the first pbass i own actually. I know that tone at full have more treble than at zero, but I find that with the tone knob at full it actually cuts my bass frequencies instead of just retaining the treble. Is it normal?

allexcosta · #2 06-26-2011, 05:57 AM

I bet your lows are still there when you open your tone but you notice them less because now they have competition...

2400 · #3 06-26-2011, 06:04 AM

It's perfectly normal. What you describe is actually the opposite of what most people hear when their tone pot is turned; as it nears zero (or the closed position, as neither positions are truly 0 or 100 per cent), treble is cut and bass seems to increase. But, as mentioned, that's an auditory illusion. People that know something about psychoacoustics (I honestly don't) could tell you more, but your tone control is fine.

If I'm not mistaken, the effect you notice is because you're listening to your bass out of a mix context, and your mind is more focused on the instrument's frequency range, instead of the band's.

But then again, that might not be the exact reason, as stated.

Bongolation · #4 06-26-2011, 08:57 AM

Quote:

Originally Posted by BrandonBass

I know it sounds dumb, but what exactly does it do? I hav a 09 am std pbass

It does nothing but gradually remove high frequencies from the output by bleeding them off through a capacitor to common.

That's all.

HotRoded · #5 10-26-2011, 08:37 AM

Quote:

Originally Posted by Bongolation

It does nothing but gradually remove high frequencies from the output by bleeding them off through a capacitor to common.

That's all.

Do you know what happens if the capacitor wears off?
I'm asking this because on my P Bass, the tone knob has no effect anymore.
Trebles are cut regardless of the knob position. Also lower strings are louder than higher strings.

I am planing on changing the capacitor, and take it from there.
Next would be the pot.

Matthijs · #6 10-26-2011, 08:48 AM

Quote:

Originally Posted by HotRoded

Do you know what happens if the capacitor wears off?
I'm asking this because on my P Bass, the tone knob has no effect anymore.
Trebles are cut regardless of the knob position. Also lower strings are louder than higher strings.

I am planing on changing the capacitor, and take it from there.
Next would be the pot.

It's not very likely the capacitor is worn (they do not wear), specially since it is doing its capaciting thing by cutting the treble. Did your bass always act like this or did it start acting this way recently? Did you have a look inside? Might be some wires are crossed and shorted the pot, or the pot is bad in some exotic way I can't think off, or the whole wiring was wrong to start with. The one thing working seems to be the capacitor.

fourstringbliss · #7 10-26-2011, 08:54 AM

Quote:

Originally Posted by HotRoded

Do you know what happens if the capacitor wears off?
I'm asking this because on my P Bass, the tone knob has no effect anymore.
Trebles are cut regardless of the knob position. Also lower strings are louder than higher strings.

I am planing on changing the capacitor, and take it from there.
Next would be the pot.

If lower strings are louder than higher strings I think it might be something to do with your pickups. A "bad capacitor" wouldn't affect string-to-string volume like that.

Spinal Tapper · #8 10-26-2011, 09:01 AM

I had a CIJ 62 RI Precision that did this. When I would put the tone knob on 100%, the bass would be GONE. It only sounded good with the tone knob rolled back to 0%.

It is NOT supposed to cut the bass out like that. My buddy's 66 Precision that I play all the time sounds amazing with the tone back, and when I crank the tone, the low-end is definitely still there with a lot more treble.

I'd try a new capacitor. Take it to a tech, and see what they think. It's a cheap part, might as well give it a shot.

HotRoded · #9 10-26-2011, 11:20 AM

Quote:

Originally Posted by Matthijs

It's not very likely the capacitor is worn (they do not wear), specially since it is doing its capaciting thing by cutting the treble. Did your bass always act like this or did it start acting this way recently? Did you have a look inside? Might be some wires are crossed and shorted the pot, or the pot is bad in some exotic way I can't think off, or the whole wiring was wrong to start with. The one thing working seems to be the capacitor.

The bas used to be fine. She acted up recently. I have not looked inside yet. Maybe tonight.

Quote:

Originally Posted by fourstringbliss

If lower strings are louder than higher strings I think it might be something to do with your pickups. A "bad capacitor" wouldn't affect string-to-string volume like that.

I thought about that, but I was not clear enough in my explanations: I did not mean that the E and A strings are louder than the D and G, but I should have said:
The E is the loudest, the A not as loud as the E, the D not as loud as the A, and the G not as loud as the D. There is about the same difference between each string.

When the tone pot is 100% open, the tone is still the same. When completely rolled off, the bass is slightly louder, but that's very subtile.

HotRoded · #10 10-27-2011, 05:55 AM

Yesterday night, I took her completely apart, and inspected everything closely, and could not find anything wrong. Everything is in order and very clean.

I finally put everything back together. Now all the bad symptoms are gone. I wonder if I have moved something incenditally while checking her out.

Oh well ... end of the story. Thx to everybody who responded to try to help me out!