Hopefully this is a simple question...

capnjim · #1 05-29-2011, 09:58 PM

I am finding all my basses to be too bright. I try to use the very last bit of my tone, say zero to one, but its too sensitive...as soon as I get past 2-3 on the tone, its almost too bright.
How can I make my tone pot go zero to ten, a full rotation, yet have the same response as zero to three on the original?
Does this make sense?
Is it a cap or a pot? Can it be done? Am I nuts? Am I getting hard of hearing?
Maybe, but I really wish my zero-three could be expanded and lose the 3-10...

**line6man** · #2 05-29-2011, 10:02 PM

Set your pot to the highest setting you use, and then measure the resistance. Replace the pot with a value equal to that resistance.

walterw · #3 05-29-2011, 10:38 PM

what kind of bass is it?

odd that you get too bright with the tone on 3.

capnjim · #4 05-30-2011, 07:52 AM

I guess its my preference, as I have three or 4 basses that I really like the tone almost off. So instead of a 250K I should try a 25K? Won't that make the highs too low when its rolled off? I want the same tone I have know when its rolled off.

Matthijs · #5 05-30-2011, 08:17 AM

The zero setting will be the same as that's at zero resistance through the pot. you won't get any darker, you'll just loose the not-filtered side.

capnjim · #6 05-30-2011, 08:32 AM

Ok..I guess i will try a 50K pot to start with. I always thought the tone off was maximum resistance, not zero. I guess that makes sense with zero resistance the signal will pass thru the cap?
Thanks, will changing the value of the cap help? Or will that change the overall tone?

Testing_123 · #7 05-30-2011, 09:55 AM

This calculator will help you determine the corner frequency roll-off range when using various tone potentiometer and capacitor values. (Note that tone controls are wired as Low Pass filters; i.e. lows freqs can pass, while frequencies above the corner frequency are filtered out at 6dB per octave.)

For example, if using a 250k pot (250,000 ohms) and a .047 cap, your filter's cutoff range will vary from virtually infinite (when pot is at zero resistance) down to 13.6 hz (when pot is at 250k resistance).

If you kept same .047 cap value but changed to a 25k pot, your filter's cutoff range will vary from virtually infinite down to 135.5 hz cutoff.

In other words, if keeping the same capacitor value, you'd need to increase the pot value to lower the lowest cutoff frequency.

-------------

If you need to lower the cutoff frequency (have the capability to remove more high freqs), you may wish to keep the pot as-is, but use a higher value capacitor.

**line6man** · #8 05-30-2011, 10:02 AM

Quote:

Originally Posted by capnjim

Ok..I guess i will try a 50K pot to start with. I always thought the tone off was maximum resistance, not zero. I guess that makes sense with zero resistance the signal will pass thru the cap?
Thanks, will changing the value of the cap help? Or will that change the overall tone?

The tone pot places a series resistance between the signal, and a capacitor that runs parallel to it. At 0 Ohms, the capacitor is placed directly into the circuit, passing as much of the high frequency content to ground as possible. As you turn the tone pot up, the series resistance between the signal and cap limits how much of the high frequency content the cap can ground, by increasingly removing the capacitor from the circuit.
If you lower the pot value, you will just be stretching out the range, but without the possibility of making the bass any brighter than what X value (In this case "3") was with the old pot.

Changing the capacitance will affect the cutoff frequency.
Lower values will have a higher cutoff, higher values will have a lower cutoff.

**line6man** · #9 05-30-2011, 10:06 AM

Quote:

Originally Posted by Testing_123

This calculator will help you determine the corner frequency roll-off range when using various tone potentiometer and capacitor values. (Note that tone controls are wired as Low Pass filters; i.e. lows freqs can pass, while frequencies above the corner frequency are filtered out at 6dB per octave.)

For example, if using a 250k pot (250,000 ohms) and a .047 cap, your filter's cutoff range will vary from virtually infinite (when pot is at zero resistance) down to 13.6 hz (when pot is at 250k resistance).

If you kept same .047 cap value but changed to a 25k pot, your filter's cutoff range will vary from virtually infinite down to 135.5 hz cutoff.

In other words, if keeping the same capacitor value, you'd need to increase the pot value to lower the lowest cutoff frequency.

-------------

If you need to lower the cutoff frequency (have the capability to remove more high freqs), you may wish to keep the pot as-is, but use a higher value capacitor.

I don't think you understand how an RC filter works.

As shown in the graphic, that calculator applies to a filter in which there is a resistance in series with the signal path, with a capacitance parallel to the output. That is NOT how a tone control works. A tone control only places a capacitance parallel to the signal. The resistance comes from the pickups.

Testing_123 · #10 05-30-2011, 10:28 AM

Quote:

That is NOT how a tone control works. A tone control only places a capacitance parallel to the signal. The resistance comes from the pickups.

Thanks for the correction, line6man -- I'll need to do some brush-up on my understanding of this.

Ah, duh -- I see it. I use that RC filter info when working on pedal projects, but I forgot the different signal path arrangement in the volume/tone control combo typically used in instruments....

Capnjim -- disregard my post above, it'll lead you the wrong direction.

capnjim · #11 05-30-2011, 11:58 AM

I suppose I'll have to take one of my basses and try a couple of pots and resistors. I don't want any more highs taken out, the tone is perfect when the pot is at 1-2 and occasionally zero. I wouldn't want to go any lower, just extend that 0-3 range to a wider sweep.
Maybe I should try half round strings? I've never really experimented with flats and half's.

SGD Lutherie · #12 05-31-2011, 07:32 AM

Have you tried turning down the treble at the amp?

If you just want to get rid of the ringing top end, use halfrounds or flat wounds.

capnjim · #13 05-31-2011, 08:13 AM

I think halfrounds or flats might be what I am looking for, when I turn down the treble on the amp (GK400RB old model and Traynor Custom special) it loses something that I still need.
Maybe I can pick up some used flats right here for a decent price.

96tbird · #14 05-31-2011, 04:15 PM

Quote:

Originally Posted by capnjim

I think halfrounds or flats might be what I am looking for, when I turn down the treble on the amp (GK400RB old model and Traynor Custom special) it loses something that I still need.
Maybe I can pick up some used flats right here for a decent price.

JUST STRINGS has Fender flats for 20.00, really nice except for the green silk.