why do my tone controls always have a cocked-wah sound in the last 5% of the pot?

[vanguard]

so every time i try to use a traditional tone control in my teles, i get this weird phenomenon where, when i hit the last bit of rotation of the tone pot, the trebles stop rolling off and the mids jump forward like i just engaged a wah pedal in the middle of its sweep. it changes the whole voice of the pickup in a really nasal/unpleasant way. i use old caps from the 50's usually, but i can't imagine why that would be the problem. this never happens on stock teles i try at shops. what gives?

[vlammie]

I have exactly the same on 2 of my mad cats, according to a tech at our company it has to do with the taper of the pot.
So changing caps wouldn't make a difference...

[jefrs]

Q - are you using 250k log/audio tone pot and 47nF capacitor per stock tele wiring.

Q - have you tested any of these "old caps from the 50s". I have ditched all the old junk that I had because they were quite plainly utter rubbish.
Mylar (polyester) "orange drop" type, don't be put off by their 15p price, are as good as they get for this job.

[waparker4]

Cable capacitance?!

[vanguard]

Originally Posted by jefrs

Q - are you using 250k log/audio tone pot and 47nF capacitor per stock tele wiring.

Q - have you tested any of these "old caps from the 50s". I have ditched all the old junk that I had because they were quite plainly utter rubbish.
Mylar (polyester) "orange drop" type, don't be put off by their 15p price, are as good as they get for this job.

one guitar's 250k pots and i tried various cap values. the other is 500k's with various cap values as well. the pots were all fender-issued so. . .audio taper i think? i'm at a loss

[jefrs]

Have you tried them with modern 47nF or 22nF capacitors?
- I do suspect dead 50s caps (dried-up PIO about as much use as a dead beetle)

Have you tried them in the shops on their amps and leads?
- eliminates your amp and leads. Shops will happily oblige if they think there is half a change of you buying an amp, maybe you will...
... buy a pack of strings.

Tone pots are always log/audio taper but a volume pot can be linear (rare on a Fender but not unknown). 250k log will suit single-coil or humbucker, the long travel until anything happens on a 500k is wasted.

Are you wired as stock tele diagram? - or are you using a Fezz Parka/Ted Greene mod, or some other config? - some of these can make the vol act as a form of tone control or other weird effects.

One thing I do know that will make a wah quack from a tone control is and inductor connected to the tone circuit. Again this makes me suspect the duff old caps.

[vanguard]

Originally Posted by jefrs

Have you tried them with modern 47nF or 22nF capacitors?
- I do suspect dead 50s caps (dried-up PIO about as much use as a dead beetle)

Have you tried them in the shops on their amps and leads?
- eliminates your amp and leads. Shops will happily oblige if they think there is half a change of you buying an amp, maybe you will...
... buy a pack of strings.

Tone pots are always log/audio taper but a volume pot can be linear (rare on a Fender but not unknown). 250k log will suit single-coil or humbucker, the long travel until anything happens on a 500k is wasted.

Are you wired as stock tele diagram? - or are you using a Fezz Parka/Ted Greene mod, or some other config? - some of these can make the vol act as a form of tone control or other weird effects.

One thing I do know that will make a wah quack from a tone control is and inductor connected to the tone circuit. Again this makes me suspect the duff old caps.

i use this little wiring mod:

[editorjuno]

Originally Posted by vanguard

i use this little wiring mod:

I think you might be hitting a midrangey LCR resonance due to an additional variable resistance from that little mod of yours -- in the standard wiring only the tone control setting is relevant to the resonance, but with your the mod the volume control setting will also influence that. Try different volume control settings (compensating with the amp) and see if the effect varies depending on where the guitar's volume knob is set -- it does, then going back to the standard wiring scheme should eliminate the problem.

[jefrs]

Originally Posted by vanguard

i use this little wiring mod:

That's the Fezz Parka/Ted Greene. It moves the tone after the vol, it is supposed to keep the treble up as you roll off the vol, but if you have the tone rolled back then the vol becomes a tone control of sorts too. It's ok if one of the knobs is at 10, but for me the rather defeats the point of them for me.

To test whether it is this wiring causing your problem, you need to move the red wire back to the hot top tag of the vol pot and try again using stock wiring.

After that I would seriously swap out your ancient cap to test something modern and reliable in there.

[jefrs]

Can you flip the control plate and post a pic here so we can see what's what?

I'm not aware of the FP mod making a wah-quack.
It could be a wiring fault bringing in the second pickup as you dial 10 on the tone pot. An inductor coil will do that, I once did it on purpose with an Epi Varitone coil and a cap on a TBX (but didn't like it).
Stray bits of wire or solder whiskers do strange unpredictable things..

[vanguard]

Originally Posted by jefrs

Can you flip the control plate and post a pic here so we can see what's what?

I'm not aware of the FP mod making a wah-quack.
It could be a wiring fault bringing in the second pickup as you dial 10 on the tone pot. An inductor coil will do that, I once did it on purpose with an Epi Varitone coil and a cap on a TBX (but didn't like it).
Stray bits of wire or solder whiskers do strange unpredictable things..

it's an esquire, so only one pickup. there's also no switch involved. i'll try swapping back to stock wiring (minus fezz parka (why does he get credit for this 50's gibson wiring?) mod). i may just remove the tone pot altogether and add a kill switch instead too. . .i really don't get much use out of passive tone circuits. . .

[Ryan0594]

Do people use the last 5%? The last 50% all sounds the same on mine! :')

[EsquireOK]

Yep, that's what tone pots do IME. The jump from 1 to 0 is huge. 0 is a great tone in my opinion. Bridge pickup with the tone rolled all the way down, and hit a fifth chord real hard. Yummy! Sounds great with humbuckers too. If you don't like it, try using the pot on 1 instead of 0.

[teletwang67]

Sounds cool, I actually want mine to do that!

[psyched]

Originally Posted by vanguard

(minus fezz parka (why does he get credit for this 50's gibson wiring?) mod)..

He didn't perpetuate it, and credits Ted Greene with showing it to him initially. I think it snowballed, and now it's the easiest shorthand way of referring to this particular mod. I mean, what're we supposed to do, call it a Gibson mod on a tele forum? Not in my America.

[editorjuno]

Originally Posted by vanguard

it's an esquire, so only one pickup. there's also no switch involved. i'll try swapping back to stock wiring (minus fezz parka (why does he get credit for this 50's gibson wiring?) mod). i may just remove the tone pot altogether and add a kill switch instead too. . .i really don't get much use out of passive tone circuits. . .

You might want to consider this circuit -- it's much more effective than a simple capacitor for all but the lowest-inductance Tele bridge pickups: Bill Lawrence's Special Esquire Wiring

[jefrs]

Originally Posted by editorjuno

You might want to consider this circuit -- it's much more effective than a simple capacitor for all but the lowest-inductance Tele bridge pickups: Bill Lawrence's Special Esquire Wiring

What is the EQ1200? - I cannot read the start of the handwritten note.

[jefrs]

Originally Posted by vanguard

it's an esquire, so only one pickup. there's also no switch involved. i'll try swapping back to stock wiring (minus fezz parka (why does he get credit for this 50's gibson wiring?) mod). i may just remove the tone pot altogether and add a kill switch instead too. . .i really don't get much use out of passive tone circuits. . .

The Esquire uses a 3-way selector switch to change the tone circuit

Ted Greene probably used a 50s Gibson with that wiring mod ?

I was assuming the cocked-wah was between 9-10

From 1-0 it is normal to go from treble cut to mud. You can add a small resistor to lift the cap from 0ohms on the pot so that you cannot get the mud position. You have to experiment, try 120ohm for starters. The Esquire uses a 47nF+3k3+47nF (=3k3+22nF) to do just that but it is a fixed setting.

fyi a 47nF is just a 50nF with a different number written on it, it will be the same cap. Thanks to the "preferred series" making things easy like that.

[chipbutty24]

I thot tone pots were almost always linear...

[sacizob]

I would love to have that half cocked sound on the high end of my tone knob. I rarely put the tone up all the way and I always loved that sound on my Wha pedal, but I always had trouble with the pedals making unwanted noises.