Fender TBX tone control

[Kac]

I love the Fender TBX tone control and I’ve been installing it in all of my guitars. I understand the first half 1-5 is like a regular 250k tone pot and after that you switch to the 1MEG pot and it “extends” the bass and treble (which makes my pickups sound less muddy to my ears, and I love it.)

What I would like to do is skip the first half all together. How would I make a just the TBX part of the circuit? I’ve got available 1MEG pots here waiting to make it happen.

please help

[ICTGoober]

A TBX is $15. What you want is more expensive.

[Kac]

It’s not more expensive if I’ve got the parts sitting at home ready to go.

[freefrog]

I love the Fender TBX tone control and I’ve been installing it in all of my guitars. I understand the first half 1-5 is like a regular 250k tone pot and after that you switch to the 1MEG pot and it “extends” the bass and treble (which makes my pickups sound less muddy to my ears, and I love it.)

What I would like to do is skip the first half all together. How would I make a just the TBX part of the circuit? I’ve got available 1MEG pots here waiting to make it happen.

please help

Not sure to understand your request but it's not possible to extend the high range by adding a resistive load, even if it's a high one.

A TBX "extends" the high range only relatively to a lower resistive load, as explained here:

https://guitarnuts2.proboards.com/thread/7187/tbx-tone-control

Now, you can use a 1M pot (or a TBX) to build a "bass cut" (hi-pass) filter involving a capacitor in series with the pickup.

Just think to wire any regular tone pot BEFORE this filter, like in the schematic shared in the page below:

https://tonefiend.com/guitar/two-band-ptb-tone-control-useful-easy-cheap-awesome/

That's the signal path applied for such filters by G&L or Reverend guitars and there's a reason for that.

Also: be aware that series capacitors don't cooperate nicely with some circuits (like fuzz pedals; in the video shared by tonefiend, listen when Joe Gore lowers his "bass-cut" control while in drive mode and how it kills the gain, and you should understand what I mean).

[Mikelamury]

Has anyone installed or seen a TBX in a bass? I'm wanting to put one in my JMJ mustang bass but I'm wandering if I should use the same .022 capacitor or should I use a .047 which is already on the bass(250k pots). I know the wiring diagram that comes with the TBX shows a strat and tele so I understand why the .022 capacitor was recommended. Does anyone for sure know what value capacitor to use for a bass?

[ICTGoober]

I posted this video recently. I like using a TBX in guitar or bass. They work very well.

Chris and the Toby DX 4 - YouTube

[GuitarDoc]

Not sure to understand your request but it's not possible to extend the high range by adding a resistive load, even if it's a high one.

A TBX "extends" the high range only relatively to a lower resistive load, as explained here:

https://guitarnuts2.proboards.com/thread/7187/tbx-tone-control

Now, you can use a 1M pot (or a TBX) to build a "bass cut" (hi-pass) filter involving a capacitor in series with the pickup.

Just think to wire any regular tone pot BEFORE this filter, like in the schematic shared in the page below:

https://tonefiend.com/guitar/two-band-ptb-tone-control-useful-easy-cheap-awesome/

That's the signal path applied for such filters by G&L or Reverend guitars and there's a reason for that.

Also: be aware that series capacitors don't cooperate nicely with some circuits (like fuzz pedals; in the video shared by tonefiend, listen when Joe Gore lowers his "bass-cut" control while in drive mode and how it kills the gain, and you should understand what I mean).

Great post.
Thanks for the links, this is gonna make a great improvement on the guitar I'm currently building.

[ICTGoober]

Just my 2 cents - Joe Gore can do no wrong.

[eclecticsynergy]

Using a no-load tone pot is a simple way to extend the highs and increase definition.
Does not affect the lows of course, but it gives you noticeably more brightness up top.

[GuitarDoc]

A no-load pot may sometimes give you a slight bit more brightness. I use a bypass switch to totally remove the tone pot from the circuit and I can't tell ANY difference from when the tone pot is in the circuit and on "high". But even if it did, it wouldn't be the same thing as removing some bass from the circuit like the TBX could do. If you spend your life playing your guitar for oscilloscopes or other frequency measuring devices, then you NEED a no-load tone pot or a bypass switch. But if you play in a band, forget all the hype and conspiracy about no-load pots...they won't have any effect at all on the perceived tone/brightness/clarity/definition of your guitar. And isn't THAT what all this tone chasing is about...how we sound to those that are listening to us play? I think the TBX would have as much or more difference to our tone than going from an Invader pup to a Jazz.

I've got the Fender dual shaft TBX in a couple guitars and it really does make a huge difference to brightness and clarity.

[Kac]

A no-load pot may sometimes give you a slight bit more brightness. I use a bypass switch to totally remove the tone pot from the circuit and I can't tell ANY difference from when the tone pot is in the circuit and on "high". But even if it did, it wouldn't be the same thing as removing some bass from the circuit like the TBX could do. If you spend your life playing your guitar for oscilloscopes or other frequency measuring devices, then you NEED a no-load tone pot or a bypass switch. But if you play in a band, forget all the hype and conspiracy about no-load pots...they won't have any effect at all on the perceived tone/brightness/clarity/definition of your guitar. And isn't THAT what all this tone chasing is about...how we sound to those that are listening to us play? I think the TBX would have as much or more difference to our tone than going from an Invader pup to a Jazz.

I've got the Fender dual shaft TBX in a couple guitars and it really does make a huge difference to brightness and clarity.

Agreed. I’ve got the TBX in 3 strats, just installed in a 4th that I’m still working on putting back together and imagine that I might be putting it in a couple more guitars after that as well. I just wish I could make a circuit with my 1 Meg pots and wire that in instead of having to get the whole TBX circuit to put in there.

[freefrog]

I just wish I could make a circuit with my 1 Meg pots and wire that in instead of having to get the whole TBX circuit to put in there.

See the topic on guitarnuts2 that I've shared in my first answer: all the necessary informations are at disposal there.

[eclecticsynergy]

A no-load pot may sometimes give you a slight bit more brightness. I use a bypass switch to totally remove the tone pot from the circuit and I can't tell ANY difference from when the tone pot is in the circuit and on "high". But even if it did, it wouldn't be the same thing as removing some bass from the circuit like the TBX could do. If you spend your life playing your guitar for oscilloscopes or other frequency measuring devices, then you NEED a no-load tone pot or a bypass switch. But if you play in a band, forget all the hype and conspiracy about no-load pots...they won't have any effect at all on the perceived tone/brightness/clarity/definition of your guitar. And isn't THAT what all this tone chasing is about...how we sound to those that are listening to us play? I think the TBX would have as much or more difference to our tone than going from an Invader pup to a Jazz.

I've got the Fender dual shaft TBX in a couple guitars and it really does make a huge difference to brightness and clarity.

I think no-load makes an audible difference on a 250K tone pot at band volume. Likely not as perceptible with a 500K.

Of course bass cut is an entirely different animal, far more apparent.

Didn't mean to sound as if I were recommending a no-load over the TBX.
Just as a simpler intermediate option.

[GuitarDoc]

I think no-load makes an audible difference on a 250K tone pot at band volume. Likely not as perceptible with a 500K.

Of course bass cut is an entirely different animal, far more apparent.

Didn't mean to sound as if I were recommending a no-load over the TBX.
Just as a simpler intermediate option.

OK, I got it.

[freefrog]

I understand the first half 1-5 is like a regular 250k tone pot and after that you switch to the 1MEG pot and it “extends” the bass and treble.

BTW, it doesn't work like that.

In a TBX as wired by Fender, there's a 82k to ground at the end of the 1M part and in parallel with the 250k when it's engaged.

IOW, from 0/10 to 4,9/10, the tone pot puts zero resistance to 250k // 82k = 61k only between the pickups and the tone cap to ground.

@5/10, the 250k part of the pot is totally disabled, since it's no load. it's out of the circuit. But a resistive load remains, due to the 82k resistor alone at this point: it does roughly the same than a regular tone pot set between 5/10 and 2/3.

@10/10, the 1M part adds itself to the 82k, for a total resistive load of 1082k. It doesn't actually "extend" bass AND treble: it just let the resonant peak reach a greater amplitude (close to the maximum amplitude offered by the no load option). So it gives more brightness than with 250k or 500k controls. The impression of more bass is a psychoacoustic artefact due to a higher "Q factor" (higher but narrower resonant peak feeding an illusory sensation of "scooped mids"), itself due to the higher resistive load.

A 1M pot wired as a normal tone control should do largely the same, to be honest. There's no need of fancy wiring for that - and the TBX dual pot itself can be used MUCH more efficiently: I've shared only an idea among others by mentioning somewhere above the G&L / Reverend BT control...