re wiring Nocaster, capacitor question

[tube.tone]

Hi all, I just replaced the original circuit on my Nocaster, the blending option is interesting but missed the tone control on both pickups.

When I was sourcing a good capacitor match to the pickups I noticed some weird frequency bump effect when the tone pot is close to zero.

I lack better words to discribe it, but the tone goes progressively darker as i rotate potit rotate pot, then before the pot reaches the end of its travel the is a bump in the frequency and the tone gets a bit grittier with crazy resonance.

Considering that caps have same value. This is more evident with "paper in oil" than with ceramic or polyester film caps.

I have experience on guitar circuits, There are no mistakes on the wiring and pots are fully functional and measure 250k.

Can you explain me wants going on

Apologies for any confusion or for my English.
Thank you

 

[The Ballzz]

Ahhhh,
You found the magic sweet spot! now part of the trick is finding the cap that accentuates that "hump" in exactly the right frequency range for your taste and use. With the right cap, it can make a single coil pup sound strangely like a humbucker! While some may look at this phenomenon as a flaw and do their best to negate it, I embrace it and use it as kind of a secret weapon.
Just My $.02 & Likely Worth Even Less,
Gene

 

[tube.tone]

Ahhhh,
You found the magic sweet spot! now part of the trick is finding the cap that accentuates that "hump" in exactly the right frequency range for your taste and use. With the right cap, it can make a single coil pup sound strangely like a humbucker! While some may look at this phenomenon as a flaw and do their best to negate it, I embrace it and use it as kind of a secret weapon.
Just My $.02 & Likely Worth Even Less,
Gene

Interesting, I find that smaller caps (.01uf) expand that range and move the resonance "hump" to higher frequencies, bigger caps (.033-.047uf) make it almost unnoticeable.

What I am going to say may defie one or two electronic principles, the two caps below measure the same capacitance but have diferente effects, the grey one has a brighter "hump" the molded plastic enfasizes the lower mid range...

 

[JD0x0]

That 'Hump' is the new resonant peak forming. The size of the cap, pickup specs, and cable specs determine exactly where that 'hump' is.
On some brighter guitars I use a really small cap (2nF-3nF) to get that 'hump' right around where a meatier P90 or Humbucker pickup resonant frequency sits. In this case, the tone knob almost becomes like a single coil/humbucker blend switch, in how it effects the tone. Rather than the tone control muffling thing up, it fattens the pickup by moving the resonant frequency down.

The paper in oil likely effects this differently, because...
1. It may be the same claimed value, but I can almost guarantee that value has drifted over the years, and probably differs from a newer cap with tighter tolerance.
2. PIO caps are known to leak as well. This leak can effect their performance. Personally, I'm not a fan of PIO composition because they are leaky and drift. There's no secret mojo or magic, it's just an old cap that's beginning to malfunction.

 

[JD0x0]

Interesting, I find that smaller caps (.01uf) expand that range and move the resonance "hump" to higher frequencies, bigger caps (.033-.047uf) make it almost unnoticeable.

What I am going to say may defie one or two electronic principles, the two caps below measure the same capacitance but have diferente effects, the grey one has a brighter "hump" the molded plastic enfasizes the lower mid range...

View attachment 390784

Uhh you sure about that???

One cap clearly reads .022MFD the other reads .033-200 (.033MFD/33nF -200Volts)

THOSE ARE DIFFERENT VALUES. If they measured the same, like you seem to be claiming that means one is HUGELY out of tolerance.

The grey one, which you claim is brighter and has a higher hump, has the smaller value. So your claim actually does make sense. They're not they same value, though.



In guitars, if the caps have the same measured value, and both caps are functioning as originally intended (not leaking) they will create the same filter, and sound the same. Composition isn't making some crazy difference. As we can see, it's the value that makes the difference. In other applications, I would agree that cap composition has an effect on tone. It certainly does in amps, as I've experienced it first hand. In a passive guitar filter bleeding high frequencies to ground, the composition has nearly no effect. I use what is most stable which tends to be polypropylene. Feel free to use what you desire, but there's a lot of snake oil around this stuff, which I'm trying to separate from reality. If someone feels confident spending $20+ on an old leaky (PIO) cap, good for them. I'd rather they not post misinformation though, that makes other people go out and overspend on components based on that misinformation.

 

[tube.tone]

Thank you for your feedback.

I have many caps and got confused, in any event the blue cap sounds weird, I also think its out of spec or faulty.

Exploring the resonance peak's position is a very nice alternative way to approach the tone circuit, I never look at it from this perspective.

 

[sothoth]

That 'Hump' is the new resonant peak forming.

Can you explain what this means? What is resonating with what? I'm not a guitar wiring expert but I've been wiring them for quite a few years and never heard of this. Learn something new every day.