Guys who think different types of capacitors sound different

supergenius365

Silver Supporting Member
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10,659
what will the different types give me? How will a PIO sound different from a chiclet? NOS Bumblebee vs foil in oil? Etc?

Those who don't believe need not reply. I WANT TO BELIEVE!
 

mjtripper

Silver Supporting Member
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1,580
One sounds like a caPACitor and the other sounds like a CApacitor :)

The different types can be smoother or crunchier but a lot depends on the circuit they are in. Some circuits you can tell the difference and others not so much. Before you start testing different types though you should measure them to make sure you are testing the types and not the types plus x amount of drift/variance in the values.
 

walterw

Platinum Supporting Member
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38,267
it took me a while to figure out why the idea was entirely specious with the tone on "10", why in that case it didn't even matter what the value was or whether it was a cap at all or a straight piece of wire!

(crude layman's analogy version):

caps work by "filling up" with voltage, at which point they don't pass any more signal until that voltage gets "drained out" back the other way.

with the tone knob on 10, the signal a normal guitar cap gets is so faint that the cap never "fills up", instead passing the signal right through to ground the same as a straight piece of wire. it's only when you turn the tone knob down a lot, to like "5" or lower, that enough signal goes through the cap to "fill it up", at which point it starts blocking lows and only letting highs through to ground, actually affecting those frequencies differently and doing what a tone cap does.

above that and on 10 you're just hearing the dulling effect of the tone pot itself letting a little bit of everything to ground, through that cap that's not blocking anything.
 
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Wagster

Silver Supporting Member
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8,154
To my ears all caps of the same value sound the same in a guitar tone circuit except PIO. I've tried a lot of PIO caps I just don't like them. They take off some highs even with the tone on 10 and I have no idea why. I'm sure other will disagree with me but after trying quite a few and finding that they all did the same thing I'm incline to trust my ears.

BTW I seriously doubt that you will hear the subtle differences in a compressed YouTube video.
 

David Collins

Member
Messages
2,246
This guy does the testing for you. Listen up. ( I hear no difference)

Much like the water concierge here, narrating what one should be drawn to notice does not make for a reliably objective comparison.


Not to mention, the particular qualities he attributes to the cap changes are beyond a bit of a stretch.
 

Tone_Terrific

Silver Supporting Member
Messages
33,081
To my ears all caps of the same value sound the same in a guitar tone circuit except PIO. I've tried a lot of PIO caps I just don't like them. They take off some highs even with the tone on 10 and I have no idea why. I'm sure other will disagree with me but after trying quite a few and finding that they all did the same thing I'm incline to trust my ears.

BTW I seriously doubt that you will hear the subtle differences in a compressed YouTube video.
They ALL take some highs off at 10 as soon as the ground is available through the pot, as does a wire.
You have a perfect opportunity to test yourself by simply shorting out a PIO with the pot on 10 and hearing if you can tell.

BTW op- if you want to pursue this you will have to do it under the table as there is a general consensus at TGP amongst those who have tested that there is no diff.
Believers remain but have moved to small underground groups where their activities are less scorned.:D
 
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StratoCraig

Member
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3,213
icaps work by "filling up" with voltage, at which point they don't pass any more signal until that voltage gets "drained out" back the other way.
Uh... no, at least, what I think you're saying is not my understanding. A cap consists of two conductors separated by a dielectric (basically an insulator). As current enters one side of the cap, it accumulates on the plate on that side until it has enough of a charge to break through the dielectric. Basically, it sparks across. This is the same thing that happens with lightning. Static electricity accumulates in a cloud until it has enough power to arc to earth. That arc we call a lightning bolt. So a cap doesn't pass any signal at all until it fills up, at which point it suddenly discharges to the other side and then begins accumulating charge again.
 
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walterw

Platinum Supporting Member
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38,267
Basically, it sparks across. This is the same thing that happens with lightning.
no EE i, but that really doesn't sound right.

a cap passes a DC spark when it fails.

as i understand it, the dialetric "gap" allows for a charge to accumulate on one side, meaning the opposite charge accumulates on the other side, and this action happening back and forth is what allows AC to show up on the other side of the dialectric.
 

Tone_Terrific

Silver Supporting Member
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33,081
So a cap doesn't pass any signal at all until it fills up
Fils up may be misnomer.
Consider that capacitance exist between 2 adjacent wires, such as twisted pairs.
Fills up implies that a .1mfd would not conduct as readily as .0001mfd would as it takes 'more' electricity to 'fill' it.
I don't know of an accurate analogy. Time to call the EE's.
 

walterw

Platinum Supporting Member
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38,267
So a cap doesn't pass any signal at all until it fills up
i think it's the opposite, a cap happily passes all signal until it "fills up".

caps pass AC and block DC, because the AC keeps reversing direction before filling the cap up. that's why lower frequencies get blocked, they're more like DC, they keep going in one direction for longer.
 
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Sweetfinger

Silver Supporting Member
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As current enters one side of the cap, it accumulates on the plate on that side until it has enough of a charge to break through the dielectric. Basically, it sparks across. This is the same thing that happens with lightning. Static electricity accumulates in a cloud until it has enough power to arc to earth. That arc we call a lightning bolt. So a cap doesn't pass any signal at all until it fills up, at which point it suddenly discharges to the other side and then begins accumulating charge again.
You have just described catastrophic failure of a capacitor.
 

Wagster

Silver Supporting Member
Messages
8,154
They ALL take some highs off at 10 as soon as the ground is available through the pot, as does a wire.
You have a perfect opportunity to test yourself by simply shorting out a PIO with the pot on 10 and hearing if you can tell.

BTW op- if you want to pursue this you will have to do it under the table as there is a general consensus at TGP amongst those who have tested that there is no diff.
Believers remain but have moved to small underground groups where their activities are less scorned.:D
Of course but they take off a little more from my findings. I personally don't like PIO caps for this reason.
 

supergenius365

Silver Supporting Member
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10,659
i think it's the opposite, a cap happily passes all signal until it "fills up".

caps pass AC and block DC, because the AC keeps reversing direction before filling the cap up. that's why lower frequencies get blocked, they're more like DC, they keep going in one direction for longer.
Until they kick the lead singer out!
 

StratoCraig

Member
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3,213
Okay, so I did a bit more reading up last night and it turns out Walter is basically right. There are "pulse capacitors" that seem to work more or less as I described, but they're used in high-voltage applications and are have self-healing properties that allow them to instantly recover from dielectric breakdown. More typical capacitors, such as the ones we use in guitars, store up energy and eventually discharge it back in the same direction it came from, but at the same time, the accumulation of a negative charge on one plate causes the accumulation of a positive charge on the other plate, so in a sense current does flow through a capacitor even though no electrons actually jump from one plate to the other.

So that's what I get for trying to remember my college electronics without actually checking the books I still have on my shelf. :) I tend to remember the mathematical aspects better than the actual physical behaviors of components. I think I was getting confused because of the often-repeated analogy between capacitors and static electricity in clouds discharging as lightning.

You get lower impedance with either higher capacitance or a higher-frequency signal, so the tone cap in a typical guitar is basically blocking low frequencies from the tone pot; that, I think, is why turning down the tone pot affects high frequencies much more than low ones (which is what makes it a tone pot rather than a second volume control). The tone pot is basically an additional load on the pickup, in parallel with the volume pot, but due to the presence of the cap, it adds only to the higher frequencies as you turn it up. Additionally, its capacitance should sum with the other capacitances in the circuit (the pickup and the guitar cord) in the RLC equation, so there's an overall effect on frequency response and resonance as well.
 




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