the tone cap myth...

[Possum]

....

Well they don't have those caps in Mouser's catalog, the model number is on the original WIMA link. They only have nylon guitar strings, kazoos, and banjo parts, so what good are they :-)

[Joe Gwinn]

I couldn't find anyone selling the WIMA caps, those specific ones, Mouser doesn't even list film caps in their catalog, yeah $5 is alot but they do sound identical to NOS bumble bees.....

Mouser does have equivalents. No magic here. Do a search on the Mouser website for "metallized paper".

[MattT]

What myth? I thought it was common knowledge that a tone pot/cap loaded the circuit and affected the tone...even when the pot is on '10'. Change the pot and/or cap and you change the loading...and change the tone.

The op said that the values were different...going from a green ceramic .047uF to a singlecoil.com .022uF. I'd have been shocked if there wasn't a noticeable difference. So this just shows that a value change is noticeable.

But the op also stated that when going from BB .022uFs to singlecoil.com .022uFs there wasn't a noticeable difference. And that certainly doesn't help the 'cap type matters' arguement. What am I missing?

[David Schwab]

Dave I just got that catalog yesterday, it's "November 2007 - January 2009, Catalog 636"

OK.. I got the last catalog out of the recycling bin... In the old catalog (Aug-Oct 2008 #635) the axial film caps start on page 809.

Film and foil are on 819. They are pretty expensive. Some are $25!

Orange Drops are on 820. Then the WIMA radial caps start on the next page. Xicon start on page 824.

These pages should correspond to the PDF catalog on line.

[Possum]

....

there are alot of guitar players who thinks caps have NO effect on anything, I was one of them :-) Reread the singlecoil.com info they did alot of research to find an equivalent tone, no its not a paper in oil or is it? But it PERFORMS the same as the bumble bee, I couldn't hear any difference at all....

[hasserl]

Actually this DOES blow the myth out of the water, because supposedly when you're not using your tone control the cap should have no effect right? So why would changing the value have any effect at all, then, if its "not in the circuit." I almost never use the tone control, yet changing the caps changed the the pickups tone for the better.

OK, I do see WIMA in the Mouse catalog now but mine is 2008 you must have just gotten yours. What page guitar strings on?

Even when the Tone pot is dimed there is still significant loading of the circuit, the value of the cap WILL make a difference. So no, the myth is not blown out of the water at all, it is still floating there just fine, that shot missed by a mile.

Re "not in the circuit." That means the signal does not pass thru the cap on it's way from the pickups to the amplifier. The cap allows part of the signal to be drawn away and dumped to ground where it will never be amplified. The larger & more efficient the cap is the more signal will be drawn away and dumped. IF there is any effect in tone between cap types, it is with what part of the signal it draws away from the rest, and how much of the original signal is left to go on to the amp.

What myth? I thought it was common knowledge that a tone pot/cap loaded the circuit and affected the tone...even when the pot is on '10'. Change the pot and/or cap and you change the loading...and change the tone.

The op said that the values were different...going from a green ceramic .047uF to a singlecoil.com .022uF. I'd have been shocked if there wasn't a noticeable difference. So this just shows that a value change is noticeable.

But the op also stated that when going from BB .022uFs to singlecoil.com .022uFs there wasn't a noticeable difference. And that certainly doesn't help the 'cap type matters' arguement. What am I missing?

You got it right Matt, from this report there may be no difference at all between the most prized vintage Black Beauty cap and a cheap ceramic disc. I'm not saying there is not, just that from the OP and any following posts, unless I missed it, there is nothing to show that there is any difference.

there are alot of guitar players who thinks caps have NO effect on anything, I was one of them :-) Reread the singlecoil.com info they did alot of research to find an equivalent tone, no its not a paper in oil or is it? But it PERFORMS the same as the bumble bee, I couldn't hear any difference at all....

All I saw at Singlecoil.com is this: http://singlecoil.com/docs/caps.pdf

I'm sorry, that doesn't explain anything. The dude's selling caps, did you expect him to say there is no difference between types? I've seen your posts here and your youtube clips. You obviously have an ear for details and don't mind spending time getting things right. You can do better than the singlecoil.com stuff. Let's see some real tone experiments! Compare caps of different types with the same measured capacitance and let's see the effect that type has on tone. I don't doubt there is some difference, I do doubt it is very significant.

[Mike Sulzer]

Even when the Tone pot is dimed there is still significant loading of the circuit, the value of the cap WILL make a difference.

Yes, there is loading of the circuit; the tone pot loads the circuit just as any resistor does, but in this case it does it through the capacitor, which has an impedance much lower than the resistance of the pot (at frequencies that affect brightness). The effect of the capacitor is tremendously reduced by the pot that is in series with it; that is, the loading on the circuit is almost entirely resistive, not capacitive. So what does doubling the cap from .02 to .04 do? It makes the small voltage across the cap get even smaller. Changing something that is negligible to something even more negligible is, well, still negligible.

And has for hearing the difference between two different brands of .022 microf caps with the 500K pot in series? Show me the results of a real double blind listening test involving many listeners.

[MattT]

Changing something that is negligible to something even more negligible is, well, still negligible.

True...but we're not changing something that is negligible to something more negligible. We're changing something significant to something that is still significant but slightly different. That's what I meant by 'what myth'. I thought it was common knowledge that cap value makes a difference even when the pot is on 10. It doesn't take a particularly good ear to hear it either imo.

[salvarsan]

And has for hearing the difference between two different brands of .022 microf caps with the 500K pot in series? Show me the results of a real double blind listening test involving many listeners.

While their differences are less audible in subtractive tone circuits,
they are especially evident when you go cheap, viz., use disc ceramic caps.

The common criteria are ESR, dissipation factor, microphonics, and hysteresis
and are considered "finished" component science as of the early 1980's.

Polypropylene film caps are generally very good in all respects, though
more expensive and larger than all other film capacitors save teflon.

The ceramic disc dielectrics are cheap and quite microphonic.

Electrolytics are lossy and tend to have more observable hysteresis.
The worst of them are audibly microphonic. While an AC signal 20% loss is
expected, audiofool-grade electrolytics control the other parasitic mechanisms well
though at significant cost.

Oil+paper caps tend to damp microphonics and have very low hysteresis
in the audio range. DF is variable depending on the oil type. The preferred
application is in tube amplifier coupling circuits having a high voltage swing, e.g.,
phase inverters.

Polyester/mylar caps can be somewhat microphonic depending on the
producer, have low hysteresis, low DF, and low cost.

For me, Panasonic low inductance polyester types satisfy the good+cheap+fast trinity.
Where they aren't good enough, I've used polypropylene film caps.

-drh

[Mike Sulzer]

We're changing something significant to something that is still significant but slightly different.

Are we? I explained why it is insignificant. Can you tel me why my explanation is wrong?

[Mike Sulzer]

While their differences are less audible in subtractive tone circuits,
they are especially evident when you go cheap, viz., use disc ceramic caps.

When the tone pot is on 10, this is not even a subtractive tone circuit. It is a tone circuit in which the capacitor does almost nothing because it has a large resistor in series. Why would you expect to hear significant differences in this case?

[MattT]

Are we? I explained why it is insignificant. Can you tel me why my explanation is wrong?

I say it's significant because it's easy to hear the difference between say, a .047uF cap and a .022uF tone cap even when the pot is on '10'.

Why would you expect to hear significant differences in this case?

I wouldn't say I 'expected' it...just that I 'experienced' it.

[orangedrop]

Even the value of the tone pot will make a difference. Lower value gives less treble - at least in my ears.

There's a lot of good posts at the LP forum on the subject "Tone caps and tone pots".
GlassNuff have some really good posts.

[Mike Sulzer]

Even the value of the tone pot will make a difference. Lower value gives less treble - at least in my ears.

That's right. With the tone pot on 10, it is loading the pickup through the cap which is low impedance at the higher frequencies. Changing the value of the tone pot changes the load on the pickup almost exactly as changing the value of the volume pot does (on 10) and so has the same effect on the sound: lower value, less treble. When you turn down the tone pot, you are lowering its resistance and so cutting treble. The capacitor has a big effect only as you get more towards zero.

[David Schwab]

Electrolytics are lossy and tend to have more observable hysteresis. The worst of them are audibly microphonic. While an AC signal 20% loss is expected, audiofool-grade electrolytics control the other parasitic mechanisms well though at significant cost.

I remember seeing some audiophile website where they claimed if you remove the shrink wrap label from the aluminum can, it will improve the tone! They reasoned it was because plastic sounds bad.

What do you think of tantalum caps? (not for tone controls of course)