The Great Capacitor Smackdown

[TGwaH]

A question for all you electronics gurus:

The other day I was looking at the instructions for shielding a strat on the Guitar Nuts website. In the Flash slideshow showing the pictorial of the process, they show a "film-type tone capactior" which they claim are "far more stable, accurate, and quiet than the ceramic discs..."

The second slide shows a better picture of the capacitor in question, referring to it as the "Chiclet" type. Then providing an axiom of "Looks like it should go in the mouth=good, looks like a squished booger=bad"

So my question is two fold: i.) what are the fundamental differences between the two types of capacitors, and ii.) is it worth the extra few cents per capacitor for a film v. ceramic?

[Mike Sulzer]

Well, there are capacitors more "stable and accurate" than ceramic disk, but I do not think this matters in a guitar. Never noticed any noise either, has anyone else?

A question for all you electronics gurus:

The other day I was looking at the instructions for shielding a strat on the Guitar Nuts website. In the Flash slideshow showing the pictorial of the process, they show a "film-type tone capactior" which they claim are "far more stable, accurate, and quiet than the ceramic discs..."

The second slide shows a better picture of the capacitor in question, referring to it as the "Chiclet" type. Then providing an axiom of "Looks like it should go in the mouth=good, looks like a squished booger=bad"

So my question is two fold: i.) what are the fundamental differences between the two types of capacitors, and ii.) is it worth the extra few cents per capacitor for a film v. ceramic?

[lovekraft]

The only caps that aren't suitable for passive guitar electronics are polar electrolytics and tantalums. Film caps are without dispute superior to most ceramic disc caps in performance, and should be preferred in most precision applications, but this isn't exactly Mission Control work we're doing. As for audible differences between types, only you can decide if there are any - I personally doubt it, but I'm willing to see evidence to the contrary (provided it involves repeatable double-blind testing and results significantly above chance ). IMO, using Hovlands or Orange Drops or any other sort of audiophile specialty caps says more about the mindset of the buyer ("This one goes to eleven!! ") than the sound of the guitar.

The only valid way to find out for sure if you have a preference is to install both types on a switch, make sure they're fairly closely matched, and listen while somebody else plays the guitar out of your sight, randomly flipping the switch for a few thousand trials. Anything short of that invites self-delusion and conformation bias. Me, I don't have the time, so I reckon those little greenies will have to do, at least until I run out of 'em.

[badsnap]

I have gotten a lot of good ideas from Guitar Nuts, but here is my smack..... a film capacitor has a tighter toerance, stablity, and breakdown characteristics that a ceramic one. For a few cents more...it's a good option, and I would most likely and often do use them, but not necessary. If we were building an effect box or something that was timing dependent then I would say definitely go with the best components you can afford...wire wound resistors and film capacitors...but lets look at what we have inside a guitar...2 or 3 antennas (called pickups), connected using antennas (wire) to antennas (pots and jacks). So...the small, imperceptable difference in using a film cap over a ceramic cap will NOT be heard. Not by me anyway, and my money is on not by MOST either. The difference in a film cap and a ceramic cap (functionally) is in it's tolerance...a film cap is 1% and a ceramic is anywhere between 5% and 20% depending on which one you purchase. If you already know this...I apologize...but basically if I claim a cap is .02mfd, then a film cap would be + or - 1% of that value and a ceramic cap would be + or - say 10% (if that is the rating) of that value. So unless you are using a set resistance (or inductance) in combination with the capaitor it really doesnt matter that much, certainly not enough to hear, and especially because in guitars they are used as filters and usually in combination with variable resistance (pots) so we can adjust the frequency. Sorry for being so long winded but sometimes it gets frustrating when people present their personal preferences as fact. Don't get me wrong, guitar nuts is one of my referance sites for all things guitar related and I respect their knowledge and experience, but I never stop asking questions and forming my own opinions..Rog

[JoeAArthur]

it gets frustrating when people present their personal preferences as fact. Don't get me wrong, guitar nuts is one of my referance sites for all things guitar related and I respect their knowledge and experience, but I never stop asking questions and forming my own opinions..Rog

+1

[mammoth guitars]

Some of you may have heard about orange drop caps that are so great for audio, well the green "chiclet" as they are called here are made from the same material as the orange drop caps and work very well. The poly-film caps are not available in all sizes so for some things you will need to use a ceramic disc cap.

As the cap's farad value get's smaller its resistance to frequency change also changes. Different size caps are sugguested between single coil and humbucker setups because of the different frequencies that are rolled off by the cap. So your typical guitar tone control acts like low pass filter, dumping the higher frequencies to ground.

[TGwaH]

Thanks for all the responses guys.

As the cap's farad value get's smaller its resistance to frequency change also changes. Different size caps are sugguested between single coil and humbucker setups because of the different frequencies that are rolled off by the cap. So your typical guitar tone control acts like low pass filter, dumping the higher frequencies to ground.

I'm planning on dropping in a couple new pick ups into my Epiphone Dot in the next few weeks. I'm going to split a humbucker at the neck (SD Stag Mag with an on/on/on switch) and a Humbucker sized P90 from guitar fetish. It is only a single tone, single volume. What value would you recommend for the capacitor? As it stands now I was just thinking of leaving it with the stock cap on it. A wise choice?

[JoeAArthur]

Thanks for all the responses guys.

As the cap's farad value get's smaller its resistance to frequency change also changes. Different size caps are sugguested between single coil and humbucker setups because of the different frequencies that are rolled off by the cap. So your typical guitar tone control acts like low pass filter, dumping the higher frequencies to ground.

I'm planning on dropping in a couple new pick ups into my Epiphone Dot in the next few weeks. I'm going to split a humbucker at the neck (SD Stag Mag with an on/on/on switch) and a Humbucker sized P90 from guitar fetish. It is only a single tone, single volume. What value would you recommend for the capacitor? As it stands now I was just thinking of leaving it with the stock cap on it. A wise choice?

The cutoff frequency of a cap is dependent on two thingies (yes, that is a technical term) - one is the value of the cap in farads (or microfarads as is normally used in guitar circuits) and the output impedance of the pickup. These two values make up the primary determining characteristics. Although many will argue that the resistance of the "pots" mean something - at best concering a treble cut tone circuit, can only determine the depth of the treble cut - it has nothing to do with the -3db frequency or where the cut actually starts.

The higher the pickup output impedance, the lower the value of capacitor is needed to maintain the same frequency of cuttoff. That's why lower output impedance pickups, like single coils, usually use a higher value of capacitor (e.g .047mfd) than higher output impedance pickups like humbuckers (e.g. .022mfd).

There is no magic number, and very few pickup makers even give you their product's output impedance.

Note: DC resistance of a pickup is not related to the output impedance of that pickup. It just happens to be the easiest thing to measure.

As with everything on the internet - it will all resolve down to being something dependent on "personal preference" - so go ahead, and experiment - it can't hurt anything.

I'd suggest a .022mfd.

[Paul Marossy]

IMO, a high voltage ceramic cap (1kV min.) is just as good as a 50V film cap. Both types will exhibit about the same amount of hysteresis, and they will virtually be the same thing in a guitar.

[yerffej]

http://www.diyguitarist.com/Misc/CapacitorFieldGuide.htm

http://members.aol.com/sbench102/caps.html

a couple sites I have bookmarked

[cocaine]

this isnt directly on topic, but i am wondering about some other properties of pots that i jsut dont understand. my first electric guitar might as well have had a toggle switch controlling volume. on the other hand, an ebmm steve morse model that tried out at a store seemed to have unbelievably reponsive volume and tone knobs--i swear i could change the tone by glaring at the knobs hard enough. this isnt really a fair comparison, considering all the other differences in every aspect of the two guitars, but something tells me the main difference here is the pots.

so who can tell me what accounts for the difference in the range and sensitivity of a pot, not necessarily the small differences in fidelity, as you guys seem to be talkin about here. while we're at it, what is the difference between audio and linear taper pots? i would like to know what the specs for the most sensitive/usable pot would be. i heard some more sensitive pots sound brighter, but i dont know how this will be a problem as i can just put the pot at 8 or 9 AND still have a wider range of sounds to choose from.

thanks

[TGwaH]

The only valid way to find out for sure if you have a preference is to install both types on a switch, make sure they're fairly closely matched, and listen while somebody else plays the guitar out of your sight, randomly flipping the switch for a few thousand trials. Anything short of that invites self-delusion and conformation bias. Me, I don't have the time, so I reckon those little greenies will have to do, at least until I run out of 'em.

It looks like someone did just that, with a paper in oil capactior thrown in to make it interesting.

Steven Kersting at S.K. Guitars

Ceramic v. Polyester v. Paper in Oil

Differences were noted, but the author notes that "there is NO WAY [he] would be able to discern these differences under any other conditions. They were so minor that [he] often had to compare between two caps several times to be sure I was hearing it. The heavyness of the picking stroke made much more difference than the cap type."

Here is a similar test with the results run through an oscilliscope, linked from the SK tone cap test page.

The Sound of Capacitors - Capacitor Linearity

[lovekraft]

This confirms my suspicions - I don't think anybody's saying that there aren't any differences in linearity between the various types of caps, but I'm not convinced that even one out of a hundred thousand people can reliably pick out any audible differences without visual cues (ie, in a double blind test), and I doubt seriously that anybody can hear any difference from the third row. Use whatever makes you most comfortable - I'll admit to an irrational (and embarrassing) personal bias towards film caps, but there are plenty of older guitars that sound absolutely incredible with cheap Asian ceramic discs in them, and I doubt that they would improve noticably from the installation of a Hovland on the tone pot. Better is only truly better if it improves the result - anything else is just hubris!

[Paul Marossy]

Differences were noted, but the author notes that "there is NO WAY [he] would be able to discern these differences under any other conditions. They were so minor that [he] often had to compare between two caps several times to be sure I was hearing it. The heavyness of the picking stroke made much more difference than the cap type."

I rest my case!

I'm not convinced that even one out of a hundred thousand people can reliably pick out any audible differences without visual cues (ie, in a double blind test), and I doubt seriously that anybody can hear any difference from the third row.

Agreed.

We're talking about a guitar that produces maybe 1.5V peak to peak on the initial attack. You're not going to hear differences in caps until you are in high voltage/tube amp land, and even then, some of that is still hard to hear and somewhat subjective.