nickmv said:
I'm using [a paper/oil cap] at this point because I had already bought a Firebird wiring kit from RS Guitarworks like 2 months ago.
I'm trying to avoid using new one's, but I'm realistic about the fact that it may not be feasible. Regardless, it's the pickups that primarily make the sound of the guitar, so I'm OK with whatever they have to do.
Paper over oil caps are designed for high voltage circuits. They typically have a very high dielectric rating, so they can live in electrically harsh environments. Because they contain oil, they need some serious sealing so as to prevent leaking and drying out and thereby changing value and/or destroying surrounding circuitry. It's usually an aluminum can with an epoxy plug. So, they're very expensive relative to most other caps, due to the tricky construction.
Guitar players and amp builders sometimes equate the high price with superior tonal characteristics. Nothing could be farther from the truth. Capacitors don't have tonal characteristics. They have what's called "capacity", which is dependent on a number of variables. In any event, a .022μf capacitor has .022μf of capacity regardless of its construction/packaging. In other words, there is no difference between a .022μf mica, .022μf ceramic, .022μf mylar, .022μf paper, etc. capacitor. They are all .022μf capacitors, and will all behave
exactly the same way. That behavior is called "reactance" in an AC circuit.
Now, before anyone gets excited, it's true that there are other differences. For instance, a rolled cap will introduce some inductance. It's tiny, but it's there. An axial lead cap will also have impedance factors that are different than one that's terminated radially. The size and makeup of the leads will change resistance values, adding yet another variable to the equation.
However, all those variables only have an effect at
very high frequencies. Frequencies that a guitar will never in a million years generate, or that even a bat could hear. We're talking up in the megahertz/gigahertz range, while guitars are down in the very low kilohertz range. We're also talking about
millivolts of working range, so no way do you need any kind of heroic dielectric strength.
There is no doubt that some people can hear the difference between various capacitors, but it has nothing whatsoever to do with their construction. It has to do with the surprisingly wide variations in the advertised or marked value of caps vs. the
actual value. Capacitor tolerances can be surprisingly wide, so that what you think is a .022μf cap may actually be anywhere between .017μf or .029μf. You think a .022μf Sprague "Orange Drop" sounds better than a .022μf "Bumblebee" from 45 years ago (or vice-versa)? Chances are about 99.9% or better that you're not comparing .022μf caps. They'll have different values, and so will react differently in a given circuit. If you simply changed one .022μf Orange Drop after another for the same thing, you'd find that they all "sound" different, even though they're theoretically the same part.
So, save yourself some grief. Buy the little ceramic rascals in the value you think is right that are the size of tomato seed, and call it a love story. They're only $.50 cents if you buy them wrong, less if you do it right. If anybody asks why your fiddle sounds so badass, tell 'em you sold your soul to a Portuguese Shaman <grin>
ccasion14:
