This is a subject I was planning on writing an article on till I found this excellent video by John Cooper from PlanetZ. I think technical stuff like this is easier to digest this way, at least for some people. Anyway, if you have been trying to figure out what people are talking about when they say stuff like- they just upgraded their tone cap to an “Orange Drop” .022uf – then this may help you get a handle on it.
You may notice that this video says it’s part two. I didn’t link to part one because it dealt with whether different tone capacitors, all of the same value, but made of different materials, sounded differently. The reason for such a shootout is that there are a lot of people who will tell you that all good tone capacitors are made of “Paper in Oil” or that if it ain’t a “Silver Mica” capacitor your guitar will sound like its got a blanket wrapped around it. And many other tone aficionados say the best capacitors were made back in the “Golden Era” of guitars, mainly the 50s and 60s. After researching this topic myself I came to the conclusion that the difference in tone among all these different types, brands and age were so slight as to not really matter. One of the best articles I found about all the voodoo surrounding tone caps can be found here: The Truth About Tone Capacitors