Why do preamplifiers have so many capacitors?

Which preamps have the best use of capacitors and tubes? Since that seems to be really important for preamp.

am told Teflon capacitors are really good and use of foil, whatever that means

Jumia,

You are looking at this the wrong way. You are trying to evaluate the ride of a car based on the color of the brakes.

While it’s good to understand the composition of your purchase as one way to evaluate the financial outlay at the end of the day the only thing that matters is performance. To reuse the car metaphor, do you like the ride or not?

Only after you have spent time figuring out what kind of ride you like, then you start looking for patterns.  "Oh, I really like the sound of x tubes or wax/paper capacitors..."

If you try to look at parts first you'll never figure out what kind of listening makes you happy.

Best,

Erik

I dare say many who buy preamplifiers have no idea how they work internally. It would be wonderful if there was a diagram, a visual guide, allowing someone to understand the internal flow of a preamplifier. Further I never see commentary explaining the flow, and variations, within a preamplifier.

I think many would be grateful with something that illustrates how these mystery boxes work.

Look at a schematic (circuit diagram) to see how parts are connected. 

@jumia-

        IF you are sincerely interested; the first few magazines/books/resources mentioned on the following link, are an excellent place to gain such knowledge.

         They were great to, "grow up" on and: even decades old, they're still fun to bring out and reread.

                          I miss the DIY/hobbyist PAPER rags!

                       http://www.nutshellhifi.com/Linkstxt.html