Which caps to use where?

In the process of designing my Aleph Ono, I ran into pondering where it comes to choosing capacitors. With the Farnell Catalogue on my desk, I find various materials used, with all their own characteristics. Farnell Sells (amongst others):
- (Multilayer) Ceramic
- Polyester
- Polypropylene
- Polystyrene
- Silverd Mica
- Plastic Film

And then there are those special brands and types like Black Gates and Audyncap. I don't know all these brands, nor where to get them

On the other side, there are the applycations. Some caps are more important to the sound than others. I found these groups of applications the most interesting and important:

- Audio coupling / decoupling
- Filtering (the RIAA network)
- Noise suppression (on the power rails)
- Loading for the MM stage

My question is: which type of capacitor is best suited for which job, and where should I use those really special caps like Black Gates?

Thanx in advance,

For audio coupling and filtering (riaa) use polystyrene or polypropylene.

Loading for the MM stage is usually small value, so polystyrene's are easier to find.

For power supply filtering, a combination of electrolytic, ceramic and tantalum is usually recommended. However, you must be careful not to set up a tank circuit. For safety, just use an electrolytic.

Do NOT use a ceramic or silvered mica for coupling or filtering, they have horrible distortion. Polycarbonates are only marginally usable, and rarely seen in good audio components today.

My 2 cents gleamed from years of reading about this stuff, and even a bit of actual testing :) An excellent article on this topic can be read at http://www.capacitors.com/pickcap/pickcap.htm