Capacitor types - experts please help rank

[Bill Fitzpatrick]

I am interested in your ranking of film capacitor types.

Film and foil, metalized film, dielectric type (mylar, polyester, etc.) Best to worst.

You know the drill. This will be valuable info. for all.

[sreten]

do a search, already covered in some detail, sreten.

[claudio]

I suggest: http://www.capacitors.com/picking_ca...rs/pickcap.htm

Claudio

[serengetiplains]

In my experience, and all other things being equal, capacitor ranking generally follows the dielectric constant of the dielectric: the lower the DC, the better the cap. With a lower dielectric constant comes lower dielectric absorption and related losses. Teflon and certain types of oil, wax and paper (DC ~ 2) are head-runners, therefore, as capacitor dielectrics, followed by polystyrene (2.2) and polypropylene (2.3), mylar (3.1) being somewhat further down the list. Air, of course, is the best dielectric (1.0). The better Nordost cables sound so good because they achieve a very low dielectric constant in their insulating material (1.3), combining teflon and air in a manner allowing very little contact between cable and teflon, rendering a mostly air dielectric. Polyethylene (2.25) is also quite good (Jena cables, I believe, are insulated with this substance).

The problem with low dielectric constant is a larger capacitor is required for a given capacitance. Manufacturers therefore may prefer a mylar capacitor over an electrically better performing cap simply due to size and $$ considerations.

[Yank]

It all depends on what you want to accomplish.

Bob Carver explains how he uses capacitors on his website. No one person out there knows more than he.

www.sunfire.com

[jwb]

What's the application? In cetain applications Teflon film caps are unbeatable. But they don't make very good power supply filters.

If you are talking about dc-blocking caps in a signal path, I guess I'd say Teflon (but can't get large ones), Polypropylene film, Metallized polypropylene, Polyester, then the rest. Polypropylene film are staggeringly popular coupling caps in diy audiophile gear.

[sam9]

"Bob Carver explains how he uses capacitors on his website. No one person out there knows more than he."

I looked in the white papers and didn't see anything on the topic. Where should I be looking?

[analog_sa]

looked in the white papers and didn't see anything on the topic. Where should I be looking?

There is a short paragraph about caps in his amp essays. You are, however, excused for missing it as the essay makes such a hilarious reading that one can be easily distracted. It's even funnier if you've ever listened to a Carver amp.

[serengetiplains]

In my experience, teflon caps make fantastic power supply bypass caps. Their effect on distortion is measurable.

[tom1356]

Originally posted by Yank
It all depends on what you want to accomplish.

Bob Carver explains how he uses capacitors on his website. No one person out there knows more than he.

www.sunfire.com

He should start putting some of that knowledge to use in amp designs.. I wonder why hes been saving it.