Substituting Electro Capacitors for mylar/film ones??

[hubble]

ive been looking thru mouser's catalog compiling a parts list with parts numbers and prices and have noticed a lot of lower values like .22uF and .47uF that are available as metal film and aluminum electrolytic.  when a schematic calls for a regular capacitor is it possible to substitute an electro of the same value?

[kurtlives]

The circuit will work find as long as you get the polarity right...

I would rather use film caps for sound quality though...