Capacitor questions

[cmacdon at ix.netcom.com]

I apologize if this is a worn-out retread of an old topic, I'm a bit new
at this.

I am breadboarding a diode ladder filter and have bought polystyrene and
polypropylene capacitors for the project based on what I have been
reading on various diy web sites (thanks a million to those of you who
put those up BTW!).

I erroneously assumed that all low-value capacitors are small and paid
no attention to the dimensions listed for the polypropylene caps in the
Mouser catalog.  Well the .22uf items are about as big as my thumb!

So my questions are, am I making a silly error here?  Do others use
these giant caps in their filters?  The dimensions for metallized
polypropylene caps are somewhat smaller, are those okay instead?  Does
the capacitor type affect the audio qualities of a filter circuit or is
it mainly for stability or some other reason?


Thanks,

Chris