Does it matter what the voltage is on a film cap? (noob)

[Goom]

I'm buying parts for a Fuzz Face germ build—and I can't find 0.01uF film cap at exactly 250v. So does it even matter?

[jacobyjd]

nah

[Goom]

nah

tanx 

[petemoore]

  If they start at smaller voltage rating, that'd probably be smaller size.

[Mark Hammer]

If it was a high-voltage circuit like an amp, then obviously it would matter, but if power is always going to be a 9v battery then i doesn't.  If, for whatever reasons, you are using a cap type aimed at high-voltage applications, then you may find it foolish to look for lower voltage-ratings.

Historically, people would skimp on voltage ratings, because a) you paid noticeably more money for higher voltage ratings and b) the caps with higher voltage ratings could be bulky and awkward.  Consequently, manufacturers would often take it down to the lowest possible rating they could get away with because it made for lower production costs and smaller footprint.  For example, you might see a 6.3V rated cap in the Vref circuit (where 9v is divided down to 4.5v for a simulated ground).  Those days are long gone, though.  One can easily get 35v rated caps that are a fraction the size of what the 10v and 16v ones were a mere 20 years ago.