Cap question

[buckle]

Will the voltage rating of an electrolytic cap matter?

[JakeFuzz]

Yes but only if it is too low. If you run a higher voltage through the capacitor than it is rated for you will reach breakdown for the electric field (based on Paschens curve). Electric field breakdown will arc through the electrolyte material and actually drill out holes as it finds its current path. After this your cap is useless, probably just shorting between the two leads and will potentiall explode if it gets too hot from the (theoretically) infinite current that might be passing through it if it were being used as say a power filtering cap. Running them at lower voltages is fine though.