Determing Cap Voltage Ratings

[skypn]

On many of the schematics for effect pedals I find on line, there is no mention of what voltage rating needed for electrolytic caps. how do I determine this? TIA

[Axldeziak]

I just aim higher than the voltage the circuit uses. If it's 9V, I use 16V or higher.

[skypn]

Ok then, so 25vdc should be cool

[somnif]

Only thing to be careful of is higher voltage means bigger cap, and you may run into cases of things being a bit too thick to fit. Usually not a big issue if you keep things under 50V (maybe under 35V for higher values) but some layouts can be finicky.