For my next build, I'm taking on the Queen of Bone 2 (http://www.rullywow.com/product/queenofbone2/).
The build docs don't specify the type of caps to use. For the electrolytics, I assumed that since this board has a charge pump to bump the voltage to 18V, that I couldn't use 16V caps. Does the voltage rating matter as long as it's above the voltage you'll be using? Some parts were out of stock on Smallbear, so I ended up ordering a few of these (http://smallbear-electronics.mybigcommerce.com/electrolytic-radial-50v/) and a few of these (http://smallbear-electronics.mybigcommerce.com/electrolytic-radial-35v-4-7-mf-1000-mf/).
Will there be any problems with using the 35V and 50V caps interchangeably as long as they're the correct capacitance value?
General practice is to get caps with a rating roughly 2x that of your voltage. I usually buy 35V or 50V because they're common and I'll never need to worry about it if I do that.
AFAIK there's no problem with using different voltage ratings as long as they're the right capacitance.
Thanks!
one thing to consider as well is size. The higher the voltage rating, the bigger the caps get. I generally try to use the small caps, which usually are 16V. Those are ok for all standard 9V builds, but that also means that you can't use 18V on those builds.