Stuff you wanted to know but were afraid to ask

[Feral Feline]

Morning fellas, dumb question alert. I'm sourcing parts for the first time, having only built from kits and in true paint-by-numbers fashion, my knowledge is severely lacking. I'm looking to take a stab at Chuck's Bass Klon and following the *parts list below but have some confusion about the capacitors and their voltages. How do I know which voltage I should be going for? Some caps have 35s, 50s and 100s while others only have 100s and above (on Tayda at least).

Am I right in thinking that I can use just about any of them, as if I'm running the pedal at 9V it won't get close to the max that the caps can handle? I'm thinking I should aim for 35-50 where possible.

*Parts list
View attachment 121358

One of the things not mentioned yet... well, size was mentioned, but not that some caps are the same size regardless of voltage.

Check the physical dimensions of the caps in the datasheets. If you're ordering from Tayda, Mouser, etc they'll often have a link to the datasheet for the part-page you're viewing online.

I have bought Electrolytics in various capacities 16v and 25v and 50v to have all my bases covered — and they were pretty much the same physical size. Given that you want to have some headroom and have caps roughly double the voltage of the pedal...

Let's take 47µ as a prime example — why even bother with 16v if the 35v is the same size and price? The 35v will cover 18v-builds.
Why bother with 35v if you can buy 50v for that extra margin of safety when building a circuit to run at 18v?


47uF 16V 105C Radial Electrolytic Capacitor 5x11mm 2¢
47uF 25V 105C Radial Electrolytic Capacitor 5x11mm 2¢ [I usually get 35v]
47uF 50V 105C Radial Electrolytic Capacitor 6.3x11mm 3¢

Of course, if you buy higher quality caps, the cost jumps, for example...
47uF 50V 105C Aluminum Electrolytic Capacitor 6.3x11.2mm PANASONIC 17¢

Economies of scale: if you're building commercially, maybe you aren't willing to pay 3¢ per cap when a 2¢ cap will do.
Then there's the issue of quality — do you want to buy a pedal from a builder who cheaps out on electrolytics? The electros will be likely the first thing to go wrong with a pedal down the road. If you're building pedals commercially maybe you want to keep a good reputation and buy some more expensive caps at 17¢ each, bought in bulk bringing the cost down to 16¢ or 15¢ each...

I'm just a hobbyist. I build on the cheap, but I'm willing to pay a penny more per cap to keep one type of 47µ that can cover most any type of build I'll be doing.

Whatever the quality/cost, I don't bother buying 16v caps anymore. It's got to be an EXTREMELY tight layout if you can't squeeze a 6.3mm footprint into a 5mm-space on a PCB.