Same questions that I posted on another response: 1) Can I use either ceramic OR box capacitors, if they're rated properly (the packshot of the assembled PCB uses both); and 2) Can I use a 100v electrolytic, if it fits (presumably that just means that it can handle the 9/18v with ease); and 3) Does the 5mm refer to the size of the cap itself, or is it the lead/pin spacing?
1.) I think so yes, I usually use ceramic for the pF values and film box for nF (and then usually electrolytics are in the uF range so it's easy to wrap your head around them). Ceramics and film box are mostly interchangeable from what I understand - there might be some small differences, maybe in the noise? But I don't know what exactly.
2.) Yes, that just means it's rated
up to 100V, so less will also work. But keep in mind that for larger values the size will get bigger once the voltage increases. So for smaller values you can go for 100V, for bigger ones you will probably have trouble with them fitting.
3.) For the electrolytic I believe 5mm is the diameter. For film caps 7.2mm is the length and 2.5mm or 5mm is the width. The pin spacing will usually be correct like that, plus even if you mess that up, you can just bend the pins to make them fit. But I don't really ever pay heed to pin spacing, it all just works out. I guess there are probably some weird parts too that might be funky, but with the same grey/cream/red film box caps the spacing is always the same. Ceramics are usually a bit smaller, but again, not an issue.
And yeah, the 6.2mm electrolytic someone linked is bigger than what the BOM specifies, but you can see on the PCB that there's plenty of extra room. At least PedalPCB layouts are always laid out so well that I haven't had any issues with electrolytics fitting. But even if you messed that part up, you could probably just leave the pins a bit longer and bend it over some other parts or something like that.
It might be more important if you're building in a 1590A or 1590B or something small, but I just stick with 125B where there's usually a bunch of room.
