Using electrolytics instead of box film caps

zachguitar

New member
I'm putting together the aionfx lumitron and for c11 it calls for a 2.2uf box film cap I only have 2.2uf electrolytics can I use those instead?
Also in a few spots I need 100uf caps and the pedal has a charge pump can I use 25v caps or do I need higher rated ones
 
I'm fairly sure the 100uF caps are fine - for one it looks like the charge pump is used to generate +/- 9V, so even if the caps were somewhere where they could be hit with the full 18V, using 25V caps should be fine. However, looking at the schematic I think both are essentially before the charge pump so 9V is the most they will see. 100uF caps are usually always used for power filtering (at least in non-tube pedals), which means they will be before charge pumps - but I can't say for sure that is always the case.

As for the electrolytic instead of film cap, hopefully someone more knowledgeable can help out - AFAIK it's usually fine, but needs to be oriented a certain way, and I don't know which way. Electrolytics also have more leakage AFAIK which might matter in this circuit, but probably not. For anyone else curious, here's the link to the kit documentation https://aionfx.com/app/files/docs/lumitron_kit_documentation.pdf with schematic on page 27.
 
The + side of an El cap needs to be oriented to the side with the higher voltage potential, unless you use bipolar caps.
You also should use low ESR caps if you have them.
That said, I don't see any reason you couldn't use a 1u film in its place.
 
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