Voltage Rating on Runt Caps?

[Pedro Fontacos]

Hi all,  any idea what the voltage rating on the electrolytics for the runt are?  I wish the schematics contained this info since the rating could affect the tone as well as potential damage occuring.  I assume 63V films are sufficient but don't know about the electrolytics.  Please advise and thank you!

[DutchMF]

Hey Pedro, welcome! Provided you power the pedal with +9V (which is most likely), caps rated at 16V should be more than enough, for all types. You could go to 25V or 35V to sure. I definitely don't believe you can hear the difference between a Runt with 16V caps, or one with 63V caps, though....

Paul

[Pedro Fontacos]

Hey Pedro, welcome! Provided you power the pedal with +9V (which is most likely), caps rated at 16V should be more than enough, for all types. You could go to 25V or 35V to sure. I definitely don't believe you can hear the difference between a Runt with 16V caps, or one with 63V caps, though....

Paul

Thanks Paul, I figured the supply caps can be 2x the voltage but am not sure about the electrolytics in the actual circuit itself; I'm guessing they'd be higher just not sure how much.

It would really make the ordering process much easier if the schematic contained voltage ratings.

[DutchMF]

Don't worry about it to much, dude. Just keep them higher than the voltage you put into the pedal and you'll be fine!

Paul

[midwayfair]

It would really make the ordering process much easier if the schematic contained voltage ratings.

Schematics don't contain this information for the same reason the bypass switching isn't usually included: It's considered common knowledge and there isn't necessarily one answer. Yes, it's a common beginner question, but once someone learns that 16v is sufficient for a 9v circuit and 25v is sufficient for an 18v circuit etc., they never need to relearn it. In reality, the voltages seen in most parts of a circuit are far lower than the power rails and you can get away with lower values (I've used 6.3v caps in digital delays, for instance), so it wouldn't even be necessarily accurate to tell people what value cap you use. And then you've got guys who run a circuit designed for 9v on 18v, and then if they do that after you've told them to use 16v caps, they blow up their power caps and call the schematic crap.

Also, putting that sort of information in a schematic makes for informational noise.

I think one reason amps always put the minimum voltage/wattage ratings in for various components is because there are more concerns about the physical size of the caps and resistors.

[Pedro Fontacos]

It would really make the ordering process much easier if the schematic contained voltage ratings.

Schematics don't contain this information for the same reason the bypass switching isn't usually included: It's considered common knowledge and there isn't necessarily one answer. Yes, it's a common beginner question, but once someone learns that 16v is sufficient for a 9v circuit and 25v is sufficient for an 18v circuit etc., they never need to relearn it. In reality, the voltages seen in most parts of a circuit are far lower than the power rails and you can get away with lower values (I've used 6.3v caps in digital delays, for instance), so it wouldn't even be necessarily accurate to tell people what value cap you use. And then you've got guys who run a circuit designed for 9v on 18v, and then if they do that after you've told them to use 16v caps, they blow up their power caps and call the schematic crap.

Also, putting that sort of information in a schematic makes for informational noise.

I think one reason amps always put the minimum voltage/wattage ratings in for various components is because there are more concerns about the physical size of the caps and resistors.

Thanks midwayfair, and I partially agree with you.  Since I'm nowhere near the guy who's going to change stuff like the supply voltage then a simple line like "1/8 watt resistors and 16V capacitors are sufficient" or something like that wouldn't be confusing and would give the builder peace of mind and 2 less things to be concerned/unsure about.  Thanks for the info though, it was very helpful 😊