Using higher rated voltage caps in pedals?

Discussion in 'Effects, Pedals, Strings & Things' started by GibsonGeek, May 15, 2020.

  1. GibsonGeek

    GibsonGeek Supporting Member

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    888
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    I’m still learning diy pedal mods, builds, and such. Looks like I ordered the wrong capacitors for my project because this thing is huge. My question, can I still use it? This thing is rated for up to 1600V.

    [​IMG]
     
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  2. mulekicker

    mulekicker Member

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    You can use it if you can fit it in there. Maybe insulate the legs like on that big resistor.
     
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  3. captaincoconut

    captaincoconut Member

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    It will add extra mojo.
     
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  4. East Texas

    East Texas Member

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    The voltage rating isn't a problem, but dang. That thing is huge. Just get another capacitor with an appropriate size and rating. Seriously.
     
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  5. drbob1

    drbob1 Silver Supporting Member

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    What IS the value of that cap? By size and voltage rating I'd expect power supply level, 100 uF or bigger?
     
  6. mulekicker

    mulekicker Member

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    I think its just a 4.7nf just rated for 1600 volts! If getting a smaller cap is too complicated during these trying times I'd just use it. It'll work fine and you can claim mojo if anyone asks.
     
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  7. sanfi4u

    sanfi4u Silver Supporting Member

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    As a rule of thumb the higher voltage rating the better cap. Size is the price you pay for it. If you can fit this cap into PCB just use it. It's for the better.
     
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  8. jlo

    jlo Member

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    I don’t think thats gonna fit. That is huge!
     
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  9. drbob1

    drbob1 Silver Supporting Member

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    Now that I look at the PCB, the only open spot is that axial cap right in the middle. I don't know what kind of box you're going to put this in, but you'll either need to wire the switch and pots with LONG patch wires or mount that cap on the back of the board. Hmmm, how about a pedal sized cardboard box with a remote, relay based switch beside it! Plug in and play something angry and no one will believe it's coming out of that cardboard...
     
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  10. GibsonGeek

    GibsonGeek Supporting Member

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    888
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    Thanks for the input, guys. The cap does not go into the Fuzz Face pcb pictured. If it did, I would be inclined to drill tiny holes in the top of the housing for the cap legs and let it live on top like an air intake on a street rod.

    I believe I ordered this cap for an ABY ground lift switch, but it appears Ive ordered the wrong value. Pretty sure I need a 473 rather than 472. Learning.

    I have also learned since this post that the desired voltage for the chosen cap should be approx 2x the circuit voltage. Does this sound correct?
     
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  11. jquanmusic

    jquanmusic Member

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    You should find a way to mount that thing on the outside of the enclosure.
     
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  12. 8len8

    8len8 Supporting Member

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    Derating depends on the type of cap. Tantalums need as much derating as possible, but for other caps, like the one you show, 2x is fine.
     
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  13. aussie_owner

    aussie_owner Member

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    I have a .1uF capacitor at work that’s not quite the size of a 28 oz can of tomatoes. Of course, it’s rated at 30kV.
     
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  14. analogmike

    analogmike Gold Supporting Member Vendor

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    #bigasscapacitors
     
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  15. GibsonGeek

    GibsonGeek Supporting Member

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    888
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    Cool thanks. The more I read about capacitors, the more I learn. However, I’ve sort of become confused/lost in terms of knowing what to buy. For example, I’d like to order a few caps for a Crybaby mod project. I want to order .022uf, .047uf, .068uf. I now know I need the voltage rating to be above 18v but crazy high ratings result in huge caps. Got it.
    I’ve gotten lost with the various material types and what is used for what. What exactly should I order in this case? Metal poly ceramic mica film? That’s the confusion.
     
  16. 8len8

    8len8 Supporting Member

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    I’d just go to the pedal parts sites and see the types they offer. The type won’t make a huge difference, but pedal parts sites will likely only sell smaller parts.
     
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  17. captaincoconut

    captaincoconut Member

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    As long as you stick to pedal projects (= low voltage) I wouldn't worry about capacitor voltage unless we're talking about electrolytic caps. The most common types of capacitors used in pedals such as MKTs/polyester films/etc., "orange drops", "greenies", Silver Mica, Styroflex etc. are usually rated for 50V+ or even way higher, so you're safe.

    As to which caps to put in your wah I would just replace with the same type that was used by the manufacturer. Dunlop has used several different types over the years, most probably MKT caps in the most recent ones. Watch out for the leg/lead spacing defined by the manufacturer when buying new caps. This will tell you if it will fit your pcb. The most common lead spacing is 5 or 10mm. When in doubt, take a look at the datasheet of the specific part in question.
     
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  18. GibsonGeek

    GibsonGeek Supporting Member

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    888
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    Will these 100v polypropylene caps be decent? These would be for the freq range mod on a Crybaby GCB-95. I’m following the mods on the Stinkfoot site.

    [​IMG]

    I have these on hand...

    [​IMG]

    And these ancient caps from a 1940’s radio. The round one is a mystery to me, from a piece of telephone test equipment. Is it 47uf/40v?

    [​IMG]
     
    Last edited: May 17, 2020

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