Will these caps work in our pedals? This is for the Tycho Octavia

[jimbob]

I just noticed it said 6.3v.


USA0J330MDD
Mouser Part #: 647-USA0J330MDD
Manufacturer: Nichicon
Description: 7mm Radial Aluminum Electrolytic Capacitors 6.3V 33uF 5X7 20%Tol 2LS 85Deg
  Data Sheet 
Will these caps work in our pedals? This is for the Tycho Octavia

[jpm83]

I Wouldn't use them. I usually use caps that can handle twice the voltage that the circuit is going to see. 16 volt caps are the minimum that I use for stomp boxes.

Janne

[Mark Hammer]

You can use caps rated that low when they are in series with the signal.  For instance, if they were just before an output volume pot, a 6.3v rating would be fine.  You can also use 6.3v caps to decouple the reference voltage in 9v circuits (the V+ divided by half will be 4.5v, so 6.3v rating is safe).

[jimbob]

So according to this http://www.generalguitargadgets.com/pdf/ggg_toct_lo.pdf
would these caps be ok?

[asfastasdark]

Probably not. 

[Celadine]

Different types of capacitors react to over-voltage in different ways; electrolytic caps could leak their gooey insides all over your circuit board/enclosure/et. al.  Why risk it?

When the 'capacitance tolerance' is listed, it refers to the voltage range over which the capacitor can function.  The ones you refer to have a +/-20% tolerance.  This means that the cap may fail at a voltage of 6.3v +/- 6.3 x 20%; 5.04v to 7.56v.  A 10v cap with +/-20% tolerance may fail at 8 to 12v.  Its good to err on the side of caution with electrolytics, which is why 16v caps (as jpm83 mentioned) are recommended for 9v projects.  16v caps with +/-20% tolerance fail at ~13v in the worst case, a good margin of error.

[calpolyengineer]

Are you sure about that? I was under the impression that it was a relation to their actual capacitance. I know at least with resistors that they are tested on the assembly line. Resistors that are within 1% are separated and labeled as such, then resistors that are 2% are separated, and on and on. So theoretically, a 10% tolerance resistor should be at least 5% off. With capacitors I imagine they do a similar process, but I'm not sure how you would measure failure voltage.

-Joe

[Celadine]

Hmmm....  Yeah, I was probably thinking of AC power supplies, where capacitance is linked to total output voltage, so you have to factor in the tolerance when choosing caps.     And over-voltage from a 9V battery probably won't cause the cap to leak.*  But its still good to have a margin of error!   


* - aluminum electrolytic cautions/failure modes/info:
http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/CautionAlumi_Eng.pdf#Page=1