newbie: cap voltage questions???

[hss]

im getting ready to order parts, and im wondering if the voltage of caps matter, a local store carries a ton but most are 200V, is that too much...

thanks
hss

[AL]

Since most circuits for pedals are only 9V anything over that will work - but a little overkill never hurts. 200V is some serious overkill. The pedal should work OK with them but you may have some "real estate" issues. They may take up too much space. I usually use anywhere from 16V to 50V in my pedals.

AL

[hss]

thanks Al, I will try to find something smaller.

hss

[Mark Hammer]

Whiule there is nothing wrong with using higher voltage-rated caps, generally speaking, both cost and size increase with voltage ratings.  Consequently most folks find the optimum strategy is to aim for the lowest voltage rating from the ranges available that can safely be used.   One of the benefits is that you know you'll have parts that will comfortably fit the various layouts posted around.  For example, while Francisco Pena's Tonepad layout are terrific, they are frequently quite cramped, and caps that are too large for the allotted space can get problematic.

Since one would like the option of running some things at somewhat higher voltages, it's a good idea to have an available supply of 25v rated electrolytics on hand for larger (10uf or higher).  These will work just fine for things running at 15 and 18v (two batteries).   These are also useful for LFOs and similar nonaudio parts of the circuit where voltages higher than signal level are found.

In the majority of instances, caps in the audio path really don't need to be rated more than maybe 10-16v, if that, though such caps tend to be smaller values which end up being in tiny packages anyways despite very high voltage ratings.  So, even though you don't NEED a 100v rated .01uf cap, the 100v package is likely a reasonable size and may well be the most commonly availably and best-priced one you stumble onto because of that.

[mlabbee]

I just tried the AVX caps you can get from Mouser.  The values are all in the same package and cover pretty much the whole range you might need for effects except the 1 uf and larger.  The consistent size makes it much easier to layout circuits, plus, the look cool  :-)

I don't recall who first recommended them, but hat tip to whomever it was.  They're great.