when i was at the electronics store looking at resistors it seemed to me that smaller was better so i got 1/4 watt but now that im home they look awfully small compared to the resistors in my pedals. so "watts" the deal(harde har har).

Are your resistors old carbon composition, or are they in effects employing tubes, or higher voltages?  Other than that, unless the mfgr used them for cost-related reasons, I can't think of a good reason.

1/4 watt is the typical size, but 1/8 watt is becoming more and more common. The only place you commonly need something larger is in tube circuits. Build away!

Take care,
-Peter

the pedal i was just poking around in was a reissue blue box.they look to be half watt. i just wonder how size will affect the sound(im building a univox superfuzz)

There is a tiny tiny tiny difference in the thermal noise that you can hear in tube amps where the resistors are dealing with high voltage, but beyond that application.... no difference at all.

Take care,
-Peter

I was reading this post and thought of a question...

How do you know the wattage rating of resistors?

I know that the tolerance.. or whatever its called gold or silver is marked with a band but what about the watts?  I have a box of new resistors that I bought a while ago and I can't remember what they were rated.

Thanks, Matt.

If you have not bought the resistors with accurate forehand knowledge of their wattage rating, just hold them up against a pair of known wattage resistors and look for the closest match.  1/4W are standard, the old brown cylindrical ones are usually 1/2W, and the tiny ones where the bands are hard to read are 1/8W.

In the case of capacitors, size is sort of proportional to voltage rating within a product line, but since voltage/capacitance rating is also a function of the dielectric properties inherent in the materials used, you can easily find caps of higher capacitance and higher voltage ratings substantially smaller than caps of lower capacitance and lower voltage ratings.  Across cap-manufacturing history cap types and cap manufacturers there is a correlation between size and capacitance/voltage ratings of practically zero.

Since resistor wattage ratings are a function of heat dissipation, which is, in turn, a partial function of surface area to volume, there is far more standardization of size/wattage across resistors over time and manufacturers.  Since useful-wattage resistors have been smaller than caps for quite a while now, I suspect there has also been less incentive for manufacturers to try and find ways to miniaturize them like there has been for caps.  I'm sure there ARE small resistors with high wattage ratings if you are willing to pay more, but among standard types you can be fairly sure that wattage=size.

Thanks Mark.  Good to know.  

Matt.