caps in series or parallel

[12AX7]

Just wondering, when you parallel or series caps to achieve a particular value, can this in any way affect the tone over using the value you want in a single cap? In this case i'm talking about 2 silver micas for the tone stack. Either two 500pf's in series for 250pf, then a switch to bypass one of them to achieve 500pf. Or two 250pf and a switch to add one in parallel to achieve 500. The reason i ask is when i do this it seems like it doesn't sound quite the same. I won't discount placebo effect, but i wanted to see what you all say because it sue seems real. By the way, i tested them with a meter putting the leads directly into the meter's jacks so as to eliminate the cables for a more accurate reading. The values both alone and together read very close, much to close to account for differences between series or parallel and a single cap of the correct value.

This has got to me my ears, but for all I knew you guys may know something i dont. (which you usually do )

[mpayne]

I think the difference is that capacitors have a resistance based on their capacitance and the frequency across them.   So for any given frequency a 250pf cap might not have the same resistance as two 500pf in parallel, even though their capacitance is the same.  This would give them different filtering characteristics causing them to sound different.   I think.

[Colas LeGrippa]

remember that caps in series permit twice the voltage rating and in parallel don't.

[tubenit]

I am fully convinced that sometimes, mixing different types of caps creates a different tone than one cap in the same value.  Such as an Orange Drop with a ceramic cap.  Or an OD with a Mallory.

And other times, I don't think it makes any difference at all that I can tell.

That is my impression from experimenting with that.

However, I have not noticed a difference between series and parallel caps?

With respect, Tubenit

[tubeswell]

For something as ballpark as a geetar tube amp, there is no noticeable difference in sound quality between using 2 x 500pF in parallel instead of 1 x 250pF. Manufacturing tolerances mean that capacitances vary even between caps that have the the same capacitance values stamped on them anyhow. So trying to compare tonal differences is like looking for a needle in a haystack.

[Colas LeGrippa]

agreed