Caps in series

[zener]

I'm building the MXR Noise Gate from Tonepad. There's a 1uf non-polarized cap. I can't find any here.

Can I put two .47uf in series?

Thanks.

Zener

[smoguzbenjamin]

Put 'em in parralel and their values add up

[Mark Hammer]

Yup.

Caps work opposite to resistors.  Place two resistors in series and their values sum.  Place them in parallel, and the effective value is given by 1/Ra+1/Rb+....1/Rn = 1R.  With caps, the values of any caps placed in parallel is their sum (assuming that orientation is observed with polarized caps).  When placed in series, the effective capacitance is given by 1/Ca+1/Cb+...1/Cn = 1/C.

In the case of parallel resistors or series capacitors, the effective resistance or capacitance will always be lower than the resistor/cap with the lowest value.

In actual practice, designers will often use several parallel resistors to substitute for a smaller value because any heat in the circuit is dissipated across multiple components.  Not at all unlike feeding an amp output into multiple speakers so that the wattage is distributed.

In a similar vein, it is not uncommon for designers to use multiple caps in parallel to facilitate signal transfer.  In some instances, this can be because a large capacitance is required but broad bandwidth is needed, so combinations of larger and smaller values are placed in parallel to reduce phase distortion, etc.

[zener]

That's weird :shock: .

I've just finished the MXR Noise Gate at exactly 2 AM  :shock:  here. I actually put two .47uf in series for the non-polarized 1uf. Seems to be no problem at all (but I'm still going to change it).

The noise gate works great. I use to have a noisy Rocket and Hot Silicon before. After putting, the noise gate in front, ssssshhh! no more hum, no more hiss, no more noise when I stop playing. I only notice one thing. I really have to set pot past the halfway mark or better, close at full. Otherwise, I can hear a gating effect due probably to the powerful muting effect of this noise gate.

Could it be my caps in series?

Overall, it's a nice noise gate.

Thanks.

Zener

[aron]

Essentially what Mark said:

Capacitors:

   You can put these capacitors in parallel and they add up: CT = C1 + C2 + CN...
   You can put them in series to get other values as well:
   For 2 values: CT = (C1 X C2 )/ (C1 + C2)
   For 2 or more: CT = 1 / ( 1/C1 + 1/C2 + 1/CN ...)


Resistors:

   You can add these in series to get other values. RT = R1 + R2 + R3 etc...
   You can put resistors in parallel to get other values.
   For 2 values: RT = (R1 X R2 )/ (R1 + R2)
   For 2 or more: RT = 1 / ( 1/R1 + 1/R2 + 1/RN ...)