Anonymous
Anonymous asked in Science & MathematicsEngineering · 8 months ago

# Would you replace a 5uf cap in an audio ckt with a 4.7uf or a 10uf? Explain?

All three capacitors have the same working voltage, but you must choose between the standard values of 4.7uf and 10uf.

Thanks.

Relevance
• 8 months ago

In an audio circuit a 5 uf cap may be part of a band pass or band stop filter and will alter the tone of the circuit but It probably isn't because it is a bit large. It is probably a supply filter and a 4.7 will work.

The 5 is probably 20%. so the 4.7 should work.  You can just try it and find out. What makes you think it needs replacing?

• qrk
Lv 7
8 months ago

You would need to see how that capacitor is used in the circuit to make any sort of decision.

Do you need precision? There are precision polymer capacitors out there and they sure are pricey.

What's the DC bias across the capacitor? DC bias affects capacitance in class II dielectric. Will this be an issue for the circuit?

What sort of leakage can your circuit withstand?

Do you need a non-polarized capacitor?

• M.
Lv 7
8 months ago

4.7 μF is likely an electrolytic capacitor and they have a big percentage value tolerance range.  4.7 μF is almost 5 μF.  10 μF is double.

So use 4.7 μF.

Make sure the voltage rating of the replacement capacitor is the same or greater.

• 8 months ago

Caps are usually ±20% at best, so 20% of a 5 µF is between 4 and 6 µF. Therefore a 4.7 µF would be fine.

10 µF would probably work also, depends on the circuit. But it will be larger and may not fit.

• Anonymous
8 months ago

The coupling capacitor must must have a low reactance to minimize low-frequency attenuation. use 10uF to minimize low-frequency attenuation.

• A.J.
Lv 7
8 months ago

I was a capacitor engineer for the IBM corporation many years ago. It isn't "working voltage". It is voltage rating and larger is better. The capacitance value is sometimes critical, but often in an audio circuit the impedance is critical. Even with the same capacitance and voltage rating, it may not function properly. Further, it may not be an old standard aluminum cap, and could be a polymer based. Often, a 5uF cap is often a film polypropylene capacitor rather than aluminum electrolytic.With a photograph of the part, I might be able to identify it, but otherwise you normally need the circuit diagram. Capacitance value is standard as +/- 20%, but a lot of the 5uf are +75%,-10%.

• 8 months ago

PICK THE 4.7uF IS CLOSE ENOUGH.