In an opamp circuit for audio purposes like the following, I'd like to know about the capacitor C1:
- Which type is the best in this application (polyester, Al electrolytic, tantalum, bi-polar electrolytic?)
- If polarized, what is the correct polarity in the circuit and why?
The choice of electrolytic capacitor is justified because it needs a large value if you want to keep a good lower cutoff frequency (in the example, about 70Hz) and low resistor values to reduce noise; but I'd like to know if there are troubles with the polarization (and maybe the distortion due to non-ideality.)
Moreover, is it correct that C1 reduces op-amp offset effects at the output?