A low-pass filter circuit using JRC 4558 is an electronic circuit designed to allow low-frequency signals to pass through while attenuating higher-frequency signals. It uses a JRC 4558 operational amplifier (op-amp) as the core component to filter the signals. The circuit typically consists of a resistor and capacitor (RC) network to determine the cutoff frequency, below which the signal is passed and above which it is reduced. This type of filter is commonly used in audio processing, signal conditioning, and noise reduction applications to remove high-frequency noise from signals.