The JRC4558 integrated circuit by Japan Radio Company is a dual high gain operational amplifier internally compensated and constructed on a single silicon chip. The high voltage gain (100 dB typ.), good input impedance (5 MΩ typ.) and versatile power supply (± 4 to 18 Volts) make it perfect to fit in pedal circuit designs. This part has industry-standard pinout, meaning that there are several different suppliers manufacturing 4558 devices.