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. The first dual opamp was developed by Raytheon Semiconductors in 1974.
The 4558 dual amp is linked with the history of the guitar pedals development. Many designers included this part in some of the most successful effects like the Orange Squeezer, DOD YJM 30, Boss OD1, Tube Screamer or Peavey equipment.
for more infor Please Click Here