The device is an operational amplifier (usually shortened to op amp, opamp or op-amp), and it has been the Swiss Army knife of analog electronics since it first appeared in integrated circuit form in 1963. As the name might suggest, it is an amplifier, providing signal boost. But, thanks to a deceptively simple arrangement of input and output connections, the op amp leverages this gain to perform a dazzling array of essential functions in almost every piece of electronic technology in use today, from seismographs to cell phones. Inside the chip the circuitry raised the incoming audio to this voltage so that both the positive and negative parts of the waveform could be equally amplified. Without this reference the negative part of the wave would have been clipped off since 0 volts is the lowest extreme of the power supply and the output can go no lower.