MC33078, MC33079, Low Noise Dual/Quad Operational Amplifiers, ON Semiconductor The MC33078/9 series is a family of monolithic op-amps employing Bipolar technology with for audio and data signal processing applications. They use high frequency PNP input transistors to produce amplifiers with low input voltage noise, high gain bandwidth product and slew rate. The MC33078/9 family is available in both dual and quad versions in either plastic DIP or SOIC packages (P and D suffixes).