Out of stock 4313 Discrete Operational Amplifier $145.00 Based on the PYE™ discrete output stage, the 4313 is housed in a standard discrete op-amp package and designed for differential feedback for the inputs and driving an output transformer. The PYE™4313 can be used in microphone preamplifiers, equalizers, compressors, bussing system amplifiers, and other areas where a high impedance input and low impedance output gain amplifier is necessary. Details