Filtered Differential Amplifier

This document contains a detailed electronic schematic for the Filtered Differential Amplifier (Model G590), produced by Digital Equipment Corporation in 1969. It provides the full transistor-level circuit diagram, including component values for resistors, capacitors, and transistors (such as the 2N4250, DEC 6534D, and DEC 2219). The document also includes a transistor and diode conversion chart that maps DEC proprietary part numbers to industry-standard (EIA) equivalents for maintenance and testing purposes.