Echo Wiring Diagram - Enter your engine's type number in this search field to show the parts that match your engine. Your engine's type number is the second part of the model number stamped on your Briggs & Stratton engine (see picture).. Welcome to getMANUAL.com on-line store!We sell electronic versions of service and user manuals, part lists, schematic diagrams for home and professional audio-visual equipment, PCs and other electrical appliances.. Description. This is the circuit diagram of a fully transistorized sub woofer amplifier that can produce an output of 100W.There are seven transistors including four in the output stage..